The High Cost of Digital Mammograms

Newer Breast Cancer Screening Tools Such as CAD and Digital Mammography are Linked to Higher Regional Medicaid Costs without Evidence of Better Outcomes

The Takeaway

1.  Regional analysis in the US indicated that  more frequent use  of computer assisted diagnosis (CAD) and digital mammography to detect breast cancer was linked to higher rates of Medicaid spending, both because these technologies were more expensive and because they led to more follow-ups.

2. Women living in the highest-cost regions were more likely to be diagnosed with early stage breast cancer than those living in the lowest-cost regions.

3.  If finding more early stage cancers were an effective preventive strategy fewer stage IV cancers should have been found in the highest-cost regions.  This was not the case.  Highest-cost regions and lowest-cost regions did not vary significantly in the number of late stage breast cancers detected, nor in overall cancer treatment costs.

4.  Medicaid spent 15% of its breast cancer screening budget on women between ages 75 and 100, despite lack of evidence for its effectiveness in this age cohort.

6.  As the authors note in their discussion, this study, like the Norwegian Screening Trial, suggests that early-stage breast cancer is being overdiagnosed in the United States. 

The One-Minute Summary

Since the 1980s, the goal of breast cancer screening has been to find cancer at the earliest stage (in situ or stage I) in order stop the progression to metastatic cancer (stage IV).  The effectiveness of this approach was called into question recently by a Norwegian Screening Trial which showed that widespread breast cancer screening has indeed found more early-stage cancers but it has not reduced the number of late stage cancers found.  This suggests that a substantial number of breast cancers (up to 25%) being detected today would not have gone on to cause disease. New technologies in imaging are causing early stage cancers to be overdiagnosed resulting in unnecessary treatment and cost.

A study published this month in JAMA Internal Medicine online looked at the use of newer screening technologies such as computer-aided detection (CAD) and digital mammography in the Medicaid population of the United States for the years 2006 and 2007.  A sample of 137,234 women ages 66 to 100 who had not had breast cancer were drawn from the Linked Surveillance, Epidemiology and End Results─Medicare Database.  Recipients were assigned to one of 75 Health Referral Regions (HRRs) based on zip code.  Age-standardized screening costs were then compared across regions and divided into quintiles by cost.

The total cost of screening and subsequent work-ups to Medicare was one billion dollars. Women living in the highest cost HRRs were more likely to receive digital screening mammography, CAD and breast biopsy, with digital mammography accounting for 47% of the cost difference between the most expensive and least expensive regions.  Those living in the regions with the highest screening expenditures per beneficiary were also more likely to receive a diagnosis of stage I or in situ breast cancer.  The amount spent on treatment did not differ significantly by region.  This is line with the recent Norwegian study, suggesting overdiagnosis is also a problem in the United States.

TL:DR Living in regions with high medical costs could put women at risk for overdiagnosis of breast cancer.

Read the Study: Jama Internal Medicine, Published online January 7, 2013