Trends, clinicopathological features, surgical treatment patterns and prognoses of early-onset versus late-onset gastric cancer: A retrospective cohort study.

[INTRODUCTION] This study investigates the differences between early-onset gastric carcinoma (EOGC) and late-onset gastric carcinoma (LOGC) by examining trends, demographics, clinical and molecular features, treatments, and outcomes at a leading cancer center in China.

[OBJECTIVES] To delineate the distinctions between EOGC and LOGC in terms of patient characteristics, disease progression, and treatment outcomes, and to suggest appropriate screening strategies.

[METHODS] We analyzed 18,877 gastric carcinoma cases treated at Fudan University Shanghai Cancer Center (FUSCC) from 2000 to 2022. Descriptive statistics were performed using IBM SPSS. Survival rates were assessed via the Kaplan-Meier method and log-rank test, while COX regression analysis identified factors affecting disease-free survival (DFS) and overall survival (OS).

[RESULTS] The average age of gastric cancer diagnosis has increased slightly since 2000, with a steady rise in both EOGC and LOGC cases, though EOGC's proportion has slightly decreased. EOGC had a higher proportion of female patients and was more common in the gastric body and antrum pylorus. EOGC cases showed lower levels of cancer biomarkers, HER2 expression, vascular and lymphatic invasion, and lower differentiation and invasion depth. They also exhibited more advanced N and TNM staging, Borrmann IV type, and low adhesive carcinoma. EOGC underwent more extensive D2 lymphadenectomy and neoadjuvant chemotherapy. There were no significant differences in Claudin18.2 and MMR protein status between EOGC and LOGC. EOGC had higher rates of ovarian and peritoneal metastases, with a better early prognosis but faster late-stage progression.

[CONCLUSION] EOGC and LOGC cases have increased over the past two decades. EOGC presents unique clinical and pathological features, requiring thorough surgical treatment and has a better early prognosis but more rapid late-stage progression. Enhanced screening for younger adults is recommended to address the rising EOGC trend.