Carcinoma of Unknown Primary Origin: Frequently Asked Questions

Here are answers to some frequently asked questions about carcinoma of the unknown primary.

What is carcinoma of unknown primary origin (CUP)?

The location where cancer starts is called the site of the primary tumor. Many cancers are named for the part of the body in which they begin. For instance, liver cancer is cancer that starts in the liver. When cancer has spread to other areas of the body, it’s said to have metastasized. Cancer that has metastasized keeps the name where it started. For instance, lung cancer that spreads to the bone is called metastatic lung cancer. CUP is cancer that starts in an unknown place and then spreads. It often goes to a lymph node, lung, liver, brain, or the bones. Another name for this cancer is unknown primary cancer or UPC. The cancer is found in one of these distant places, while the original starting place stays unknown. 

What are the symptoms of CUP?

People with CUP may have any or all of these symptoms. They depend on which organs the cancer affects the most:

• Swollen lymph nodes

• Pain in the bones

• Chest or stomach pain or fullness

• Poor appetite or weight loss

• Fatigue or weakness

• Tumors or unusual lesions on your skin

• Shortness of breath

• Low red blood cell levels (anemia)

• Confusion, headache, blurry vision, vomiting, or seizures

It’s important to remember that all of these symptoms can be, and are more commonly, caused by other health issues. If you have these symptoms, see a healthcare provider right away.

How is CUP treated?

CUP may be treated using chemotherapy (chemo), radiation, hormone therapy, surgery, or a combination of these. Chemo is most commonly used. Treatment for CUP depends on where healthcare providers think the cancer most likely started. It’s also based on your medical history, physical exam, imaging studies, and lab tests.

Should everyone get a second opinion if they are told they have CUP?

Many people with cancer get a second opinion from another healthcare provider. These are some reasons to get a second opinion:

• If the person isn’t comfortable with the treatment decision

• If the type of cancer is rare (as is the case with CUP)

• If there are different ways to treat the cancer

• If the person is not able to see a cancer expert

Many people have a hard time deciding which treatment to have. It may help to have a second healthcare provider look at the diagnosis and treatment options before starting treatment. It’s important to note that in most cases, a short delay in treatment will not lower the chance that it will work. Some health insurance companies even require that a person with cancer seek a second opinion. Many insurance companies will pay for a second opinion.

How can someone get a second opinion?

There are many ways to get a second opinion. Here are some of them:

• Ask a primary care healthcare provider. He or she may be able to suggest a specialist. This may be a surgeon, medical oncologist, or radiation oncologist. Sometimes, specialists work together at cancer centers or hospitals. Never be afraid to ask for a second opinion.

• Call the National Cancer Institute’s Cancer Information Service. The number is 800-4-CANCER (800-422-6237). They have information about treatment facilities. These include cancer centers and other programs supported by the National Cancer Institute.

• Seek other options. Check with a local medical society for healthcare providers who can give you a second opinion. You can also check with a nearby hospital or medical school. Or ask other people who’ve had cancer or members of a support group for their suggestions.

What are clinical trials?

Clinical trials are studies of new kinds of cancer treatments. Healthcare providers do clinical trials to learn how well new treatments work. They also use clinical trials to understand which side effects may occur. If the treatment looks promising, it’s then compared with the best current treatment. Healthcare providers want to know if it works better or has fewer side effects. People who participate in these studies may benefit. That’s because they have access to new treatments before the U.S. Food and Drug Administration (FDA) approves them for the public. People who join trials also help further our understanding of cancer. This helps future cancer patients.