Correlation of CA 27.29 and circulating tumor cells before, at the end, and 2 years after adjuvant chemotherapy in patients with primary breast cancer: The SUCCESS trial

10626 Background: While evidence for the prognostic value of circulating tumor cells (CTC) in the adjuvant setting is swiftly increasing the role of tumor markers like CA27.29 in this setting is still controversial. In the SUCCESS Trial CTC and CA27.29 have been measured before, after and 2 years after adjuvant chemotherapy. Our goal was to examine the correlation of these 2 factors at the 3 points in time. Methods: The SUCCESS Trial compared FEC-docetaxel (Doc) vs. FEC-Doc-gemcitabine (Doc-G) regime and 2 vs. 5 year treatment with zoledronat in 3754 patients with primary breast cancer (N+ or high risk). CA27.29 has been measured with ST AIA-PACK Ca27.29 reagent using MUC-1 for AIA-600II (Tosoh Bioscience, Belgium). The cutoff for positivity of CA27.29 was >31 U/ml. CTC were assessed with the CellSearchSystem (Veridex, USA). After immunomagnetic enrichment with an anti-Epcam-antibody, cells were labeled with anti-cytokeratin (8,18,19) and anti-CD45 antibodies to distinguish between epithelial cells and le...