Compared to TNBC and HER2 + tumors, the prognosis of HR +/HER2 - cancers was marginally improved; hazard ratio for RFS and OS in HR +/HER2 – (0.49 (95% CI 0.33 – 0.71) and 0.43 (95% CI 0.23–0.71)) versus hazard ratio for RFS and OS in HR -/HER2 + (0.15 (95% CI 0.09 – 0.27) and 0.08 (95% CI 0.09 – 0.22)), hazard ratio for RFS in TNBC (0.24 (95% CI 0.18 – 0.33)). This evidence concerns the gene ERBB2 and cancer.