[CA 15-3 and breast cancer].

The precise clinical value of CA 15-3 antigen has yet to be determined. With no role in screening for early breast cancer and, even if CA 15-3 seems to be correlated with bulky initial tumor burden, it appears to have no independent prognostic value. The clinical interest of CA 15-3 remains the early detection of the first recurrence. In this regard, more than 75% of first recurrences (all sites included) are associated with a significant rise in CA 15-3 levels, with a particular sensitivity for bone, liver, and lung metastases but which appears lower for locoregional recurrences. More sensitive and specific than CEA, and this whatever the site of recurrence, the rise of CA 15-3 may precede the clinically or radiologically diagnostic of recurrence by a mean lead time from 6 to 9 months. Furthermore CA 15-3 is a reliable marker for clinical course and seems to be of potential interest in monitoring disease follow-up during therapy. In the situation of a clinically isolated elevation of CA 15-3, which investigations, if any, have to be done?, and if negative must do we initiate a treatment for a "biological recurrence"? All these questions remain still opened, and today on consensual attitude can be recommended. In this issue, only results of well-designed prospective trials could help us to determine more rationally, an optimal diagnostic and therapeutic strategy.