Abstract 3434: Neighborhood obesogenic environment and the risk of prostate cancer: The Multiethnic Cohort
Authors: Tao Li , Gomez Scarlett L. , Shariff-Marco Salma , Yang Juan , Park Song Yi , Albright Cheryl , Monroe Kristine , Henderson Brian , Kolonel Laurence , Le Marchand Loic , Wilkens Lynne , Cheng Iona 
Published: July 2016

Abstract
Background: Obesity is a potentially modifiable risk factor for advanced prostate cancer (PCa). However, the role of the neighborhood obesogenic environment, characterized by obesity-related built and social environment measures, has not been evaluated in relation to PCa risk.
Objective: To examine the association of neighborhood obesogenic environment with PCa risk in African American (AA), Japanese American (JA), Latino (LA), and White (WH) men in the California component of the Multiethnic Cohort (MEC) Study.
Method: Individual-level sociodemographic data and health behaviors were linked with neighborhood measures of built and social environment for 42,850 men in the MEC, who predominately live in Los Angeles County. A principal components factor analysis was used to create indices based on 10 measures—neighborhood SES, population density, total businesses, recreational facilities, retail food environment, restaurant environment, parks, street connectivity, commuting by car, and traffic density—resulting in 4 obesogenic environment indices: physically active, low SES urban, businesses density, and unhealthy food. During a mean follow-up of 15 years and through linkage to the California Cancer Registry, 4,775 incident PCa cases were identified. Multivariable Cox proportional hazards regression was used to estimate hazard ratios (HR) and 95% confidence intervals (CI) for associations between each index and PCa risk, overall and stratified by race/ethnicity and disease aggressiveness. For Latinos, additional stratified analyses were conducted by nativity.
Results: Associations between the obesogenic indices and PCa risk varied by race/ethnicity. WH residing in low business environments experienced lower PCa risk (quintile [Q] 1 [low] vs. Q5 [high]: HR, 0.56 [95% CI, 0.41-0.77], p-trend: 0.0002). Among AA, unhealthy food environments were associated with greater risk of aggressive disease (advance stage or Gleason score &gt; = 7) (more vs. no: HR, 1.36 [95% CI, 1.09-1.70], p-trend: 0.0026). Among LA, living in Hispanic enclaves was associated with reduced risk (Q3-5 [high] vs. Q1-2 [low]: HR, 0.86 [95% CI, 0.75-0.98]), but living in high business environments was associated with increased risk of PCa (Q1 [low] vs. Q5 [high]: HR, 1.35 [95% CI, 1.05-1.73], p-trend: 0.0002) for those born in the US (p-trend: 0.0059). Lower SES urban environments were associated with a decreased risk of non-aggressive disease among LA (Q5 [low] vs. Q1 [high]: HR, 0.78 [95% CI, 0.63-0.98], p-trend: 0.0026), and was more marked among foreign-born (p trend = 0.0074) than US-born (p trend = 0.1211).
Conclusions: Built and social environment factors are associated with PCa risk, but their associations varied by race/ethnicity, nativity (among LA), and disease aggressiveness. An unhealthy food environment was strongly associated with the risk of aggressive prostate cancer in AA men, warranting further investigation into the underlying mechanisms.
Citation Format: Li Tao, Scarlett L. Gomez, Salma Shariff-Marco, Juan Yang, Song Yi Park, Cheryl Albright, Kristine Monroe, Brian Henderson, Laurence Kolonel, Loic Le Marchand, Lynne Wilkens, Iona Cheng. Neighborhood obesogenic environment and the risk of prostate cancer: The Multiethnic Cohort. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3434.