Abstract 4929: Differences in cancer risk by environmental disparities in Puerto Rico: findings from 2016-2020 cancer data

Abstract Background: Chemical contaminants have been established as risk factors for certain types of cancer including breast and prostate, which are the most commonly diagnosed cancers in Puerto Rico among women and men, respectively. By law, industries report their chemical emissions to air, water, and soil to the Environmental Protection Agency’s Toxic Release Inventory Sites (TRI) program. In 2006, Puerto Rico had 148 TRI facilities across 49 of the 78 municipalities, releasing 518 chemicals, including 170 carcinogens such as arsenic, benzene, radon, and trichloroethylene. This ecological study assesses the strength of the association between cancer risk and municipalities with environmental disparities (contaminated vs. non-contaminated sites) in Puerto Rico. Methods: Cancer incidence data from 2016 to 2020 were obtained from the Puerto Rico Central Cancer Registry. Contaminated sites, defined as municipalities with TRI facilities, were identified using data from the TRI program in 2006 (10 years before the estimation of cancer risk). To estimate cancer risk between contaminated and non-contaminated sites, we calculated the standardized incidence relative risk (RR = standardized rate of contaminated sites / standardized rate of non-contaminated sites) with 95% confidence intervals (95% CI) from 2016 to 2020 by type of cancer and sex. All analyses were conducted using SEER*Stat v8.4.4. Results: Between 2016 and 2020, 71,814 new cancer cases were diagnosed in Puerto Rico, 37,582 among males and 34,232 among females. The RR for residents of contaminated sites showed a significant excess risk of 7% (95%CI: 1.05-1.09, p<0.0001) for all types of cancer compared to residents of non-contaminated sites; similar findings were observed in both men (9%, CI 1.06-1.12, p<0.0001) and women (6%, CI 1.03 -1.09). When evaluating the risk of female-related cancers, excesses of 6% (95%CI: 1.01-1.11, p=0.01) and 24% (95%CI: 1.04-1.49, p=0.02) were observed for breast and ovarian cancers, respectively, among residents of contaminated sites compared to residents of non-contaminated sites. For male-related cancers, an excess risk of 10% (95%CI: 1.06-1.14, p<0.0001) was observed for prostate cancer among residents of contaminated sites compared to residents of non-contaminated sites. Conclusions: Our findings suggest a significant excess in cancer incidence among residents in municipalities with TRI facilities overall and for certain cancer types. These results underscore the need for targeted environmental interventions and public health actions to mitigate exposure to carcinogens in Puerto Rico. Acknowledgments: This study was supported by the Caribbean Climate Change Adaptation, Cancer, and Health Disparities Research Center (CARIB-CARES) funded by the National Cancer Institute (NCI, award # 1P20CA294096-01). Citation Format: Nancy Raquel Cardona, Ana P. Ortiz, Carlos R. Torres, Polaris Torres-Rodríguez, Karen Ortiz-Ortiz, Noreen Michael, Pablo Mendez-Lazaro, Marievelisse Soto-Salgado. Differences in cancer risk by environmental disparities in Puerto Rico: findings from 2016-2020 cancer data [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 4929.