ObjectiveThe present paper estimates the cost-effectiveness of population-based breast cancer (BC) screening strategies in Brazil for women under 50 years from the perspective of the Brazilian public health system.MethodsA Markov model, simulating the natural history of female BC sufferers in Brazil, was developed. This model compares the lifetime effects, costs, and cost-effectiveness of seven BC screening strategies in women between 40 to 49 years: (A) usual care; (B) annual screen-film mammography (SFM); (C) SFM every 2 years; (D) annual full-field digital mammography (FFDM); (E) FFDM every 2 years; and (F and G) age-targeted options, with FFDM annually until 49 years and SFM annually (or biannually) from 50 to 69 years.ResultsAdopting SFM every 2 years (Strategy C) was found to be slightly more costly but also more effective in terms of quality-adjusted life years (QALYs), yielding an incremental cost-effectiveness ratio (ICER) of R$ 1,509 per QALY gained. Annual SFM (Strategy B) was the next best option at an additional R$ 13,131 per QALY gained. FFDM annual screening (Strategy E) was dominated by Strategy F, the age-targeted option. For younger women, the age-based strategy had an ICER of R$ 30,520 per QALY gained. In the sensitivity analysis, the ICERs ranged from R$ 15,300 to R$ 257,899 in different regions of the country, depending on BC incidence, population age distribution, and mammography coverage.ConclusionsSFM every 2 years for all women starting between the ages of 40 and 49 would be a cost-effective strategy. Taking into account regional specificities, age-targeted FFDM is one option to improve the outcomes of BC patients in an emerging country.