While there is much debate about the risks and benefits of early breast cancer screening, most guidelines agree that average-risk women should receive mammography screening between ages 50 and 74 years. A recent statement from the American College of Physicians noted that while clinicians should discuss screening with average-risk women patients ages 40 to 49, in most cases “the potential harms [of screening] outweigh the benefits.”

There are substantial costs associated with breast cancer screenings for US women in their 40s, a new Yale-led study finds, and these costs vary widely by region.

The study, conducted by researchers at Yale, University of Oslo, and New York University, found that over 40% of the eligible, privately insured women ages 40-49 received annual breast cancer screening in 2017 and estimated the national cost of those procedures to be $2.13 billion per year. While experts still debate the benefits of breast cancer screenings for women under age 50, the study authors write, there have been few studies related to associated costs.

The study appears in the March 23 edition of JAMA Internal Medicine.

“These high costs underscore the importance of ramping up our research efforts to determine whether screening women in their 40s is beneficial or not,” said senior author Dr. Cary Gross, Yale professor of medicine and a member of the Yale Cancer Center. Breast cancer is the most common type of cancer impacting US women and the fourth leading cause of cancer death in the United States. “Because there is no consensus about the appropriate approach to breast cancer screening in this population, it is impossible to know how we should be investing our prevention dollars.”

For the study, researchers looked at the records of over 2 million women ages 40-49 from the Blue Cross Blue Shields Axis, a large commercial claims database accessed via a secure portal. Of these women, 41.2% were screened with standard mammography, 24.1% with 2-dimensional mammography, and 17.2% with DBT (digital breast tomosynthesis), also known as 3-dimensional mammography.

Costs for these tests varied substantially across different regions of the country. The mean cost of breast cancer screening was $353 per beneficiary, but screening costs ranged from $151 in some regions to $751 in others. Screening costs were highest in regions in California, New York, Alaska, Wisconsin, and Michigan, and lowest in regions of Alabama and Arkansas.

“We found substantial variation in the screening cost across US regions,” said first author Natalia Kunst, a Yale research fellow and PhD candidate at the University of Oslo. “The identified costs were substantially higher than previously published cost estimates.”

Cost considerations identified by the Yale study may provide additional reason to delay screenings, said the researchers. “We hope that our results can assist local and national public health policymakers in making more informed choices about screening women ages 40 to 49 and identifying opportunities for research,” Kunst said.

Yale researchers who contributed to the study include Jessica Long, Xiao Xu, Susan Busch, and Ilana Richman. Data for this project was contributed through a collaboration between Yale University and Blue Cross Blue Shield Association (BCBSA). Yale researchers obtained no funding from BCBSA to conduct this research, which was supported by a grant from the American Cancer Society.