[CA 15.3 and early diagnosis of recurrence in breast cancer]

This retrospective study shows the advantage of the CA 15.3 assay for the early detection of relapse in breast cancer. It involved 473 women with invasive canalar carcinoma who had local recurrence or metastasis and/or an elevation of CA 15.3 (> 35 kU/l). The positive predictive value is excellent (97.7%). Sensitivity is poor for local relapse (13.7%), but a marker elevation at this time is a good prognostic factor of further distant metastasis (88%). It is better in the case of distant metastasis (74%), especially in bone and and liver localizations. CA 15.3 measurement at two month intervals may allow an early detection in 40% of distant metastasis. These results confirm the need of trials to test the benefits in terms of survival of early treatment of breast cancer metastasis only proved by CA 15.3 elevation, without any clinical or radiological finding.