CA15-3 Assay Contribution in the Management of Breast Cancer: Study of 177 Cases

Introduction: Breast cancer is the leading cause of cancer mortality in women worldwide. CA15-3 is the most widely used serum marker in this cancer. The aim of this study is to investigate the CA15-3 assay in breast cancer and its correlation with classical prognostic factors for the disease, as well as with the post-therapeutic evolution of patients. Materials and Methods: This is a retrospective study, carried out at the Clinical Biochemistry Laboratory of the Tangier university hospital center, involving 177 patients treated at the Tangier Oncology Center, having benefited from a CA15-3 assay according to the ELFA (Enzyme Linked Fluorescent Assay) immunoassay technique, with a threshold value of 30U/ml, as part of their therapeutic management, for a period of 10 months. Results: A statically significant correlation was found between the marker's level and TNM classification, the expression of hormonal receptors for estrogen (ER) and for progesterone (RP). The high value of CA15-3 is correlated with the number and location of metastatic sites, and also with an unfavourable outcome. Furthermore, monitoring and post-therapeutic evaluation of patients during the metastatic phase, using biomarker kinetics, shows that an increase in biomarker levels relative to the initial value correlates with radiological progression of metastasis and therefore with the advancement of disease. Conclusion: This study supports the interest of CA15-3 assay in the post-treatment follow-up and in the prognostic evaluation of breast cancer patients.