Phase Ii Trial Of Neoadjuvant Chemotherapy With Ts-1/L-Ohp (Sox) For Resectable Advanced Rectal Cancer (Nccsg-09)

e15028 Background: A multicenter, single-arm, open-label phase II study design was used in a planned phase II trial to evaluate the efficacy and safety of SOX as neo-adjuvant therapy for patients with advanced rectal cancer. Methods: Patient inclusion criteria were resectable advanced rectal cancer (Ra or Rb), clinical T3-4 (cT3-4) stage, any N, cMo with confirmed diagnosis of adenocarcinoma, and no previous chemo-radiotherapy. S-1 was administered a daily dose of 80 mg/m2 p.o. on days 1-14, and Oxaliplatin was administered 130 mg/m2 i.v. on day 1 of a 21-day cycle. The primary endpoint was the response rate (RR). The secondary endpoints included relapse-free survival, overall survival, safety, and operation, curative resection, and anus preservation rates. Results: Thirty-six patients were enrolled between February 2013 and December 2014. Thirty-five patients were investigated. The RR, CR, PR, SD, PD, and NE were 48.6%, 0%, 48.6%, 48.6%, 0%, and 0%, respectively. Grade 2, Grade 1b, and Grade 1a, histological RRs were 17.1%, 8.6%, and 54.3%, respectively. On safety analysis, the incidences of Grade 3 or 4 adverse reactions were anorexia (11.4%), leucopenia (2.9%), neutropenia (2.9%), thrombocytopenia (2.9%), nausea (2.9%), diarrhea (2.9%), and fatigue (2.9%). Both the operation and curative resection rates were 100%. Twenty-five of 26 patients who were scheduled to undergo anus-preserving operation, and 3 of 6 patients who were scheduled to undergo APR, underwent anus-preserving operations. Post-operative complication rate was 37.1%, and complications included leakage (14.3%), enteritis, neurogenic bladder, paralytic ileus, UTI, and diarrhea. The mortality rate was 0%. Conclusions: SOX is efficacious and a well-tolerated neo-adjuvant chemotherapy for patients with advanced resectable rectal cancer. Clinical trial information: UMIN000009764.