Getting diagnosed with cancer of unknown primary (CUP)
It can be hard for GPs to decide who may have cancer and who might have a more minor condition. For some symptoms, your doctor may ask you to wait to see if the symptoms get better or respond to treatment, such as antibiotics.
There are guidelines for GPs to help them decide who needs a referral for a possible cancer. However there aren't specific referral guidelines for cancer of unknown primary (CUP).
Your GP should arrange for you to see a specialist if you have any symptoms that could be due to cancer.
Read about general signs and symptoms of cancer
There are guidelines for GPs to help them decide who needs a referral. These vary slightly between the different UK nations. Your GP will use these guidelines as well as their own experience and judgement.
Your GP looks at your symptoms and decides what specialist to refer you to. For example:
you see a gastroenterologist or a gastrointestinal surgeon if you have bowel or stomach problems
you see a chest or respiratory specialist if you have problems with your breathing
you see a urologist if you have problems passing urine or have blood in your urine
you might see a head and neck specialist if you have a lump in your neck
Your GP may also refer you to a rapid diagnostic centre (RDC). These are clinics for people with symptoms that could be due to cancer and need to have rapid investigations.
Your specialist:
asks about your medical history and symptoms
examines you
They also arrange any tests that you need such as blood tests and scans. These will depend on your symptoms.
Find out about the tests you might have
If tests show that you have a cancer that has spread (secondary cancer), but your doctors can’t find where it started (the primary tumour), it is initially referred to as a malignancy of unknown primary origin (MUO). You usually have more specialist tests to look for the primary cancer.
Your doctor may then refer you to a team of health professionals who specialise in CUP. The specialist CUP team usually includes:
a doctor specialising in cancer and its treatment (an oncologist)
a palliative care consultant (a doctor that specialises in controlling symptoms)
a CUP specialist nurse (a clinical nurse specialist or CNS)
The CUP team will examine you and review your medical history and test results. They may arrange for more specialised tests to search for the primary cancer.
You have a confirmed cancer of unknown primary (cCUP) if no primary cancer is found after the specialised tests. The CUP specialist team will then work together to decide on the best way to manage your care.
Sometimes doctors find the primary cancer at a later date. When this happens, the cancer is no longer a CUP and your treatment will follow the guidelines for the specific cancer type.
Last reviewed: 15 May 2024
Next review due: 15 May 2027
Cancer of unknown primary (CUP) means that cancer spread (secondary cancer) has been found in your body, but doctors don't know where the cancer started (the primary tumour).
You should see your GP if you notice a change that isn't normal for you. They will examine you and might refer you for tests or to a specialist.
The tests you have to diagnose CUP depend on your symptoms and where in your body the cancer is.
Treatment for CUP depends on a number of things, including where the cancer is and your general health. You might have a targeted cancer drug or chemotherapy. Sometimes you may have surgery or radiotherapy to help control your symptoms.
Advice and support is available to help you cope with cancer of unknown primary (CUP) and its treatment.

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