When doctors find cancer cells, they can often tell which part of the body had them first. It could be a certain organ, type of tissue, or part of your blood. If it can’t be pinpointed, then you have what’s called a cancer of unknown primary (CUP).
What Are the Causes?
All cancers happen because of changes called mutations in a cell’s DNA. This is the genetic material inside each of your cells that controls how they behave. In most cases, multiple mutations need to happen before a cell becomes cancerous.
Doctors believe the DNA changes that cause CUP aren’t passed down through families, but happen during your lifetime. It could be because you’ve been exposed to things that are known to cause cancer, like radiation, tobacco smoke, or chemicals.
But these harmful changes can also take place for no clear reason. Many people with CUP are at a healthy weight, exercise often, and eat right. If you’ve been diagnosed with CUP, it’s important to note that there’s likely nothing you could have done differently to prevent it.
What Are the Symptoms?
The symptoms of CUP will vary, based on where the cancer is in your body. Some signs include:
- Swollen lymph nodes
- A mass in your belly
- Feeling full
- Pain in your chest or belly
- Short of breath
- Bone pain, often in your back, hips, and legs
- Skin tumors
- Anemia (low red blood cell count)
- Not feeling hungry
- Weight loss
- Changes in your bathroom habits
- Chronic cough
- Night sweats
- Bleeding or discharge
There’s also a chance you won’t have symptoms. Some people only learn they have CUP after a medical test for a different reason.
How Is CUP Diagnosed?
Your doctor will give you a thorough exam and ask about any symptoms you have. She’ll also want to hear about any past health problems and if any cancer runs in your family.
Tests of your blood, pee, and poop can provide your doctor with more information. So can the following:
Biopsy: Based on where the tumor is, your doctor will get a sample of cells, fluid, or bone marrow. This will be sent to a lab and looked at under a microscope. There are also new genetic tests that can pinpoint where in your body the cancer started.
What’s the Treatment for CUP?
Most cancers are “staged.” This explains where they are in your body and how much they’ve spread. It also helps doctors devise a treatment plan. This can’t be done with CUP, since it’s already spread by the time it’s found.
Instead, your doctor will decide how to treat you based on where the cancer is, what the cancer cells look like under a microscope, your symptoms, your test results, and whether this is the first time you’ve had cancer or if it has returned.
Treatment is usually chemotherapy, and depends on if a primary site, or at least a primary tissue can be identified. Your treatment could include:
Surgery: Your doctor will remove the cancer plus some healthy tissue around it.
Radiation therapy: High energy X-rays or other forms of radiation can be used to kill cancer cells. This may be given to you through a machine, or the radiation can be put into your body through a needle, wire, or tiny sealed “seed.”
Hormone therapy: If hormones are believed to play a part in your cancer, your doctor will try to reduce the amount that your body makes or keep the ones it does make from working. Sometimes this is done with drugs, but surgery and radiation can be used, too.
Targeted therapy: Drugs or other substances can attack cancer cells without harming the rest of your body.
Immunotherapy (biologic therapy): This treatment boosts your immune system in general or uses it to attack cancer cells.
Clinical trial: In some cases, being part of a clinical trial may be your best choice. These studies test new cancer drugs and treatments to see if they work as well or better than treatments already in use.
CUP is different in each person. How well treatment works is hard to predict.
Make sure to speak to your doctor. Since she’s aware of your cancer, test results, and health in general, she’ll have a better idea about your chance of recovery.