Significant improvement in recurrence-free survival (RFS) when capecitabine (X) is integrated into docetaxel (T) → 5-FU + epirubicin + cyclophosphamide (CEF) adjuvant therapy for high-risk early breast cancer (BC): interim analysis of the FinXX-trial.

Abstract

Abstract Abstract #82 Background: Adding X to T extends survival in patients (pts) with metastatic BC. The primary objective of the FinXX-trial is to compare RFS with XT→CEX vs. T→CEF as adjuvant therapy in pts with early BC. Secondary objectives are comparison of overall survival, distant RFS and safety. Methods: Between Jan 2004 and May 2007, 1500 pts were randomized to receive T x 3 → CEF x 3 (T 80mg/m² d1 → C 600mg/m² d1, E 75mg/m² d1, F 600mg/m² d1, q3 wks) or XT x 3 → CEX x 3 (T 60mg/m² d1 + X 900mg/m² bid d1–15 → C 600mg/m² d1, E 75mg/m² d1, X 900mg/m² bid d115, q3 wks). Results: 1496 pts were included in the ITT analysis (two pts withdrew consent, two had metastatic disease). The study population represented a high-risk group (90% node positive, 19% HER2 positive, 88% poorly or moderately differentiated tumors). The baseline characteristics were well balanced in the two treatment arms. After median follow-up of 3 years, there have been 134 events (deaths, distant or local relapses; Table). The significantly improved RFS rate was achieved despite a higher number of study treatment discontinuations in the X-containing arm (178 vs. 23 pts in the control arm; when XT was discontinued, the remaining XT cycles were replaced with an equal number of T cycles, and CEX cycles with CEF cycles). 75% of pts in the X-containing arm received all six planned cycles of therapy compared with 96% in the control arm. The adverse effect profiles of XT→CEX and T→CEF were in part different (Gr. 3/4 neutropenic fever/infection 10.0% vs. 20.2%, hand-foot syndrome 11.1% vs. 0.3%, diarrhea 6.2% vs. 3.4%, stomatitis 4.2% vs. 1.6%, myalgia 1.9% vs. 8.0%, respectively).
 
 Conclusions: The primary endpoint of this trial, to demonstrate a significant improvement in RFS, was achieved after median follow-up of 3 years. The hazard ratio of 0.66 (95% CI 0.47–0.94; p=0.020) for RFS translates into a 34% reduction in the rate of recurrences or deaths in pts receiving XT→CEX. This significant benefit was seen using an X dose of 900 mg/m² bid, and with a lower T dose in the XT arm than with T monotherapy. Overall survival data are not yet mature but a trend towards improvement (hazard ratio 0.66 [95% CI 0.401.07]; p=0.089) can be seen in the XT→CEX arm. The results suggest that the risk of breast cancer recurrence can be reduced substantially with integration of capecitabine into a taxane-/anthracycline-based regimen. Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 82.