A rectal cancer feasibility study with an embedded phase III trial design assessing magnetic resonance tumour regression grade (mrTRG) as a novel biomarker to stratify management by good and poor response to chemoradiotherapy (TRIGGER): study protocol for a randomised controlled trial

Table 2 Assessment schedule summary: control arm

Control arm		Registration period	Intervention phase						Annual follow-up			Disease status^g
Visit type	Prior to patient entry	Registration	Randomisation (baseline)	Post CRT	MDT	surgery	Surgical follow-up	Adjuvant chemotherapy for 24 weeks	12	24	36	60
Timelines		≤4 weeks prior to CRT	During CRT	4–6 weeks post CRT		6–12 weeks post CRT	6 weeks post surgery	Toxicity assessed at end of each chemotherapy cycle	Months from end of CRT
Informed consent^a		X	X
Check eligibility criteria		X	X
Diagnosis, history and clinical assessment		X
Randomisation			X
Quality of life		X							X		X
Chemoradiotherapy			X
Blood sample^b		X		X			X		X	X	X
Baseline MRI	X
Restaging MRI^c				X
Surgery						X
Surgical morbidity^f							X		X
Pathology^d							X
Chemotherapy								X end of each cycle
Toxicity assessment								X end of each cycle	X
Annual follow-up						X			X	X	X	X
Adverse events^e				X		X	X	X end of each cycle
Concurrent medications		X	X	X		X	X	X end of each cycle

CRT pre-operative chemoradiotherapy, MDT multidisciplinary team, MRI magnetic resonance imaging
The X also denotes that Clinical Report Forms (CRFs) need completing
^aEligible subjects will be asked to provide written informed consent at registration and before randomisation
^bIf patient has consented to additional blood sample collection for research
^cThe post-CRT MRI should to be performed within 4–6 weeks (maximum of 10 weeks) from completion of CRT
^dResected specimen will be prepared and evaluated using a standardised protocol
^eAll adverse events will be recorded from the date the post-CRT MRI scan is performed until 30 days after the last dose of chemotherapy is administered during the intervention phase of the trial
^fBoth early (4–6 weeks) and late surgical complications (at 12 months) will be recorded
^gDisease status at 5 years (does not require clinic visit): alive without metastatic or recurrent disease, alive with metastatic and/or recurrent disease (date diagnosed), dead (date of death)

ISSN: 1745-6215