Reporting of patient characteristics and stratification factors in phase 3 trials investigating first-line systemic treatment of metastatic colorectal cancer: A systematic review

•Prognostic factors are pivotal for the outcome of randomised trials.•Sixty-seven first-line phase 3 metastatic colorectal cancer trials published between 2005 and 2016 showed the following results.•Large heterogeneity in patient characteristics reporting and use of stratification.•No clear improvement in standardised reporting following a proposal made in 2007.•Consensus must be reached to improve quality and interpretation of trial results.