LAUSR

Inconsistent, varied and selective outcome reporting is problematic in clinical trials. Core outcome sets (COS) standardise the outcomes that should be measured and reported in all trials in a specific area of health or health care. We reviewed available cancer COS and assessed their uptake in cancer clinical trials through surveying members of the European Organisation for Research and Treatment of Cancer (EORTC). This study employs an exploratory cross-sectional design across two phases. The Core Outcome Measures in Effectiveness Trials (COMET) Initiative database was searched for cancer-specific COS on June 1st, 2023. Awareness and use of COS amongst EORTC trialists was assessed in November 2023 via an online survey. We identified a total of 85 cancer-related COS on the COMET database. Of these, 69 related to the tumour types as categorised by the EORTC and their disease orientated groups. A total of 710 EORTC members responded, of whom half (50%) stated they were unfamiliar with COS. Relevant COS were available to over a quarter of respondents, with a tenth utilising available COS. Those who chose not to use an available COS cited volume of outcomes, lack of time and infrastructure for implementation as key barriers. While COS are becoming increasingly available to, and acknowledged by, cancer clinical trialists, their implementation is currently still limited. Our findings indicate that further development of COS to fill gaps for missing tumour types, greater involvement of trialists in the COS development process, and increased awareness and understanding of COS amongst trialists are all required to ensure widespread implementation of COS in cancer clinical trials.