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This article waslast modified on July 10, 2017.

The American Cancer Society (ACS) recently released new guidelines for breast cancer screening that recommend that women with average risk of breast cancer consider waiting until age 45 to have their first mammogram and annually thereafter, switching to having the test every other year beginning at age 55. Previously, the ACS recommended annual mammograms beginning at age 40.

The new recommendations, published October 20, 2015 in the Journal of the American Medical Association, were based on an external review, requested by the ACS, of new data on mammograms. According to the Society's Chief Cancer Control Officer, Dr. Richard C. Wender, MD, "The committee…considered all of this evidence over a period of months, did the very difficult job of balancing the benefits and harms, and that's what led to the change in the guidelines that we're publishing now."

The new guidelines also no longer recommend clinical breast examinations (CBE) performed by healthcare providers. Recommendations for self-examination were not addressed in either earlier or revised guidelines and remain unaddressed at this time. The ACS continues to urge, however, that women be familiar with the appearance and feel of their breasts and to tell their provider right away about any changes they notice.

Women with a higher-than-average risk of breast cancer because of factors such as family or personal history of breast cancer, BRCA mutation or history of radiotherapy to the chest area at an early age should consult with their healthcare provider about when to start screening, as well as how and how often it should be done, according to the ACS. Women with a high risk (about 20-25% or greater risk) should have a yearly mammogram and MRI.

The reason, in part, behind the significant changes for average-risk women, says the ACS, is to minimize harm. Both manual breast exams and mammograms can lead to follow-up testing such as biopsies that bring anxiety or risk, but no detection of cancer. The exams also can detect small tumors that may not progress to life-threatening illness but whose treatment brings its own risks, including rare, but real risk of death from surgery or chemotherapy.

The ACS chose 45 as the starting age for mammograms because that is when the benefits "substantially outweigh the harms," in terms of cancer incidence, says Dr. Wender. Breast cancer is not common enough in women under 45 to make mammograms worthwhile for that age group.

By age 55 most women have gone through menopause and breast tumors are less likely to be aggressive. "Once a woman turns 55 screening every other year preserves most of the benefit of screening every year – with fewer risks." says Elizabeth T.H. Fontham, MPH, DrPH, dean of the School of Public Health at Louisiana State University and a member of the ACS' Guideline Development Group. Though the new guidelines generally recommend less screening for average-risk woman, the ACS has left some room for personal choice. Women may choose to start screening with mammograms at age 40, and some may decide to continue having yearly mammograms instead of switching to every other year at age 55. Women should make informed decisions by talking to their healthcare providers to consider the harm as well as the benefit of earlier and more frequent mammograms before making a decision about what is right for them.

And though the new guidelines are based on the latest evidence, don't expect them to be the last word on screening for breast cancer. An article in the New York Times on the new recommendations says the action by the American Cancer Society "seems unlikely to settle the issue" since a variety of other organizations have mammography recommendations, including some that are earlier and more frequent than the ones just released. (For details, read the Breast Cancer screening articles for Young Adults, Adults and Adults 50 and Up.)

A conference will convene in January, according to the New York Times, that will bring together several groups with current mammogram recommendations, including the ACS, the American College of Obstetricians and Gynecologists (ACOG), and the United States Preventive Services Task Force (USPSTF), an advisory group appointed by the U.S. Department of Health and Human Services, to discuss issuing consistent guidelines.

Even if several groups offer consensus guidelines on mammograms, it's likely those might only last a few years, according to the report by the New York Times. New breast imaging devices, genetic tests for breast cancer, and breast cancer treatment are all in development that could change the calculation in the next few years for who should be screened when and how often.


Simon, Stacy. American Cancer Society Releases New Breast Cancer Guidelines. October 20, 2015. Available online at Accessed October 27, 2015.

American Cancer Society. Breast Cancer Prevention and Detection. Available online at Accessed October 27, 2015.

Breast Cancer Screening for Women at Average Risk. Journal of the American Medical Association. October 20, 2015, vol. 314, No. 15. Available online at Accessed on October 27, 2015.

Grady, Denise. American Cancer Society, in a Shift, Recommends Fewer Mammograms. The New York Times. October 20, 2015. Available online at Accessed October 27, 2015.