Abstract
CA 15–3 has been most widely used as a serum tumor marker in follow-up and detection of breast cancer recurrence. In this study we have specifically focused upon the prognostic implications and utility of preoperative CA 15–3 levels. We have identified on our database 414 patients with breast cancer in whom serial levels of the serum tumor marker CA 15–3 had been determined at diagnosis and follow-up. We have analyzed the follow-up and clinical outcomes in these patients and from this data we have assessed the potential of CA 15–3 as a predictor of five-year overall and disease-free survival.
Our results show that an initially elevated CA 15–3 level is associated with a very poor prognosis in both early and late stage disease. Elevated pre-biopsy CA 15–3 levels are associated with 14% five-year disease-free survival rates and 17% overall survival rates at five years. In contrast, normal CA 15–3 levels are associated with 47% five-year disease-free survival rates and 54% overall survival rates at five years (p<0.01). Comparison of five-year survival rates between patients with elevated and normal CA 15–3 levels in early breast cancer (stage I and II) also showed significant differences, with survival being 41% and 75%, respectively (p<0.01).