ERBB2 and breast cancer: In all breast cancer patients, there was no distinct difference in the 5-year OS and DFS rates among the HER-2-negative, low expression, and positive subgroups (69.7% vs. 68.0% vs. 76.0%, X2 = 1.1, P = 0.58; 57.6% vs. 52.0% vs. 49.3%, X2 = 1.7, P = 0.42; Figures 5(a) and 5(b)).