Related Terms

• Astrocytomas, benign, brain tumor, carcinogen, chemotherapy, choroid plexus papillomas, Cushing's disease, electromagnetic, ependymomas, gliomas, headache, hydrocephalus, hypoglycemia, magnetic resonance imaging (MRI), malignant, meninges, meningiomas, metastatic, neoplasia, noncancerous, oligodendrogliomas, pancreatitis, pituitary adenomas, polyvinyl chloride (PVC), primitive neuroectodermal tumors, radiation, rehabilitation, subarachnoid, thyroxine, triiodothyronine, vestibular schwannomas.

Background

• Brain cancer is abnormal growths of cells in the brain. Brain cancer and brain tumor are terms commonly used interchangeably. However, not all brain tumors are cancerous, and cancer is a term reserved for malignant tumors.

• Malignant tumors grow and spread aggressively, overpowering healthy cells by taking their space, blood, and nutrients. Malignant brain tumors can grow more rapidly, invading or destroying nearby brain tissue. Unlike cancers elsewhere in the body, primary malignant brain tumors rarely spread from the brain.

• Tumors that do not spread aggressively are called benign. Benign brain tumors usually grow slower, are easier to remove surgically (depending on their location), and less likely to recur than malignant brain tumors. Benign brain tumors don't invade the surrounding normal brain or other nearby structures, but they can still place pressure on sensitive areas of the brain. A noncancerous primary brain tumor is life threatening when it compromises vital structures (such as an artery).

• Approximately 1 in 16,000 in the United States develops brain cancer or brain tumors. According to the American Cancer Society, brain cancer accounts for approximately 1.4 % of all cancers. It is estimated that there are 13,000 deaths/year as a result of brain tumors, and brain cancer is the leading cause of cancer-related death in patients younger than age 35.

• Primary tumors: Primary tumors occur when one type of cell transforms from its normal characteristics. Once transformed, the cells grow and multiply in abnormal ways. As these abnormal cells grow, they become a mass or tumor. The most common primary brain tumors are gliomas, meningiomas, pituitary adenomas, vestibular schwannomas, and primitive neuroectodermal tumors (medulloblastomas). The term glioma includes astrocytomas, oligodendrogliomas, ependymomas, and choroid plexus papillomas. Most of these are named after the part of the brain or the type of brain cell from which they arise. Primary brain tumors are less common than secondary brain tumors.

• Secondary brain tumors: Secondary or metastatic brain tumors are made of cancerous cells from a tumor elsewhere in the body. The cells spread to the brain from another tumor in a process called metastasis. Metastatic brain cancer indicates advanced disease and has a poorer prognosis. About 25% of tumors elsewhere in the body metastasize to the brain. Secondary brain cancer occurs in 20 - 30% of patients with metastatic disease, and the incidence increases with age. In the United States, about 100,000 cases of secondary brain cancer are diagnosed each year.

Risk Factors

• History of cancer: Patients with a history of melanoma, lung, breast, colon, or kidney cancer are at risk for secondary brain cancer.

• Heredity: Although not directly linked, in rare cases brain tumors strike several members of a family, suggesting heredity may be a risk factor.

• Environmental: Exposure to radiation or certain chemicals, such as those found in oil refining, rubber manufacturing and chemical and nuclear industries may increase cancer. Vinyl chloride is an environmental risk factor for brain cancer. It is a carcinogen (cancer causing substance) found in the environment as the by-product of manufacturing plastic products, such as PVC pipes, wire coatings, furniture, car parts, and house wares. Vinyl chlorides are also present in tobacco smoke. Manufacturing and chemical plants may release vinyl chloride into the air or water, and it may leak into the environment as a result of improper disposal. People who work in these plants or live in close proximity to them have an increased risk for brain cancer.

• Electromagnetic fields and the use of cell phones have been studied as causes of primary brain tumors, but no definitive evidence indicates that either causes brain tumors.

• Age: Although brain tumors can occur at any age, they're most common in children 3 to 12 years old and also adults 40 - 70 years old.

• Gender: Overall, males and Caucasians are more likely to develop a brain tumor.

Causes

• Genetic factors: Genetic mutations and deletions of tumor suppressor genes (genes that suppress the development of malignant cells) increase the risk for some types of brain cancer. Inherited diseases that are associated with brain tumors include multiple endocrine neoplasia type 1 (pituitary adenoma), neurofibromatosis type 2 (brain and spinal cord tumors), retinoblastoma (malignant retinal glioma), tuberous sclerosis (primary brain tumors), and Von Hippel-Lindau disease (retinal tumor, CNS tumors).

• Primary tumors: Primary brain tumors originate in the brain or close by in the skull, brain membranes (meninges), cranial nerves, pituitary gland or pineal gland. The causes of primary brain tumors are reported to include vinyl chloride exposure, radiation exposure to the head, certain inherited conditions, and HIV infection.

• Secondary tumors: Secondary tumors are caused by cancer that starts elsewhere in the body and then spreads (metastasizes) to the brain. Cancers of the lung and breast are most likely to spread to the brain. Sometimes, a brain tumor is the first sign of cancer that began elsewhere in the body.

Signs and Symptoms

• Brain tumors may have a variety of symptoms ranging from headache to stroke. Symptoms that immediately raise the question of a brain tumor include a new seizure in an adult, gradual loss of movement or sensation in an arm or leg, hearing problems, unsteadiness or imbalance (especially if it is associated with headache), loss of vision in one or both eyes (especially if it is more peripheral vision loss), unexplained nausea or vomiting, double vision (especially if it is associated with headache), hearing loss with or without dizziness, and speech difficulty of gradual onset.

• Headache: Headache is probably the most common symptom of a brain tumor. Generally, individuals with headaches, even persistent or severe headaches, do not have a tumor; however, some kinds of headache may be particularly worrisome. A steady headache that is worse in the morning than the afternoon, a persistent headache that is associated with nausea or vomiting, or a headache accompanied by double vision, weakness, or numbness all suggest a possible tumor.

• Behavioral changes: A change in behavior may also be caused by a brain tumor. The development of an "I don't care" attitude, memory loss, loss of concentration, and general confusion may all be subtle signs.

• Hormonal changes: Infertility or amenorrhea (abnormal cessation of menstruation).

• Others: Some health conditions that appear to be other diseases, but may in fact be tumors include stroke and unexplained falls. Sometimes a fall can come from a seizure caused by a tumor, and a pituitary tumor can act like a subarachnoid hemorrhage (a type of stroke).

• Not all brain tumors cause symptoms, and some (such as tumors of the pituitary gland) are found mainly after death.

Diagnosis

• Angiogram: This test involves injecting a special dye into the bloodstream. The dye, which flows through the blood vessels in the brain, can be seen on X-ray. This test helps show the location of blood vessels in and around a brain tumor.

• Computerized tomography (CT) scan: A CT scan uses a sophisticated X-ray machine linked to a computer to produce detailed, two-dimensional images of the brain. The patient lies on a movable table that's guided into what looks like an enormous doughnut where the images are taken. A special dye may be injected into the bloodstream after a few CT scans are taken. The dye helps make tumors more visible on X-rays. A CT scan generally takes less than 10 minutes.

• Magnetic resonance imaging (MRI) scan: An MRI scan uses magnetic fields and radio waves to generate images of the brain. The patient lies inside a cylindrical machine for 15 minutes to an hour. MRI scans are particularly useful in diagnosing brain tumors.

• Neurological examination: A complete neurological examination by a qualified neurologist will be performed. These tests include checking a patient's vision, hearing, balance, coordination and reflexes.

• X-rays: An X-ray of the head may show alterations in skull bones that could indicate a tumor. It may show calcium deposits, which are sometimes associated with brain tumors, but a routine X-ray is a far less sensitive test than the brain scans.

• Other brain scans: Other tests, such as magnetic resonance spectroscopy (MRS), single-photon emission computerized tomography (SPECT), or positron emission tomography (PET) scanning help doctors gauge brain activity by studying brain metabolism, chemistry and blood flow within the brain. An electroencephalography (EEG) may play a marginal role in the diagnosis of brain tumors.

• Tissue sample: The only test that can absolutely make a diagnosis of a brain tumor is a biopsy. Tissue sampling can be done as part of surgery to remove the tumor, or can be done in a separate procedure where only a small sample of tissue is obtained using a needle biopsy. Pathologists then view the tissue and determine if it is malignant or benign.

Complications

• Brain damage: The brain is divided into different parts that are responsible for a variety of functions. Depending on its size and location, a brain tumor can cause temporary or permanent brain damage. A brain tumor in the frontal lobe, which is responsible for thought and motor skills, may result in learning or memory difficulties, and may make talking or walking more difficult. A brain tumor in the occipital lobe (located in the back of the head) can result in vision problems, because that area of the brain controls the ability to see and comprehend what is seen.

• Hydrocephalus: Brain tumors may lead to an emergency complication known as hydrocephalus, which is the buildup of fluid in and around the brain. This occurs when a tumor blocks the flow of cerebrospinal fluid in and around the brain, causing the fluid to build up within the confined spaces of the skull. This buildup can create pressure on the delicate brain structures, and must be drained so it can be relieved and the risk of brain injury is reduced.

• Bleeding: Another emergency situation that can be caused by brain tumors is bleeding in the brain. This might cause an extremely severe headache with an abrupt onset. If this occurs, emergency medical treatment is necessary.

Treatment

• Treatment for a brain tumor and survivability of brain cancer depends on the type, size and location of the tumor, as well as the age and overall health of the patient.

• Surgery: Surgery is the mainstay of brain tumor treatment, and involves removing as much of the tumor as possible while trying to minimize damage to healthy tissue. Some tumors can be removed completely, while others can be removed only partially or not at all. If a tumor is slow growing, doctors may not operate immediately.

• If the tumor has resulted in a buildup of fluid in the brain (hydrocephalus), a shunt may be inserted surgically. A shunt is a long, thin tube that's placed in the brain and then threaded under the skin to another part of the body, usually the abdomen. The tube allows excess fluid to be removed from the brain.

• Radiation: Radiation therapy is an important part of the treatment for high-grade gliomas. In typical situations, patients begin radiation treatments within two to four weeks after tumor resection. Treatments are given daily, Monday through Friday for four to six weeks. Each treatment takes only a few minutes. An MRI (magnetic resonance imagine) is usually obtained about two to four weeks after the end of radiation therapy in order to judge the effect of treatment. Most of the time this scan will show no change from the post-operative MRI, which is good, but some shrinkage is even better. Growth during radiation therapy is an unwanted sign of an aggressive tumor. High-energy radiation can be used to destroy tumor cells in the brain, but side effects such as nausea, vomiting, dry mouth, difficulty swallowing, fatigue, hair loss, and skin burns are common.

• Chemotherapy: Astrocytomas and high grade glioblastomas have been extensively treated with chemotherapy. There have been several controlled clinical trials of chemotherapy combined with radiation after resection. Effectiveness has been shown for the drugs carmustine (BCNU), lomustine (CCNU), procarbazine, streptozocin, and combination therapies of each of these agents.

• Combination therapies that include nitrogen mustard type drugs appear to be superior to treatment with a single agent. A study using procarbazine, CCNU, and vincristine (PCV) showed doubling of time to tumor progression and doubling of survival in patients with anaplastic glioma. Patients with high-grade glioblastomas appeared to benefit also, although the results did not reach statistical significance. Another study compared PCV chemotherapy with or without radiotherapy in patients with anaplastic astrocytoma or glioblastoma multiforme. Patients who received PCV and radiotherapy had a significantly longer time to tumor progression and survival time.

• Patients with newly diagnosed and recurrent low-grade oligodendrogliomas and oligoastrocytomas respond to procarbazine, lomustine, and vincristine (PCV) therapy. In 3 out of 5 patients recurrent disease was found, and 13 of 16 newly diagnosed patients responded to PCV. Median time to progression was 24 months.

• There is a general consensus that some form of chemotherapy with radiation appears to be of benefit after resection of primary glioblastoma with high-grade histology. These drugs, taken by mouth or intravenously, can help kill cancerous tumor cells.

• Temozolomide (Temodar®), a newer oral chemotherapy agent, appears to have activity in certain brain tumors including refractory anaplastic astrocytoma. Clinical improvement was noted in 51% of patients, while the improvement using radiation was 31%. Temozolomide is given orally once daily for five consecutive days per 28-day treatment cycle, for as long as the disease warrants. Side effects of chemotherapy include diarrhea, nausea, vomiting, weight loss, hair loss, tiredness (fatigue), and a decreased immune system (making the individual more susceptible to colds, viruses, and other illnesses.

• Other medications: Initial treatment of a brain tumor may include steroid medications to reduce swelling and inflammation of brain tissue. Dexamethasone (Decadron®, a steroid) is generally used to decrease swelling of the brain. In the first few weeks of steroid use, alteration of mood (euphoria or depression), elevation of blood sugar and development of clinical diabetes in susceptible individuals, and fluid retention may be seen. Patients who take the medication for a longer period of time may develop cataracts or glaucoma, muscle weakness and loss of muscle mass, osteoporosis and fractures, damage to the head of long bones of arm and leg, stomach or duodenal ulcers with associated complications, and pancreatitis. After prolonged use, dexamethasone can cause impaired wound healing, thin fragile skin with black and blue marks and discoloration, menstrual irregularities, and increase in body hair. A particularly troublesome complication of prolonged dexamethasome use is the development of symptoms of Cushing's disease (an adrenal gland disorder that produces high levels of the stress hormone cortisol), such as weight gain and fat accumulation around the face and neck.

• Anticonvulsant medications may help prevent or control seizures.

• Rehabilitation: Because brain tumors can develop in parts of the brain that control motor skills, speech, vision and thinking, rehabilitation may be a necessary part of recovery. The brain can sometimes heal itself after trauma or treatment of a brain tumor, but this can take time and patience. Rehabilitation includes cognitive rehabilitation (helping one cope with or regain lost cognitive skills), physical therapy (helping one regain lost motor skills or muscle strength), vocational training (helping get back to work after brain tumor or brain surgery, and speech pathology.

• Once treated, a brain tumor may remain in remission for years, or may never recur. When a brain tumor is in remission, it means that tests do not show any signs of the cancer. Sometimes this means the cancer will never return, but in other cases the cancer may be too small for tests to detect, and it may recur at a later date. As part of follow-up for brain tumor treatment, the patient may need to be monitored on a regular basis for tumor recurrence with MRI or CT scans.

• Stereotactic localization: This technique utilizes a MRI scan to map a tumor's exact location within the brain. Techniques using lasers and ultrasound also make removal of the tumor more precise, reducing the risk that cancer cells will be left behind or that healthy tissue will be harmed.

• Drug-delivering implants: Researchers are also studying new ways to deliver cancer-fighting drugs to brain tumors. Biodegradable wafers containing cancer-fighting drugs are being implanted in some tumors during surgery. Also nanotechnology (microscopic) delivery of cancer drugs may be part of the future of brain tumor treatment.

• Gene therapy: Gene therapy, drugs that cut off a tumor's blood supply and agents that may be able to interrupt tumor growth or to seek out and kill brain cancer cells are all under investigation.

• Other: Patients with brain tumors that are either infrequently curable or unresectable may be considered candidates for clinical trials that evaluate interstitial brachytherapy, radiosensitizers, hyperthermia, or intraoperative radiation therapy in conjunction with external-beam radiation therapy to improve local control of the tumor.

Integrative Therapies

• Good scientific evidence:

• Boswellia: Boswellia has been used as a cancer treatment, including for brain tumors, but there is currently not enough human data to support this use over standard therapies.

• Avoid if allergic to boswellia. Avoid with a history of stomach ulcers or stomach acid reflux disease (GERD). Use cautiously if taking lipid-soluble medications, agents metabolized by the liver's cytochrome P450 enzymes, or sedatives. Use cautiously with impaired liver function or liver damage or lung disorders. Use cautiously in children. Avoid if pregnant or breastfeeding.

• Greater celandine: Ukrain™, a semisynthetic drug derived from greater celandine (Chelidonium majus), has been studied in clinical trials of various types of cancer with consistently positive outcomes. However, the quality of the research performed to date is inadequate, and higher quality studies are needed.

• Use cautiously in patients taking amphetamines, morphine, hexobarbital, MAOIs, or dopaminergic or serotonergic drugs, or in patients undergoing radiation therapy. Avoid in patients with liver disease or in pregnant and lactating women.

• Guided imagery: Early research suggests that guided imagery may help reduce cancer pain. Further research is needed to confirm these results.

• Guided imagery is usually intended to supplement medical care, not to replace it, and guided imagery should not be relied on as the sole therapy for a medical problem. Contact a qualified health care provider if mental or physical health is unstable or fragile. Never use guided imagery techniques while driving or doing any other activity that requires strict attention. Use cautiously with physical symptoms that can be brought about by stress, anxiety or emotional upset because imagery may trigger these symptoms. If feeling unusually anxious while practicing guided imagery, or with a history of trauma or abuse, speak with a qualified health care provider before practicing guided imagery.

• Meditation: There is good evidence that various types of meditation may help improve quality of life in cancer patients. Studies have shown benefits for mood, sleep quality, and the stresses of treatment. The specific effects of meditation are not fully understood. Additional research is needed in this area.

• Use cautiously with underlying mental illnesses. People with psychiatric disorders should consult with their primary mental healthcare professional(s) before starting a program of meditation, and should explore how meditation may or may not fit in with their current treatment plan. Avoid with risk of seizures. The practice of meditation should not delay the time to diagnosis or treatment with more proven techniques or therapies, and should not be used as the sole approach to illnesses.

• Psychotherapy: Psychotherapy is an interactive process between a person and a qualified mental health care professional (psychiatrist, psychologist, clinical social worker, licensed counselor, or other trained practitioner). There is good evidence that psychotherapy may enhance quality of life in cancer patients by reducing emotional distress and aiding in coping with the stresses and challenges of cancer. Therapy may be supportive-expressive therapy, cognitive therapy or group therapy. While some patients seek psychotherapy in hopes of extending survival, there conclusive evidence of effects on medical prognosis is currently lacking. Psychotherapy may help people come to terms with the fact that they may die of cancer, which is the 4th stage of dealing with a terminal illness, including denial, anger, bargaining, and acceptance.

• Psychotherapy is not always sufficient to resolve mental or emotional conditions. Psychiatric medication is sometimes needed. The reluctance to seek and use appropriate medication may contribute to worsening of symptoms or increased risk for poor outcomes. In order to be successful, psychotherapy requires considerable personal motivation and investment in the process. This includes consistent attendance and attention to treatment recommendations provided by the practitioner. Not all therapists are sufficiently qualified to work with all problems. The client or patient should seek referrals from trusted sources and should also inquire of the practitioner's training and background before committing to work with a particular therapist. Some forms of psychotherapy evoke strong emotional feelings and expression. This can be disturbing for people with serious mental illness or some medical conditions. Psychotherapy may help with post-partum depression, but is not a substitute for medication, which may be needed in severe cases.

• Yoga: Yoga is an ancient system of relaxation, exercise, and healing with origins in Indian philosophy. Several studies report enhanced quality of life in cancer, lower sleep disturbance, decreased stress symptoms and changes in cancer-related immune cells after patients received relaxation, meditation and gentle yoga therapy. Yoga is not recommended as a sole treatment for cancer but may be helpful as an adjunct therapy.

• Yoga is generally considered to be safe in healthy individuals when practiced appropriately. Avoid some inverted poses with disc disease of the spine, fragile or atherosclerotic neck arteries, risk for blood clots, extremely high or low blood pressure, glaucoma, detachment of the retina, ear problems, severe osteoporosis, or cervical spondylitis. Certain yoga breathing techniques should be avoided in people with heart or lung disease. Use cautiously with a history of psychotic disorders. Yoga techniques are believed to be safe during pregnancy and breastfeeding when practiced under the guidance of expert instruction (the popular Lamaze techniques are based on yogic breathing). However, poses that put pressure on the uterus, such as abdominal twists, should be avoided in pregnancy.

• Unclear or conflicting scientific evidence:

• Acupuncture: Acupuncture, or the use of needles to manipulate the "chi" or body energy, originated in China over 5,000 years ago. There has been limited research on acupuncture for cancer pain, and the research that was done was shown to have mixed results. More studies are needed to determine potential benefits. Evidence from several small studies supports use of acupuncture at a specific point on the wrist (P6) to help chemotherapy patients reduce nausea and vomiting. Acupuncture may also reduce the pain associated with cancer.

• Needles must be sterile in order to avoid disease transmission. Avoid with valvular heart disease, infections, bleeding disorders or with drugs that increase the risk of bleeding (anticoagulants), medical conditions of unknown origin, or neurological disorders. Avoid on areas that have received radiation therapy and during pregnancy. Use cautiously with pulmonary disease (like asthma or emphysema). Use cautiously in elderly or medically compromised patients, diabetics or with history of seizures. Avoid electroacupuncture with arrhythmia (irregular heartbeat) or in patients with pacemakers.

• Aloe: Transparent gel from the pulp of the meaty leaves of Aloe vera has been used on the skin for thousands of years to treat wounds, skin infections, burns, and numerous other skin conditions. Dried latex from the inner lining of the leaf has traditionally been used as an oral laxative. Preliminary research suggests that aloe may help in the area of cancer prevention or may aid in the regression of cancerous tumors. Additional research is needed in this area.

• Caution is advised when taking aloe supplements as numerous adverse effects including a laxative effect, cramping, dehydration and drug interactions are possible. Aloe should not be used if pregnant or breast-feeding, unless otherwise directed by a doctor.

• American pawpaw: Evidence supporting the use of the American pawpaw (Asimina triloba) tree for cancer treatment in humans is largely anecdotal and subjective. However, use in humans has reported minimal side effects, and evidence from animal and test tube studies suggest that American pawpaw extract does have some anticancer activity. Pawpaw standardized extract has been used for 18 months in patients with various forms of cancer. Well-designed studies on the long-term effects of pawpaw extracts are currently lacking. Pawpaw should not be used if pregnant or breast-feeding, unless otherwise directed by a doctor.

• Antineoplastons: Antineoplastons are a group of naturally occurring peptide fractions, which were observed by Stanislaw Burzynski, MD, PhD in the late 1970s to be absent in the urine of cancer patients. There is inconclusive scientific evidence regarding the effectiveness of antineoplastons in the treatment of cancer. Several preliminary human studies (case series, phase I/II trials) have examined antineoplaston types A2, A5, A10, AS2-1, and AS2-5 for a variety of cancer types. It remains unclear if antineoplastons are effective, or what doses may be safe. Until better research is available, no clear conclusion can be drawn.

• Avoid if allergic or hypersensitive to antineoplastons. Use cautiously with high medical or psychiatric risk, an active infection due to a possible decrease in white blood cells, high blood pressure, heart conditions, chronic obstructive pulmonary disease, liver disease or damage, or kidney disease or damage. Avoid if pregnant or breastfeeding.

• Arabinoxylan: Arabinoxylan is made by altering the outer shell of rice bran using enzymes from Hyphomycetes mycelia mushroom extract. Arabinoxylan has been found to improve immune reactions in patients with diabetes and cancer of various types. Arabinoxylan products may contain high calcium and phosphorus levels, which may be harmful for patients with compromised renal (kidney) function. Caution is advised when taking arabinoxylan supplements, as numerous adverse effects including drug interactions are possible. Arabinoxylan should not be used if pregnant or breast-feeding, unless otherwise directed by a doctor.

• Aromatherapy: Healing with fragrant oils has been used for thousands of years. Aromatherapy is often used in people with chronic illnesses (frequently in combination with massage), with the intention to improve quality of life or well-being. There is currently not enough scientific evidence to form a firm conclusion about the effectiveness of aromatherapy for quality of life in cancer.

• Essential oils should only be used on the skin in areas without irritation. Essential oils should be administered in a carrier oil to avoid toxicity. Avoid with a history of allergic dermatitis. Use cautiously if driving or operating heavy machinery. Avoid consuming essential oils. Avoid direct contact of undiluted oils with mucous membranes. Use cautiously if pregnant.

• Art therapy: Art therapy involves the application of a variety of art modalities including drawing, painting, clay and sculpture. Art therapy enables the expression of inner thoughts or feelings when verbalization is difficult or not possible. Limited evidence suggests that art therapy may be of benefit in cancer caregiving for families of cancer patients. Possible benefits include reduced stress, lowered anxiety, increased positive emotions and increased positive communication with cancer patients and health care professionals. Art therapy may also reduce pain and other symptoms in cancer patients. More studies are needed to determine how best to use this form of intervention with this population. Art therapy may also benefit children hospitalized with leukemia during and after painful procedures. Limited available study suggests that art therapy improves cooperation with treatment. Children requested art therapy again when procedures were repeated, and parents reported that children were more manageable after art therapy.

• Art therapy may evoke distressing thoughts or feelings. Use under the guidance of a qualified art therapist or other mental health professional. Some forms of art therapy use potentially harmful materials. Only materials known to be safe should be used. Related clean-up materials (like turpentine or mineral spirits) that release potentially toxic fumes should only be used with good ventilation.

• Astragalus: Astragalus (Astragalus membranaceus) has been used in Chinese medicine for centuries for its immune enhancing properties. Although early laboratory and animal studies report immune stimulation and reduced cancer cell growth associated with the use of astragalus, reliable human evidence in these areas is currently lacking. In Chinese medicine, astragalus-containing herbal mixtures are also sometimes used with the intention to reduce side effects of chemotherapy and other cancer treatments. Astragalus-containing herbal combination formulas may also have beneficial effects in aplastic anemia. Due to a lack of well-designed research, a firm conclusion cannot be drawn.

• Caution is advised when taking astragalus supplements, as numerous adverse effects including drug interactions are possible. Astragalus should not be used if pregnant or breast-feeding, unless otherwise directed by a doctor.

• Baikal skullcap: Although the outcomes of early studies using baikal skullcap for cancer are promising, high-quality clinical studies are needed in this area before a conclusion can be made. Avoid if allergic or hypersensitive to Baikal skullcap (Scutellaria barbata), its constituents, or members of the Lamiaceae family. Use cautiously if taking sedatives and/or operating heavy machinery. Use cautiously if taking antineoplastic (anticancer) agents or agents metabolized by cytochrome P450 enzymes. Avoid if pregnant or breastfeeding. Baikal skullcap is an ingredient in PC-SPES, a product that has been recalled from the U.S. market and should not be used.

• Bee pollen: Bee pollen is considered a highly nutritious food because it contains a balance of vitamins, minerals, proteins, carbohydrates, fats, enzymes, and essential amino acids. Research has found that bee pollen may reduce some adverse effects of cancer treatment side effects. Additional study is needed before a firm recommendation can be made. Caution is advised when taking bee pollen supplements as allergic reactions may occur in sensitive individuals. Bee pollen should not be used if pregnant or breast-feeding, unless otherwise directed by a doctor.

• Beta-glucan: Treatment with a beta-glucan, called lentinan, plus chemotherapy (S-1) may help prolong the lives of patients with cancer that has returned or cannot be operated on. More research is needed in this area. Avoid if allergic or hypersensitive to beta-glucan. When taken by mouth, beta-glucan is generally considered safe. Use cautiously with AIDS or AIDS-related complex (ARC). Avoid using particulate beta-glucan. Avoid if pregnant or breastfeeding.

• Bitter melon: Bitter melon (Momordica charantia) is used in Avurvedic medicine from India to lower blood sugar levels. Research has also found that bitter melon extracts may be beneficial in cancer therapies. MAP30, a protein isolated from bitter melon extract, is reported to possess anti-cancer effects in laboratory studies. Potential anti-cancer effects have not been studied appropriately in humans. Caution is advised when taking bitter melon supplements, as numerous adverse effects including blood sugar lowering and drug interactions are possible. Bitter melon should not be used if pregnant or breast-feeding, unless otherwise directed by a doctor.

• Black tea: Black tea (Camellia sinensis) is from the same plant as green tea, but the leaves are processed differently. Black tea usually contains more caffeine than green tea. Several studies have explored a possible association between regular consumption of black tea and rates of cancer in several populations. This research has yielded conflicting results, with some studies suggesting benefits, and others reporting no effects. Laboratory and animal studies report that components of tea, such as polyphenols, have antioxidant properties and effects against tumors. However, effects in humans remain unclear, and these components may be more common in green tea rather than in black tea. Some animal and laboratory research suggests that components of black tea may actually be carcinogenic, or cancer causing, although effects in humans are not clear. Overall, the relationship of black tea consumption and human cancer prevention remains undetermined.

• Avoid if allergic or hypersensitive to caffeine or tannins. Skin rash and hives have been reported with caffeine ingestion. Use caution with diabetes. Use cautiously if pregnant. Heavy caffeine intake during pregnancy may increase the risk of SIDS (sudden infant death syndrome). Very high doses of caffeine have been linked with birth defects. Caffeine is transferred into breast milk. Caffeine ingestion by infants can lead to sleep disturbances/insomnia. Infants nursing from mothers consuming greater than 500 milligrams of caffeine daily have been reported to experience tremors and heart rhythm abnormalities. Tea consumption by infants has been linked to anemia, decreased iron metabolism, and irritability.

• Bovine cartilage: In early study, bovine tracheal cartilage (preparations such as Catrix® and VitaCarte®) has been studied for the treatment of cancer with encouraging results. High quality clinical research is needed to better determine the effectiveness of bovine tracheal cartilage preparations for cancer treatment.

• Avoid if allergic or hypersensitive to bovine cartilage or any of its constituents. Use cautiously with cancer, renal (kidney) failure, or hepatic (liver) failure. Avoid if pregnant or breastfeeding.

• Bromelain: Bromelain is a sulfur-containing digestive enzyme (proteins which help with digestion) that is extracted from the stem and the fruit of the pineapple plant (Ananas comosus). There is not enough information to recommend for or against the use of bromelain in the treatment of cancer, either alone or in addition to other therapies. One small study found that a bromelain supplement decreased tumor size in 12 breast cancer patients. Patients took the supplements for different periods of time, lasting from months to years. Caution is advised when taking bromelain supplements, as numerous adverse effects including blood thinning and drug interactions are possible. Bromelain should not be used if pregnant or breast-feeding, unless otherwise directed by a doctor.

• Cat's claw: Originally found in Peru, the use of cat's claw (Uncaria tomentosa) has been said to date back to the Inca civilization, possibly as far back as 2,000 years. Cat's claw has anti-inflammatory properties, and several low-quality studies suggest that cat's claw may slow tumor growth. However, this research is early and has not identified specific types of cancer that may benefit; thus, the results are not clear. A few studies suggest that cat's claw may also boost the immune system. Caution is advised when taking cat's claw supplements, as numerous adverse effects including blood thinning and drug interactions are possible. Cat's claw should not be used if pregnant or breast-feeding, unless otherwise directed by a doctor.

• Chaparral: Chaparral was used by the Native Americans for various health conditions. The chaparral component nordihydroguaiaretic acid (NDGA) has been evaluated as a treatment for cancer but due to risk of toxicity is considered unsafe and not recommended for use. Chaparral and NDGA have been associated with cases of kidney and liver failure, liver cirrhosis, kidney cysts, and kidney cancer in humans. In response to these reports, the U.S. Food and Drug Administration (FDA) removed chaparral from its "generally recognized as safe" (GRAS) list in 1970. Chaparral and NDGA are generally considered unsafe and are not recommended for use.

• Avoid if allergic to chaparral or any of its components, including nordihydroguaiaretic acid. Use cautiously if taking blood thinners (anticoagulants), blood sugar medication, or drugs that are broken down by the liver (like amiodarone, phenobarbital, valproic acid). Stop use two weeks before surgery/dental/diagnostic procedures with bleeding risk, and do not use immediately after these procedures. Use cautiously if driving or operating heavy machinery. Avoid if pregnant or breastfeeding.

• Chlorophyll: Preliminary evidence in suggest that chlorophyll may aid in the reduction of side effects associated with photodynamic therapies, such as those used in management of malignant tumors. Further research is required to support the use of chlorophyll as a laser therapy adjunct for cancer treatment.

• Avoid if allergic or hypersensitive to chlorophyll or any of its metabolites. Use cautiously with photosensitivity, compromised liver function, diabetes or gastrointestinal conditions or obstructions. Use cautiously if taking immunosuppressant agents or antidiabetes agents. Avoid if pregnant or breastfeeding.

• Chrysanthemum: Early study indicates that hua-sheng-ping (includes Chrysanthemum morifolium, Glycyrrhiza uralensis, and Panax notoginseng) may be beneficial for patients with precancerous lesions. However, more research is needed.

• Avoid if allergic or hypersensitive to Chrysanthemum, its constituents, or members of the Asteraceae/Compositae family, such as dandelion, goldenrod, ragweed, sunflower, and daisies. Use cautiously if taking medication for gout, cancer, or HIV. Use cautiously with compromised immune systems or if taking immunomodulators. Avoid with photosensitivity or if taking photosensitizers. Avoid large acute or chronic doses of ingested pyrethrin. Avoid pyrethrin with compromised liver function, epilepsy, or asthma. Avoid ocular exposure to pyrethrin. Avoid if pregnant or breastfeeding.

• Coenzyme Q10: Further research is needed to determine if coenzyme Q10 (CoQ10) may be of benefit for cancer when used with other therapies.

• Allergy associated with Coenzyme Q10 supplements has not been reported, although rash and itching have been reported rarely. Stop use two weeks before surgery/dental/diagnostic procedures with bleeding risk and do not use immediately after these procedures. Use caution with a history of blood clots, diabetes, high blood pressure, heart attack, or stroke, or with anticoagulants (blood thinners) or antiplatelet drugs (like aspirin, warfarin, clopidogrel (like Plavix®), or blood pressure, blood sugar, cholesterol or thyroid drugs. Avoid if pregnant or breastfeeding.

• Copper: Copper is a mineral that occurs naturally in many foods, including vegetables, legumes, nuts, grains and fruits, as well as shellfish, avocado, and beef (organs such as liver). Preliminary research reports that lowering copper levels theoretically may arrest the progression of cancer by inhibiting blood vessel growth (angiogenesis). Copper intake has not been identified as a risk factor for the development or progression of cancer. Copper is potentially unsafe when used orally in higher doses than the RDA. Copper supplements should not be used if pregnant or breast-feeding, unless otherwise directed by a doctor.

• Cranberry: Several laboratory studies have reported positive effects of proanthocyanidins, flavonoid components of cranberry (Vaccinium macrocarpon) and other fruits such as blueberries, grape seed, and pomegranate, on health. Based on early laboratory research, cranberry has been proposed for cancer prevention. Additional study is needed in humans before a conclusion can be made.

• Avoid if allergic to cranberries, blueberries or other plants of the Vaccinium species. Sweetened cranberry juice may effect blood sugar levels. Use cautiously with a history of kidney stones. Avoid more than the amount usually found in foods if pregnant or breastfeeding.

• Dandelion: Limited animal research does not provide a clear assessment of the effects of dandelion on tumor growth. Well-conducted human studies are needed to better determine dandelion's effects on cancer.

• Avoid if allergic to chamomile, feverfew, honey, yarrow, or any related plants such as aster, daisies, sunflower, chrysanthemum, mugwort, ragweed, or ragwort. Use cautiously with diabetes or bleeding disorders, gastroesophageal reflux disease (GERD), kidney or liver diseases, or a history of stroke or electrolyte disorders. Monitor potassium blood levels. Stop use two weeks before surgery/dental/diagnostic procedures with bleeding risk and do not use immediately after these procedures. Avoid if pregnant or breastfeeding.

• Echinacea: There is currently a lack of clear human evidence that echinacea affects any type of cancer. The evidence from a small number of clinical trials evaluating efficacy of echinacea in the treatment of radiation-induced leukopenia (decrease in white blood cells) is equivocal. Studies have used the combination product Esberitox®, which includes extracts of echinacea (Echinacea purpurea and pallida) root, white cedar (Thuja occidentalis) leaf, and wild indigo (Baptisia tinctoria)root. Additional clinical studies are needed to make a conclusion.

• Caution is advised when taking echinacea supplements, as numerous adverse effects including drug interactions are possible. Echinacea should not be used if pregnant or breast-feeding, unless otherwise directed by a doctor.

• Essiac®: Essiac® contains a combination of herbs, including burdock root (Arctium lappa), sheep sorrel (Rumex acetosella), slippery elm inner bark (Ulmus fulva), and Turkish rhubarb (Rheum palmatum). The original formula was developed by the Canadian nurse Rene Caisse (1888-1978) and is thought to be effective in cancer therapies, although currently there is not enough evidence to recommend for or against the use of this herbal mixture as a therapy for any type of cancer. Different brands may contain variable ingredients, and the comparative effectiveness of these formulas is not known. None of the individual herbs used in Essiac® has been tested in rigorous human cancer trials, although some components have anti-tumor activity in laboratory studies. Numerous individual patient testimonials and reports from manufacturers are available on the Internet, although these cannot be considered scientifically viable as evidence. Individuals with cancer are advised not to delay treatment with more proven therapies. Caution is advised when taking Essiac® supplements, as numerous adverse effects including drug interactions are possible. Essiac® should not be used if pregnant or breast-feeding, unless otherwise directed by a doctor.

• Focusing: Focusing (experiential therapy) is a method of psychotherapy that involves being aware of one's feelings surrounding a particular issue and understanding the meaning behind words or images conveyed by those feelings. Early evidence suggests focusing may improve mood and attitude in cancer patients. Firm recommendations cannot be made until well-designed clinical trials are available.

• Side effect reporting is rare, but patients should consult with a qualified healthcare practitioner before making decisions about medical conditions and practices. Individuals with severe emotional difficulties should not abandon proven medical and psychological therapies but rather choose focusing as a possible adjunct.

• Folic acid: Folic acid or folate is a form of a water-soluble B vitamin needed for human health. Preliminary evidence suggests that folate may decrease the risk of several types of cancer. Additional research is needed to make a conclusion. Folic acid supplementation may mask the symptoms of pernicious, aplastic, or normocytic anemias caused by vitamin B12 deficiency and may lead to neurological damage.

• Avoid if allergic or hypersensitive to folate or any folate product ingredients. Use cautiously if receiving coronary stents and with anemia and seizure disorders. It is recommended that pregnant women consume 400 micrograms daily in order to reduce the risk of fetal defects. Folate is likely safe if breastfeeding.

• Gamma linolenic acid (GLA): GLA is an omega-6 essential fatty acid. Some laboratory and human studies indicate that GLA may have anti-tumor activity and may be used as a cancer treatment adjunct. Additional research is needed in this area.

• Caution is advised when taking GLA supplements, as numerous adverse effects including an increased risk of bleeding and drug interactions are possible. GLA should not be used if pregnant or breast-feeding, unless otherwise directed by a doctor.

• Garlic: Preliminary human studies suggest that regular consumption of garlic (Allium sativum) supplements may reduce the risk of developing several types of cancer. Some studies use multi-ingredient products so it is difficult to determine if garlic alone may play a beneficial role in cancer prevention. Further well-designed human clinical trials are needed to conclude whether eating garlic or taking garlic supplements may prevent or treat cancer.

• Caution is advised when taking garlic supplements, as numerous adverse effects including an increased risk of bleeding and drug interactions are possible. Garlic should not be used if pregnant or breast-feeding, unless otherwise directed by a doctor.

• Ginseng: Early studies report that ginseng taken by mouth may be of benefit in cancer prevention, especially if ginseng powder or extract is used. Weak studies suggest that ginseng in combination with other herbs may improve cell activity, immune function, and red and white blood cell counts in patients with aplastic anemia; however, other studies have found decreases in blood cell counts. Early studies suggest that ginseng may decrease radiation therapy side effects and may be used as a chemotherapy adjunct to improve body weight, quality of life, and the immune response. There is currently not enough evidence to recommend the use of Panax ginseng or American ginseng for these indications. Study results are unclear, and more research is needed before a clear conclusion can be reached.

• Caution is advised when taking ginseng supplements, as numerous adverse effects including an increased risk of drug interactions are possible. Ginseng should not be used if pregnant or breast-feeding, unless otherwise directed by a doctor.

• Goji: Polysaccharide constituents, such as alpha- and beta-glucans from a variety of plants, are reported to have immune system enhancing properties. In clinical study, Lycium barbarum polysaccharides (LBP) demonstrated a synergistic effect in various cancer treatments, when administered in conjunction with powerful immune stimulating drugs.

• Use cautiously in patients who are taking blood-thinning medications, such as warfarin. Use cautiously in asthma patients and in patients with sulfite sensitivities. The New York Department of Agriculture has detected the presence of undeclared sulfites, a food additive, in two dried goji berry products from China. Avoid in patients who are allergic to goji, any of its constituents, or to members of the Solanaceae family.

• Grape seed: There is currently little information available on the use of grape seed extract in the treatment of human cancer. Further research is needed before a recommendation can be made.

• Avoid if allergic or hypersensitive to grapes or other grape compounds. Use cautiously with bleeding disorders or if taking blood thinners such as warfarin, aspirin, non-steroidal anti-inflammatory drugs (NSAIDS), or anti-platelet agents. Use cautiously with drugs processed using the liver's cytochrome P450 enzyme system. Use cautiously with blood pressure disorders or if taking ACE inhibitors. Avoid if pregnant or breastfeeding.

• Green tea: Green tea is made from the dried leaves of Camellia sinensis, a perennial evergreen shrub. Green tea has a long history of use in health and longevity, dating back to China approximately 5,000 years ago. Although used for centuries to help prevent diseases, the relationship of green tea consumption and human cancer in general remains inconclusive. Evidence from well-designed clinical trials is needed before a firm conclusion can be made in this area.

• Caution is advised when taking green tea supplements, as numerous adverse effects including an increased risk of drug interactions are possible. Green tea should not be used if pregnant or breast-feeding, unless otherwise directed by a doctor.

• Healing touch: Preliminary data suggests that healing touch (HT) may increase quality of life in cancer. However, due to weaknesses in design and the small number of studies, data are insufficient to make definitive recommendations. Studies with stronger designs are needed. HT should not be regarded as a substitute for established medical treatments. Use cautiously if pregnant or breastfeeding.

• Hoxsey formula: "Hoxsey formula" is a misleading name, because it is not a single formula, but rather is a therapeutic regimen consisting of an oral tonic, topical (on the skin) preparations, and supportive therapy. The tonic is individualized for cancer patients based on general condition, location of cancer, and previous history of treatment. An ingredient that usually remains constant for every patient is potassium iodide. Other ingredients are then added and may include licorice, red clover, burdock, stillingia root, berberis root, pokeroot, cascara, Aromatic USP 14, prickly ash bark, and buckthorn bark. A red paste may be used, which tends to be caustic (irritating), and contains antimony trisulfide, zinc chloride, and bloodroot. A topical yellow powder may be used, and contains arsenic sulfide, talc, sulfur, and a "yellow precipitate." A clear solution may also be administered, and contains trichloroacetic acid.

• Well-designed human studies available evaluating the safety or effectiveness of Hoxsey formula are currently lacking. Caution is advised when taking the Hoxsey formula supplements, as numerous adverse effects including an increased risk of drug interactions are possible. Hoxsey formula should not be used if pregnant or breast-feeding, unless otherwise directed by a doctor.

• Hydrazine sulfate: Hydrazine is an industrial chemical marketed as having the potential to repress weight loss and cachexia (muscle wasting) associated with cancer, and to improve general appetite status. However, in large randomized controlled trials, hydrazine has not been proven effective for improving appetite, reducing weight loss, or improving survival in adults. The National Cancer Institute (NCI) sponsored studies of hydrazine sulfate that claimed efficacy in improving survival for some patients with advanced cancer. Trial results found that hydrazine sulfate did not prolong survival for cancer patients. The U.S. Food and Drug Administration (FDA) has received requests from individual physicians for approval to use hydrazine sulfate on a case-by-case "compassionate use" basis on the chance that patients with no other available effective cancer treatment options might benefit from this therapy. The overall controversy in the use of hydrazine sulfate is ongoing, and relevance to clinical practice is unknown. The use of hydrazine sulfate needs to be evaluated further before any recommendations can be made.

• Hydrazine sulfate may cause cancer. Avoid if allergic or hypersensitive to hydrazine sulfate or any of its constituents. Use cautiously with liver or kidney problems, psychosis, diabetes or seizure disorders. Avoid if pregnant or breastfeeding. Side effects have been reported, including dizziness, nausea, and vomiting.

• Iodine: Iodine is an element (atomic number 53), which is required by humans for the synthesis of thyroid hormones (triiodothyronine/T3 and thyroxine/T4). The potential role of non-radioactive iodine in cancer care remains unknown. Antioxidant and anti-tumor effects have been proposed based on laboratory research. In contrast, some scientists have asserted that tumors may uptake more iodine than normal tissues. It has been suggested that high rates of gastric (stomach) cancer or low rates of breast cancer in coastal Japan may be due to high iodine intake, although this has not been demonstrated scientifically. Povidone-iodine solutions have been used as a part of alternative cancer regimens, such as the Hoxsey formula. Preliminary study has also indicated povidone-iodone solution as a potential rectal washout for rectal cancer. Overall, no clear conclusion can be drawn based on the currently available evidence.

• Reactions can be severe, and deaths have occurred with exposure to iodine. Avoid iodine-based products if allergic or hypersensitive to iodine. Do no use for more than 14 days. Avoid Lugol solution and saturated solution of potassium iodide (SSKI, PIMA) with hyperkalemia (high amounts of potassium in the blood), pulmonary edema (fluid in the lungs), bronchitis, or tuberculosis. Use cautiously when applying to the skin because it may irritate/burn tissues. Use sodium iodide cautiously with kidney failure. Avoid sodium iodide with gastrointestinal obstruction. Iodine is safe in recommended doses for pregnant or breastfeeding women. Avoid povidone-iodine for perianal preparation during delivery or postpartum antisepsis.

• Jiaogulan: Preliminary evidence indicates that gypenosides extracted from Gynostemma pentaphyllum may decrease cancer cell viability, arrest the cell cycle, and induce apoptosis (cell death) in human cancer cells. Immune function in cancer patients has also been studied. Additional study is needed in this area.

• Avoid if allergic or hypersensitive to jiaogulan (Gynostemma pentaphyllum), its constituents, or members of the Cucurbitaceae family. Use cautiously with blood disorders or taking anticoagulants or anti-platelet drugs (blood thinners). Use cautiously with diabetes. Avoid if pregnant or breastfeeding.

• Lavender: Perillyl alcohol (POH), derived from lavender (Lavendula officinalis), may be beneficial in the treatment of some types of cancer. Preliminary small studies in humans, involving the use of POH suggest safety and tolerability, but effectiveness has not been established.

• Avoid if allergic or hypersensitive to lavender. Avoid with a history of seizures, bleeding disorders, eating disorders (anorexia, bulimia), or anemia (low levels of iron). Avoid if pregnant or breastfeeding.

• Lutein: Currently, there is insufficient available evidence to recommend for or against the use of lutein for cancer. Available evidence in humans is conflicting.

• Avoid if allergic or hypersensitive to lutein or zeaxanthin. Use cautiously if at risk for cardiovascular disease or cancer. Avoid if pregnant or breastfeeding.

• Lycopene: High levels of lycopene are found in tomatoes and in tomato-based products. Tomatoes are also sources of other nutrients such as vitamin C, folate, and potassium. Several laboratory and human studies examining tomato-based products and blood lycopene levels suggest that lycopene may be associated with a lower risk of developing cancer and may help stimulate the immune system. However, due to a lack of well-designed human research using lycopene supplements, its effectiveness for cancer prevention remains unclear.

• Avoid if allergic to tomatoes or to lycopene. Due to a lack of conclusive data, avoid if pregnant or breastfeeding.

• Maitake mushroom: Maitake is the Japanese name for the edible mushroom Grifola frondosa. Maitake has been used traditionally both as a food and for medicinal purposes. Early studies in the laboratory as well as in humans suggest that beta-glucan extracts from maitake may increase the body's ability to fight cancer. However, these studies have not been well designed, and better research is needed before the use of maitake for cancer can be recommended.

• Caution is advised when taking maitake supplements, as numerous adverse effects including an increased risk of bleeding and drug interactions are possible. Maitake should not be used if pregnant or breast-feeding, unless otherwise directed by a doctor.

• Meditation: Not enough research has shown meditation to be of benefit in cancer prevention. More studies are needed.

• Use cautiously with underlying mental illnesses. People with psychiatric disorders should consult with their primary mental healthcare professional(s) before starting a program of meditation, and should explore how meditation may or may not fit in with their current treatment plan. Avoid with risk of seizures. The practice of meditation should not delay the time to diagnosis or treatment with more proven techniques or therapies, and should not be used as the sole approach to illnesses.

• Melatonin: There are several early-phase and controlled human trials of melatonin in patients with various advanced stage malignancies. There is currently not enough definitive scientific evidence to discern if melatonin is beneficial as a cancer treatment, whether it increases (or decreases) the effectiveness of other cancer therapies, or if it safely reduces chemotherapy side effects.

• Melatonin is not to be used for extended periods of time. Caution is advised when taking melatonin supplements, as numerous adverse effects including drug interactions are possible. Melatonin is not recommended during pregnancy or breastfeeding unless otherwise advised by a doctor.

• Milk thistle: Milk thistle (Silybum marianum) has been used medicinally in China for over 2,000 years, most commonly for the treatment of liver and gallbladder disorders. There are early reports from laboratory experiments that the components silymarin and silibinin found in milk thistle may reduce the growth of human cancer cells. However, effects have not been shown in high-quality human trials.

• Caution is advised when taking milk thistle supplements, as numerous adverse effects including an increased risk of bleeding and drug interactions are possible. Milk thistle should not be used if pregnant or breast-feeding, unless otherwise directed by a doctor.

• Mistletoe: Mistletoe is one of the most widely used unconventional cancer treatments in Europe. Mistletoe extracts have been studied for a variety of human cancers as well as melanoma and leukemia. However, efficacy has not been conclusively proven for any one condition. In fact, some studies have shown lack of efficacy of certain preparations for a variety of cancers. Larger, well-designed clinical trials are needed.

• Caution is advised when taking mistletoe supplements, as numerous adverse effects including nausea, vomiting, and drug interactions are possible. Mistletoe should not be used if pregnant or breast-feeding, unless otherwise directed by a doctor.

• Moxibustion: Moxibustion is a healing technique employed across the diverse traditions of acupuncture and oriental medicine for over 2,000 years. Moxibustion uses the principle of heat to stimulate circulation and break up congestion or stagnation of blood and chi. Moxibustion is closely related to acupuncture as it is applied to specific acupuncture points. Preliminary evidence suggests that moxibustion may reduce side effects of chemotherapy or radiation therapy. More studies are needed.

• Use cautiously over large blood vessels and thin or weak skin. Avoid with aneurysms, any kind of "heat syndrome," cardiac disease, convulsions or cramps, diabetic neuropathy, extreme fatigue and/or anemia, fever, inflammatory conditions, over allergic skin conditions or ulcerated sores, or skin adhesions. Avoid if pregnant or breastfeeding. Avoid areas with an inflamed organ, contraindicated acupuncture points, face, genitals, head, inflamed areas in general, nipples, and skin adhesions. Avoid in patients who have just finished exercising or taking a hot bath or shower. Use cautiously with elderly people with large vessels. It is considered not advisable to bathe or shower for up to 24 hours after a moxibustion treatment.

• Oleander: Laboratory studies of oleander (Nerium oleander) suggest possible anti-cancer effects, although reliable research in humans is not currently available. There are reports that long-term use of oleander may have positive effects in patients several types of cancer. More research is needed.

• Caution is advised when taking oleander supplements, as numerous adverse effects including drug interactions are possible. Oleander should not be used if pregnant or breast-feeding, unless otherwise directed by a doctor.

• Omega-3 fatty acids: Omega-3 fatty acids are essential fatty acids found in some plants and fish. A balance of omega-6 and omega-3 fatty acids is advised for health. Several population studies report that dietary omega-3 fatty acids or fish oil may reduce the risk of developing several different types of cancer. Well conducted clinical trials are necessary before a clear conclusion can be drawn regarding the use of omega-3 fatty acids for cancer prevention.

• Caution is advised when taking omega-3 fatty acid supplements, as numerous adverse effects including an increase in bleeding and drug interactions are possible. Omega-3 fatty acid supplements should not be used if pregnant or breast-feeding, unless otherwise directed by a doctor.

• Para-aminobenzoic acid: N-butyl-p-aminobenzoate (BAB) has been shown to be a lipid-soluble local anesthetic. Early study found significant pain relief in patients with intractable cancer pain after an epidural injection of BAB suspension. Larger scale clinical study is needed to confirm these findings.

• Avoid with known hypersensitivity to PABA or its derivatives. Avoid oral use in children and pregnant or nursing women. Use cautiously in patients with renal disease, bleeding disorders or taking anticoagulants, diabetics or patients at risk for hypoglycemia. Discontinue use if rash, nausea, or anorexia occurs. Pharmaceutical doses of PABA and its derivatives should only be taken under appropriate medical supervision. PABA should not be given concurrently with sulfonamides.

• Perillyl alcohol: Perillyl alcohol has been used to treat cancer. However, high quality scientific studies are lacking. Further research is required before recommendations can be made.

• Avoid if allergic/hypersensitive to perillyl alcohol. Avoid use in the absence of medical supervision. Use cautiously in patients under medical supervision. Avoid if pregnant or breastfeeding.

• Prayer: Initial studies of prayer in patients with cancer (such as leukemia) report variable effects on disease progression or death rates when intercessory prayer is used. Better quality research is necessary before a firm conclusion can be drawn.

• Prayer is not recommended as the sole treatment approach for potentially serious medical conditions, and should not delay the time it takes to consult with a healthcare professional or receive established therapies. Sometimes religious beliefs come into conflict with standard medical approaches, and require an open dialog between patients and caregivers. In clinical study, patients certain that they were receiving intercessory prayer had a higher incidence of complications following cardiac bypass surgery than those who did not know they were being prayed for.

• Reiki: Reiki may contribute to reduced perception of pain, improved quality of life, and reduced fatigue in cancer patients. More studies are needed.

• Reiki is not recommended as the sole treatment approach for potentially serious medical conditions, and should not delay the time it takes to consult with a healthcare professional or receive established therapies. Use cautiously with psychiatric illnesses.

• Reishi mushroom: Reishi (Ganoderma lucidum) has been shown to have antineoplastic and immunomodulatory effects in animal studies. Human studies exist of advanced cancer patients using Ganopoly®, a Ganoderma lucidum polysaccharide extract. Results show improved quality of life and enhanced immune responses, which are typically reduced or damaged in cancer patients receiving chemotherapy and/or radiation therapy. Well-designed long-term studies are needed confirm these results and to determine potential side effects.

• Caution is advised when taking reishi supplements, as numerous adverse effects including an increased risk of bleeding and drug interactions are possible. Reishi should not be used if pregnant or breast-feeding, unless otherwise directed by a doctor.

• Resveratrol: The effects of resveratrol cannot be adequately assessed from trials using foods, wine, or combination products containing resveratrol and other substances. Well-designed clinical trials of resveratrol alone are needed before a recommendation can be made in regards to cancer prevention and/or treatment.

• Avoid if allergic or hypersensitive to resveratrol, grapes, red wine or polyphenols. Resveratrol is generally considered safe and is commonly found in food and beverages. Use cautiously with bleeding disorders, abnormal blood pressure. Use cautiously with drugs that are broken down by the body's cytochrome P450 system or digoxin (or digoxin-like drugs). Avoid if pregnant or breastfeeding.

• Seaweed: Bladderwrack (Fucus vesiculosus) is a brown seaweed that grows on the northern coasts of the Atlantic and Pacific oceans, and the North and Baltic seas. Bladderwrack appears to suppress the growth of various cancer cells in animal and laboratory studies. However, reliable human studies to support a recommendation for use in cancer are currently lacking.

• Caution is advised when taking bladderwrack supplements, as numerous adverse effects including an increased risk of drug interactions are possible. Bladderwrack should not be used if pregnant or breast-feeding, unless otherwise directed by a doctor.

• Selenium: Selenium is a trace mineral found in soil, water, and some foods. It is an essential element in several metabolic pathways. Several studies suggest that low levels of selenium (measured in the blood or in tissues such as toenail clippings), may be a risk factor for developing cancer. Population studies suggest that people with cancer are more likely to have low selenium levels than healthy matched individuals, but in most cases it is not clear if the low selenium levels are a cause or merely a consequence of disease. It currently remains unclear if selenium is beneficial for cancer prevention or cancer treatment.

• Avoid if allergic or sensitive to products containing selenium. Avoid with a history of nonmelanoma skin cancer. Selenium is generally regarded as safe for pregnant or breastfeeding women. However, animal research reports that large doses of selenium may lead to birth defects.

• Shark cartilage: For several decades, shark cartilage has been proposed as a cancer treatment. Studies have shown shark cartilage or the shark cartilage product AE-941 (Neovastat®) to block the growth of new blood vessels, a process called "anti-angiogenesis," which is believed to play a role in controlling growth of some tumors. There have also been several reports of successful treatments of end-stage cancer patients with shark cartilage, but these have not been well-designed and have not included reliable comparisons to accepted treatments. Many studies have been supported by shark cartilage product manufacturers, which may influence the results. In the United States, shark cartilage products cannot claim to cure cancer, and the U.S. Food and Drug Administration (FDA) has sent warning letters to companies not to promote products in this way. Without further evidence from well-designed human trials, it remains unclear if shark cartilage is of any benefit in cancer and patients are advised to check with their doctor and pharmacist before taking shark cartilage.

• Shark cartilage available in Asian grocery stores and restaurants should not be eaten due to declining populations of sharks. Caution is advised when taking shark cartilage supplements, as numerous adverse effects including an increased risk of drug interactions are possible. Shark cartilage should not be used by patients who are pregnant or breast-feeding, unless otherwise directed by a doctor.

• Shiitake mushroom: Shiitake (Lentinus edodes) has been taken by mouth for boosting the immune system, decreasing cholesterol levels, and for anti-aging. Lentinan, derived from shiitake, has been injected as an adjunct treatment for cancer and HIV infection. Laboratory, animal and human studies of lentinan have shown positive results in cancer patients when used as a chemotherapy adjunct. Further well-designed clinical trials on all types of cancer are required to confirm these results.

• Caution is advised when taking shiitake supplements, as numerous adverse effects including an increased risk of bleeding and drug interactions are possible. Shiitake should not be used if pregnant or breast-feeding, unless otherwise directed by a doctor.

• Slippery elm: Slippery elm is found as a common ingredient in a purported herbal anticancer product called Essiac® and a number of Essiac-like products. These products contain other herbs such as rhubarb, sorrel, and burdock root. Currently, there is not enough evidence to recommend for or against the use of this herbal mixture as a therapy for any type of cancer. Avoid if allergic or hypersensitive to slippery elm. Avoid if pregnant or breastfeeding.

• Sorrel: Early evidence suggests that herbal formulations containing sorrel, such as Essiac®, do not shrink tumor size or increase life expectancy in patients with cancer. However, currently there is a lack of studies evaluating sorrel as the sole treatment for cancer. A conclusion cannot be made without further research.

• Avoid with a known allergy or hypersensitivity to sorrel. Avoid large doses due to reports of toxicity and death, possibly because of the oxalate found in sorrel. Many tinctures contain high levels of alcohol and should be avoided when driving or operating heavy machinery. Sorrel formulations may cause nausea or vomiting when taken with the prescription drugs metronidazole (Flagyl®) or disulfiram (Antabuse®). Avoid if pregnant or breastfeeding.

• Soy: Soy (Glycine max) contains compounds which have been reported to be effective as a cancer treatment. Genistein, an isoflavone found in soy, has been found in laboratory and animal studies to possess anti-cancer effects, such as blocking new blood vessel growth (anti-angiogenesis), acting as a tyrosine kinase inhibitor (a mechanism of many new cancer treatments), or causing cancer cell death (apoptosis). In contrast, genistein has also been reported to increase the growth of pancreas tumor cells in laboratory research. Until reliable human research is available, it remains unclear if dietary soy or soy isoflavone supplements are beneficial, harmful, or neutral in people with various types of cancer.

• Caution is advised when taking soy supplements, as numerous adverse effects including an increased risk of drug interactions are possible. Soy should not be used if pregnant or breast-feeding, unless otherwise directed by a doctor.

• Spiritual healing: Cancer patients, especially those who fear recurrence or are unhappy with their physicians, commonly use prayer and spiritual healing. More research is needed to address the effects of spiritual healing on anxiety, depression, and quality of life in patients with cancer.

• Spiritual healing should not be used as the only treatment approach for medical or psychiatric conditions, and should not delay the time it takes to consider more proven therapies.

• Sweet annie: Certain constituents found in sweet annie show promise for use in cancer when used in combination with standard chemotherapy. However, currently there is not enough scientific evidence in humans to make a strong recommendation for this use.

• Avoid if allergic or hypersensitive to sweet annie (Artemisia annua), its constituents, or members of the Asteraceae/Compositae family such dandelion, goldenrod, ragweed, sunflower, and daisies. Use cautiously in patients who are pregnant, taking angiogenic agents, or recovering from surgery or other wounds. Use cautiously if taking cardiotoxic or neurotoxic agents or with compromised cardiac or neural function. Use cautiously if taking immunostimulants or quinolines. Avoid if pregnant or breastfeeding.

• Transcutaneous electrical nerve stimulation (TENS): Transcutaneous electrical nerve stimulation (TENS) is a non-invasive technique in which a low-voltage electrical current is delivered through wires from a small power unit to electrodes located on the skin. Although TENS has been used with some success in cancer pain, there is not enough reliable evidence to draw a firm conclusion in this area. TENS is often used in combination with acupuncture.

• Avoid with implantable devices, like defibrillators, pacemakers, intravenous infusion pumps, or hepatic artery infusion pumps. Use cautiously with decreased sensation, like neuropathy, and with seizure disorders. Avoid if pregnant or breastfeeding.

• Thiamin (Vitamin B1): Thiamin deficiency has been observed in some cancer patients, possibly due to increased metabolic needs. It is not clear if lowered levels of thiamin in such patients may actually be beneficial. Currently, it remains unclear if thiamin supplementation plays a role in the management of any particular type(s) of cancer.

• Thiamin is generally considered safe and relatively nontoxic. Avoid if allergic or hypersensitive to thiamin. Rare hypersensitivity/allergic reactions have occurred with thiamin supplementation. Skin irritation, burning, or itching may rarely occur at injection sites. Large doses may cause drowsiness or muscle relaxation. Use cautiously if pregnant or breastfeeding.

• Thymus extract: Preliminary evidence suggests that thymus extract may increase disease-free survival and immunological improvement in several types of cancer. Additional study is needed in this area.

• Avoid if allergic or hypersensitive to thymus extracts. Use bovine thymus extract supplements cautiously due to potential for exposure to the virus that causes "mad cow disease." Avoid with an organ transplant or other forms of allografts or xenografts. Avoid if receiving immunosuppressive therapy, with thymic tumors, myasthenia gravis (neuromuscular disorder), untreated hypothyroidism, or if taking hormonal therapy. Avoid if pregnant or breastfeeding.

• Traditional Chinese Medicine (TCM): The ancient Chinese philosophy of Taoism provided the basis for the development of Chinese medical theory. TCM uses over 120 different herbs in cancer treatment, depending on the type of cancer and its cause according to Chinese medical theory. Studies have reported significant benefits include reducing tumors, reducing treatment side effects and improved response to treatment. More studies of stronger design are needed before TCM can be recommended with confidence as an adjunct to cancer treatment, although centuries of traditional use in cancer cannot be discounted.

• Chinese herbs can be potent and may interact with other herbs, foods or drugs. Consult a qualified healthcare professional before taking. There have been reports of manufactured or processed Chinese herbal products being tainted with toxins or heavy metal or not containing the listed ingredients. Herbal products should be purchased from reliable sources. Avoid ma huang, which is the active ingredient in ephedra. Avoid ginseng if pregnant or breastfeeding.

• Turmeric: Turmeric (Curcuma longa) is commonly used for its anti-inflammatory properties. Several early animal and laboratory studies report anti-cancer (colon, skin, breast) properties of curcumin. Many mechanisms have been considered, including antioxidant activity, anti-angiogenesis (prevention of new blood vessel growth), and direct effects on cancer cells. Currently it remains unclear if turmeric or curcumin has a role in preventing or treating human cancer. There are several ongoing studies in this area.

• Caution is advised when taking turmeric supplements, as numerous adverse effects including an increased risk of bleeding and drug interactions are possible. Turmeric should not be used if pregnant or breast-feeding, unless otherwise directed by a doctor.

• Vitamin C (ascorbic acid): Dietary intake of fruits and vegetables high in vitamin C has been associated with a reduced risk of various types of cancer in population studies (particularly cancers of the mouth, esophagus, stomach, colon, or lung). However, it is not clear that it is specifically the vitamin C in these foods that is beneficial, and vitamin C supplements have not been found to be associated with this protective effect. Experts have recommended increasing dietary consumption of fruits and vegetables high in vitamin C, such as apples, asparagus, berries, broccoli, cabbage, melon (cantaloupe, honeydew, watermelon), cauliflower, citrus fruits (lemons, oranges), fortified breads/grains/cereal, kale, kiwi, potatoes, spinach, and tomatoes. Vitamin C has a long history of adjunctive use in cancer therapy, and although there have not been any definitive studies using intravenous (or oral) vitamin C, there is evidence that it has benefit in some cases. Better-designed studies are needed to better determine the role of vitamin C in cancer prevention and cancer treatment.

• Avoid if allergic or sensitive to vitamin C product ingredients. Vitamin C is generally considered safe in amounts found in foods. Vitamin C supplements are also generally considered safe in most individuals if taken in recommended doses. Large doses (greater than 2 grams) may cause diarrhea and gastrointestinal upset. Avoid high doses of vitamin C with glucose 6-phosphate dehydrogenase deficiency, kidney disorders or stones, cirrhosis (inflammation of the liver), gout, or paroxysmal nocturnal hemoglobinuria (bleeding disorder). Vitamin C intake from food is generally considered safe if pregnant or breastfeeding. It is not clear if vitamin C supplements in doses higher than Dietary Reference Intake recommendations are safe for pregnant or breastfeeding women. Vitamin C is naturally found in breast milk.

• Vitamin D: Limited research suggests that synthetic vitamin D analogs may play a role in the treatment of human cancers. However, it remains unclear if vitamin D deficiency raises cancer risk, or if an increased intake of vitamin D is protective against some cancers. Until additional trials are conducted, it is premature to advise the use of regular vitamin D supplementation for cancer prevention.

• Avoid if allergic or hypersensitive to vitamin D or any of its components. Vitamin D is generally well-tolerated in recommended doses; doses higher than recommended may cause toxic effects. Use cautiously with hyperparathyroidism (overactive thyroid), kidney disease, sarcoidosis, tuberculosis, and histoplasmosis. Vitamin D is safe in pregnant and breastfeeding women when taken in recommended doses.

• Vitamin E: Reliable scientific evidence that vitamin E is effective as a cancer treatment is currently lacking.

• Caution is merited in people undergoing chemotherapy or radiation, because it has been proposed that the use of high-dose antioxidants may actually reduce the anti-cancer effects of these therapies. This remains an area of controversy and studies have produced variable results. Patients interested in using high-dose antioxidants such as vitamin E during chemotherapy or radiation should discuss this decision with their medical oncologist or radiation oncologist. Caution is advised when taking vitamin E supplements, as numerous adverse effects including an increased risk of bleeding and drug interactions are possible. Avoid if allergic or hypersensitive to vitamin E. Avoid with retinitis pigmentosa (loss of peripheral vision). Use cautiously with bleeding disorders or if taking blood thinners. Avoid above the recommended daily level in pregnant women and breastfeeding women.

• Fair negative scientific evidence:

• Apricot: Available clinical trials on the use of whole apricots for cancer are currently lacking. However, some research has been conducted on "Laetrile™," an alternative cancer drug marketed in Mexico and other countries outside of the U.S. Laetrile™ is derived from amygdalin found in apricot pits and nuts such as bitter almond. There are multiple animal studies and initial human evidence to suggest that Laetrile™ is not beneficial in the treatment of cancer. Based on a phase II trial in 1982, the U.S. National Cancer Institute concluded that Laetrile™ is not an effective chemotherapeutic agent. Nonetheless, many people still travel to use this therapy outside the U.S.

• Multiple cases of cyanide poisoning, including deaths, have been associated with Laetrile™ therapy. Avoid if allergic to apricot, its constituents or members of the Rosaceae family, especially the Prunoideae subfamily of plants. Avoid eating excessive amounts of apricot kernels (about 7 grams daily, or more than ten kernels daily). Use cautiously with diabetes. Use cautiously when taking supplements containing beta-carotene, iron, niacin, potassium, thiamine or vitamin C. Use cautiously when taking products that may lower blood pressure. Avoid if pregnant or breastfeeding.

• Beta-carotene: While diets high in fruits and vegetables rich in beta-carotene have been shown to potentially reduce certain cancer incidences, results from randomized controlled trials with oral supplements do not support this claim.

• There is some concern that beta-carotene metabolites with pharmacological activity can accumulate and potentially have cancer-causing (carcinogenic) effects. A higher, statistically significant incidence of lung cancer in male smokers who took beta-carotene supplements has been discovered. Beta-carotene/vitamin A supplements may have an adverse effect on the incidence of lung cancer and on the risk of death in smokers and asbestos exposed people or in those who ingest significant amounts of alcohol. In addition, high-dose antioxidants theoretically may interfere with the activity of some chemotherapy drugs or radiation therapy. Therefore, individuals undergoing cancer treatment should speak with their oncologist if they are taking or considering the use of high dose antioxidants. Beta-carotene in the amounts normally found in food does not appear to have this adverse effect. Avoid if sensitive to beta-carotene, vitamin A or any other ingredients in beta-carotene products.

• Bitter almond: "Laetrile" is an alternative cancer drug marketed in Mexico and other countries outside of the United States. Laetrile is derived from amygdalin, found in the pits of fruits and nuts such as the bitter almond. Early evidence suggests that laetrile is not beneficial in the treatment of cancer. In 1982, the U.S. National Cancer Institute concluded that laetrile was not effective for cancer therapy. Nonetheless, many people still travel to use this therapy outside the United States.

• Multiple cases of cyanide poisoning, including deaths, have been associated with laetrile therapy. Avoid if allergic to almonds or other nuts. Use cautiously if driving or operating machinery. Avoid if pregnant or breastfeeding because of the risk of birth defects.

• Hypnotherapy, hypnosis: Hypnosis did not reduce radiotherapy side effects such as anxiety and did not improve quality of life in patients undergoing curative radiotherapy in early high-quality studies.

• Use cautiously with mental illnesses like psychosis/schizophrenia, manic depression, multiple personality disorder or dissociative disorders, or with seizure disorders.

• Iridology: There is currently limited available data supporting iridology as a tool for cancer diagnosis. Additional study is needed.

• Iridology should not be used alone to diagnose disease. Studies of iridology have reported incorrect diagnoses, and thus, potentially severe medical problems may go undiagnosed. In addition, research suggests that iridology may lead to inappropriate treatment. Iridology is therefore not recommended as a sole method of diagnosis or treatment for any condition.

• Vitamin E: Recent evidence from well-conducted clinical study reports no reduction in the development of cancer with the use of natural-source vitamin E taken daily. Previously, there have been laboratory, population, and other human trials examining whether vitamin E is beneficial in general cancer prevention, including that for prostate, colon, or stomach cancer. Results of these prior studies have been variable. At this time, based on the best available scientific evidence, and recent concerns about the safety of vitamin E supplementation, vitamin E cannot be recommended for cancer prevention.

• Avoid if allergic or hypersensitive to vitamin E. Avoid with retinitis pigmentosa (loss of peripheral vision). Use cautiously with bleeding disorders or if taking blood thinners. Avoid above the recommended daily level in pregnant women and breastfeeding women.

Author Information

• This information has been edited and peer-reviewed by contributors to the Natural Standard Research Collaboration (www.naturalstandard.com).

Bibliography

Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to www.naturalstandard.com. Selected references are listed below.

1. American Brain Tumor Association. http://hope.abta.org.

2. Brain Tumor Society. www.tbts.org.

3. National Brain Tumor Foundation. www.braintumor.org.

4. National Cancer Institute (NCI). www.cancer.gov.

5. National Institutes of Health. www.nlm.nih.gov.

6. Natural Standard: The Authority on Integrative Medicine. www.naturalstandard.com.