Long-term prognostic study of carcinoembryonic antigen (CEA) and carbohydrate antigen 15-3 (CA 15-3) in breast cancer

Abstract

Tumor markers are frequently used for screening and monitoring in oncology. We investigated the use of preoperative tumor marker (carcinoembryonic antigen [CEA] and carbohydrate antigen [CA] 15-3) levels in estimating the prognosis of breast cancer patients. We conducted a retrospective study in patients who underwent breast cancer surgery at National Cancer Center Hospital between 1975 and 1994 and whose serum CEA (n = 1663) and CA 15-3 (n = 1500) levels were measured prior to operation. When we excluded patients with stage IV disease from the study, the CEA level was within the normal range in 1470 patients, while 150 patients had an elevated CEA level. For CA 15-3, 1395 patients were within the normal range, while 70 patients exhibited an elevated level. The 5-year and 10-year survival rates for patients with normal CEA levels were 87% and 76%, respectively. However, the 5-year and 10-year survival rates for patients with elevated CEA levels were 76% and 65%, respectively. At both time points, patients with normal CEA levels had higher survival rates (P < 0.05). The 5-year and 10-year survival rates for the patients with normal CA 15-3 levels were 86% and 76%, respectively, while only 71% and 52% patients with elevated CA 15-3 levels survived at 5 and 10 years, respectively. These differences were also significant (P < 0.05). However, there were no significant differences in disease-free survival (DFS) according to CEA or CA 15-3 levels. There was a positive correlation between CEA levels and CA 15-3 levels and patient prognosis. Thus, the levels of these tumor markers may help to determine prognosis in breast cancer patients.