USE OF SERIAL CARCINOEMBRYONIC ANTIGEN AND CA-15.3 ASSAYS IN DETECTING RELAPSES IN BREAST-CANCER PATIENTS

To evaluate the utility of CEA and CA 15.3 for early diagnosis of recu rrence, serial serum determinations of both antigens were performed in 1023 patients (follow-up: 1-10 years, mean 6.2 years) with primary br east cancer (CA 15.3 in 533 cases) and no evidence of residual disease (NED) after radical treatment (radical mastectomy or simple mastectom y and radiotherapy). 246 patients developed metastases during follow-u p. Results: CEA and CA 15.3 were elevated (> 10 ng/ml or > 60 U/ml, re spectively) prior to diagnosis in 40% (98/246) and 41% (37/91) of the patients with recurrence, with a lead time of 4.9 +/- 2.2 and 4.2 +/- 2.3 months, respectively. When patients;with locoregional recurrences were excluded, sensitivity improved to 46% (CEA) and 54% (CA 15.3), an d to 64% with both tumor markers (CEA and/or CA 15.3). Higher levels o f both CEA and CA 15.3 at diagnosis of recurrence, higher sensitivity in early diagnosis of relapse, and a higher lead time were found in ER + (CEA) or PgR+ patients (CA 15.3) than in those that were negative fo r these receptors in the primary tumor (p < 0.001). Specificity of the tumor markers was 99% for both CEA (777 NED patients) and for CA 15.3 (444 NED patients), respectively. In conclusion, CEA and CA 15.3 are useful tools for early diagnosis of metastases, mainly in those patien ts with ER+ or PR+ tumors.