Breast Density and Risk Factors Indicate Breast Cancer Screening Intervals
Authors of a modeling study recommend triennial mammography for 12% of women aged 50 years, and 20% aged 65 years with low breast density and few or no risk factors.
Authors of a modeling study recommend triennial mammography for 12% of women aged 50 years, and 20% aged 65 years with low breast density and few or no risk factors. Less than 1% of high-risk women with high breast density, however, require annual screening.1
“The findings support [the notion] that mammography is important to reduce breast cancer deaths for women age 50-74,” co-first author Amy Trentham-Dietz, PhD, of the University of Wisconsin-Madison Carbone Cancer Center in Wisconsin, told Cancer Therapy Advisor.
“Recommendations based on risk rather than just age alone, however, may help to reduce the number of women who have negative experiences. Most women will never be diagnosed with breast cancer. This study will be a success if more women better understand their breast cancer risk, breast density, and the possible consequences of a mammogram before they have one.”
The US Preventive Services Task Force (USPSTF) recommends biennial screening mammography for average-risk women aged 50 to 74 years.2 The American Cancer Society (ACS) recommends such screening from 55 onwards.3
The authors of the present study noted that “implementing screening in clinical practice should involve shared decision-making to consider preferences, risk levels, and breast density.” This conversation is being assisted by national efforts to ensure every woman knows her breast density.
Are You Dense Advocacy, Inc., reports that although “40% of women have dense breast tissue…95% of women do not know their breast density…1 of the strongest predictors of the failure of mammography to detect cancer.”4
In 2009, Connecticut enacted a “breast density notification law.” To date, 27 states have followed suit, and federal legislation was reintroduced in 2015. The use of additional screening tests for women with dense breasts has the potential to increase detection of small, node negative, early-stage invasive disease, the advocacy group reports.
When asked how clinicians can clearly express risks and benefits of screening mammograms, Dr Trentham-Dietz wrote in an email, “This can be challenging, because each woman will place a different value on the possible outcomes of screening, [such as] call-back for additional mammography views, ultrasound, biopsy, diagnosis, and a death averted from breast cancer. Plus, outcomes have a different chance of occurring: a breast cancer diagnosis is rare, and death from breast cancer even more rare; false alarms, however, are common.
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“Women may have a different willingness to experience false alarms,” she added. For example, a false positive “is something that some women want to avoid, while others are more willing to experience this, as long as they are told they don't have breast cancer. Both preferences are reasonable, so the decision needs to be personal.”
Dr Trentham-Dietz noted it is likely that the USPSTF or ACS will consider the study's results when revising guidelines.
- Trentham-Dietz A, Kerlikowske K, Stout NK, et al. Tailoring breast cancer screening intervals by breast density and risk for women aged 50 years and older: Collaborative modeling of screening outcomes. Ann Intern Med. 2016 Aug 23. doi: 10.7326/M16-0476 [Epub ahead of print]
- Siu AL. Screening for breast cancer: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2016;164:279-96. doi: 10.7326/M15-2886
- Oeffinger KC, Fontham ET, Etzioni R, et al. Breast cancer screening for women at average risk: 2015 guideline update from the American Cancer Society. JAMA. 2015;314:1599-614. doi: 10.1001/jama.2015.12783
- Are You Dense Advocacy, Inc. D.E.N.S. E. Facts. http://areyoudenseadvocacy.org/facts/. Accessed August 22, 2016.