Related Experiment Video
Updated: Nov 22, 2025
Testing Targeted Therapies in Cancer using Structural DNA Alteration Analysis and Patient-Derived Xenografts
Published on: July 25, 2020
Randomized phase II study comparing the efficacy and safety of SOX versus mFOLFOX6 as neoadjuvant chemotherapy
Keisuke Miwa1, Eiji Oki2, Masanobu Enomoto3
1Multidisciplinary Treatment Cancer Center, Kurume University Hospital, Kurume, Japan.
Background:
Preoperative chemoradiotherapy (CRT), the current standard of care for locally advanced rectal cancer (LARC), is associated with many radiotherapy (RT)-related side effects. We aimed to evaluate whether S-1 and oxaliplatin (SOX) or folinic acid, 5-FU, and oxaliplatin (mFOLFOX6) can be as effective as neoadjuvant chemotherapy (NAC) regimens for LARC without RT.
Methods:
Patients with untreated resectable LARC were randomly assigned to receive SOX or mFOLFOX6. The NAC protocol period was 3 months. The primary endpoint was 3-year disease-free survival (DFS), and the secondary endpoints included pathological effects, surgical completion rate, 3-year survival, and safety.
Results:
From September 2013 to October 2015, 56 and 54 patients were enrolled in the SOX and mFOLFOX6 arms, respectively. The 3-year DFS rates were 69.4% (95% confidence interval [CI] 54.9-83.6) and 73.4% (95% CI 58.7-83.6) in the SOX and mFOLFOX6 arms, respectively; no significant differences were found between the arms (log-rank test; P = 0.5315, hazard ratio: 0.808, 95% CI 0.414-1.578). The 3-year survival rates were 92.3 and 91.8% in the SOX and mFOLFOX6 arms, respectively. The surgical completion rate was 98.1% overall, 100% in the SOX arm, and 96.0% in the mFOLFOX6 arm. The incidences of pathological response rates ≥grade 1b were 41.5 and 43.8% in the SOX and mFOLFOX6 arms, respectively. Both treatments were manageable and tolerable.
Conclusion:
We demonstrated the effectiveness and safety of SOX and mFOLFOX6, both of which may be new neoadjuvant treatment candidates in previously untreated LARC cases.
Trial Registration:
Date of enrolment of the first participant to the trial: 3rd Oct 2013; This study was registered in the UMIN clinical trials registry on 14th Aug, 2013. (Prospectively registered, UMIN-CTR number UMIN000011486). https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr.cgi?function=brows&recptno=R000013441&language=J.
