Clinical-pathological study of HER2-low expressing breast cancer in our department (JBCS 2024)
Of the 327 cases, 51 (16%) were HER2 negative, 200 (61%) were HER2 low expression, 58 (18%) were HER2 positive, and 18 (5%) were HER2 low expression or positive. By hormone receptor status, of the 243 HR positive cases, 29 (12%) were HER negative, 171 (70%) were HER2 low expression, 27 (11%) were HER2 positive, and 16 (7%) were HER2 low expression or positive. Of the 84 HR-negative cases, 22 (26%) were HER2-negative, 29 (35%) were HER2-low expressing, 31 (37%) were HER2-positive, and 2 (2%) were either HER2-low expressing or positive.