02. Breast Cancer Screening

Bottom Line

  • Shared decision-making should be used in discussing screening.
  • Screening strategies differ based on the estimated risk of breast cancer (starting at age of 40 vs age 50)

Background:

  • Breast cancer is the most frequent type of non-skin cancer and second most frequent cause of cancer death in US women.
  • Majority of breast cancers in the US are diagnosed as a result of an abnormal screening study.
  • Majority of women are at average risk (less than 15 percent lifetime risk) of developing breast cancer.

Guidelines: All North American expert groups recommend mammography for women age 50 and older. There is controversy about screening women in their 40s.

Starting age

USPSTF, AAFP

ACS, AMA, NCI, ACOG, NCCN

Starting age

50

40

Interval

Every 2 years

Yearly

Stopping age

75

Until life expectancy is less than 5-7 years

Risk Factors

  • Major risk factors: age, breast density, genetic predisposition (BRCA1/2 ) obesity, family history and estrogen exposure, history of previous radiotherapy to the chest between ages 10 and 30 
  • If a woman has a family hx of breast, ovarian, adnexal or peritoneal cancer, further family hx should be obtained and genetic testing should be considered.
  • Risk prediction tools include the Breast Cancer Risk Assessment Tool (BCRAT)/Gail Model (www.cancer.gov/bcrisktool) or the Breast Cancer Surveillance Consortium (BCSC) model (http://tools.bcsc-scc.org/BC5yearRisk/intro.htm) can be used to consider earlier or more frequent screening.

Other screening modalities

  • Breast self-exam
    • USPSTF recommends against teaching, as there is no mortality benefit and increases harm.
    • ACS recommends women be educated about the benefits and limitations.
    • ACOG recommends breast self-awareness, which can include breast self-examination.
  • MRI
    • More sensitive for cancers in young women, pre-menopausal women, or women with high breast density.
    • USPSTF states evidence is insufficient.
    • ACS recommends annual MRI (in addition to mammography) for women who:
      • Have known BRCA mutations
      • Have first-degree relatives with BRCA mutations
      • Lifetime risk of >20-25%
      • p53 (Li-Fraumen) or PTEN (Cowden syndrome) mutation carriers, or untested 1st degree relatives of a carrier
      • Women with hx of chest irradiation at age 10-30