Temporal trend of breast cancer burden among younger and older Brazilian women, 1990-2019.

Objective: To analyze the temporal trend of the burden of breast cancer in Brazilian women under 40 years of age compared to the age group over 40 years of age, between 1996 and 2019.

Methods: An ecological time trend study was conducted in Brazil between 1996 and 2019 using data from the Global Burden of Disease (GBD) study. The segmented regression method (Joinpoint Regression) was applied to analyze rates among women under and over 40 years of age. To capture differences in the level and trend of mortality and DALYs, the rate ratio was calculated for the two groups on a year-by-year basis.

Results: Regarding DALY, an average annual decline of 0.7% (95%CI -0.8 to -0.5, p<0.01) was observed among women over 40 years old, while an annual increase of 1.0% (95%CI 0.9 to 1.1, p<0.001) was noted for women up to 40 years old. For mortality, the decline among older women was 0.3% per year (95%CI -0.4 to -0.2, p<0.001), and the increase among young women was 0.8% per year (95%CI 0.7 to 1.0, p<0.001). The average rate ratio for DAILY was 5.2, while for mortality, the average rate ratio was 8.1.

Conclusion: the analysis reinforces the idea that the magnitude and trend of breast cancer mortality among young women is a health issue requiring attention from health decision-makers. This diagnosis underscores the importance of initiating discussions on the need to review population screening criteria, incorporating clinical prediction rules.