However, the intercase comparison in the premenopausal subgroup showed an evidence of heterogeneity only for the HER-2/neu+ women who had ever had an abortion (ratio of the OR's = 3.12, 95%C.I:1.18–8.24), while use of oral contraceptives (OR = 0.16, 95%C.I: 0.04–0.60, p = 0.007) and a positive first degree family history (OR = 0.09, 95%C.I: 0.01–0.85, p = 0.035) showed a stronger association for HER-2/neu negative tumours. This evidence concerns the gene ERBB2 and neoplasm.