Radiation therapy for cancer of unknown primary
Radiation therapy uses high-energy rays or particles to destroy cancer cells.
Radiation therapy is sometimes used to treat cancer of unknown primary (CUP). Your healthcare team will use what they know about the cancer and about your health to plan the type and amount of radiation, and when and how it is given.
You may have radiation therapy to:
- destroy cancer cells in the body
- destroy cancer cells left behind after surgery or chemotherapy to reduce the risk that the cancer will come back (recur) (called adjuvant therapy)
- relieve pain or control the symptoms of advanced CUP (called palliative therapy)
Radiation therapy and chemotherapy may be given during the same time period to treat squamous cell CUP that is found in the lymph nodes in the neck or the groin. This is called chemoradiation.
External radiation therapy
During external radiation therapy, a machine directs radiation through the skin to the tumour and some of the tissue around it. External radiation therapy is also called external beam radiation therapy.
Radiation therapy may be used for the following types of CUP or for CUP in certain parts of the body.
Squamous cell CUP in lymph nodes in the neck or groin may be treated with radiation therapy. It may be used as the main treatment, or it may be given after surgery to remove the lymph nodes that have cancer in them.
Adenocarcinoma of unknown primary in the lymph nodes under the arm in people who were assigned female at birth may be treated with radiation therapy. Doctors will also treat the breast on the same side of the body as the lymph nodes with cancer. Radiation therapy may be given after surgery to remove the lymph nodes and the breast.
Adenocarcinoma of unknown primary in the lung,
CUP in a bone may be treated with radiation therapy to shrink the tumour and to reduce pain.
A single CUP tumour may be treated with radiation therapy. It may be given after surgery to remove the tumour, or it may be used as the main treatment.
Side effects of radiation therapy
During radiation therapy, your healthcare team protects healthy cells in the treatment area as much as possible. Side effects of radiation therapy will depend mainly on the size of the area being treated, the specific area or organs being treated, the total dose of radiation and the treatment schedule. Tell your healthcare team if you have side effects that you think are from radiation therapy. The sooner you tell them of any problems, the sooner they can suggest ways to help you deal with them.
These are common side effects of radiation therapy for CUP:
Radiation to the head and neck can also cause:
Find out more about radiation therapy
Find out more about radiation therapy and side effects of radiation therapy. To make the decisions that are right for you, ask your healthcare team questions about radiation therapy.