ERBB2 and breast cancer: The analysis also revealed OS benefits in both luminal and non-luminal breast cancers, including luminal A (aHR = 0.62, p = 0.002), luminal B/HER2-negative (aHR = 0.30, p < 0.0001), Basal-like (aHR = 0.40, p < 0.0001), and HER2-enriched (aHR = 0.50, p = 0.03), except for luminal B/HER2-positive breast cancers.