1225 Gastric Adenocarcinoma Incidence and Incidence-Based Mortality: A Population-Based Study of 62,863 Cases From the Surveillance, Epidemiology and End Results (SEER) Program Over Last Four Decades

Abstract

INTRODUCTION: Gastric cancer (GC) is the third deadliest cancer worldwide therefore tracking its morbidity and mortality trends is necessary to identify the most susceptible population groups, and develop targeted clinical management strategies. METHODS: We searched the SEER 9 databases to investigate the incidence and incidence-based mortality (IBM) rates of gastric adenocarcinoma (GAC) from 1973 to 2015 according to patients' gender, age, race, state of residence, and GAC stage. We analyzed the annual percent change (APC) of the incidence and IBM of GAC via Joinpoint® regression software. RESULTS: We analyzed 62,863 GAC cases. GAC incidence and IBM rates decreased by 1.66% and 1.53% (P < 0.001) annually, respectively (Table 1). Incidence rates were highest among males, African Americans, and patients aged 65 years or more, whereas the IBM rates were the highest among males, American Indians, Alaska Natives, Asians and Pacific Islanders and patients aged 65 years or older. GAC incidence in stomach cardia increased by 0.66% annually, while GAC incidence in the antrum and lesser curvature decreased by 1.77% and 3.04% annually, respectively. Likewise, GAC IBM in stomach cardia increased by 0.52%, while GAC IBM in antrum and lesser curvature decreased by 1.4% and 2.2% annually, respectively. Geographically, the incidence and IBM rates of GAC decreased in all states over the study period. Notably, Hawaii (HI) had the highest incidence and IBM rates (Table 2). Also, we found that cardia GAC was the most prevalent sub-type in all states except HI, where antrum GAC was the highest. CONCLUSION: Despite an overall decrease in GAC incidence and IBM, there is an increase in cardia GAC, which may be secondary to rise in obesity and alcohol consumption along with decrease in H. pylori prevalence. The incidence rate of GAC is higher in HI, Michigan and Connecticut, which is in concordance with the published data from State Cancer Profiles between 2011-2015. We could not evaluate the underlying risk factor for each state due to study's nature; however, the higher incidence rates in HI may be attributed to genetic environmental interactions, as supported by migrant studies. In conclusion, we were able to outline trends in incidence and IBM of GAC in USA over last four decades, which suggest a need for tailoring treatment and preventive strategies to fit each state population.