Based on BC treatment modality, the Chemotherapy + Hormonal therapy + Immunotherapy groups achieved the highest OS across three BC subgroups at 55.13 (35.58–), 42.35 (36.04–55.36), and 31.34 (7.82–), for the HR( +)/HER2( − ), HR( +)/HER2( +), and HR( − )/HER2( +) subgroups, respectively. Here, ERBB2 is linked to breast cancer.