Phase II trial of capecitabine plus oxaliplatin (CAPOX) as perioperative therapy for locally advanced rectal cancer

Purpose: The standard strategy for locally advanced lower rectal cancer is chemoradiotherapy followed by total mesorectal excision (TME) in Western countries and TME followed by adjuvant chemotherapy without preoperative treatment in Japan. Methods: This phase II trial evaluated the efficacy of a preoperative CAPOX chemotherapy regimen without radiation therapy for patients with locally advanced rectal cancer. The primary endpoint was 2-year disease-free survival. Results: The trial enrolled 45 patients from 9 institutions between 2012 and 2014. The mean age was 63.5 (29–74) years; 31 patients were male. Most patients (n = 41) received preoperative chemotherapy (CTx), and the preoperative CTx completion rate was 95.2%. R0 resection after CTx was performed in 41 patients. The pathological complete response rate was 7.3% (3/41). After surgery, 35 patients (85.3%) received adjuvant CTx, and 22 of 35 completed the protocol treatment. The follow-up period ranged from 0.71 to 4.68 years (median 2.86 years). There was recurrence in 13 of 40 patients who underwent R0 resection, and the 2-year disease-free survival rate and overall survival rate were 71.6 and 92.7%, respectively. Conclusions: Here we report the completion rates for neoadjuvant CTx and adjuvant CTx, the pathological complete response rate, and the mid-term prognosis. The results indicate that CAPOX followed by TME may be a safe treatment strategy for locally advanced rectal cancer.