In the present study, the authors investigated the clinical, histopathological, and immunohistochemical features in familial breast cancer (FBC) patients and compared them with findings in sporadic breast cancers (SBCs); hormone receptor status was stratified by age. A total of 849 patients treated for breast cancer were included in the study. The patients were stratified into 2 groups: FBC, 160 patients (19%), and SBC, 689 patients (81%). FBC tumors differed from SBC tumors by earlier age of diagnosis and low content of progesterone receptor (PR). These characteristics should be of value in evaluating the possibility of mutation and in targeting mutation screening in such families. PR gene polymorphism leads to an increased risk of breast cancer because it determines inadequate control of estrogen receptor (ER)-driven proliferative function. ER+/PR- tumors more frequently showed HER2 (human epidermal growth factor receptor) overexpression and represent a distinct subset in FBC patients. The authors suggest that late-onset FBCs need more intensive therapy and a more careful follow-up.