Efficacy of capecitabine in patients with locally advanced or metastatic breast cancer with or without prior treatment with fluoropyrimidine: a retrospective study

We conducted a retrospective study to assess the outcomes of capecitabine for advanced breast cancer (ABC) after perioperative fluoropyrimidines (FPs). The charts of patients with ABC who received capecitabine between 2008 and 2016 at the National Cancer Center Hospital (Tokyo, Japan) were reviewed. Progression-free survival (PFS), overall survival (OS), tumor response, and adverse events (AEs) were compared between two groups: an FP group (prior perioperative FP use) and a non-FP group (no prior FP use). Overall, 288 patients (FP n = 105; non-FP n = 183) were analyzed. The two groups had similar patient characteristics. The FP group had significantly poorer PFS than the non-FP group (multivariate hazard ratio [HR] 1.33; 95% confidence interval [CI] 1.02-1.73; p = 0.036), although the OS did not differ significantly between the groups (multivariate HR 1.00; 95% CI 0.67-1.50; p = 0.994). With different cut-off values (relapse-free interval [RFI] = 3, 4, and 5 years), multivariate HRs for PFS were 1.32-1.67 (short RFI), and 1.00-1.25 (long RFI). A trend for a larger HR in the FP group compared to the non-FP group with short RFI than in that with long RFI was also seen for OS. Response rate (RR) and disease control rate (DCR) did not differ significantly between the groups (RR in FP vs non-FP 13.8 vs 21.0%; p = 0.173; DCR 54.0 vs 59.9%; p = 0.418). No significant difference in AEs existed between the groups. Extra caution is needed when capecitabine is considered for patients with ABC who used perioperative FP, especially those who had early recurrence.