Is the carcinoembryonic antigen test a valid predictor of response to medical therapy in disseminated breast cancer?

In 30 of 63 patients with disseminated breast cancer, CEA became positive before medical therapy. Treatment response was obtained in 63.3% of CEA-positive patients compared to 15.2% of CEA-negative patients. The CEA-positive patients also had a longer relapse-free survival, a longer survival from diagnosis of metastases, and a longer overall survival from primary surgery than CEA-negative patients. CEA production appears to be an important and favorable prognostic factor in disseminated breast cancer and determinant of treatment response.