Modulation of capecitabine administration to improve continuity of adjuvant chemotherapy for patients with colorectal cancer: A phase II study

Adjuvant chemotherapy with capecitabine is frequently not completed due to adverse events, including hand-foot syndrome. A higher completion rate of capecitabine by reduction of the side effects may improve disease-free survival and quality of life of affected patients. In the present study, colorectal cancer (CRC) patients were treated with capecitabine (2,500 mg/m(2)/day), which was taken for five days, followed by an interval of two days (5-days-on/2-days-off schedule). One course lasted three weeks, and eight courses (24 weeks) were administered. The median number of treatment courses was significantly higher in patients in the 5-days-on/2-days-off regimen group compared with that of patients in the retrospectively included conventional regimen group (P=0.0438). The frequency of completion of the scheduled treatment by patients in the 5-days-on/2-days-off regimen group was significantly higher (P=0.0389). The present phase II study suggests that toxicities associated with the 5-days-on/2-days-off regimen are lower compared with those of the conventional regimen, and that the occurrence of adverse events was higher, but less high-grade toxicities were reported. The time to treatment failure was also favorable in the new regimen and it demonstrated good feasibility. In conclusion, the present study demonstrated good feasibility with retained quality of life and acceptable adverse effects (mostly low-grade), and the 5-days-on/2-days-off regimen should be further evaluated in future randomized controlled trials. The present study was registered in the University Hospital Medical Information Network (UMIN) clinical trial registry (no. UMIN000012813).