OBJECTIVES: We estimated loss-of-life expectancy (LE) and lifetime medical expenditures (LME) stratified by stages to evaluate the cost-effectiveness of breast cancer (BC) screening in Taiwan using real world data.

METHODS: We interlinked four national databases- Cancer Registry, Mortality Registry, National Health Insurance, and Mammography Screening. A total of 106,199 females with breast cancer were identified 2002-2014 and followed until the end of 2015. We estimated the lifetime survival function, LE, and loss-of-LE by rolling extrapolation algorithm using age-, sex-, and calendar-year-matched referents and estimated LME by summing up the average monthly costs weighted by survival probability and adjusted for consumer price index and annual discount rate (3%) throughout life. We calculated incremental cost-effectiveness ratio (ICER) by comparing those diagnosed within 6 months after screening versus not through screening.

RESULTS: The loss-of-LE of stage I, II, III, IV, and unknown were 3.0, 4.2, 11.2, 22.4, 12.0 years respectively. The LME of each stage were US$ 77,071, 70,102, 76,672, 67,516, and 65,422 respectively. The difference of LE between stages I and IV is 21.7 years, while that of loss-of-LE is 19.4 years, indicating adjustment for lead time bias. Subjects with stage 0 showed almost the same survival curve as those of age-, sex, and calendar-year matched referents and spent US$5,340 by the end of the first year after diagnosis. During 2004-2014, the ICER of mammography screening was US$ -51.4 per life year saved considering the basic administration fee of screening, which must be further adjusted for costs spent after false-positive results.

CONCLUSIONS: Mammography can detect BC early and would be cost-effective. The ICER seems decreased when coverage of population expanded.