Incidence trends, demographic disparities, and survival outcomes of gastrointestinal malignancies in young adults: A focus on stomach and pancreatic cancers.

339 Background: The incidence of gastrointestinal (GI) cancers has been rising among younger populations. While prior research has highlighted the increasing incidence of colorectal cancer (CRC) in adolescents and young adults (AYA), defined as individuals aged 15-39, there is less focus on non-CRC GI malignancies, such as stomach and pancreatic cancers, within this age group. This study aims to further elucidate the incidence, mortality, and demographic disparities in the AYA population for stomach and pancreatic cancers compared to older populations (>50 years old). Methods: Data was extracted from the SEER database spanning from 2000 to 2020. Demographic, clinical, and secondary cancer characteristics were summarized across the sample, stratified by cancer type. Overall survival (OS) and disease-specific survival (DSS) were analyzed using the Kaplan-Meier method, with comparisons performed via the log-rank test. Univariate and multivariate analyses were conducted to identify predictors of survival outcomes. Results: We identified 19,983 AYA patients diagnosed with non-CRC GI malignancies (including esophageal, stomach, small intestine, anal, hepatobiliary, and pancreatic cancers) between 2000 and 2020. Among these patients, the majority were male (58%), White (47%), and resided in metropolitan areas (90%). The median age at diagnosis was 38 years. Pancreatic cancer was 20% more common in the AYA group compared to those over 50 years old (12%), while stomach cancer was also more prevalent in the AYA group (27% vs. 17%). Survival outcomes were significantly better in the AYA group, with a median OS of 24 months compared to 9 months in the older population, and a median DSS of 52 months versus 13 months (p<0.001). Predictors of worse OS and DSS included male sex, African American race, income below $45,000/year, lack of surgical intervention, and delayed initiation of treatment. Conclusions: The incidence of stomach and pancreatic cancers is notably higher in the AYA population compared to older adults, with AYA patients demonstrating better overall and disease-specific survival outcomes. However, certain demographic factors, such as male sex, African American race, and lower income, are associated with worse survival, underscoring the need for targeted interventions to address these disparities. Early diagnosis and timely treatment are critical to improving outcomes in this younger population.