Core outcome set in surgical oncology: why, what and how to measure

Safety and effectiveness of healthcare innovations must be assessed before entering routine clinical practice. Selection of outcome measures is therefore essential to inform clinical practice and the health-related decision-making process. However, recent studies have demonstrated a largely inconsistent approach to the selection, definition, measurement and reporting of outcomes in oncology, thus making it difficult to synthesize the results of different research studies. The inconsistencies due to incomparable data available on the effects of interventions could be addressed with the development of agreed standardized sets of outcomes, known as core outcome sets (COS). The COMET (Core Outcome Measures in Effectiveness Trials) database, a publicly available internet-based platform that includes published accounts of COS development, reveals that oncology is the most prevalent disease category (16%) among included studies, and surgery is the focus of 8% of all entries. We identified eight studies defining relevant outcome sets in surgical oncology, as mortality/survival measures, adverse events and complications, symptoms, delivery of care and resource use, quality of life. Patient-reported outcomes (PROs) have been traditionally neglected by the clinical and performance data records. In an era of personalized medicine and patient-centered policy making, it is instead of paramount importance to include PROs in COS