Fig. 2: Kaplan–Meier plots of survival and metastatic recurrence outcomes.

a Overall Survival in unmatched high-risk patients (n = 1495). Adjusted HR 0.87 (95% CI 0.58–1.28, p = 0.47). b Overall survival in matched high-risk patients (n = 542). Adjusted HR 0.79 (95% CI: 0.50–1.26, p = 0.32). c Breast cancer-specific survival in unmatched high-risk patients (n = 1486). Adjusted HR 0.92 (95% CI: 0.56–1.53, p = 0.76). d Breast cancer-specific survival in matched high-risk patients (n = 539). Adjusted HR 0.93 (95% CI: 0.52–1.66, p = 0.80). e Metastatic recurrence in unmatched high-risk patients (n = 1498). Adjusted HR 0.36 (95% CI: 0.19–0.68, p = 0.002). f Metastatic recurrence in matched high-risk patients (n = 541). Adjusted HR 0.53 (95% CI: 0.26–1.07, p = 0.08).