Abstract PO-165: Renal cell carcinoma health disparities in American Indians/Alaska Natives and Hispanic Americans
Authors: Valencia Celina I. , Gachupin Francine C. , Hsu Chiu-Hsieh , Chipollini Juan , Lee Benjamin R. , Batai Ken 
Published: December 2020

Abstract
Background: American Indians/Alaska Natives (AIs/ANs) and United States (U.S.)- born Hispanic Americans (HAs) have higher kidney cancer mortality rates compared to non-Hispanic Whites (NHWs). However, causes for the disparities have not been well understood. The aim of our study was to assess if socioeconomic factors and residence pattern (urban vs. rural) account for renal cell carcinoma (RCC) health disparities in AIs/ANs and HAs focusing on advanced stage (stage III/IV) diagnosis and survival. Methods: RCC patients diagnosed between 2004 and 2015 (n=405, 073) in National Cancer Database (NCDB) and between 2007 and 2016 (n=9,982) in Arizona Cancer Registry (ACR) were analyzed. Logistic regression and Cox regression analysis were performed to ascertain the effect of race/ethnicity on stage at diagnosis and overall survival adjusting for patient’s characteristics, including census tract socioeconomic status (SES), Rural-Urban Continuum Codes (RUCC), and other relevant factors. High school graduate rate, median income (or poverty rate), and unemployment rate was used to measure socioeconomic status. In ACR data, sub- distribution Cox proportional hazards regression was performed to study time to death due to RCC accounting for competing risks. Results: There were a total of 405,073 cases in NCDB and 9,982 cases in ACR. In both NCDB and ACR data, AIs/ANs had significantly increased odds of having advanced stage at diagnosis in unadjusted model (OR 1.20, 95% CI: 1.08-1.33 and OR 1.29, 95% CI: 1.06-1.56 respectively in NCDB and ACR), but the association was not significant after adjusting for patient’s characteristics. In both datasets, Mexican Americans had higher odds of having advanced stage diagnosis compared to NHWs (OR 1.22, 95% CI: 1.11-1.35 and OR 2.02, 95% CI: 1.58-2.58 respectively) even after adjusting for patient’s characteristics, including SES and RUCC. In ACR, advanced stage diagnosis was particularly common in U.S.-born Mexican Americans (49.1%) compared to NHWs (26.4%). AIs/ANs showed increased mortality risk in unadjusted model in both datasets (HR 1.10, 95% CI:1.01-1.20 and HR 1.20, 95% CI: 1.05-1.37 respectively in NCDB and ACR). The association was no longer significant in NCDB after adjusting for patient’s characteristics, while it remained significant in ACR (HR 1.33, 95% CI: 1.03-1.72). In Arizona, Mexican Americans had significantly higher risk of mortality compared to NHWs in both unadjusted and adjusted models (HR 2.46, 95% CI: 2.23-2.72 and HR 2.34, 95% CI: 1.93-2.90). The greatest risk of all-cause and RCC-specific mortality was observed in U.S.-born Mexican Americans (HR 3.21, 95% CI: 2.61-3.98 and sub- distribution HR 2.79, 95% CI: 2.05-3.81). Conclusion: RCC disparities in AIs/ANs is partially explained by neighborhood socioeconomic and residence characteristics, but the neighborhood characteristics did not affect the associations for HAs. Greater RCC health disparities were observed among Mexican Americans in Arizona than the national level.
Citation Format: Celina I. Valencia, Francine C. Gachupin, Chiu-Hsieh Hsu, Juan Chipollini, Benjamin R. Lee, Ken Batai. Renal cell carcinoma health disparities in American Indians/Alaska Natives and Hispanic Americans [abstract]. In: Proceedings of the AACR Virtual Conference: Thirteenth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2020 Oct 2-4. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(12 Suppl):Abstract nr PO-165.