The impact of breast cancer screening among younger women in the Barretos Region, Brazil.

AIM To verify the impact of breast cancer screening in women aged 40-49 years in one region of Brazil. PATIENTS AND METHODS This is a cross-sectional study, targeted to asymptomatic women aged 40-69 years who had breast cancer screening mammography performed between January 2003 and December 2007. Logistic regression was used to estimate the risk of breast cancer by age groups (40-49, 50-59, 60-69 years). RESULTS Of the 27,133 screened women, 51.9% (14,082) were aged between 40-49 years. The odds ratio (OR) of breast cancer among the 45-49 year age cohort was not significantly different from that of 60 to 69-year-old women (OR=0.64; 95% Confidence Interval 0.39 to 1.03). CONCLUSION The risk of breast cancer among women aged 45 to 49 years is equivalent to that of women aged 60 to 69 years, indicating that breast cancer screening in this region of Brazil should start at the age of 45 years or immediately thereafter.