Marsh 1994.

Methods	Randomisation method not available. Enrolment period: 1982 to 1986 Abdominal imaging: not stated Chest imaging: not stated Study arm: 143 randomised, 0 excluded; median time from randomisation to surgery 27 days (IQR 21 to 33) Control arm: 141 randomised , 0 excluded; median time from randomisation to surgery 19 days (IQR 12 to 26)
Participants	Rectal cancer Location: </= 13 cm Resectability: locally advanced (tethered or fixed) but operable (within 13 cm of the anal verge)
Interventions	Surgery: not stated RT: 2000 in 4 fr BED: 31.8 Gy10 RT volume: 10x10x10 cm posterior pelvis RT‐S: </= 1 week Technique: rotational field Co‐intervention: none
Outcomes	Duration of FU: minimum 96 months Perioperative mortality: not stated Mets @ lap: not given Curative resection: S 75/141, RTS group 69/143 Overall resection: S 121/141, RTS 118/143 Compliance to radiotherapy: 6/143 did not receive protocol therapy, with 2 < 20 Gy and 4 > 20 Gy Overall survival: yes Cause‐specific survival: yes Tox post RT: not reported Acute toxicity postsurgery: not reported Late toxicity postsurgery: not reported Local recurrence: yes Quality of life: not reported Others: subgroup analysis for participants treated by curative surgery only. Survival outcome in relationship flow cytometry in a subgroup of 186 participants treated at 1 institution
Notes	Definition for: Local recurrence: by clinical examination +/‐ pathology or CT scan, include patients with known residual at surgery Postoperative mortality: not reported Toxicity classification: not reported Quality of life: not reported Quality score: 0.57
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	It was unclear how the method of randomisation was performed.
Allocation concealment (selection bias)	Unclear risk	It was unclear how allocation of participants was concealed.
Blinding of participants and personnel (performance bias) All outcomes	High risk	Blinding is not possible with the type of intervention.
Blinding the outcome assessor (detection bias; objective outcomes) Outcomes: mortality; local recurrence; distant metastases; curative resection Outcomes: mortality; local recurrence; distant metastases; any recurrence; curative resection	Low risk	Mortality: no information was provided on the blinding of the outcome evaluator. Recurrence: no information was provided on the blinding of the outcome evaluator. Metastases: no information was provided on the blinding of the outcome evaluator. Curative resection: It was unclear whether the operating surgeon or the pathologist was blinded. Quote: "The operating surgeon recorded a 'curative' resection if the carcinoma was removed with neither spillage nor perforation, and there was no macroscopic evidence of residua I local disease or distant metastases. The degree of local invasion present at operation was also noted. Pathologic information on the resected tumour was recorded prospectively by pathologists from the referral hospital on a standard form for each of the 284 patients. Lymph nodes were sampled and assessed in the normal way, as was the presence of venous invasion." Since the outcomes were objective, we considered the study to be at low risk of detection bias for the listed outcomes.
Blinding the outcome assessor (detection bias): subjective outcomes: Postoperative morbidity; sphincter preservation; acute and late toxicities; quality of life Outcomes: Postoperative morbidity; sphyncter preservation	Unclear risk	Postoperative morbidity was not assessed.
Incomplete outcome data (attrition bias) All outcomes	Low risk	Although intention‐to‐treat was not stated, it appears that all participants were analysed according to their initial allocation. No apparent significant loss to follow‐up
Selective reporting (reporting bias)	Low risk	Relevant clinical outcomes were considered.