ERBB2 and neoplasm: Concerning the tumor biology, patients with LM had significantly more often HR+/HER2-disease (45.2 vs. 31.8 %, P < 0.001), significantly more often an invasive-lobular tumor biology (13.4 % vs. 6.3 %, P < 0.001), significantly less common HER2+ tumors (34.2 % vs. 46.3 %, P < 0.001) and significantly less common G3 tumor differentiation grade (51.4 vs. 58.1 %, P < 0.001).