NICE 2020 guideline for the management of colorectal cancer

The study by Amy Lord and colleagues1 presents outcomes using MRI-based selection criteria to determine the need for neoadjuvant radiotherapy before surgery for rectal adenocarcinoma. There was moderate quality evidence from randomised controlled trials of a benefit with preoperative radiotherapy and chemoradiotherapy in terms of overall survival and local recurrence-free survival. Previous work from this group has ascertained that MRI does not predict local control.4 An unintended consequence of following the protocol as published here in less expert settings could even be an increase in positive circumferential resection margin rates since it is clear that microscopically positive circumferential resection margins have been shown to negatively affect oncological outcomes in rectal cancer.5 Neoadjuvant radiotherapy to reduce local recurrence rates has a firm evidence base reflecting evidence from randomised trials.2 The findings published by Lord and colleagues, based on a single-centre retrospective experience, are hypothesis-generating observational evidence.