Colorectal cancer disparities in Latin America: Mortality trends 1990-2019 and a paradox association with human development.

backgroundColorectal cancer mortality is growing in Latin America. It is known for a marked income disparity between its countries, and there is a consistent association with development. Our purpose was to describe trends in colorectal cancer mortality in Latin America between 1990 and 2019, identifying differences by human development categories.

methodsWe extracted age-adjusted mortality rate from the Global Burden of Disease (GBD) Study from 22 Latin American countries, subregions, and country groups previously ranked by the GBD study due to Sociodemographic Index (SDI) between 1990 and 2019. We applied the segmented regression model to analyze the time trend. Also, we estimated the correlation between mortality rates and Human Development Index (HDI) categories for countries.

resultsBetween 1990 and 2019, colorectal cancer adjusted mortality rate increased by 20.56% in Latin America (95% CI 19.75% - 21.25%). Between 1990 and 2004, the average annual percentage change (APC) was 0.11% per year (95% CI 0.10-0.12), and between 2004 and 2019 there was a deceleration (APC = 0.04% per year, 95% CI 0.03%- 0.05%). There is great heterogeneity among the countries of the region. Correlation between these two variables was 0.52 for 1990 and 2019. When separated into HDI groups, the correlation varied in the direction of the association and its magnitude, typifying an effect modification known as Simpson's Paradox.

conclusionsHuman development factors may be important for assessing variation in cancer mortality on a global scale. Studies that assess the social and -economic contexts of countries are necessary for robust evaluation and provision of preventive, diagnostic and curative services to reduce cancer mortality in Latin America.