Role of plasma carcinoembryonic antigen in evaluating patients with breast cancer treated with adjuvant chemotherapy.

Serial plasma carcinoembryonic antigen (CEA) levels were determined in 84 patients with breast cancer who were receiving postsurgical adjuvant chemoimmunotherapy or adjuvant chemotherapy. CEA values were correlated with clinical status, scintiscans, alkaline phosphatase, LDH, and SGOT. CEA values greater than 2.5 ng/ml were considered abnormal. Thirty patients had normal serial CEA values; all remain disease-free. In 54 patients one or more abnormal CEA values were recorded; nine of 54 developed overt metastatic disease. Relapses occurred in four of 38 patients in whom values up to 5 ng/ml were recorded, in three of 14 patients in whom values up to 10 ng/ml were recorded, and in two of two patients in whom values greater than 10 ng/ml were recorded.