Performance of two prognostic scores that incorporate genetic information to predict long-term outcomes following resection of colorectal cancer liver metastases: An external validation of the MD Anderson and JHH-MSK scores

Introduction Two novel clinical risk scores (CRS) that incorporate KRAS mutation status (modified CRS (mCRS) and GAME score) were developed. However, they have not been tested in large national and international cohorts. The aim of this study was to validate the prognostic discrimination utility and determine the clinical usefulness of the two novel CRS. Methods Patients undergoing hepatectomy for CRLM (2000-2018) in ten centers were included. The discriminatory abilities of mCRS, GAME, and Fong CRS were evaluated using Harrel's C-index and Akaike's Information Criterion. Results In the entire cohort, the C-index of the GAME score (0.61) was significantly higher than those of Fong score (0.57) and mCRS (0.54), while the C-Index of mCRS was significantly lower than that of Fong score. When we compared the models in the various geographical regions, the C-index of GAME score was significantly higher than that of mCRS in North America, Europe, and South America. The AIC of Fong score, mCRS, and GAME score were 14405, 14447, and 14319, respectively. Conclusion In conclusion, using the largest and most heterogenous population of CRLM patients with known KRAS status, this independent, external validation demonstrated that the GAME score outperforms both the traditional Fong score and mCRS.