Does the Pre-operative Value of Serum CA15-3 Correlate with Survival in Breast Cancer?

Introduction: CA15-3 is a well-known tumour marker for breast cancer. Currently it is not recommendedfor screening or diagnosis of breast cancer and its main application is in monitoring response to treatment inwomen with metastatic breast cancer The aim of this study was to correlate serum CA15-3 at presentation withthe stage of disease and overall survival in women with breast cancer in the University Malaya Medical Centre.
Methods: This is a retrospective study of 437 women who had CA15-3 levels determined at initial presentationof breast cancer to UMMC between Jan 1999 and Oct 2003.
Results: Of those patients who were adequatelystaged, CA15-3 was found to be elevated (defined as >51 U/ml) in 0% of Stage 1, 7.9% of Stage 2, 36.7% of Stage3 and 68.6% of Stage 4 cases. In a subset of 331 patients with survival data, patients with normal CA15-3 hada 85% five year overall survival rate compared to 38% in their counterparts with elevation of the tumor marker.The level of elevation was also significantly related to survival; patients with values more than 200 U/ml exhibitedonly a 28% five year survival. The association of elevated CA15-3 at initial presentation with poor outcome wasmaintained over univariate and multivariate analyses.
Conclusion: Estimation of CA15-3 at presentation ofbreast cancer is important as it is an independent prognostic indicator and may prompt the physician to investigatefor metastases if elevated.