# Preoperative radiotherapy versus selective postoperative chemoradiotherapy in patients with rectal cancer (MRC CR07 and NCIC-CTG C016)

Source: https://onco.cc/key-papers/paper-sebag-montefiore-cr07-preoperative-radiotherapy-lancet-2009/  
OnCo record `paper-sebag-montefiore-cr07-preoperative-radiotherapy-lancet-2009` (Key paper). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

The British trial that settled the timing question: giving everyone a short course of radiotherapy before surgery beats operating first and irradiating only those whose margins turn out to be involved.

## Summary

Sebag-Montefiore, Stephens, Steele and colleagues randomised 1,350 patients with operable rectal adenocarcinoma in 80 centres in four countries to short-course preoperative radiotherapy (25 Gy in five fractions, 674 patients) or to initial surgery with selective postoperative chemoradiotherapy (45 Gy in 25 fractions with concurrent fluorouracil) restricted to patients with an involved circumferential resection margin (676 patients). The primary outcome measure was local recurrence, analysed by intention to treat.

At analysis, 330 patients had died and median follow-up of survivors was four years; 99 patients had developed local recurrence.

## Fields

- Kind: Key paper
- Last checked: 2026-09-24
- Tags: colorectal-evidence
- Journal: The Lancet
- Year: 2009
- DOI: 10.1016/S0140-6736(09)60484-0
- Authors: Sebag-Montefiore D, Stephens RJ, Steele R, et al.
- Findings: 27 local recurrences with preoperative radiotherapy against 72 with selective postoperative chemoradiotherapy: hazard ratio 0.39 (95 percent CI 0.27 to 0.58, p<0.0001), a 61 percent relative reduction.; Absolute difference in local recurrence at three years 6.2 percent (4.4 against 10.6 percent).; Disease-free survival improved 24 percent (hazard ratio 0.76, 95 percent CI 0.62 to 0.94, p=0.013); absolute difference at three years 6.0 percent (77.5 against 71.5 percent).; Overall survival did not differ (hazard ratio 0.91, 95 percent CI 0.73 to 1.13, p=0.40).
- What it means: The trial that made preoperative rather than postoperative radiotherapy the UK standard, and the one whose circumferential resection margin pathology protocol, led by Quirke, became the quality measure for rectal surgery worldwide.
- Caveats: Selective postoperative chemoradiotherapy was given only for an involved margin, so the comparison is against a deliberately restrictive policy rather than against no radiotherapy.; No overall survival difference, as in the Dutch TME trial.; Late toxicity of universal short-course radiotherapy is the cost of the local control gain and is not captured in the primary endpoints.

## Sources

- Lancet 2009: https://doi.org/10.1016/S0140-6736(09)60484-0
- PubMed: https://pubmed.ncbi.nlm.nih.gov/19269519/
- Europe PMC full text (PMC2668947): https://europepmc.org/article/MED/19269519

## Connected records

- key papers: [Preoperative radiotherapy combined with total mesorectal excision for resectable rectal cancer (Dutch TME trial)](https://onco.cc/key-papers/paper-kapiteijn-dutch-tme-preoperative-radiotherapy-nejm-2001/), [Sauer 2004: chemoradiotherapy before rather than after surgery for rectal cancer (CAO/ARO/AIO-94)](https://onco.cc/key-papers/paper-sauer-preoperative-chemoradiotherapy-rectal-nejm-2004/), [The mesorectum in rectal cancer surgery: the clue to pelvic recurrence?](https://onco.cc/key-papers/paper-heald-mesorectum-rectal-cancer-surgery-br-j-surg-1982/)
- cancers: [Colorectal cancer](https://onco.cc/cancers/colorectal/), [Rectal cancer](https://onco.cc/cancers/rectal-cancer/)
- fronts: [Radiation Therapy](https://onco.cc/fronts/radiation/), [Surgery & Interventional](https://onco.cc/fronts/surgery/)
- terms: [Chemoradiation (chemoradiotherapy, CRT)](https://onco.cc/terms/chemoradiation/), [Radiotherapy](https://onco.cc/terms/radiotherapy/), [Total mesorectal excision (TME)](https://onco.cc/terms/total-mesorectal-excision/)
- technologies: [IMRT / IGRT (modern external beam)](https://onco.cc/technologies/imrt-igrt/)
- drugs: [Fluorouracil (5-FU)](https://onco.cc/drugs/fluorouracil/)
- bottlenecks: [Surgery and radiotherapy cure most, get least](https://onco.cc/bottlenecks/b-surgery-radiation-innovation/)
- journals: [The Lancet](https://onco.cc/journals/lancet/)
- roadmaps: [Colorectal cancer roadmap: from the adenoma-carcinoma sequence and the first screening trials to total mesorectal excision, oxaliplatin, RAS testing, immunotherapy for mismatch repair-deficient disease, ctDNA-guided treatment and organ preservation](https://onco.cc/roadmaps/colorectal-roadmap/)

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