Abstract PR006: Temporal Trends in the Incidence of Obesity-Associated Cancers in Puerto Rico, 2000–2022: Disproportionate Increases Among Younger Adults

Abstract Purpose: Obesity is a growing public health crisis and a known risk factor for several malignancies. Rising trends in obesity-associated cancers have been documented in the United States and globally, yet data specific to Puerto Rico remain limited. This study aims to characterize the burden and temporal trends of obesity-associated cancers (OAC) among adults in Puerto Rico from 2000 to 2022. Methods: We analyzed invasive cancer cases diagnosed between 2000 and 2022 among adults aged ≥20 years using data from the Puerto Rico Central Cancer Registry. OACs were defined according to CDC criteria and included esophageal adenocarcinoma, gastric cardia, colorectal, liver, gallbladder, pancreas, multiple myeloma, postmenopausal female breast, corpus and uterus (not otherwise specified), ovary, kidney, meningioma, and thyroid cancers. Age-adjusted incidence rates for 2018–2022 were standardized to the 2000 U. S. population. Temporal trends were assessed using Joinpoint regression to estimate Average Annual Percent Change (AAPC) by sex, age and cancer type. Data for 2017 are based on the first half due to Hurricane Maria; 2020 was excluded due to COVID-19 disruptions. Results: Between 2018 and 2022, 35, 468 cases of OACs were reported, with an overall rate of 213. 18 per 100, 000 population. From 2000 to 2022, the incidence of OACs increased significantly, with an average annual percentage change (AAPC) of 1. 4%, while non-obesity-associated cancers remained stable (AAPC = 0. 1%). Women showed statistically significant increases in OACs compared to men (AAPC: 1. 55% vs 1. 11%; p 0. 05, each). Women under 50 had the highest increase in OACs with an AAPC of 4. 9% and 4. 6% among 230-39 and 40-49 years-old, respectively. Similarly, men 20-39 and 40-49 years-oldunder 50 showed significant increases with (AAPCs of: 4. 8%and 3. 8% respectively (, p 0. 05, each) ). The AAPC for men in the 20-39 age group was twice that observed in men aged 50-59. Trends varied by cancer type, sex, and age group. Among men younger than 40, the largest increases were observed for thyroid cancer (AAPC: 7. 5%), kidney cancer (AAPC: 4. 4%), and colorectal cancer (AAPC: 4. 0%). In women under 40, the highest increases occurred in thyroid (AAPC: 6. 1%), colorectal (AAPC: 5. 0%), and uterine cancers (AAPC: 4. 9%). Among individuals aged 40–49, both women and men showed rising trends in colorectal, kidney, and thyroid cancers. In addition, women experienced significant increases in endometrial, ovarian, and pancreatic cancers, while men had increases in multiple myeloma. Conclusions: Obesity-associated cancers are rising at an alarming rate in Puerto Rico, with the steepest increases among adults under 50. The stability of non-obesity-associated cancers highlights obesity's role in driving these trends. These findings underscore an urgent public health challenge and call for comprehensive strategies that promote healthy lifestyles, strengthen obesity prevention and management, and improve the early identification of high-risk individuals. Citation Format: Carola T. Sánchez-Díaz, Génesis Rodríguez-Ortiz, Valeria S. Rivera-Alvarado, Tonatiuh Suárez-Ramos, Carlos R. Torres-Cintrón, Jan C. Gómez-Pérez, Cynthia M. Pérez-Cardona, Karen J. Ortiz-Ortiz. Temporal Trends in the Incidence of Obesity-Associated Cancers in Puerto Rico, 2000–2022: Disproportionate Increases Among Younger Adults abstract. In: Proceedings of the AACR Special Conference in Cancer Research: The Rise in Early-Onset Cancers—Knowledge Gaps and Research Opportunities; 2025 Dec 10-13; Montreal, QC, Canada. Philadelphia (PA): AACR; Clin Cancer Res 2025;31 (23Suppl): Abstract nr PR006.