S80 Clinical and Socioeconomic Determinants of Survival in Gallbladder and Biliary Adenocarcinoma

Abstract

Introduction: Cholangiocarcinomas (CCAs) are the second most common primary hepatic malignancy, accounting for 20% of hepatobiliary cancer deaths and among the lowest 5-year survival rates. A recent analysis of Surveillance, Epidemiology and End Results (SEER) data reported the incidence of intrahepatic CCAs was rising by 128%. Gallbladder cancers, while representing only 1.2% of global cancer diagnoses, account for 1.7% of all cancer deaths. There have been limited studies on the significance of socioeconomic status and environmental factors on gallbladder and biliary cancer survival. Methods: We extracted U.S. survival data from the SEER Database for biliary and gallbladder adenocarcinomas from 1975 to 2016 for individuals >30 years of age. Demographic data included age, sex, race, marital status. Clinical information included date of diagnosis, primary cancer site, tumor grade, survival time, and chemotherapy status. We included relevant county-level socioeconomic data: smoking, poverty level, education, adjusted household income, percent of foreign-born persons, and percent urban population. Relative hazard ratios for death in the 5-year period following diagnosis were calculated with Cox proportional hazards models, adjusted for covariates, with significance set at p< 0.05. Data were analyzed using SAS 9.4 software and R. Results: There were 19,328 gallbladder, 14,237 intrahepatic biliary, 16,078 extrahepatic biliary, and 9,566 ampulla of Vater cancer cases. Results are summarized in Table. Survival was lower with older age at time of diagnosis and in men (p< 0.001). When stratified according to race/ ethnicity, Asians and Pacific Islanders had higher survival (p< 0.001) while Blacks had the lowest survival (p< 0.001). Divorced, separated, single, or widowed patients had worse survival outcomes compared to married patients (p< 0.001). Counties with the highest income quartile had the highest survival rates, while those with the highest percentage of people below the poverty level had the lowest (p< 0.05). College education level was associated with better survival outcomes (p< 0.001). Conclusion: Higher income and education level as well as Asian/ Pacific Islander ethnicity were associated with higher survival among gallbladder and biliary malignancies. Blacks and patients from counties with the most people below the poverty level had worse survival outcomes. Future studies should help determine potential etiologies for these findings and develop strategies to improve outcomes.Table 1.: Cox proportional hazard ratio for 5 year mortality following diagnosis; CI = confidence interval.