Table 4

 Probability of breast cancer cases related to BRCA1 germline mutations for different groups of patients with breast cancer, on the basis of a combination of age at diagnosis, percentage of Ki67-positive cells in the primary tumour and EGFR status of the primary tumour

ClassificationDecision treeNumber of sporadic casesNumber of cases with BRCA1 mutationsProbability of BRCA1-related disease (%)Number of intermediate-risk casesNumber of high-risk casesNumber of cases with BRCA2 mutations
EGFR, epidermal growth factor receptor; Neg, negative; Pos, positive.
SporadicAge ⩾54 years and EGFR = Neg332002430
IntermediateAge ⩾54 years and EGFR = Pos6223223
IntermediateAge <54 years and Ki67<25%21292622
BRCA1 relatedAge <54 years and Ki67⩾25%618757120