Feasibility and Efficacy of Neoadjuvant Chemotherapy without Radiotherapy for Locally Advanced Rectal Cancer

OBJECTIVES: This retrospective study explored the feasibility of neoadjuvant chemotherapy (NAC) without radiotherapy in patients with locally advanced rectal cancer (LARC). METHODS: Patients with clinical stage of T3-T4 and/or N-positive LARC patients were included. We retrospectively analyzed patients' NAC-related and perioperative outcomes. RESULTS: The study enrolled 30 patients. mFOLFOX6 or SOX plus cetuximab was administered to 12 patients with the wild-type RAS gene and FOLFOXIRI or SOXIRI to 18 patients with mutant-type RAS. The NAC completion rate was 90.0%. All patients underwent total mesorectal excision, and 29 patients underwent combined bilateral lateral lymph node dissection. The R0 operation rate was 90.0%. Although the postoperative complication rate was 40%, no complications were associated with NAC. The response rate of NAC and the proportion of histological anti-tumor effect grade ≥ 2 were 56.7% and 46.7%, respectively. CONCLUSIONS: NAC was considered to be a safe, feasible treatment option for LARC.