CA 15.3 and CEA plasma level monitoring in patients with breast cancer

CA 15.3 and CEA were determined in the serum of 217 patients with early and advanced breast carcinoma. CA 15.3 was high (greater than 30 U/ml) in 1/6 (17%) patients with stage I-II primary tumor, in 4/77 (5%) patients without clinical signs of disease after mastectomy, in 67/102 (65%) patients with advanced disease in progression, and in 13/32 (41%) patients with advanced disease not in progression and undergoing therapy. The corresponding incidences of pathological CEA values (greater than 2.5 ng/ml) were 33, 8, 55 and 14%. The combination of the two markers brings about a certain improvement in the sensitivity for recognising patients with advanced disease in progression (79/102 = 77%). The presence of high values of CA 15.3 is statistically correlated to the prevalent site of metastases (bone and viscera greater than soft tissues). Monitoring the two markers during antitumor therapy in 36 patients showed good accordance (56%) between CA 15.3 changes and response to therapy. The decrease of the marker in patients who achieved partial remission was statistically significant. In conclusion, CA 15.3 is more sensitive than CEA in recognising patients with advanced disease in progression and gives better accordance with the response to therapy. The simultaneous use of the two markers may be useful in the follow-up of operated patients and in monitoring the disease during treatment.