Treatment for cancer of unknown primary (CUP)
The aim of treatment is to try to control the cancer, help you live longer and treat your symptoms.
When cancer of unknown primary (CUP) is definitely confirmed it can be very hard to accept that even with tests, the primary cancer still can’t be found. You’ll probably be coping with difficult feelings, so it’s important to get the support you need. Some people may feel relieved that the tests are over and treatment can now start.
Your specialist will take into account different factors before advising on the best treatment for you. This includes where the secondary cancer or cancers are, how likely you are to benefit from the treatment and how you will cope with its side effects.
Usually the main treatment for CUP is chemotherapy. Chemotherapy is a systemic treatment, which means it treats cancer in more than one area of the body. Radiotherapy, hormonal therapy and sometimes surgery may also be used.
Supportive or palliative care with medicines to control your symptoms is an important part of treatment for people with CUP. Sometimes doctors advise palliative care on its own rather than treating the cancer. This may be because the cancer is very advanced and the disadvantages of treatment outweigh the advantages. It’s important to have enough information to help you make your decision. You may find our section about making treatment decisions helpful.
Sometimes, even when the primary cancer can’t be found, the secondary cancer, your symptoms, the cell type and test results may give an indication of where it might be.
Your specialist may suggest that you are treated as if you have a particular cancer. For example, women with an adenocarcinoma in the peritoneum (which lines and covers the organs in the abdomen) and a raised CA125 may be treated with chemotherapy for ovarian cancer. If you’re a man with a raised PSA and adenocarcinoma in the bones, you may be treated with hormonal therapy for prostate cancer.
Some people may have a type of CUP that has a much better outlook with treatment, even when the primary can’t be found. This is usually when the secondary cancer is confined to a small area of the body, such as in the lymph nodes:
Squamous cell lymph nodes in your neck may mean the primary cancer is in the head and neck area. You’ll be referred to a head and neck specialist team for assessment. You may have surgery to remove the lymph nodes followed by radiotherapy.
Adenocarcinoma in lymph nodes in one armpit may mean the primary cancer is in the breast. You’ll be referred to a specialist breast cancer team for assessment. You may have surgery or radiotherapy to the lymph nodes followed by chemotherapy and hormonal therapy.
Squamous cell lymph nodes in the groin may mean the cancer started in the leg or in the back passage. You’ll be referred to a specialist surgeon to have the nodes removed, which may be followed by radiotherapy.
How treatment is planned
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In most hospitals a team of specialists will talk to you about the treatment they feel is best for your situation. Some hospitals have a team of specialists who diagnose and treat people with CUP (CUP team) and you’ll be referred to them.
A multidisciplinary team (MDT) or the CUP team may include a:
clinical oncologist (radiotherapy and chemotherapy specialist)
medical oncologist (chemotherapy specialist)
doctor who specialises in palliative care
pathologist (specialises in how disease affects the body)
radiologist (analyses x-rays and scans).
It may also include other healthcare professionals such as a dietitian, physiotherapist, occupational therapist, psychologist or counsellor.
Before you have any treatment, your doctor will explain its aims. They will usually ask you to sign a form saying that you give permission (consent) for the hospital staff to give you the treatment. No medical treatment can be given without your consent, and before you are asked to sign the form you should be given full information about:
the type and extent of the treatment
its advantages and disadvantages
any significant risks or side effects
any other treatments that may be available.
If you don’t understand what you’ve been told, let the staff know straight away, so they can explain again. Some cancer treatments are complex, so it’s not unusual for people to need repeated explanations. It’s a good idea to have a relative or friend with you when the treatment is explained, to help you remember the discussion. You may also find it useful to write a list of questions before your appointment.
People sometimes feel that hospital staff are too busy to answer their questions, but it’s important for you to know how the treatment is likely to affect you. The staff should be willing to make time for your questions. You can always ask for more time if you feel that you can’t make a decision when your treatment is first explained to you.
The benefits and disadvantages of treatment
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Many people are frightened at the idea of having cancer treatments, particularly because of the side effects that can occur. However, these can usually be controlled with medicines.
Your doctor will explain the possible benefits of treatment and also the risks and side effects. In some people with CUP, treatment helps to control the cancer, improve symptoms and quality of life. It may also help some people live longer. But in others the treatment may have little effect on the cancer and they will get the side effects without any of the benefits.
Making a decision about treatment sometimes involves thinking about whether the side effects of treatment outweigh the possible benefits.
If you decide at any time not to have treatment, you will be given supportive (palliative) care with medicines to control your symptoms.
Your multidisciplinary team (MDT) uses national treatment guidelines to decide on the most suitable treatment for you. Even so, you may want another medical opinion. If you feel it will be helpful, you can ask either your specialist or GP to refer you to another specialist for a second opinion.
A second opinion can help reassure you that your doctors have made the right diagnosis and are giving you the appropriate treatment. If you go for a second opinion, it may be a good idea to take a relative or friend with you, and to have a list of questions ready, so that you can make sure your concerns are covered during the discussion.
David Plume explains the benefits and disadvantages of getting a second opinion about your treatment.