Work

NEO-RT Organ Preservation Trial for Early Rectal Cancer: CCTG CO.32 Phase III Randomized Trial of Neoadjuvant Chemotherapy, Excision and Observation Versus Chemoradiotherapy

Year: 2026

Type: article

Abstract: Management of early-stage rectal cancer is evolving, with increasing emphasis on organ preservation.The development of transanal endoscopic techniques has improved surgeons' ability to excise lesions endoluminally with clear margins, generating growing interest in organ-preserving strategies.In the randomized phase III NEO-RT trial (CCTG CO.32, Clin-icalTrials.govidentifier: NCT06205485), patients are treated with either induction chemotherapy or chemoradiotherapy, followed by minimally invasive surgery, with the goal of maximizing organ preservation and function.The trial builds on results from the successful CCTG CO.28 NEO study, 1 which demonstrated high downstaging rates and a 79% organ-preservation rate using 3 months of induction modified folinic acid, flurouracil oxaliplatin/capecitabine oxaliplatin chemotherapy followed by transanal endoscopic surgery (TES).Mature results 2 reported a 3-year locoregional relapse-free survival of 93% (95% CI, 82 to 97) and a 3-year distant disease-free survival of 95% (95% CI, 85 to 98).The NEO-RT trial has recently been amended to include patients with T3abN0 tumors.Traditionally, early rectal cancer has been defined as magnetic resonance imaging (MRI) stage T1, T2, and T3ab (tumor invasion within 5 mm beyond the muscularis propria) node-negative tumors.The 2024 ASCO Guidelines Expert Panel on Locally Advanced Rectal Cancer 3 agreed that node-negative T3ab N0 tumors with MRI-assessed extramural depth of invasion ≤5 mm should be considered low-risk T3 tumors, with a local recurrence risk of <5%.4,5 Such patients are excellent candidates for organ-preservation strategies.Management of early-stage rectal cancer remains highly variable in North America.Previous randomized trials of organ preservation in T1-T3ab rectal adenocarcinoma have shown that patients treated with chemoradiotherapy and TES achieved disease-free survival comparable with those undergoing radical total mesorectal excision (TME) surgery.[6][7][8] National Comprehensive Cancer Network (NCCN) rectal cancer guidelines recommend that patients with pT1 high-risk or T2 rectal tumors treated with TES may receive adjuvant pelvic chemoradiation, with consideration of folinic acid, flurouracil oxaliplatin/capecitabine oxaliplatin (FOLFOX/CAPOX) chemotherapy, followed by observation without TME.Despite these recommendations, National Cancer Data Base data show that as of 2020, 80% of US patients with stage I rectal cancer were still managed with radical TME surgery; a significant proportion of these patients are eligible for multimodal therapy combined with TES with the aim of organ preservation.9 One barrier to wider adoption of organ preservation is concern about acute and long-term organ dysfunction resulting from pelvic irradiation.Long-term results from the CARTS trial 10 suggest rectal function may be impaired after chemoradiation followed by TES.At 48-68 months after

Source: JCO oncology advances.

DOI: 10.1200/oa-25-00176