ERBB2 and neoplasm: In the univariate analysis (n = 569), low HER2 expression was significantly correlated with sex (odds ratio 0.409, 95 % CI 0.178–0.940, P = 0.035), histological type (odds ratio 0.257, 95 % CI 0.131–0.507, P < 0.001), hepatic metastasis (odds ratio 4.598, 95 % CI 2.013–10.505, P < 0.001), depth of tumor invasion (odds ratio 0.405, 95 % CI 0.215–0.763, P = 0.005), and formalin concentration (odds ratio 1.949, 95 % CI 1.035–3.669, P = 0.039).