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BRCA1/BRCA2 gene mutation positive

Clinical significance: - BRCA1/BRCA2 gene mutation-related cancers include: - breast cancer - ovarian cancer - peritoneal cancer - fallopian tube cancer Laboratory: - BRCA1/BRCA2 genotyping Radiology: - women with BRCA gene mutation should begin breast cancer screening at age 25 with MRI & mammography beginning at age 30 years. Complications: - risk of ovarian cancer 4% between age 35-40 years in women with deleterious BRCA1 mutation [1] - risk of ovarian cancer 1% between age 35-50 years in women with deleterious BRCA2 mutation [1] Management: - prophylactic bilateral mastectomy (by age 35 ?)* reduces risk of breast cancer 90% in women with BRCA gene mutation - prophylactic bilateral salpingo-oophrectomy (BSO) by age 35 reduces risk of ovarian cancer 80% in women with BRCA1 gene mutation - does not reduce risk of breast cancer [3] - prophylactic BSO by age 45 for BRCA2 mutation [1] * age = 35 suggested by analogy to prevention of ovarian cancer

Related

BRCA1/BRCA2 genotyping breast cancer type 1 susceptibility protein (BRCA1) breast cancer type 2 susceptibility protein (Fanconi anemia group D1 protein, BRCA2, FACD, FANCD1)

Specific

BRCA1 gene mutation positive BRCA2 gene mutation positive

General

BRCA gene mutation (BRACAnalysis CDx) abnormal laboratory test susceptibility to breast cancer

References

  1. Medical Knowledge Self Assessment Program (MKSAP) 16, 17, 18. American College of Physicians, Philadelphia 2012, 2015, 2018
  2. Chen S, Parmigiani G. Meta-analysis of BRCA1 and BRCA2 penetrance. J Clin Oncol. 2007 Apr 10;25(11):1329-33. PMID: 17416853
  3. Terry MB, Daly MB, Phillips KD et al. Risk-reducing oophorectomy and breast cancer risk across the spectrum of familial risk. J Natl Cancer Inst 2018 Nov 28 Not indexed in PubMed https://academic.oup.com/jnci/advance-article/doi/10.1093/jnci/djy182/5212812