Big news hit in October during Breast Cancer Awareness month as the American Cancer Society (ACS) released 2015 recommendations for breast cancer screenings for women who are considered average-risk. The new recommendations are evidence-based and balance the benefits and harms of both mammograms and clinical exams.
While any examination or screening still depends on the discretion of the physician and the patient, the American Cancer Society has produced evidence-based recommendations that are aimed particularly at women younger than 40 years old due to cumulative lifetime risks of false-positive exams. According to the 2015 Guideline Update From the American Cancer Society:
“Estimates of the cumulative lifetime risk of false-positive examination results are greater if screening begins at younger ages because of the greater number of mammograms, as well as the higher recall rate in younger women. The quality of the evidence for overdiagnosis is not sufficient to estimate a lifetime risk with confidence. Analysis examining the screening interval demonstrates more favorable tumor characteristics when premenopausal women are screened annually vs biennially. Evidence does not support routine clinical breast examination as a screening method for women at average risk.”
Ramifications for mammograms
Annual screenings via mammography are still recommended for women aged 45 to 54 years. Women ages 55 and older are recommended to transition to screening every other year and should continue the biennial screenings as long as they are expected to live 10 years or longer.
The ACS is not recommending the clinical breast exam, where the physician examines the breast for unusual lumps, among women of any age who are considered to be average-risk.
ACS Guidelines for Breast Cancer Screening At-a-glance:
Recommendations published in JAMA suggest the following:
- Women with an average risk of breast cancer should undergo regular screening mammography starting at age 45 years (strong recommendation).
- Women aged 45 to 54 years should be screened annually (qualified recommendation).
- Women 55 years and older should transition to biennial screening or have the opportunity to continue screening annually (qualified recommendation).
- Women should have the opportunity to begin annual screening between the ages of 40 and 44 years (qualified recommendation).
- Women should continue screening mammography as long as their overall health is good and they have a life expectancy of 10 years or longer (qualified recommendation).
- The ACS does not recommend clinical breast examination for breast cancer screening among average-risk women at any age (qualified recommendation).
Other groups suggest menopause – not age – as a biological marker
Not everyone agrees that age should be the only benchmark for determining how to screen with mammograms. In an editorial by Wendy Y. Chen, MD, MPH, published in JAMA Oncology, entitled “Measuring the Effectiveness of Mammography,” Chen cites opinions from the Breast Cancer Surveillance Consortium that “menopausal status is a more relevant biologic marker than age.” Chen says: “Although the authors1 do not endorse annual or biennial screening, they imply that biennial screening would be acceptable for postmenopausal women but inferior for premenopausal women owing to their findings of a higher proportion of “less favorable” cancers with biennial screening in that subgroup.”
It is important to remember that guidelines are just that: guidelines. As with all medical diagnostic imaging, ultimately the ordering physician must weigh the benefits and risks according to the individual patient’s history and needs. Perhaps the recent guidelines issued by the ACS will result in routine testing becoming less “routine” and more individualized to each patient’s situation.
1 Miglioretti DL, Zhu W, Kerlikowske K, et al; Breast Cancer Surveillance Consortium. Breast tumor prognostic characteristics and biennial vs annual mammography, age menopausal status [published online October 20, 2015]. JAMA Oncol. doi:10.1001/jamaoncol.2015.3084.