Abstract 417P
Background
Preoperative chemoradiotherapy (PCRT) followed by surgery and adjuvant chemotherapy is the current standard treatment for locally advanced rectal cancer. Several studies reported that preoperative magnetic resonance imaging (MRI) helped to selectively avoid PCRT. This study aims to evaluate the efficacy of upfront radical surgery with total mesorectal excision (TME) followed by adjuvant chemotherapy with FOLFOX in locally advanced rectal cancer.
Methods
This study is a phase II, multicenter, randomized, non-inferiority trial, participants were recruited from 5 centers. Eligible patients were randomized 1:1 to receive upfront radical surgery with TME followed by 12 cycle of adjuvant FOLFOX chemotherapy (experimental group) or fluoropyrimidine-based PCRT followed by TME and adjuvant chemotherapy (standard-of-care group). Key inclusion criteria is T3N0 or T1-3N+ rectal cancer below 10 cm from the anal verge and located apart from more than 2 mm from mesorectal fascia (MRF) defined using preoperative MRI. The primary endpoint is 3-year disease-free survival (DFS).
Results
A total of 90 patients were enrolled, of whom 84 were eligible for analysis (44 in the experimental group; 40 in the standard-of-care group). The 3-year DFS rates was 88.6% in the experimental group versus 85.0% in the standard-of-care group (hazard ratio 0.71, 95% CI 0.22–2.34; p=0.578). Serious adverse events occurred in 7 (15.9%) in the experimental group and 6 (15.0%) in the standard-of-care group during the whole treatment period. Temporary diverting stoma formation was done in 20 (45.5%) in the experimental group vs. 24 (61.5%) in the standard-of-care group (p=0.143). In 8 (18.2%) patients (18.2%) in experimental group, postoperative pathologic stage was confirmed as stage 0 (n=1) and 1 (n=7) and these patients did not receiving adjuvant chemotherapy as well as radiotherapy.
Conclusions
Upfront surgery followed by adjuvant FOLFOX chemotherapy might be considered as an alternative treatment option in in locally advanced rectal cancer with tumor-MRF distance ≥ 2 mm assessed by MRI.
Clinical trial identification
NCT02167321.
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
1420270.
Disclosure
All authors have declared no conflicts of interest.