Assessment of transparency and selective reporting of interventional trials studying colorectal cancer.

<bold>Background: </bold>Colorectal cancer (CRC) is currently one of the most frequently diagnosed cancers. Our aim was to evaluate transparency and selective reporting in interventional trials studying CRC.<bold>Methods: </bold>First, we assessed indicators of transparency with completeness of reporting, according to the CONSORT statement, and data sharing. We evaluated a selection of reporting items for a sample of randomized controlled trials (RCTs) studying CRC with published full-text articles between 2021-03-22 and 2018-03-22. Selected items were issued from the previously published CONSORT based peer-review tool (COBPeer tool). Then, we evaluated selective reporting through retrospective registration and primary outcome(s) switching between registration and publication. Finally, we determined if primary outcome(s) switching favored significant outcomes.<bold>Results: </bold>We evaluated 101 RCTs with published full-text articles between 2021-03-22 and 2018-03-22. Five trials (5%) reported all selected CONSORT items completely. Seventy-four (73%), 53 (52%) and 13 (13%) trials reported the primary outcome(s), the allocation concealment process and harms completely. Twenty-five (25%) trials were willing to share data. In our sample, 49 (49%) trials were retrospectively registered and 23 (23%) trials had primary outcome(s) switching. The influence of primary outcome(s) switching could be evaluated in 16 (16/23 = 70%) trials, with 6 (6/16 = 38%) trials showing a discrepancy that favored statistically significant results.<bold>Conclusions: </bold>Our results highlight a lack of transparency as well as frequent selective reporting in interventional trials studying CRC. [ABSTRACT FROM AUTHOR]