Long-term outcomes of Türkiye's first population-based mammography screening program: a decade of breast cancer detection and survival analysis in Bahçeşehir.

Background: The Bahçeşehir population-based mammography screening program (BMSP) is an example of Türkiye's first population-based screening program. This study aims to reveal the successful implementation of population-based secreening program in one of the low- and middle-income countries, Türkiye and long-term results of patients diagnosed with breast cancer during BMSP.

Methods: This study was conducted between 2009 and 2019, in the Bahçeşehir county of Istanbul. Women between the ages of 40 and 69 living in this region were invited every two years to undergo clinical breast examination (CBE) and mammography screening. All data was recorded in a dedicated software program. Women diagnosed with breast cancer were followed as a separate cohort.

Results: During the 10-year screening period, 8,825 women were screened and 146 (1.7%) breast cancers were detected. The median age at diagnosis for these patients was 52.9 years (40-69). The risk of breast cancer was 1.39 times higher (95% CI: 1.01-1.93) in women aged ≥ 50 compared to those less than 50 years (p = 0.045). The Cox regression analysis revealed that age at first birth, and number of births were significant predictors of breast cancer risk (p < 0.001, and p = 0.011). The breast cancer rate tends to increase as the breast density category progresses from A to D (p < 0.001). The median follow-up time for 146 breast cancer patients was 95.3 months. The 10-year breast cancer specific survival rate was 85%.

Conclusions: This study demonstrates that with a committed team and sufficient infrastructure, screening mammography can be effectively carried out in Türkiye, leading to early detection and lower mortality rates. The recommended age to commence screening is 40 years old.