Exposure to ultraviolet light is one of the most common skin cancer causes, and it can lead to a deadly form of skin cancer, melanoma.
Like other forms of cancer, skin cancer is caused by cells mutating and growing out of control, creating dangerous tumors instead of healthy skin cells. Many skin cancer sites begin as moles, though not all moles develop into cancer.
What are the skin cancer causes that happen in the first place?
Our genes control what happens within our cells. Genes that trigger cells to divide and grow are known as oncogenes. Those that control cell growth or cause cells to die at the right time are called tumor suppressor genes. Factors in your lifestyle, environment, or personal health can either turn on oncogenes or turn off tumor suppressor genes. When that happens, healthy skin cells begin to mutate and turn into skin cancer.
Ultraviolet light exposure causes skin cancer
Exposure to ultraviolet (UV) light is one of the most common skin cancer causes, and it can cause a deadly form of skin cancer, melanoma. UV rays damage the DNA in skin cells, triggering mutations and growth of cancer cells.
Most ultraviolet light comes from sun exposure. The light in tanning beds is also a major skin cancer cause. The Centers for Disease Control and Prevention estimates that UV exposure from tanning beds causes around 400,000 cases of skin cancer in the United States every year.
Tanning or burning are particularly dangerous, but any amount of unprotected sun exposure can cause skin cancer. Many times, the damage caused by exposure to ultraviolet light occurs years before cancer cells appear. Sunburns during childhood and adolescence can develop into skin cancer well into adulthood.
Though people with light skin and red or blonde hair are at the highest risk for burning from UV exposure, ultraviolet radiation can damage any color skin. Even those with dark skin that never burns are at risk for skin cancer from UV exposure.
Genetic risks for skin cancer
Inherited melanomas run in families and are generally due to a change in CDKN2A, a tumor suppressor gene. Squamous cell cancers are often caused by changes in the gene TP53.
Genetic conditions can also cause skin cancer. Basal cell nevus syndrome, also known as Gorlin syndrome, runs in families and alters the PTCH1 gene your body’s cells. The change often causes people with Gorlin syndrome to develop basal cell cancers.
Xeroderma pigmentosum, or XP, is another inherited condition that can cause skin cancer. People with XP have a defect in the enzyme that repairs their cells’ DNA. As a result, their skin is less able to recover from sun damage and more prone to developing skin cancer.
Skin cancer is just one of many forms of cancer that has inherited genetic causes. As with other types of cancer, however, new drugs and treatments can target genetic causes of skin cancer. Melanomas, for example, often contain changes in the BRAF oncogene, which can be treated with targeted tumor therapy.
Other skin cancer causes
Factors in your immediate environment can cause skin cancer, including exposure to pollutants, chemical carcinogens, and environmental radiation. Research has found that lifestyle factors such as diet and smoking can also make you more likely to develop skin cancer, though other causes usually contribute to the cancer’s development, such as sun exposure.
Skin with existing damage — such as scars, ulcers, burns, or nonhealing wounds — is more susceptible to cancer growth, especially if those spots are regularly exposed to UV light or environmental carcinogens.
Because your immune system plays a role in fighting the growth of cancer cells, conditions that suppress your immune system can cause skin cancer. They include human immunodeficiency virus (HIV), acquired immune deficiency syndrome (AIDS), and some non-Hodgkin’s lymphomas. Immunosuppression drugs, such as those given to organ transplant patients, can also put you at risk for developing skin cancer.
Preventing skin cancer
Skin cancer is one of the most common cancers in the United States, with more than 5 million Americans being treated for some form of skin cancer every year.
According to the U.S. Surgeon General, most cases of skin cancer are preventable if you protect yourself from environmental causes. Prevention includes:
- Avoiding tanning, both in sunlight and in artificial UV light
- Wearing sun protection outside
- Avoiding environmental and workplace toxins, such as arsenic and pollution
While medical and genetic causes of skin cancer are not preventable, protecting yourself from everyday causes will greatly reduce the chances you develop skin cancer in your lifetime.
May 25, 2023
Christopher Nystuen, MD, MBA