Gastric cancer occurring at a younger age, referred to as early-onset gastric cancer (EOGC), represents 2–8% of all cases. This study aimed to define and describe this younger patient population using registry data. Patient records from the German Cancer Registry Group of the Society of German Tumor Centers—Network for Care, Quality and Research in Oncology (ADT) between 2000 and 2016 were examined. Age percentiles were used to stratify histological subtypes of gastric adenocarcinoma, allowing precise identification of EOGC. Demographics, tumor characteristics, therapeutic approaches, and survival outcomes were analyzed.
Out of 46,110 patients, the youngest 20% displayed a higher prevalence of signet ring cell carcinoma (SRCC), surpassing the combined occurrence of diffuse and intestinal subtypes; this group, with a median age of 53, was designated as EOGC. Female representation was slightly lower in EOGC compared to older patients (43% vs. 45%; p < 0.001). Younger patients more frequently presented with aggressive disease: poorly differentiated tumors (G3/4: 77% vs. 62%), advanced T stage (T3/4: 51% vs. 48%), nodal involvement (57% vs. 53%), and distant metastasis (35% vs. 30%; p < 0.001). Curative treatment was less commonly administered (42% vs. 52%; p < 0.001). Despite these adverse features, five-year survival was higher in the EOGC cohort (44% vs. 31%; p < 0.0001), with age identified as an independent predictor of better prognosis (HR 0.61; p < 0.0001). Using a population-based approach, this study objectively defines the EOGC population and highlights that, although younger patients present with more aggressive tumors and are less frequently treated curatively, their survival is superior to that of older patients, with younger age serving as a strong independent predictor of improved outcome.
