IntroductionTotal mesorectal excision (TME) is the highly effective standard treatment for rectal cancer but is associated with significant morbidity and may be overtreatment for low-risk cancers. This study is designed to determine the feasibility of international recruitment in a study comparing organ-saving approaches versus standard TME surgery.Methods and analysisSTAR-TREC trial is a multicentre international randomised, three-arm parallel, phase II feasibility study in patients with biopsy-proven adenocarcinoma of the rectum. The trial is coordinated from Birmingham, UK with national hubs in Radboudumc (the Netherlands) and Odense University Hospital Svendborg UMC (Denmark). Patients with rectal cancer, staged by CT and MRI as ≤cT3b (up to 5 mm of extramural spread) N0 M0 can be included. Patients will be randomised to either standard TME surgery (control), organ-saving treatment using long-course concurrent chemoradiation or organ-saving treatment using short-course radiotherapy. For patients treated with an organ-saving strategy, clinical response to (chemo)radiotherapy determines the next treatment step. An active surveillance regime will be performed in the case of a complete clinical regression. In the case of incomplete clinical regression, patients will proceed to local excision using an optimised platform such as transanal endoscopic microsurgery or other transanal techniques (eg, transanal endoscopic operation or transanal minimally invasive surgery). The primary endpoint of this phase II study is to demonstrate sufficient international recruitment in order to sustain a phase III study incorporating pelvic failure as the primary endpoint. Success in phase II is defined as randomisation of at least four cases per month internationally in year 1, rising to at least six cases per month internationally during year 2.Ethics and disseminationThe medical ethical committees of all the participating countries have approved the study protocol. Results of the primary and secondary endpoints will be submitted for publication in peer-reviewed journals.Trial registration number ISRCTN14240288, 20 October 2016. NCT02945566; Pre-results, October 2016.

Falcarinol (FaOH) and falcarindiol (FaDOH) are found in many food plants of the Apiaceae family. Carrots are a major dietary source of these polyacetylenes. Feeding azoxymethane (AOM)-induced rats with carrots and purified FaOH have previously been shown to inhibit neoplastic transformations in the colon. FaOH and FaDOH have also shown to have a synergistic effect in vitro, resulting in a significant increased cytotoxic activity. Based on these findings the antineoplastic effect of FaOH and FaDOH (purity > 99%) was investigated in the AOM-induced rat model. Twenty rats received rat diet containing 7 μg FaOH per g feed and 7 μg FaDOH per g feed and 20 rats were controls receiving only rat diet. Then carcinogenesis was induced in all 40 rats with the carcinogen AOM. All animals received the designated diet for 2 weeks before AOM induction and continued on the designated diet throughout the experiment. Rats were euthanized 18 weeks after the first AOM injection and macroscopic polyp/cancers were measured, harvested and stained for histology. The difference in sizes of aberrant crypt foci (ACF) were analysed in a Wilcoxon rank sum test, in which the median number of small ACF was 218 in controls and 145 in polyacetylene treated rats (P < 0.001). Fifteen control rats and 8 treated rats had macroscopic tumors (P = 0.027). The number of tumors larger than 3 mm were 6 and 1 in control and treated rats, respectively (P = 0.032). In conclusion dietary supplements with FaOH and FaDOH reduced the number of neoplastic lesions as well as the growth rate of the polyps suggesting a preventive effect of FaOH and FaDOH on the development of colorectal cancer.

Objective: The purpose of this systematic review was to investigate the incidence and nature of minor adverse events (MAEs) after colonoscopy, and response rates to questionnaires concerning MAEs in patients undergoing colonoscopy. Materials and methods: A systematic literature search was conducted in the databases PubMed and Embase. Predictor variables were patient-reported MAEs after colonoscopy. The outcome was frequency and types of MAEs and the patients' response rate to questionnaires after colonoscopy. Quality assessment for potential risk of bias and level of evidence was evaluated using the National Health and Medical Research Council guidelines. Results: Seven prospective cohorts were included with a pooled total of 6172 participants. Patients undergoing colonoscopy had a response rate to questionnaires ranging from 64% to 100%, with a mean of 81%. One-third of the patients experienced MAEs, most prominently in the first 1-2 weeks after colonoscopy, and less common at 30 days post colonoscopy. The most frequently reported MAEs were abdominal pain, bloating and abdominal discomfort. Conclusions: In general, patients undergoing colonoscopy have a high response rate to questionnaires about MAEs. MAEs after colonoscopy are commonly seen. High age and score of American Society of Anesthesiologists (ASA) classification, female gender and duration of procedure seem to be associated with a higher risk of MAEs, whereas adequate sedation seems to decreases the risk. MAEs after colonoscopy seems to be underreported in the current literature and the existing evidence is based on inhomogeneous reports. In the current study, it was not possible to conduct a meta-analysis. There is a need for larger scale studies addressing the MAEs patients experience in conjunction with a colonoscopy. Furthermore, the assessment of the MAEs should rely on questionnaires tested for validity, comprehensibility and reliability, to reflect the patient-reported experience of a colonoscopy as precise as possible.