Dense breasts: Usefulness of adjunctive screening modalities
Breast density is categorized into 4 groups, from category a (breasts are almost all fatty with little fibro nodular tissue) to category d (breasts are extremely dense).1 About 43% of women ages 40 to 74 are in categories c and d.1 Dense breasts adversely affect the accuracy of mammography, decreasing sensitivity and specificity. In one study, sensitivity was 87% in category a and 63% in category d; specificities were 97% and 89%, respectively.5
Tomosynthesis, magnetic resonance imaging, and ultrasound, when used in addition to mammography, all appear to detect more cancers, but they also yield more false-positive results.6 The long-term outcome of detecting more tumors is not known. For an individual, there are 3 possibilities when a tumor is detected earlier: a better outcome, no difference in outcome, or a worse outcome resulting from overdiagnosis and overtreatment. The TF felt that the available data are insufficient to judge benefits and harms of an increased frequency of screening or the use of adjunctive screening methods in women with dense breasts.
Benefit for women ≥75 years is inconclusive
There are limited data on the impact of mammography on outcomes for women older than 70. The TF feels that, since women ages 60 to 69 benefit the most from mammography, this benefit is likely to carry over into the next decade. Modeling also predicts this.
However, women ages 70 to 74 who have chronic illnesses are unlikely to benefit from mammography. The conditions specifically mentioned are cardiovascular disease, diabetes, lung disease, liver disease, renal failure, acquired immunodeficiency syndrome, and dementia.
For all women ages 75 and older, the TF feels the evidence is insufficient to make a recommendation.
Insurance coverage
The ACA mandates that 4 sets of preventive services be included in commercial health insurance plans with no out-of-pocket expenses to the patient: immunizations recommended by the Advisory Committee on Immunization Practices; children’s preventive services recommended by the Health Resources and Services Administration (HRSA); women’s preventive services recommended by HRSA; and recommendations with an A or B rating from the USPSTF.7
For children, HRSA opted to use those preventive services listed by the American Academy of Pediatrics in Bright Futures, the society’s national initiative providing recommendations on prevention screenings and well-child visits.8 For women, HRSA asked the Institute of Medicine to form a panel to construct a list of recommended preventive services.
At the time the ACA was passed, the TF had just made new recommendations on breast cancer screening, which were very similar to the current draft recommendations. Due to the resulting controversy, Congress mandated that the new recommendations not be used to determine first-dollar insurance coverage, and it cited the TF’s pre-2009 recommendations as the applicable standard.
Those earlier recommendations included annual mammography starting at age 40. The wording of the law, however, was not clear as to future mammography recommendations. One interpretation is that the TF recommendations in place before 2009 are the basis for first-dollar coverage until changed by Congress. Another interpretation is that the ACA special provision trumped only the 2009 recommendations and the 2015 recommendations will become the standard. If the latter turns out to be true, it is not clear if commercial insurance plans will begin to charge co-payments for mammography before age 50 or for mammograms ordered more frequently than every 2 years for women ages 50 to 74.
The issue of insurance coverage is important because of the lack of uniformity in recommendations regarding mammography. The American Congress of Obstetricians and Gynecologists,9 the American Cancer Society,10 and the American College of Radiology11 all recommend annual mammography starting at age 40. The American Academy of Family Physicians recommendations12 mirror those of the USPSTF, and the Canadian Task Force on Preventive Health Care recommends against routine screening for women ages 40 to 49 and recommends mammography every 2 to 3 years for women ages 50 to 74.13
USPSTF rationale is informed and accessible for review
Breast cancer screening remains a highly controversial and emotional topic. The USPSTF has made a set of recommendations based on extensive and rigorous evidence reports that consider both benefits and harms. There will be those who vigorously disagree. The evidence reports, recommendations, and rationale behind them are easily accessible on the TF Web site (www.uspreventiveservicestaskforce.org) for those who want to read them.1