TABLE 1.

STAR‐TREC trial registration data

Data category	Information
Primary registry and trial identifying number	ISRCTN14240288
Date of registration in primary registry	20 October 2016
Secondary identifying numbers	EudraCT 2016‐000862‐49 ClinicalTrials.gov: NCT02945566
Source(s) of monetary or material support	Cancer Research UK, Dutch Cancer Society, Danish Cancer Society, Against Cancer Flanders
Primary sponsor	University of Birmingham, Birmingham, B15 2TT, UK Email: researchgovernance@contacts.bham.ac.uk
Secondary sponsor(s)
Contact for public queries	STAR-TREC@Trials.bham.ac.uk
Contact for scientific queries	STAR-TREC@Trials.bham.ac.uk
Public title	Can we Save the rectum by watchful waiting or TransAnal surgery following (chemo)Radiotherapy versus Total mesorectal excision for early REctal Cancer
Scientific title	Can we Save the rectum by watchful waiting or TransAnal surgery following (chemo)Radiotherapy versus Total mesorectal excision for early REctal Cancer
Countries of recruitment	Current: UK, Netherlands, Denmark Future: Belgium, Sweden
Health condition(s) or problem(s) studied	Early rectal cancer
Intervention(s)	Randomized comparator: organ preservation with short‐course radiotherapy A total dose of 25 Gy in five daily fractions over a total time of 1 week, using 5 Gy per fraction
	Randomized comparator: organ preservation with long‐course chemoradiotherapy A total dose of 50 Gy in 25 daily fractions over a total time of 5 weeks, using 2.0 Gy per fraction, combined with capecitabine 825 mg/m2 twice daily on radiotherapy days
	Non‐randomized comparator: radical total mesorectal excision Encompassing reconstructive (low anterior resection) and non‐reconstructive (abdominoperineal excision, low Hartmann's procedure) approaches
Key inclusion and exclusion criteria	Ages eligible for study: ≥16 years in UK, ≥18 years in other countries Sexes eligible for study: both Accepts healthy volunteers: no
	Main inclusion criteria: Biopsy proven adenocarcinoma of the rectum MRI or ERUS staged TX/T1‐3b, NX/N0, MX/M0 rectal tumour The MDT determines that the following treatment options are all reasonable and feasible: (a) TME surgery, (b) CRT, (c) SCRT and (d) TEM ECOG performance status 0–1 Willing and able to consent
	Main exclusion criteria: Concomitant or previous malignancies within 3 years prior to trial entry, except those that in the opinion of the MDT are unlikely to relapse within 3 years or lead to death within 5 years MRI node positive (≥N1, defined by protocol guidelines) MRI extramural vascular invasion (mriEMVI) present (defined by protocol guidelines) MRI defined mucinous tumour Mesorectal fascia threatened by tumour (≤1 mm on MRI or ERUS) Maximum tumour diameter >40 mm (measured from everted edges on either sagittal MRI or ERUS examination) Anterior tumour location above the peritoneal reflection on MRI or ERUS No residual luminal tumour following endoscopic mucosal resection Prior pelvic radiotherapy Definite evidence of regional or distant metastases (M1) in the opinion of the MDT Uncontrolled cardiorespiratory comorbidity (inadequately controlled angina or myocardial infarction or arrhythmia within 6 months prior to trial entry) Known complete dihydropyrimidine dehydrogenase deficiency Known Gilbert's disease Taking coumarin‐derivative oral anticoagulants that cannot be stopped or substituted by low molecular weight heparin Taking metronidazole, phenytoin, sorivudine or its analogues, such as brivudine Women who are pregnant or lactating
Study type	Interventional
	Open, parallel assignment, partially randomized intervention model Patients will choose organ preservation or standard surgery. Those who prefer organ preservation will be randomized 1:1 between (i) organ preservation with mesorectal CRT versus (ii) organ preservation with mesorectal SCRT. Those who prefer standard surgery or have no preference will undergo standard TME surgery without neoadjuvant radiotherapy treatment
	Primary purpose: treatment
	Rolling phase II–III
Date of first enrolment	14 June 2017
Target sample size	380 patients randomized to the organ preservation arms (CRT and SCRT) Estimated 120 patients recruited to the standard surgery comparator arm
Recruitment status	Recruiting
Primary outcome(s)	See Table 3
Key secondary outcomes	See Table 3

Abbreviations: CRT, chemoradiotherapy; ECOG, Eastern Cooperative Oncology Group; ERUS, endorectal ultrasound; MDT, multidisciplinary team; SCRT, short‐course radiotherapy; TEM, transanal endoscopic microsurgery; TME, total mesorectal excision.