Supplemental screening rates in North Carolina not impacted by breast density legislation

Breast density notification laws do not always lead to drastic changes in supplemental screening utilization, according to a new study published in the Journal of the American College of Radiology.

“The rationale for supplemental screening … is that use of additional imaging has the potential to increase screening sensitivity,” Sarah J. Nyante, MSPH, PhD, department of radiology at the University of North Carolina at Chapel Hill, and colleagues. “This could be particularly advantageous for women with dense breasts, for whom the sensitivity of mammography is known to be lower than mammographic sensitivity among women with nondense breasts.”

However, the authors added, many industry societies and advocacy groups recommend only turning to supplemental screening when the patient with dense breasts has a high breast cancer risk.

“It is unclear how breast density notification affects patterns of supplemental screening given the increasing prevalence of notification requirements and lack of evidence to support the contention that notification is beneficial,” they wrote.

To examine this issue using a real-life example, the authors turned to the breast density notification law that went into effect in North Carolina on Jan. 1, 2014. The law suggested that women with dense breasts discuss supplemental screening, but it was not required. Nyante et al. focused on Carolina Mammography Registry participants between the ages of 40 and 79 years old who had no prior history of breast cancer. Patients with breast implants were excluded.

Overall, supplemental screening was “similar” before implementation (from 2012 to 2013) and after implementation (from 2014 to 2016). This is different from other states, where researchers have observed significant increases in supplemental screening following the passage of breast density notification laws.

“There are likely multiple reasons why supplemental screening rates in North Carolina did not show increases similar to those observed in California, New Jersey, and Texas,” the authors wrote. “One possible reason is that the North Carolina law does not require insurance coverage for supplemental screening. As a result, women without insurance coverage, with limited coverage, or with high-deductible plans may forgo supplemental screening that they otherwise might have undergone in the absence of economic barriers.”

In addition, the team added, there are just 41 accredited MRI facilities in North Carolina as opposed to the 259 mammography providers. This may have made an impact on supplemental screening trends in the state.

Nyante and colleagues did observe an increase in the use of screening digital breast tomosynthesis of more than 600% during the study period, which is similar to what research has found in other states following the passage of breast density notification laws. In addition, the use of screening DBT was greater for women with dense breasts than those with nondense breasts.