Breast cancer screening tacked on more than $1 billion to Medicare costs, but its effect on Medicare patient outcomes remains unclear, according to a study published online Jan. 7 in JAMA Internal Medicine. The researchers suggested overdiagnosis in higher-cost regions, and also cautioned that the cost curve may grow steeper as Medicare covers newer screening modalities without proof of impact on outcomes.
In 2009, the U.S. Preventive Services Task Force concluded that there was insufficient evidence about the harms and benefits of breast cancer screening in women ages 75 years and older. In addition, research has not tackled the topic of breast cancer screening costs in the Medicare population.
As providers adopt newer modalities such as digital mammography and computer-aided detection (CAD), the need to understand costs and outcomes sharpens, according to Cary P. Gross, MD, of Yale Comprehensive Cancer Center in New Haven, Conn., and colleagues. New technologies can increase costs via higher reimbursement and also lead to higher rates of supplementary imaging, biopsy or cancer detection, according to the researchers.
Gross and colleagues undertook a retrospective cohort study of female Medicare beneficiaries, mining the Surveillance, Epidemiology and End Results-Medicare database. The study population was comprised of 137,274 women ages 66 to 100 years who had not had breast cancer and underwent screening and work-up during 2006 to 2007.
A total of 43.5 percent of women had a mammogram during the study period. Gross and colleagues extrapolated screening and suspicious lesion work-up costs to the entire Medicare population and calculated screening costs of $723.1 million and work-up costs of $359 million. This screening-related total cost of $1.08 billion accounts for more than 45 percent of the $2.42 billion that Medicare spends on breast cancer screening and treatment.
For women older than 75 years, screening-related and treatment costs were $410.6 million and $498.5 million, respectively, despite a lack of evidence about the benefits and harms of screening in this group. “This reinforces the need to develop evidence to guide both clinical decision making and coverage decisions,” wrote Gross and colleagues.
When the researchers evaluated costs by Hospital Referral Region (HRR), they found the screening-related cost per beneficiary ranged from $40 to $110. Women in higher-cost regions were significantly more likely to undergo digital mammography, reported Gross et al. Screening CAD use was 38.6 percent in the highest HRR regions and 19.6 percent in the lowest regions.
“Patients in HRRs with the highest screening-related costs also tended to have higher utilization of work-up procedures such as diagnostic mammography, other breast imaging, or biopsy when compared with lower-cost regions,” wrote Gross and colleagues. The relative difference in biopsy rates across regions may be related to increase use of digital mammography and CAD in high-cost regions, according to the researchers.
Women living in higher screening-related cost per beneficiary regions were significantly more likely to be diagnosed with breast cancer, with the increase attributable to a significantly higher incidence of early-stage (in situ and Stage I) cancers. However, the researchers did not find a significant difference in diagnosis of Stage IV cancer by high and low-cost areas. “Taken together, these findings suggest overdiagnosis of breast cancer in the higher-cost regions,” wrote Gross et al.
The researchers noted the findings suggest limited effectiveness of CAD and digital mammography in older, average-risk women, and wrote, “[The] cost and effectiveness of such evolutions of technology should be promptly and rigorously evaluated; higher costs associated with adoption of newer modalities may not necessarily yield superior outcomes.”
Ultimately, the study demonstrated costs of breast cancer screening and treatment are “substantially higher” than previous estimates, concluded Gross et al.