Twenty years of colon cancer epidemiology and treatment patterns in São Paulo, Brazil: A population-based analysis of observed vs. expected treatment utilization.

Abstract

e13625 Background: Colon cancer disproportionately impacts survival in individuals living in low to middle-income countries, with higher incidence-to-mortality ratios compared to high-income countries. In this large retrospective cohort study, we examine the stage distribution and survival outcomes for colon cancer over time in São Paulo, Brazil, and compare observed treatment prescription to model-based estimates. Methods: Using the São Paulo Oncocentre Foundation (FOSP) database, we identified patients diagnosed with colon cancer between 2000 and 2019. Demographic, socioeconomic, and cancer diagnosis and treatment variables were extracted. Survival data was analyzed using Kaplan-Meier curves. Actual chemotherapy, radiotherapy and surgery utilization were compared to estimates of optimal treatment utilization based on published models. Results: 32,065 cases of colon cancer were included in this cohort. 49% were male, and the median age was 63. Most patients presented with late-stage disease (30.3% with stage III and 28.4% IV). Stage distribution has remained stable over time. The median overall survival ranged from 13.7 years for those with stage I disease, to 1 year with stage IV disease. Actual chemotherapy utilisation was higher than expected for stage I and stage II disease, but lower than expected for stage III and IV disease. The use of surgery was lower than expected for Stage I-III disease, and higher than expected for stage IV disease. Conclusions: The stage distribution of colon cancer in São Paulo, Brazil has remained stable over time, while survival has improved. Despite this, gaps exist between expected and optimal treatment utilization, highlighting areas for further research and investment.