Costs and Effects of Implementing Digital Tomosynthesis in a Population-Based Breast Cancer Screening Program: Predictions Using Results from the To-Be Trial in Norway

Abstract

Background Although several studies from Europe and the US have shown promising screening results favoring digital breast tomosynthesis compared with standard digital mammography (DM), both costs and efects of implementing tomosynthesis in routine screening programs remain uncertain. The cost efectiveness of using tomosynthesis in routine screening is debated in the literature, and model inputs from randomized trials are lacking. Using parameters mainly from a randomized controlled trial (the To-Be trial), we simulated costs and efects of implementing tomosynthesis in the national screening program BreastScreen Norway.<p> <p>Methods The To-Be trial was performed in Bergen from 2016 to 2017 within BreastScreen Norway, where females were randomized to either digital breast tomosynthesis including synthetic mammograms (DBT) or DM. The trial was followed by a cohort study ofering all females DBT in 2018–2019. The trial included over 37,000 females, and allowed for estimation of short-term costs and efects related to screening, recall examinations and cancer detection. Using these and recent Norwegian estimates for 10-year stage-specifc survival and treatment costs, the cost efectiveness of replacing DM with DBT in BreastScreen Norway was simulated in a decision tree model with probabilistic sensitivity analyses. Outcomes included false-positive screening results, screen-detected and interval cancers, stage at diagnosis, all-cause deaths, life-years gained, costs at recall and treatment and incremental cost-efectiveness ratio. <p>Results The estimated additional cost of DBT was €8.10. Simulating ten rounds of screening from 2018 and 10-year survival and costs, 500 deaths were averted and 2300 life-years gained at an additional screening cost of €29 million for females screened with DBT versus DM. Taking over-diagnosis, recall and treatment costs into account, DBT was dominant in the deterministic analysis. The incremental cost-efectiveness ratio indicated cost savings of €1400 per life-year gained. Probabilistic sensitivity analyses showed that DBT was cost efective in over 50% of the simulations at all willingness-to-pay levels per life-year gained, and in 80% of the simulations at levels above €22,000. If willingness-to-pay levels up to €35,000 were assumed, DBT would be cost efective in over 50% of the simulations for additional costs of DBT of up to €32, almost four times the estimated additional cost of €8.10. <p>Conclusion DBT may be cost efective if implemented in BreastScreen Norway. However, generalizability of results could depend on factors varying between countries, such as recall rates, program sensitivity and specifcity, treatment cost and willingness-to-pay levels.