• Most common cancer in women (~225,000 cases/yr. with ~40,000 deaths/yr.)
• Second most common cause of cancer death in women (lung #1)
• Three major subtypes
  • ER+/Her-2 negative (50-65%)
  • Her-2 + (10-20%)
  • Triple negative – ER/PR/Her-2 negative (10-20%)
• Breast cancers in African American women are more aggressive biologically, and are more likely to be ER-negative and high nuclear grade

Risk Factors

• 99% of cases are in females
• 5-10% of patients have a germline mutation
• Risk increases with increased lifelong exposure to estrogen (early age of menarche and later age of birth of first child)
  • 20% increased risk with menarche before age 11
  • 50% risk reduction for women with full-term pregnancy before 20 compared first ful-term pregnancy after age 35.
• High breast density (4-6 fold increased risk)
• Radiation exposure (e.g. Treatment for Hodgkin lymphoma)

References

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