Organ Systems, Breast

Breast Carcinoma – Genetic Characteristics

Approximately 12% of breast cancers are due to inheritable mutations (most common BRCA1, BRCA2, TP53, and CHEK2)

  • BRCA1
    • Chromosome 17q21
    • Strong associated risk for ovarian cancer (20-40% of carriers)
    • Also associated with other epithelial malignancies (pancreatic, prostate, etc.)
    • Breast cancers are 
      • commonly poorly differentiated (“medullary features”)
      • ER/PR/Her-2 negative (triple negative) with basal-like genotype
  • BRCA2
    • Chromosome 13q12.3
    • Associated with male breast cancer
    • Breast cancers are
      • Poorly differentiated
      • More likely to be ER+ compared to BRCA1 tumors
References

Kumar, Vinay, Abul K. Abbas, and Jon C. Aster. Robbins and Cotran Pathologic Basis of Disease. Ninth edition. Philadelphia, PA: Elsevier/Saunders, 2015.