However, in multivariate analysis, including all significant variables from univariate analysis, the only independent predictors of BRCA2 mutation were the age at onset under 50 years (OR = 3.7, 95% CI = 1.5 to 8.7), PR negativity (OR = 2.9, 95% CI = 1.2 to 6.9) and HER2 negativity (OR = 3705.2, 95% CI = 0 to 2.5 × 1022), as compared with sporadic tumours. This evidence concerns the gene ERBB2 and neoplasm.