Journal of the National Cancer Institute — A series of three commentaries in the October 15 issue of the Journal of the National Cancer Institute address the issue of whether premenopausal women are being accurately informed about the potential harms versus benefits of mammography before undergoing screening.

What Is The Doctor’s Reaction?

The reasons your doctor recommends a mammogram may seem clear: The test can detect cancers that are too small to feel during a breast examination, and early detection should increase the chances of cure. While this may sound reasonable, the benefits of mammography for women ages 40 to 49 have been difficult to prove. What is new here is not just the question of when to start screening women with mammography or whether the test leads to a large number of biopsies for women without cancer. This article raises the disturbing possibility that mammography for women younger than age 50 may actually be associated with a higher death rate for up to 11 years after screening, with benefits observed only after this period of time.

While the experts may debate the importance of this observation, women in this age group must decide whether or not to have a mammogram. This article discusses the fact that many premenopausal women are not informed of the potential risks of mammography. But if the risks and benefits are uncertain even to the experts, it is hard for anyone to know how best to present the information in the process of informed consent.

Keep in mind that this article focuses only on women ages 40 to 49. For older women, there is clearer evidence (and more agreement among experts) that mammography is beneficial. If you are at least 50-years-old and having yearly mammograms, this article does not present new information that should affect your decision to have mammograms.

What Changes Can I Make Now?

Talk with your doctor about whether or not you should have a mammogram. Because each person’s risk factors and preferences are a bit different, you may decide on a different course than other members of your family or your friends. If there is a strong family history of premenopausal breast cancer or if you have had breast tumors in the past, screening may be recommended at an earlier age and the benefits of screening are likely greater than in lower-risk women.

Follow the current guidelines for breast cancer screening, including mammography, self-breast examination and regular examinations by your health-care provider. Although controversies persist, it is probably best to follow the guidelines developed by experts until more definitive research suggests otherwise.

  • Make changes in your daily life that may reduce your risk of breast cancer in the future.
  • Do not start smoking; if you already smoke, do all you can to quit.
  • Exercise regularly and maintain an ideal body weight.
  • Moderate your alcohol intake — limiting your intake to no more than one alcoholic beverage a day may reduce breast cancer risk.
  • Consider genetic testing if you have a strong family history of breast cancer (although it is not at all clear which women should be screened and what to do if genetic mutations are found).

What Can I Expect Looking To The Future?

Look for ongoing research to provide more definitive answers about the benefits and risks of mammography in women at different ages. Important questions should be addressed by experts studying breast cancer screening, including:

  • Is mammography in younger women truly associated with a higher death rate, and if so, is this actually due to mammography or some other factor?
  • If mammography is associated with a higher death rate in younger women for a period of time after screening, do the benefits that follow outweigh the risk?
  • If the increased death rate among premenopausal women having mammography is confirmed, what is the mechanism? In this article, the authors speculate about the type of radiation used in mammography as a cause of breast cancer or that surgery (recommended as a result of mammography) might cause tumor cells to become more aggressive or spread.

Finding answers to these questions could lead to safer and more rational breast cancer screening programs for all women.

Robert H. Shmerling, M.D.
Harvard Medical School