Fig. 4.

SurvExpress, a publicly available tool for computation and analysis, was utilized to perform external validation of the three-gene model for predicting PFS (a) and the five-gene model for predicting OS (b) derived from LASSO without regard to ER or PR status. Expression levels of the LASSO model-identified sets of genes were extracted from the Breast Cancer Metabase (10 cohorts: 22,000 genes) and used to validate clinical outcomes represented by the Kaplan-Meier plots (n = 1888 patients for PFS and n = 198 patients for OS). SurvExpress determined risk groups, indicated by red or green in the plots, by median split of ordered linear predictors. The abscissa indicates time to event in months, and the ordinate is survival probability (Color figure online)