Abstract A054: Sociodemographic disparities in gastric adenocarcinoma: A population-based study
Authors: Gosain Rohit , Rana Navpreet , Lemini Riccardo , Wang Chong , Mukherjee Sarbajit 
Published: September 2020

Abstract
Background: Gastric cancer is one of the leading causes of cancer-related mortality worldwide, with a global burden of 5.7% new cases each year and 8.2% of cancer-related deaths. Area of residence has been found to affect survival in different cancers but their impact on gastric cancer remains largely unknown. The purpose of this study is to address the potential disparities between the rural and urban populations affected specifically by gastric adenocarcinoma. Methods: We conducted a retrospective study, analyzing different socio-economic factors associated with populations affected by gastric adenocarcinoma between 2004 and 2013. Data was obtained from the National Cancer Database (NCDB). Univariate and multivariable analyses were performed to evaluate overall survival (OS). Different socio-demographic factors, location of residence were included, urban area (UA) or rural area (RA), gender, race, insurance status and marital status were included in the analyses. Results: A total of 88,246 [RA, N=12,365; UA, N=75,881] patients were included in the study. Majority of the study population was white (N = 67,792, 77%) and male (N = 59,574, 68%). Univariate and multivariable analysis showed that RA had the worst OS (univariate - HR=1.08, p&lt;0.001; multivariate HR=1.04; p&lt;0.001) compared to UA. When comparing different racial backgrounds, univariate and multivariable analysis showed Native American and African American population had poor OS when compared to the white population, however, Asian patients tend to have better OS (univariate HR=0.66, multivariable HR=0.68, p&lt;0.01). From quality of care standpoint, UA patients median days to undergo surgery (28 vs. 33; p&lt;0.01) post diagnosis was significantly sooner, with significantly fewer positive margins (6.3% vs. 6.9%; p&lt;0.01) when compared to RA patients. Though, there is no minimum number of lymph nodes examined during resection, but total of 15 or above is an accepted practice. When comparing the lymph node dissection, 19.6% UA patients underwent more than or equal to 15 lymph nodes dissection in comparison to 18.7% patients in RA (p=0.03). Discussion: This study identifies socio-demographic disparities in gastric adenocarcinoma. Access to healthcare, variations in patient care, environmental and lifestyle factors as well as genomic differences are all potential factors that affect the OS. This is consistent with the available literature in gastric cancer, including studies demonstrating survival differences in different populations undergoing surgical treatment in the United States. Based on the above data, it is imperative for future health policy initiatives to address these disparities in an effort to improve OS.
Citation Format: Rohit Gosain, Navpreet Rana, Riccardo Lemini, Chong Wang, Sarbajit Mukherjee. Sociodemographic disparities in gastric adenocarcinoma: A population-based study [abstract]. In: Proceedings of the Twelfth AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2019 Sep 20-23; San Francisco, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(6 Suppl_2):Abstract nr A054.