In the present study, we found that among HR-negative BC patients, the DFS and OS rates were not statistically significant, although HER2-low patients had slightly better DFS and OS rates than those of HER2-zero patients, which was consistent with the results of most of the studies mentioned above; moreover, we did not find any differences in DFS and OS among the HER2-zero, HER2-1+ and HER2-2+/Fish (−) groups. Here, ERBB2 is linked to breast cancer.