CA 15-3

CA 15–3: A tumor marker most useful in following the course of treatment in women diagnosed with breast cancer, especially advanced breast cancer. CA 15–3 levels are rarely elevated in women with early stage breast cancer.

Cancers of the ovary, lung, and prostate may also raise CA 15–3 levels. Elevated levels of CA 15–3 may be associated with noncancerous conditions, such as benign breast or ovarian disease, endometriosis, pelvic inflammatory disease, and hepatitis. Pregnancy and lactation can also cause CA 15–3 levels to rise.