Key Points

  • A mammogram is an x-ray picture of the breast. Screening mammograms are used to check for breast cancer in women who have no signs or symptoms of the disease. Diagnostic mammograms are used to check for breast cancer after a lump or other sign or symptom of the disease has been found.
  • Results from randomized clinical trials and other studies show that screening mammography can help reduce the number of deaths from breast cancer among women ages 40 to 74
  • Screening mammography is also associated with potential harms, including false-negative results, false-positive results, the diagnosis and treatment of cancers and ductal carcinoma in situ lesions that would not have caused symptoms or threatened a woman’s life (i.e., overdiagnosis and overtreatment), and radiation exposure.
  • The National Cancer Institute recommends that women age 40 or older should have screening mammograms every 1 to 2 years.

Women can get high-quality mammograms in breast clinics, hospital radiology departments, mobile vans, private radiology offices, and doctors’ offices.

Source: National Cancer Institute