Kaplan-Meier analyses of relapse-free survivals of the three CMTC groups in internal and external breast cancer cohorts. (A) The 147 patients in the original training cohort with a median follow-up of 30.13 months in 2010. (B) The 147 patients in the same training cohort with an updated follow-up of 54.97 months in this study. (C) The 284 patients in the new independent internal cohort with a median follow-up of 32.13 months. (D) The combined 431 patients in both internal cohorts. (E) The 2,181 patients in the new external validation cohort with a median follow-up of 7.45 years. (F) The combined 4,420 patients in the two external cohorts from the original study and this study. The P values were determined using the log-rank test based on overall comparisons.