ERBB2 and breast cancer: In total, there were 30772 cases (87.53%) of HER-2(-) breast cancer: 269 ER(-)/PR(+) cases (0.87%), 3045 ER(+)/PR(-) cases (9.9%), 23367 ER(+)/PR(+) cases (75.94%), and 4091 ER(-)/PR(-) cases (13.29%).