Comprehensive data of 3,820 patients newly diagnosed with colorectal liver metastasis between 2005 and 2007: report of a nationwide survey in Japan.

To collect big data for further research to improve treatment outcomes in patients with colorectal liver metastasis (CRLM), the Joint Committee for Nationwide Survey on CRLM was established by the Japanese Society for Cancer of the Colon and Rectum and the Japanese Society of Hepato-Biliary-Pancreatic Surgery. The joint committee initiated data collection since 2014. The data of 4,237 patients newly diagnosed with CRLM between 2005 and 2007 were registered from 134 departments of 127 institutions (64%) among 209 departments (from 201 institutions) that agreed to participate in this study. Finally, 3,820 patients were enrolled in this report after a quality management process by the joint committee. We report the comprehensive data obtained from 3,820 patients, clinicopathological findings, treatment strategies, prognoses, and implementation status of chemotherapy. The joint committee is prospectively collecting data of patients newly diagnosed with CRLM after 2013 and will provide these raw data, including data of patients diagnosed between 2005 and 2007, to researchers who will conduct meaningful studies that meet the aim of the joint committee.