# MRC CR07

Source: https://onco.cc/trials/cr07/  
OnCo record `cr07` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

The UK trial that settled how rectal cancer is treated before surgery: five days of radiotherapy for everyone beats waiting to see who needs it afterwards.

## Summary

CR07 randomised 1,350 people with operable rectal cancer to a week of preoperative radiotherapy or to surgery first with chemoradiotherapy afterwards only if the pathologist found tumour at the circumferential resection margin. Local recurrence fell by 61 percent with preoperative radiotherapy (hazard ratio 0.39, 0.27 to 0.58, p < 0.0001), an absolute difference at three years of 6.2 percent (4.4 percent against 10.6 percent), and disease-free survival improved by 24 percent (0.76, 0.62 to 0.94, p = 0.013). Overall survival did not differ. The trial was led from Leeds with Phil Quirke's pathology, and its companion staging work (MERCURY) showed MRI could pick out who was at risk before any treatment began.

## Fields

- Kind: Trial
- Status: positive
- Last checked: 2026-09-24
- Also known as: CR07; NCIC-CTG C016; ISRCTN28785842
- Tags: uk; rectal; radiotherapy
- Registry id: ISRCTN28785842
- Phase: 3
- Setting: Short-course preoperative radiotherapy (25 Gy in five fractions) against initial surgery with selective postoperative chemoradiotherapy (45 Gy in 25 fractions with fluorouracil) restricted to people with an involved circumferential resection margin; operable rectal adenocarcinoma, 80 centres in four countries
- Sponsor: Medical Research Council
- Enrolled: 1350
- Result: Local recurrence at three years 4.4 percent with short-course preoperative radiotherapy against 10.6 percent with selective postoperative chemoradiotherapy (hazard ratio 0.39, 0.27 to 0.58); disease-free survival 77.5 percent against 71.5 percent; no overall survival difference.

## Sources

- Lancet 2009: https://europepmc.org/article/MED/19269519
- ISRCTN28785842: https://www.isrctn.com/ISRCTN28785842

## Connected records

- 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/)
- institutions: [Leeds Cancer Centre, St James's University Hospital](https://onco.cc/institutions/leeds-cancer-centre/)
- people: [David Sebag-Montefiore](https://onco.cc/people/david-sebag-montefiore/)

---
JSON: https://onco.cc/api/v1/entities/cr07.json