In operable rectal cancer, does routine short-course preoperative radiotherapy improve local control and disease-free survival compared with selective postoperative chemoradiotherapy? [MRC CR07 / NCIC-CTG C016]
In operable rectal cancer, does routine short-course preoperative radiotherapy improve local control and disease-free survival compared with selective postoperative chemoradiotherapy?
Absolute Effect
At the initial 4-year analysis, 330 deaths occurred: 157 after preoperative RT and 173 after selective postoperative CRT. The trial's major benefit was local control and DFS rather than a demonstrated OS advantage.
Absolute effect: Three-year local recurrence was 4.4% vs 10.6%: absolute reduction 6.2 percentage points. Three-year DFS was 77.5% vs 71.5%: absolute improvement 6.0 points.
NNT: 17, based on 3-year local recurrence (absolute reduction 6.2 percentage points). NNT: 17, based on 3-year DFS (absolute improvement 6.0 points).
NNH: not quantifiable from a single robust fixed-time toxicity endpoint in the primary report; short-term morbidity was described as minor.
Follow-up: Median follow-up of surviving patients was 4 years in the primary report; later analyses supported durable local-control benefit.
Clinical results and treatment burden
- Intervention: Preoperative RT: 25 Gy in 5 fractions, usually followed promptly by surgery, versus a policy of selective postoperative chemoradiotherapy for patients with involved circumferential resection margins.
- Principal toxicity: The principal treatment burden was acute perioperative morbidity rather than a dominant grade 3–5 toxicity signal. The trial reported only minor short-term morbidity overall.
- Other efficacy/recurrence findings: Three-year distant metastases were 19% vs 21%, illustrating that improved pelvic control did not translate into a large reduction in distant failure in this study.
- Quality of life: Formal patient-reported QoL was not the principal efficacy endpoint of the primary publication.
Eligibility and clinical context
1,350 patients with operable rectal adenocarcinoma, predominantly WHO performance status 0, randomized across 80 centres.
Limitations and maturity: The comparator was a treatment policy, not universal postoperative CRT. Modern MRI staging, TME quality, total neoadjuvant therapy and selective omission strategies differ substantially from the trial era.