ERBB2 and breast cancer: A comprehensive meta-analysis of 35,945 patients across 30 studies observed a trend for decreased OS in patients with HR-positive/HER2-negative BC and BRCAm versus those without BRCAm, with shorter OS observed in patients with BRCA1m (P = 0.0008) and BRCA2m (non-significant) compared with those without BRCAm [20].