Mammography is a type of x-ray specifically designed to view the breast. The x-ray films produced by mammography, called mammograms, can find small tumors or irregularities in the breast. There are two main types of mammography: screening and diagnostic. A screening mammogram is a general screening test for women with no symptoms. A diagnostic mammogram is performed if the screening mammogram identifies a suspicious area or if a person feels a lump in their breast or has other unusual symptoms.

Perspective

In response to the United States Preventive Services Task Force (USPSTF) recommendations for screening mammography, the American Society of Clinical Oncology (ASCO) emphasizes the following:

There has been a longstanding debate over the most appropriate age and frequency of mammography screening for breast cancer. There is no debate, however, over the fact that mammography reduces the risk of dying from breast cancer. As stated in the USPSTF recommendations, extensive scientific evidence shows that mammography reduces breast cancer mortality both among women aged 50 and older, as well as among women aged 40 to 49.

While mammography is not a perfect screening tool, it is the best method currently available for detecting breast cancer in the general population.

Today's recommendations from the USPSTF recognize the value of mammography in reducing breast cancer deaths, affirm the importance of mammography among women aged 50 and older, and emphasize that mammography should be seriously considered in women 40 to 49 after assessment of the risks and benefits. It is therefore of concern that at present more than a third of women who are now recommended for screening are not getting regular mammograms. While the optimal scheduling of regular mammograms is being discussed by experts in the field, ASCO would not want to see any impediments to mammography screening for any woman age 40 and above.

From ASCO's perspective, the critical message is that all women – beginning at age 40 -- should speak with their doctors about mammography to understand the benefits and potential risks, and determine what is best for them.

Questions to Ask the Doctor

Before having a mammogram, you should discuss with your doctor any breast symptoms or specific problems you're experiencing. Your doctor is the best person to help you decide at what age and how often to have a mammogram. Consider asking your doctor these questions:

• Based on my health and family history, should I receive a mammogram? If so, how often should I have one?
  
  
• What are the benefits of mammography?
  
  
• What are the risks associated with mammography?
  
  
• Where can I get a mammogram?
  
  
• When and how will I learn the results?
  
  
• Who will explain the results to me?
  
  
• What further tests will be necessary if the test results are unclear or indicate cancer?
  
  
• How can I lower my risk of breast cancer?

What This Means for Patients

Mammography is the best tool doctors have to screen for breast cancer and can detect a tumor that is too small to be felt. However, mammography is not perfect. Occasionally, mammograms may miss a cancer. Or, sometimes, a mammogram suggests that a woman has cancer when she really does not. Despite these imperfections, the best scientific evidence shows that regular mammography helps lower the risk of a woman dying from breast cancer. Women aged 40 and above should talk with their doctors about mammography and decide on a screening schedule that’s appropriate for them. Women at high risk for breast cancer should talk with their doctors even sooner.

For More Information

Guide to Breast Cancer

Cancer Screening

Mammography—What to Expect

Additional Resources

U.S. Preventive Health Services Task Force

Last Updated: November 16, 2009