Patients with an age of menarche ≤ 12 years (OR = 1.72, 95%C.I: 1.07–2.75), first degree family history (OR = 2.23, 95%C.I:1.08–4.63), use of HRT (OR = 10.70, 95%C.I: 2.71–42.31) or OC (OR = 6.47, 95%C.I:1.89–22.16) were at increased risk of developing HER-2/neu-breast cancer only, although the significance of the latter two factors was of little value due to the limited sample size. Here, ERBB2 is linked to breast cancer.