Temporal trends in cancer-specific survival for early-onset gastric cancer: Insights from a 21-year cohort.

Abstract

e22549 Background: Despite advancements in cancer care, Early-Onset Gastric Cancer (EOGC), defined as gastric cancer diagnosed in individuals under 50 years of age, remains a unique clinical challenge. Understanding temporal trends in diagnosis, disease stage distribution, and treatment modalities is critical for optimizing management strategies. This study examines the evolving landscape of EOGC over the past two decades using data from the Surveillance, Epidemiology, and End Results (SEER) database. Methods: A retrospective cohort of 13,385 patients diagnosed with EOGC from 2000 to 2021 was extracted using SEERStat software, identifying cases with the ICD-O-3 site/morphology code for the stomach. Cause-specific survival (CSS), defined as time from diagnosis to death from gastric cancer, was the primary endpoint. Temporal trends in CSS were analyzed using linear regression, while differences in stage at diagnosis, time to treatment, and treatment modalities were evaluated using chi-square tests. Results: The distribution of EOGC diagnosis from 2000 to 2021 showed significant variability across 5-year defined time intervals, with highest proportion of cases occurring in in the most recent time interval of 2016-2021, comprising of 29.72 % of the total cases (p<0.0001).When evaluated by stage of the disease, the distant stage group accounts for the largest proportion of cohort when compared to regional or localized stage (34.03 % vs 17.45% vs 14.86 %, p<000.1).Notably, 50.28% of patients did not undergo surgical intervention, while 11.88% received partial gastrectomy and 5.06% underwent total gastrectomy. Chemotherapy utilization was observed in 61.86% of patients, whereas 21.28% received radiation therapy.Time to treatment was predominantly within 30 days (0–15 days: 30.83%; 16–30 days: 29.37%, p < 0.001). CSS event rates declined significantly over time, indicating improved survival (slope: -0.0174, R² = 0.668). Conclusions: The increasing incidence of EOGC in recent years, coupled with a high proportion of advanced-stage diagnoses, highlights the need for earlier detection and optimized treatment strategies. While CSS event rates have declined over time, indicating improved survival trends, the substantial proportion of patients not undergoing surgery raises concerns about barriers to curative intent therapy. Future studies should focus on identifying determinants of treatment disparities and evaluating novel therapeutic strategies to further improve outcomes in EOGC. Time to treatment distribution. Time to treatment (days) N (%) 0-15 2690 (30.83%) 16-30 2563 (29.37%) 31-60 2400 (27.50%) 61-90 635 (7.28%) 91-120 211 (2.42%) >120 227 (2.60%) p value <0.001