Resumen de Concurrent use of capecitabine with radiation therapy and survival in breast cancer (BC) after neoadjuvant chemotherapy

Y. L. Liu, C. Chin, B. Catanese, S. M. Lee, S. Zhan, Kevin M. Kalinsky, E. Connolly

• Purpose Capecitabine has been studied as a radiosensitizer, and our study seeks to examine the association of concurrent capecitabine/radiation therapy (RT) on event-free- (EFS) and overall survival (OS) in women with breast cancer (BC) with residual disease after neoadjuvant chemotherapy (NAC).

  Methods/patients In a retrospective study of women with BC who received adriamycin/taxane-based NAC from 2004–2016, we identified 21 women administered concurrent capecitabine/RT. To assess differences in survival, we selected a clinical control cohort (n = 57) based on criteria used to select patients for capecitabine/RT. We also created a matched cohort (2:1), matching on tumor subtype, pathological stage and age (< 50 or 50+ years). Differences in EFS, using STEEP criteria, and OS, using all-cause mortality, between those who received capecitabine/RT and controls were assessed.

  Results Of the 21 women who received capecitabine/RT, median age was 52 years. The majority were pathologic stage III (n = 15) and hormone receptor-positive/HER2-negative BC (n = 20). In those receiving capecitabine/RT, there were 9 events, compared with 14 events in clinical and 10 events in matched controls. Capecitabine/RT was associated with worse OS in clinical (HR 3.83 95% CI 1.12–13.11, p = 0.03) and matched controls (HR 3.71 95% CI 1.04–13.18, p = 0.04), after adjusting for clinical size, pathological stage and lymphovascular invasion. Capecitabine/RT was also associated with a trend towards worse EFS in clinical (HR 2.41 95% CI 0.86–6.74, p = 0.09) and matched controls (HR 2.68 95% CI 0.91–7.90, p = 0.07) after adjustment.

  Conclusion Concurrent capecitabine/RT after NAC is associated with worse survival and should be carefully considered in BC.