Tumor markers for breast cancer. Current utilities and future prospects

Tumor-associated markers have potential utility in identification, screening, prognosis, detection, or monitoring breast cancer. Of the available markers, those with the greatest promise in 1994 include the yet-to-be-cloned BrCa1, the p53 tumor suppressor gene, tissue-associated prognostic factors such as HER-2/neu, cathepsin-D, and indicators of angiogenesis, and circulating tumor markers that provide an indication of clinical course, such as CA15-3 and CEA. Unfortunately, the precise clinical utilities of all of these markers remain imprecise. It is especially important that the relative independence of the markers in relation to other available markers be determined so as to avoid the unnecessary cost and expense of redundancy. Moreover, it is important that the clinician be aware of the limitations in both sensitivity and specificity of each marker so as not to over- or underinterpret the predictive value of any test. With these caveats in mind, judicial application of germline, tissue, and soluble tumor markers can improve clinical care of patients at risk for and with breast cancer.