Abstract 6228: Spatial regression analysis for colorectal cancer mortality rates in Puerto Rico: 2012-2016 and 2017-2021

Abstract Objective: Despite efforts to improve screening and early detection, colorectal cancer (CRC) remains a leading cause of cancer-related deaths in Puerto Rico. This study aimed to analyze the spatial distribution of CRC mortality rates (MR) in Puerto Rico during two time periods—2012-2016 (before Hurricane Maria) and 2017-2021 (after Hurricane Maria, earthquakes, and the onset of the COVID-19 pandemic) to identify factors contributing to the observed mortality rates. Methods: Age-adjusted CRC MR for 2012-2016 and 2017-2021 were obtained from the Puerto Rico Central Cancer Registry (PRCCR). Sociodemographic data were sourced from the American Community Survey using the tidycensus R package. The study included 34 treatment centers across Puerto Rico and employed Spatial Cross-Regressive Models (SLX) to examine the influence of factors such as distance to treatment centers, median income, transportation access, and age distribution on CRC MR. Statistical analyses were conducted using R version 4.4.1 (R Foundation for Statistical Computing) and R-Studio (Posit Software, PBC). Results: In simple models, distance to treatment centers significantly impacted CRC mortality in both periods but with reduced influence in 2017-2021 (2012-2016: coefficient = -0.5, p < 0.01; lag coefficient = -37.6, p < 0.01 vs. 2017-2021: coefficient = -0.37, p < 0.05; lag coefficient = -28.9, p < 0.05). In multivariate models, additional sociodemographic factors were significant in 2012-2016, including: Proportion of workers without vehicles (coefficient = 3.22×102, p < 0.01; lag coefficient = 2.55×104, p < 0.01), Median income (coefficient = 7.03×10-3, p < 0.01; lag coefficient = 5.24×10-1, p < 0.01), and Proportion of inhabitants aged 18 or younger (coefficient = 5.6×102, p < 0.01; lag coefficient = 3.95×104, p < 0.01). However, in 2017-2021, these variables were no longer significant, suggesting the impact of systemic disruptions from disasters and the pandemic. Conclusions: The findings indicate that CRC mortality in Puerto Rico is driven more by sociodemographic factors such as income and transportation access than by geographic proximity to treatment centers. The reduced significance of these factors in 2017-2021 emphasizes the need for further studies to understand the compounded effects of natural disasters and the COVID-19 pandemic. Addressing disparities in transportation, income, and healthcare accessibility is essential to reducing CRC mortality in Puerto Rico. Citation Format: Brenda C. Torres-Velásquez, Liliana M. Castro-Jiménez, Carlos R. Torres-Cintrón, Elba V. Caraballo. Spatial regression analysis for colorectal cancer mortality rates in Puerto Rico: 2012-2016 and 2017-2021 [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2025; Part 1 (Regular Abstracts); 2025 Apr 25-30; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2025;85(8_Suppl_1):Abstract nr 6228.