Clinical value of CA 15-3 for early detection of relapse in locally advanced breast cancer

This retrospective study evaluates the interest of CA 15-3 measurement for early detection of breast cancer recurrences. Among 804 patients with invasive breast cancer we selected 117 patients without recurrence (WR) for 5 years or more, 33 with a local recurrence (LR) and 149 with at least one distant metastasis (DM). The sensitivity of CA 15-3 depends on the type of recurrence ([LR] or [DM]), the localization of unique DM, the presence and the number of metastatic sites, on hormonal receptor status and tumor subtypes. The number of metastatic sites and hormonal receptor status are independent predictive criteria of an elevation of CA 15-3. The analysis of ROC curve in order to separate patients with DM and patients WR shows an AUC of 0.87 (p < 0.0001). The optimal discriminative threshold is 26 kU/L. In conclusion, these data confirm that CA 15-3 increase depends on the kind of evolution and on initial tumor's hormonal status.