Breast Cancer Screening in Latin America: The Challenge to Move from Opportunistic to Organized-Systematic Screening

Background: Breast cancer is the leading cause of death from cancer among women in Latin America. Most Latin American countries started national mammogram screening programs a decade ago. The implementation level and effects of screening programs in Latin America have not been evaluated. Aim: To evaluate the association between screening programs implementation and breast cancer mortality in selected North American and European countries compared to a group of Latin American countries with national screening programs. Methods: The study applied an ecological design with secondary data from official national and international sources. Join point regression analysis was conducted to describe the trends in mortality rates in a group of five Latin American countries (Brazil, Chile, Colombia, Costa Rica and Mexico) with five Non-Latin American countries (Canada, Spain, Sweden, United Kingdom and the United States of America). The association between screening and mortality rates was explored using correlation and linear regression. National cancer plans were assessed to describe screening strategies among selected countries. Results: A significant reduction in standardized breast cancer mortality rates was observed in all Non-Latin American countries with an Average Annual Percent Change (AAPC) of -2.00 (p<.05, 95%CI -3.33, -0.70) for the period 2010-2020. In contrast, Latin American countries reported a significant increase in the AAPC of +1.38 (p<.05, 95%CI 0.86,1.76) in breast cancer mortality rates for the period 2010-2020. For Latin American countries, with screening rates below 50%, there was no correlation between screening and mortality rates for the period 1985-2020 (r = -0.17, p = .78). For non-Latin American countries, with screening rates over 70%, the linear regression model explained significantly 55% of the variance in mortality rates (R2aj =.55, F (5,14) = 5.69, p = .005), with a negative and significant effect of mammogram screening on mortality rates (β = -0.14, p = .01). The National Plans analysis revealed an opportunistic screening model for Latin American countries and an organized-systematic model in Non-Latin American countries. Conclusion: There is an association between the level of implementation of screening programs and mortality rates from breast cancer. Latin American countries should transform their opportunistic strategy into an organized-systematic model.