Study risk assessment of Japan Clinical Oncology Group (JCOG) clinical trials using the European Organisation for Research and Treatment of Cancer (EORTC) study risk calculator

New Japanese ethical guidelines for medical researches and the Clinical Trials Act have come into effect and monitoring is mandated for intervention studies. Methods of monitoring can be modified according to a study risk, but there is no established method in Japan regarding how to assess a study risk. EORTC assesses a study risk using their own study risk calculator and classifies their trials into three categories. For each category, different levels of monitoring are applied. This project is aimed to assess the study risks of JCOG trials using the EORTC calculator. We selected clinical trials open to patient recruitment in JCOG as of Nov 2014. Each trial was scored based on the EORTC study risk calculator and classified into three risk categories; low, medium and high. A total of 40 studies were included in the assessment. Twenty-seven studies (67.5%) were classified into low risk group, 12 (30%) in medium risk group, and only 1 (2.5%) in high risk group. Clinical trials evaluating multimodality therapy and/or using unapproved drugs tended to be scored higher and most of them were classified into medium or high risk group. JCOG conducts central monitoring and site visit audit with sampling source data verification for every trial, which are almost compatible with the way in EORTC for the medium risk group. Because most of the JCOG studies were classified into low or medium risk group, the intensity of monitoring and audit in JCOG was considered as reasonable even from the EORTC perspective.