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Breast Cancer Gene Marker
Aka: Breast Cancer Gene Marker, BRCA, Breast Cancer Gene Marker Testing Indications
- Labs: Gene Markers
- Most common types (>20 mutations have been identified)
- BRCA (BRCA1, BRCA2): 60% of Breast Cancer gene mutations
- AT (Ataxia Telangiectasia) on Chromosome 11
- Single mutant copy
- Confers 5 fold risk of Breast Cancer
- PTEN gene (Cowden syndrome)
- CDH1 gene (hereditary diffuse Gastric Cancer)
- TP53 gene (Li-Fraumeni syndrome)
- STK11 gene (Peutz-Jeghers Syndrome)
- BRCA1
- BRCA2
- Indications: BRCA testing
- Person with Family History of Breast Cancer or Ovarian Cancer and known BRCA mutation
- Ashkenazi jewish women
- 1st degree relative with Breast or Ovarian Cancer or
- Two 2nd deg. relatives with Breast or Ovarian Cancer
- Non-Ashkenazi women
- First degree relatives
- Two with Breast Cancer (at least 1 under age 50)
- One with bilateral Breast Cancer
- First or second degree relatives
- Three with Breast Cancer
- Comorbid Breast and Ovarian Cancer at any age
- Two or more with Ovarian Cancer
- Extended family
- Breast Cancer in any male relative
- Reference
- (2005) U.S. Preventive Task Force
- Management: Known BRCA1 or BRCA2 carrier
- Risks of BRCA1 or BRCA2
- Breast Cancer risk: 85-90% lifetime risk
- Ovarian Cancer risk
- BRCA1: 40-60%
- BRCA2: 15-20%
- Management Options
- Surveillance starting at age 25 years
- Self Breast Exam Monthly
- Clinical Breast Exam every 6 months
- Mammogram yearly
- Breast MRI yearly (start at age 30 years)
- Ovarian Cancer screening
- No clear evidence-based guidelines
- NCCN guidelines (esp. BRCA1)
- Test every 6 months from age 35
- Tests
- Pelvic Ultrasound
- CA-125
- Prophylactic Mastectomy
- Breast Cancer can still occur
- References
- Garber in Harris (1996) Diseases Breast p. 335-41