Mid-term outcomes of a prospective phase II trial of preoperative sandwich-like neoadjuvant chemoradiotherapy for locally advanced rectal cancer

Abstract

Objective To evaluate the mid-to long-term survival benefits of preoperative sandwich-like neoadjuvant chemoradiotherapy (CRT) in patients with locally advanced rectal cancer (LARC). Methods A total of 45 LARC patients who underwent neoadjuvant sandwich CRT in the form of XELOX regimen prior to, concurrently with, and following volumetric modulated arc radiotherapy (VMAT) in 2012 were enrolled in this study. VMAT was given at a gross tumor volume dose of 50 Gy in 25 fractions, and a clinical target volume dose of 45-46 Gy in 25 fractions. Total mesorectal excision was performed 6 to 8 weeks after completion of VMAT.The overall survival (OS) and disease-free survival (DFS) were determined by the Kaplan-Meier method, and survival comparison and univariate prognostic analysis were performed using the log-rank test. Results The median follow-up time was 46.7 months. There was no local recurrence detected among the patients. The 3-year distant metastasis (DM) rate was 18%, and the 3-year OS and DFS were 96% and 84%, respectively. Univariate analysis indicated that perineural invasion, N1-N2 pathology (pathological stage Ⅲ), and Ca-199>35 U/ml before treatment were risk factors for DM (P=0.000, 0.000, and 0.013, respectively). Conclusions The significant short-term efficacy of preoperative sandwich-like neoadjuvant CRT can be extended to a positive mid-term survival in LARC patients. However, further phase Ⅲ clinical studies will be needed to confirm this finding. Key words: Rectal neoplasms/chemoradiotherapy; Chemoradiotherapy, neoadjuvant; Prognosis