Hereditary Breast Cancer

Breast cancer is the second most commonly diagnosed cancer in women (only skin cancer is more common), but the death rates for breast cancer have steadily decreased in women in recent years. This decrease is attributable, in part, to improvements in both early detection and treatment.

The genetic risk assessment service at UT Southwestern Simmons Comprehensive Cancer Center offers testing and genetic counseling for breast cancer and all other identified cancers. Based on your personal and family history of cancer, our genetic counselors can identify your level of risk, determine if genetic testing is appropriate, and provide guidance for an early detection and prevention strategy.

Breast Cancer Facts

One in 8 women (12 percent) will develop breast cancer in her lifetime. Of all breast cancer cases, only about 5 to 10 percent are hereditary, linked to gene mutations inherited from one’s mother or father.

Multiple genes are associated with hereditary breast cancer, but mutations in BRCA1 and BRCA2 genes are the most common cause of the hereditary form of the disease. Prediction models can estimate an individual’s risk for BRCA1 or BRCA2 mutations. Additional information on breast cancer predisposition genes can be found on the Hereditary Breast Cancer Gene List.

Approximately 15 to 20 percent of breast cancer is familial, meaning the disease occurs more often in family members than can be expected in the general population even though a particular gene mutation has not been identified in the family. With familial breast cancer, the specific cause of breast cancer is unknown but is likely due to combinations of risk factors, including genetics, lifestyle, and environment that increase risk in the family.

Screening recommendations vary for women with an increased lifetime risk for breast cancer based on a hereditary cancer syndrome or family history.

The remainder of breast cancer diagnoses (around 70 percent) is considered random or sporadic and non-hereditary, without a known etiology. Risk factors for sporadic breast cancer include:

  • Age
  • Early-onset menses/late menopause
  • Hormone exposure
  • Late or no pregnancies
  • Diets high in fat/no physical activity
  • Having “dense” breasts
  • Benign breast disease (ADH/ALH)
  • Alcohol
  • BMI/body type