Radiation-Induced Breast Cancer Incidence and Mortality From Digital Mammography Screening: A Modeling Study.

BACKGROUND: Estimates of risk for radiation-induced breast cancer from mammography screening have not considered variation in dose exposure or diagnostic work-up after abnormal screening results. OBJECTIVE: To estimate distributions of radiation-induced breast cancer incidence and mortality from digital mammography screening while considering exposure from screening and diagnostic mammography and dose variation among women. DESIGN: 2 simulation-modeling approaches. SETTING: U.S. population. PATIENTS: Women aged 40 to 74 years. INTERVENTION: Annual or biennial digital mammography screening from age 40, 45, or 50 years until age 74 years. MEASUREMENTS: Lifetime breast cancer deaths averted (benefits) and radiation-induced breast cancer incidence and mortality (harms) per 100,000 women screened. RESULTS: Annual screening of 100,000 women aged 40 to 74 years was projected to induce 125 breast cancer cases (95% CI, 88 to 178) leading to 16 deaths (CI, 11 to 23), relative to 968 breast cancer deaths averted by early detection from screening. Women exposed at the 95th percentile were projected to develop 246 cases of radiation-induced breast cancer leading to 32 deaths per 100,000 women. Women with large breasts requiring extra views for complete examination (8% of population) were projected to have greater radiation-induced breast cancer risk (266 cancer cases and 35 deaths per 100,000 women) than other women (113 cancer cases and 15 deaths per 100,000 women). Biennial screening starting at age 50 years reduced risk for radiation-induced cancer 5-fold. LIMITATION: Life-years lost from radiation-induced breast cancer could not be estimated. CONCLUSION: Radiation-induced breast cancer incidence and mortality from digital mammography screening are affected by dose variability from screening, resultant diagnostic work-up, initiation age, and screening frequency. Women with large breasts may have a greater risk for radiation-induced breast cancer. PRIMARY FUNDING SOURCE: Agency for Healthcare Research and Quality, U.S. Preventive Services Task Force, National Cancer Institute.

Program-specific cost-effectiveness analysis: breast cancer screening policies for a safety-net program.

BACKGROUND: Every Woman Counts (EWC), a California breast cancer screening program, faced challenging budget cutbacks and policy choices. METHODS: A microsimulation model evaluated costs, outcomes, and cost-effectiveness of EWC program mammography policy options on coverage for digital mammography (which has a higher cost than film mammography but recent legislation allowed reimbursement at the lower film rate); screening eligibility age; and screening frequency. Model inputs were based on analyses of program claims data linked to California Cancer Registry data, Surveillance, Epidemiology, and End Results data, and the Medi-Cal literature. Outcomes included number of procedures, cancers, cancer deaths, costs, and incremental cost per life-year. RESULTS: Projected model outcomes matched program data closely. With restrictions on the number of clients screened, strategies starting screening at age 40 years were dominated (not cost-effective). This finding was highly robust in sensitivity analyses. Compared with no screening, biennial film mammography for women aged 50 to 64 years was projected to reduce 15-year breast cancer mortality by nearly 7.8% at $18,999 per additional life-year, annual film mammography was $106,428 per additional life-year, and digital mammography $180,333 per additional life-year. This more effective, more expensive strategy was projected to reduce breast cancer mortality by 8.6%. Under equal mammography reimbursement, biennial digital mammography beginning at age 50 years was projected to decrease 15-year breast cancer mortality by 8.6% at an incremental cost per additional life-year of $17,050. CONCLUSIONS: For the EWC program, biennial screening mammography starting at age 50 years was the most cost-effective strategy. The impact of digital mammography on life expectancy was small. Program-specific cost-effectiveness analysis can be completed in a policy-relevant time frame to assist policymakers faced with difficult program choices.