Cancer of unknown primary (CUP)
CUP means a secondary cancer has been found in the body, but your doctors can't find where the primary cancer has started from.
It is sometimes called "unknown primary cancer" or "unknown primary tumour".
To help locate the primary cancer, you will have a few more investigations to see if we can find a primary diagnosis. If the primary cancer still can't be found after more tests, the cancer will be described as CUP. Sometimes, tests will find the primary cancer, and when this happens, the cancer is no longer called CUP.
When the doctors can't be sure of the primary cancer, they may be able to suggest a possible part of the body where the cancer started. This will be based on where the secondary cancers are, your symptoms and the test results. The test results will also suggest how the cancer might behave. This will help your specialist to plan your treatment.
Why the primary cancer can't be found
There are different reasons why a primary cancer can't always be found:
- It may be hidden beside a larger secondary cancer, or it may be too small to be picked up on scans.
- It may have disappeared, even though it has spread to other parts of the body, suggesting the body's immune system has successfully got rid of it.
- It may have been passed out of the body. For example, a small cancer in the wall of the bowel may become detached and leave the body when going to the toilet.
Your clinical nurse specialists
Your clinical nurse specialist (CNS) will offer support and advice to you and your family throughout your diagnosis, treatment and follow-up.
You can contact them with any questions or concerns you may have about your specialist care. They will also be a consistent point of contact for you, your family and any other healthcare professionals involved in your care.
Key contacts
Email: uhdb.acuteoncneurocupcns@nhs.net
Telephone: 07500 976 513 / 07471 140 583 / 07769 164 113
Working hours from Monday to Friday, 8am – 4pm