Some tumour marker assays that involve bodily fluids (mostly blood or urine) have a limited use in cancer screening. The tests are mostly used to screen individuals who:
- Have a high risk of the cancer type associated with the tumour marker being measured
- Have symptoms consistent with that sort of cancer.
Tumor marker tests, which are used to screen for cancer, cannot diagnose the disease. A high level of tumour markers simply indicates that you are more prone to develop cancer. Usually, a biopsy is required to diagnose or rule out cancer.
Tumor marker tests that use tumour cells may aid in the diagnosis of cancer. Typically, these “tumour cell markers” are removed during a biopsy. They may be used in conjunction with other tests to confirm a cancer diagnosis and determine the best course of treatment.