Rana, Navpreet

Background and objectives: Area of residence may adversely affect survival and outcomes in many cancers. The objective of this study was to evaluate the impact of geographical and demographic disparities on survival of patients with colorectal cancer. Materials and methods: Data were obtained from the National Cancer Database (NCDB) colon, rectosigmoid, and rectal datasets. Patients were categorized by area of residence, namely, metropolitan (MA), urban (UA), or rural (RA). Sociodemographic and tumor-related data were collected and analyzed to evaluate variables affecting overall survival (OS). Results: In total, 973,139 patients between 2004 and 2013 were included in the study, of which 83%, 15%, and 2% were MA, UA, and RA residents, respectively. RA and UA patients were mostly white male with low income and no comorbidities. In univariate analysis, OS was worse for RA (hazard ratio [HR] 1.10) and UA (HR 1.06) colorectal cancer patients than that for MA colorectal cancer patients. In multivariate analysis revealed significant association between OS and geographic residence, with worse OS for RA (HR 1.02, p = 0.04) and UA (HR 1.01, p = 0.003) patients. Black (HR 1.14) and Native American (HR 1.17) patients had worse outcomes, while Asians (HR 0.8), women (HR 0.88), and patients with higher income had improved OS (HR 0.88). Conclusion: The differences in the OS for RA and UA patients with colorectal cancer were significantly driven by economic disparity. Area of residence represents an important factor independently limiting access to care, particularly in geographically isolated individuals.

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<0.001; multivariate HR=1.04; p<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<0.01). From quality of care standpoint, UA patients median days to undergo surgery (28 vs. 33; p<0.01) post diagnosis was significantly sooner, with significantly fewer positive margins (6.3% vs. 6.9%; p<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.

e19047 Background: Colorectal cancer is one of the leading causes of cancer deaths in the US. Area of residence affects survival in many cancers, though largely unknown in colorectal cancer. The purpose of this study is to evaluate disparities between the metropolitan, urban and rural populations and the impact on survival in colorectal cancer. Methods: Data was obtained from the National Cancer Database (NCDB) colon, rectosigmoid, and rectal data sets. Patients (pts) were categorized by area of residence: metropolitan (MA), urban (UA), or rural (RA). Gender, race, insurance status, income, marital status, and tumor related data was collected. Univariate and multivariate analyses were performed to evaluate variables affecting overall survival (OS). Results: A total of 973,139 pts, spanning 2004-2013 were included in the study, 83% MA, 15% UA, 2% RA. RA and UA pts were more likely to be white than MA pts (92.7 v 91.4% v 83%). RA and UA were more likely to have lower income, with slightly lesser amounts of women and pts with no comorbidities. Uninsured rates were similar (3.3%). On univariate analysis, OS was worse for RA (HR 1.10) and UA (1.06) pts, as compared with MA. On multivariate analysis, small differences persisted with worse OS for RA (HR 1.02, p = .043) and UA (HR 1.01, p = .003). Black (HR 1.14) and native American (HR 1.17) pts had worse outcomes, while Asian (HR 0.8) pts had improved OS. Women (HR 0.88) and pts with higher incomes ( > 46K or 63K) had improved OS (HR 0.88). Conclusions: This study identifies socio-demographic disparities in colorectal cancer outcomes. Pts from rural and urban areas had worse OS, even though the proportion of minority pts with poor outcomes was lower. The difference in OS for RA and UA remained statistically significant in multivariate analysis, though it was largely corrected when adjusting for influencing variables. Part of this difference may be due to economic disparities, as lower income was linked to worse OS. This can independently limit access to care, especially for geographically isolated individuals. Additional research efforts are needed in order for us to better understand the key issues facing and the optimal means to improve outcomes in at risk populations.

Background: Gastric cancer is one of the leading causes of cancer-related mortality worldwide, accounting for 8.2% of cancer-related deaths. The purpose of this study was to investigate the geographic and sociodemographic disparities in gastric adenocarcinoma patients. Methods: We conducted a retrospective study in gastric adenocarcinoma patients between 2004 and 2013. Data were obtained from the National Cancer Data Base (NCDB). Univariate and multivariable analyses were performed to evaluate overall survival (OS). Socio-demographic factors, including the location of residence [metro area (MA) or rural area (RA)], gender, race, insurance status, and marital status, were analyzed. Results: A total of 88,246 [RA, N = 12,365; MA, N = 75,881] patients were included. Univariate and multivariable analysis showed that RA had worse OS (univariate HR = 1.08, p < 0.01; multivariate HR = 1.04; p < 0.01) compared to MA. When comparing different racial backgrounds, Native American and African American populations had poorer OS when compared to the white population; however, Asian patients had a better OS (multivariable HR = 0.68, p < 0.01). From a quality of care standpoint, MA patients had fewer median days to surgery (28 vs. 33; p < 0.01) with fewer positive margins (6.3% vs. 6.9%; p < 0.01) when compared to RA patients. When comparing the extent of lymph node dissection, 19.6% of MA patients underwent an extensive dissection (more than or equal to 15 lymph nodes) in comparison to 18.7% patients in RA (p = 0.03). Discussion: This study identifies socio-demographic disparities in gastric adenocarcinoma. Future health policy initiatives should focus on equitable allocation of resources to improve the outcomes.

INTRODUCTION: 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 by gastric cancer. METHODS: We conducted a retrospective study, analyzing different socio-demographic factors associated with populations affected by gastric cancer between 1973 and 2015. Data was obtained from the Surveillance, Epidemiology, and End Results (SEER) database. Univariate and multivariate analyses were performed to evaluate disease-specific survival (DSS) and overall survival (OS). Different socio-demographic factors including location of residence, that is urban area (UA) or rural area (RA), gender, race, insurance status and marital status were included in the analyses. RESULTS: A total of 68,959 [RA, N = 6,841; UA, N = 60,282] patients were included in the study. The incidence of gastric cancer was noted to have a steady decline during the studied time period, in both RA and UA. Majority of the study population was non-Hispanic white (N = 42,806, 62%) and male (N = 46,504, 67%). Univariate and multivariate analysis showed that RA had the worst DSS (univariate - HR = 1.15, P < 0.001; multivariate - HR = 1.13, P < 0.001) and OS (univariate - HR = 1.13, P < 0.001; multivariate HR = 1.11; P < 0.001) compared to UA. Similarly, DSS and OS was poor in uninsured and single patient population compared to insured patients and married couples respectively. Multivariate analysis further showed female patients had better DSS (HR = 0.91, P < 0.001) and OS (HR = 0.88, P < 0.001) in comparison to their male counterparts. CONCLUSION: This study identifies socio-demographic disparities in gastric cancer. 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.