There is not really any data supporting the use of surveillance tumor markers in breast cancer and is discouraged in ASCO guidelines. In known metastatic patients, I will check both CA 15-3 and CA 27-29.

There is no data that routine bloodwork of any kind is useful for early detection of metastases and moreover, that such a practice improves outcomes or survival for women who do indeed develop distant recurrences. Guidelines for routine breast cancer follow-up and treatment after primary treatm...