Screening for Breast Cancer

Screening for Breast Cancer; recommendations from medical societies and boards.

1.  US Preventive Services Task Force (USPSTF)

In 2009, in light of evidence that the benefit-risk ratio is higher among women older than 50 years and with less frequent screening, the USPSTF reversed its previous recommendation of mammography every 1 to 2 years beginning at age 40 years and recommended routine screening every 2 years starting at age 50. This was consistent with recommendations in many European countries.

The USPSTF stated that “the decision to start regular, biennial screening mammography before the age of 50 years should be an individual one and take into account patient context, including the patient’s values regarding specific benefits and harms.”

2.  American Cancer Society

·      Yearly mammograms are recommended starting at age 40 and continuing for as long as a woman is in good health

·      Clinical breast exam (CBE) about every 3 years for women in their 20s and 30s and every year for women 40 and over

·      Women should know how their breasts normally look and feel and report any breast change promptly to their health care provider. Breast self-exam (BSE) is an option for women starting in their 20s.

Some women because of their family history, genetic mutations, or other factors, MRI should be added to their screening. The number of women who fall into this category is small: less than 2% of all the women in the US.

3.  Swiss Medical Board

In January 2013, the SwissMedical Board, an independent health technology assessment initiative under the auspices of the Conference of Health Ministers of the Swiss Cantons, the Swiss Medical Association, and the Swiss Academy of Medical Sciences, was mandated to prepare a review of mammography screening.

Based on existing literature the board recommended that no new systematic mammography screening programs be introduced and that a time limit be placed on existing programs. In addition, it stipulated that the quality of all forms of mammography screening should be evaluated and that clear and balanced information should be provided to women regarding the benefits and harms of screening.

The Swiss Medical Board is nongovernmental body, and its recommendations are not legally binding.

References:

American College of Radiology Practice Guideline for Screening and Diagnostic Mammography  

American Cancer Society
Swiss Medical Board

Benefits and Risks of Mammography Screening

The article by Pace and Keating in JAMA reports on their MEDLINE search of articles and meta-analyses from 1960 to 2014 that describe benefits and/or harms of mammography, individualizing screening decisions and those promoting informed decision making.

They found that mammography screening is associated with a 19% overall reduction of breast cancer mortality (approximately 15% for women in their 40s and 32% for women in their 60s). For a 40- or 50-year-old woman undergoing 10 years of annual mammograms, the cumulative risk of a false-positive result is about 61%. About 19% of the cancers diagnosed during that 10-year period would not have become clinically apparent without screening (overdiagnosis), although there is uncertainty about this estimate.

They estimated that for every 10,000 women in their 40s who undergo annual mammograms for 10 years, 5 breast-cancer deaths will be averted. Of the remainder, about 25 would die despite being treated, and 36 would be treated unnecessarily because the cancer wouldn't have become life threatening.  For every 10,000 women in their 50s and those in their 60s screened annually for 10 years, 10 and 42 breast-cancer deaths would be averted respectively. But as many as 137 women in their 50s, and 194 in their 60s would be diagnosed and treated unnecessarily.  Women in all age groups will experience angst and inconvenience because of false positives diagnoses and unnecessary biopsies.

They conclude that although mammography screening may be associated with reduced breast cancer mortality it can also cause harm.  They suggest that in order to maximize the benefit of mammography screening, decisions should be individualized based on patients' risk profiles and preferences.

Pace LE, Keating NL; A systematic assessment of benefits and risks to guide breast cancer screening decisions: JAMA. 2014 Apr 2;311(13):1327-35.

doi: 10.1001/jama.2014.1398.