Efficacy of different dosing schedules of capecitabine for metastatic breast cancer: a single-institution experience.

Abstract

Purpose Capecitabine is widely used as a single agent on a 21-daycycle in the management of metastatic breast cancer (MBC). Our primary objective was to compare the standard dosing of capecitabine (Arm A: days 1-14 on 21-daycycle) to biweekly dosing (Arm B: days 1-7 and 15-21 on 28-daycycle) using retrospective data analysis. Methods 166 patients with MBC treated with single agent capecitabine at The Ohio State University from 2002 to 2014 were considered eligible. Median time to treatment failure (TTF) and overall survival (OS) were estimated using Kaplan-Meier (KM) methods. KM curves were compared using log-rank tests with Holm's correction for multiplicity. Results Patients were grouped by dose schedule into one of three arms: Arm A (21-daycycle; capecitabine given at 1000mg/m2 orally, twice daily on days 1-14 of 21-daycycle); Arm B (28-daycycle; capecitabine given at 1000mg/m2 orally, twice daily on days 1-7 and 15-21 of 28-daycycle); and Arm C (changeover regimen where patients started on the 21-daycycle, but changed to a 28-daycycle for tolerability). No difference was found in TTF or OS for patients with MBC between those who received capecitabine on either standard dosing (Arm A) and those on a biweekly cycle (Arm B or C). Overall, 41% of patients required dose reduction. Conclusions Our single institution experience showed that alternate dosing of capecitabine (biweekly, 28-daycycle) may be a reasonable alternative to standard 21-daycycle with similar efficacy and fewer dose reductions.