The effect of oxaliplatin plus capecitabine in combination with radiation for locally advanced lower or middle sited rectal carcinoma

Objective: To explore the effectiveness, toxicity and treatment failure patterns for patients with locally advanced rectal adenocarcinoma after pre-operative radiation and concurrent oxaliplatin plus capecitabine. Methods: Patients with histopathologically proven rectal adenocarcinoma and clinical stage Ⅱ/Ⅲ were enrolled in a prospective phase Ⅱ clinical trial at 2006-2012 years. One hundred and eighty-six patients received pre-operative chemoradiation, which consisted of 44.0-50.4 Gy in 22-28 fractions with concurrent chemotherapy of oral capecitabine 1650 mg/(m² · d) in bid from d1-35 and oxaliplatin 50 mg/m² per week for 5 times. Radical surgery was performed 4-8 weeks after chemoradiotherapy. Survival rates and multivariate prognostic factors were estimated by Kaplan-Meier method, comparisons were completed by the Log-rank test. Results: One hundred and thirty-seven patients with clinical stage Ⅱ (n=34) and Ⅲ disease (n=103) underwent radical resection. The lower (the anal distance ≤5 cm) and middle (the anal distance 5-10 cm) located lesions were 102 (74.5%) and 35 (25.5%), respectively. Diarrhea was the most frequent acute Grade 3 toxicity (n=29, 21.2%). Sixty-nine patients (50.4%) were downstaged, and 21 patients (15.3%) achieved complete regression of primary lesion, 20 patients were pathological complete response (yp T₀N₀). With a median follow-up of 22.2 months, the 2-year overall survival, locoregional recurrence free survival and disease free survival for all patients were 92.4%, 93.1% and 71.0%, respectively. In multivariate analysis, pathological stage of yp 0-Ⅱ was identified as independent factor related to OS and DFS. Conclusions: When delivering oxaliplatin plus capecitabine in combination with radiation for locally advanced lower or middle rectal carcinoma, the 2-year local control was excellent, pathological stage of yp 0-Ⅱ was correlated to the favorable survival. (authors)