Evolution of breast cancer screening in the Medicare population: clinical and economic implications.

BACKGROUND: Newer approaches to mammography, including digital image acquisition and computer-aided detection (CAD), and adjunct imaging (e.g., magnetic resonance imaging [MRI]) have diffused into clinical practice. The impact of these technologies on screening-related cost and outcomes remains undefined, particularly among older women.

METHODS: Using the Surveillance, Epidemiology, and End Results-Medicare linked database, we constructed two cohorts of women without a history of breast cancer and followed each cohort for 2 years. We compared the use and cost of screening mammography including digital mammography and CAD, adjunct procedures including breast ultrasound, MRI, and biopsy between the period of 2001 and 2002 and the period of 2008 and 2009 using χ(2) and t test. We also assessed the change in breast cancer stage and incidence rates using χ(2) and Poisson regression. All statistical tests were two-sided.

RESULTS: There were 137150 women (mean age = 76.0 years) in the early cohort (2001-2002) and 133097 women (mean age = 77.3 years) in the later cohort (2008-2009). The use of digital image acquisition for screening mammography increased from 2.0% in 2001 and 2002 to 29.8% in 2008 and 2009 (P < .001). CAD use increased from 3.2% to 33.1% (P < .001). Average screening-related cost per capita increased from $76 to $112 (P < .001), with annual national fee-for-service Medicare spending increasing from $666 million to $962 million. There was no statistically significant change in detection rates of early-stage tumors (2.45 vs 2.57 per 1000 person-years; P = .41).

CONCLUSIONS: Although breast cancer screening-related costs increased substantially from 2001 through 2009 among Medicare beneficiaries, a clinically significant change in stage at diagnosis was not observed.