The optimal cut?off values for tumor size, number of lesions, and CEA levels in patients with surgically treated colorectal cancer liver metastases: An international, multi?institutional study

Background and Objectives Despite the long-standing consensus on importance of tumor size, number carcinoembryonic antigen (CEA) levels as predictors long-term outcomes among patients with colorectal liver metastases (CRLM), optimal prognostic cut-offs for these variables have not been established. Methods Patients who underwent curative-intent resection CRLM had available data at least one three interest above were selected from a multi-institutional dataset known KRAS mutational status. The resulting cohort was randomly split into training testing datasets recursive partitioning analysis employed to determine cut-offs. concordance probability estimates (CPEs) cut offs calculated compared CPEs most widely used in surgical literature. Results A total 1643 met eligibility criteria identified. Following dataset, following identified: 2.95 cm 1.5 6.15 ng/ml CEA levels. In entire new size (0.52), (0.56) (0.53) exceeded other commonly Conclusion current study able identify factors CRLM. While per variable gains discriminatory power are modest, novel may help produce appreciable increases performance when combined context future risk scores.