Addition of oxaliplatin to capecitabine-based preoperative chemoradiotherapy for locally advanced rectal cancer: Long-term outcome of a phase II study

Our previous study reported the favorable short-term outcome and good tolerance of integrating oxaliplatin into capecitabine-based (XELOX regimen) preoperative chemoradiotherapy (CRT) for locally advanced rectal cancer (LARC). The present study reported the long-term oncological outcome of this phase II study. A total of 47 patients with rectal adenocarcinoma (stage II or III) were enrolled and received radiotherapy (46 Gy in 23 fractions) in combination with capecitabine (1,000 mg/m2, twice daily, on days 1-14 and 22-35) and oxaliplatin (130 mg/m2 on days 1 and 22). Overall survival (OS) rate, disease-free survival (DFS) rate and cumulative incidence of recurrences and long-term complications were calculated or observed. As a result, 41 patients underwent surgery after preoperative CRT, and the cumulative OS rates at 1, 3 and 5 years for these patients were 100.0, 84.5 and 81.8%, respectively. For the 38 patients who received R0 resection, the cumulative OS rates at 1, 3 and 5 years were 100.0, 89.0 and 86.2%, respectively, while the cumulative DFS rates at 1, 3 and 5 years were 94.6, 75.3 and 69.7%, respectively. After follow-up at 84 months, the cumulative incidence rates of local and distant recurrences at 5 years were 6.6 and 28.2%, respectively. Oxaliplatin-associated long-term complications were seldom observed. Overall, the addition of oxaliplatin to capecitabine-based preoperative radiotherapy achieved favorable OS and DFS without increased long-term complications in patients with LARC. Therefore, this preoperative CRT strategy is a feasible option for such patients.