ERBB2 and neoplasm: The HER2-positive BRCAmut subgroup showed overall worse survival compared with HER2-negative and BRCAwt tumours (Hazards Ratio = 3.4, 95% 1.3–16.7) but appeared not to show a significant difference to the HER2-positive BRCAwt or HER2-negative BRCAmut subgroups.