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25 October 2015

The American Cancer Society has issued new guidelines for screening mammography, and they are sparking a lot of discussion. Previous guidelines, which have been in place since 2003, have recommended:

  • Annual mammography beginning at age 40 and continuing for as long as a woman is in good health
  • Clinical breast exam (CBE) [exam by a physician] about every 3 years for women in their 20’s and 30’s, and every year for women 40 and over
  • Women should know how their breasts normally look and feel and report any breast changes to a health care provider right away. Breast self-exam (BSE) is an option for women starting in their 20’s.

The current guidelines recommend:

  • Women should undergo regular screening mammography starting at age 45
  • Women 45 to 54 years of age should be screened annually
  • Women 55 years and older should transition to biennial screening or have the opportunity to continue screening annually
  • Women should have the opportunity to begin annual screening between the ages of 40 and 44 years
  • Women should continue screening mammography as long as their overall health is good and they have a life expectancy of 10 years or longer
  • Clinical breast exam is not recommended for breast cancer screening among average risk women of any age

The full study was published in the Journal of the American Medical Association. These guidelines seem to be a drastic change, but they are based on careful evaluation of the available literature. They are also more in line with the US Preventative Services Task Force recommendations for breast cancer screening (which are in the process of being updated). Mammograms certainly are of benefit in terms of early detection. However, as we have gained a better understanding of the importance of tumor biology, the mantra “early detection saves lives” does not hold true for all.

As stated on the American Cancer Society website, “The goal of screening mammograms is to find breast cancer early, when treatment is more likely to be successful. But mammograms aren’t perfect, and they do have risks. Sometimes mammograms find something suspicious that turns out to be harmless, but must be checked out through more tests that also carry risks including pain, anxiety, and other side effects.” I disagree with using anxiety as a reason to limit screening recommendations. While some women do experience significant anxiety related to mammography callbacks, proper pre-mammogram counseling should help alleviate some of the worry. As Dr. Elaine Schattner noted in her piece published in Forbes, “concern about fear or anxiety should not form the basis of any screening recommendations”.

These guidelines apply to “average risk” women. But given that ANY woman (and any man) may develop breast cancer, what does “average risk” mean? The first part of risk assessment should be a careful history, including a careful and detailed family history. While most realize that a having a family history of breast cancer increases their risk, fewer understand that family history of other cancers, including ovarian, colon and pancreatic cancers may be “hereditary red flags”, and genetic counseling and testing might be indicated. There are several risk assessment models which can and should be used by physicians on a routine basis. Newer forms of risk assessment which include evaluations of small variations in an individual’s DNA may provide a more personalized risk assessment. The contribution of breast density as well as lifestyle factors such as weight, level of activity, and alcohol intake need to be considered. The North Shore – LIH Health System and Bright Pink both have helpful risk assessment tools.

Mammography has never been a perfect screening test. It has significant limitations in young women and those with dense breast tissue, and in older women it may find more than it needs to. We have a “one size fits all” test, and women and their breasts are most certainly NOT “one size fits all”. The decision when to begin screening and how often to be screened is now a shared decision, between a patient and her physician. Decision support tools, such as Weill Cornell Medical College’s Breast Screening Decisions program, can help women sort through the conflicting information and make a decision that is right for them.

While guidelines can be helpful in making recommendations for populations, the ideal screening method for the individual remains to be seen. For screening mammography to truly be of benefit, we need to determine who is at risk and then decide what imaging modality is most appropriate for that individual woman. We also need to know which lesions, once detected, can safely be ignored. We know where we need to be. Now the science and technology needs to catch up.

Additional information:
New Guidelines for Breast Cancer Screening in US Women – JAMA Editorial
Science Won’t Settle the Mammogram Debate
Stat News: New Guidelines Urge Later, Less Frequent Mammograms
Mammography Guidelines Revisited – Lori Marx Rubiner