Women at Average Risk for Breast Cancer Should Start Screening Mammograms at Age 40

Digital mammogram units as shown here with MSK Breast Imaging Chief Elizabeth Morris and a patient generate more vivid and precise images than older film screening technology is able to capture.

MSK Breast Imaging Chief Elizabeth Morris helps a patient through her first digital mammogram. Most mammograms today are done with units such as this one, which generate much more vivid and precise pictures than older film screening technology can.

“Women’s confusion over when to start breast cancer screening just continues to grow,” says Memorial Sloan Kettering Breast Imaging Chief Elizabeth Morris in response to the release of new US Preventive Services Task Force (USPSTF) guidelines today. The recommendations from the independent volunteer panel come just months after the American Cancer Society (ACS) issued its own updated guidelines.

The input from yet another well-respected organization following an in-depth review of scientific evidence on the benefits and harms of screening mammography as well as input from health care professionals and the public has once again brewed confusion and left countless women wondering if they’re doing the right thing. 

“The bottom line — and what our Breast Service has recommended for years now — is that women at average risk for breast cancer start getting screening mammograms at age 40,” says Dr. Morris. “We know this approach saves lives. MSK’s breast cancer screening guidelines are not changing in any way in light of recent recommendations from other organizations.”

Why Guidelines Sometimes Differ

There’s actually little disagreement among experts around the world that mammography screening for breast cancer saves lives, notes Dr. Morris. “What differs depends on the greatest relative value that the committee doing the evaluation places on certain things.”  

For example, she says, groups such as the ACS have placed the most weight on minimizing challenges for women associated with potential overdiagnosis, false-positive readings, and the need for additional procedures. As a result, the group recommends average-risk women start annual mammograms at age 45 and transition to screening every two years at age 55.

In contrast, MSK places the greatest emphasis on what’s been shown to save the highest possible number of lives: annual mammograms beginning at age 40. Groups most focused on minimizing biopsies and repeat scans, on the other hand, recommend that women start annual mammograms at age 50 and continue every other year — as do groups that place the greatest value on keeping costs down.

“Ultimately, the decision about when to start screening is a very personal one,” explains Dr. Morris. “A woman will have to talk with her doctor, decide for herself what she is comfortable with, and proceed from there.”  

The USPSTF takes care to note that “mammography is an important tool for women ages 40 to 74.” And the ACS guidelines, authored by a committee headed by MSK primary care physician Kevin Oeffinger and published in the Journal of the American Medical Association, qualify their recommendations to a point by noting that women ages 40 to 45 “should have the opportunity to start screening early if they choose.”

The USPSTF and ACS guidelines address screenings only for women at average risk for breast cancer, not for women at increased risk.

Newer Breast Screening Tools Alter the Picture

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Watch our experts explain the 3-D mammogram.
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Another thing to keep in mind when considering the USPSTF and ACS guidelines, Dr. Morris notes, is that the screening data are based on mammography technology that is “decades-old film screen technology.”

At MSK and most other screening centers across the United States and around the world today, screening mammograms are done with digital technology that generates a much more precise and vivid image than film screen technology is able to capture. As a result, some of the drawbacks that so many experienced at one time, such as misdiagnoses and getting called back for repeat images, are not nearly as common as they once were.

“We’ve progressed so much,” explains Dr. Morris, “and gotten so much more sophisticated and advanced in breast screening technology.