BRCA2

• See also BRCA

• Autosomal Dominant

  • Mutation in the Breast Cancer Type 2 gene on 13q12/13
  • Penetrance 80%

• Cancer susceptibility gene

  • Tumour suppressor, mutations inactivate this function

• Accounts for 70% of remaining (non-BRCA1) hereditary breast cancer

• Risk

  • Cumulative risk of breast cancer
    • 45-70% at 70
    • 60% risk of Contralateral Ca (higher than non-BRCA Ca)
  • Cumulative risk of ovarian cancer
    • 10-20% at 70
  • Cumulative risk of other cancers
    • Pancreatic Ca 2-5% by age 70
    • Prostate Ca 30-40% by age 70
    • Male Breast Ca - 80% of inherited (as opposed to BRCA 1)
      • Lifetime Risk: 7%
    • Laryngeal
    • Bladder

• Cancer histological subtypes not as poor as BRCA 1

  • More likely to be ER/PR+