Fig. 4
Receiver operating characteristic (ROC) curves and area under curve (AUC) values. a–c Time-dependent ROC curve in the training cohort, internal cohort, and independent cohort to assess prognostic accuracy; AUC at 1- and 2-year were calculated in the three cohorts according to the 4-miRNA signature, the spanning parameter of the NNE approach was span = 0.25×nobs−0.20. d–f Comparisons of the prognostic accuracy for trastuzumab response by the 4-miRNA signature (high score vs low score), metastatic sites (1, 2, ≥3), age (≤50 vs >50), Ki67 (>15% vs ≤15%), ER status (positive vs negative), PR status (positive vs negative), menopause (yes vs no), and 4-miRNA signature combining metastatic site. P-values showed the AUC of 4-miRNA signature vs the AUC of metastatic sites, age, Ki67, ER status, PR status, or menopause. AUC was calculated, and its 95% CI was estimated using Bootstrap method. The P-values were two-sided and based on Bootstrap test. ER estrogen receptor, PR progesterone receptor, HR hazard ratio, 95% CI 95% confidence interval
