Trends, Risk Factors, and Survival Outcomes in Stomach Cancer: A Retrospective Analysis of National Cancer Registry Data (2005–2022).

Stomach cancer remains a major global health challenge, particularly in low- and middle-income countries where late-stage diagnosis, limited access to treatment, and absence of structured screening contribute to poor survival outcomes. Despite international advancements in early detection and multimodal therapy, population-level data capturing long-term trends, risk factors, and clinical outcomes in these regions are scarce. To evaluate temporal trends, clinical characteristics, diagnostic stage, treatment patterns, and survival outcomes of stomach cancer in a nationally representative cohort from 2005 to 2022, and to identify independent predictors of advanced-stage presentation and cancer-specific mortality. A retrospective, population-based cohort study was conducted using de-identified data from the National Cancer Registry. Patients aged ≥18 years with histologically confirmed stomach cancer (ICD-O-3: C16.0–C16.9) were included. Descriptive statistics summarized baseline features. Temporal trends in incidence and mortality were assessed using line plots. Multivariable logistic regression identified risk factors for advanced-stage presentation, while Cox proportional hazards modelling evaluated predictors of mortality. Kaplan-Meier and cumulative incidence analyses estimated overall and subgroup-specific survival. Geographic disparities were visualized through heatmaps and bubble charts. Among 8,750 eligible patients, 64.8% were male, and 61.8% were diagnosed at Stage III or IV. Adenocarcinoma accounted for 60.2% of cases. While a modest decline in mortality was observed after 2012, incidence remained stable. Surgical intervention was the predominant treatment (41.3%), with low uptake of radiotherapy (10.5%). Multivariable analysis identified male sex, low socioeconomic index, mucinous histology, and central geographic region as significant predictors of late-stage diagnosis (p < 0.001). Five-year overall survival was 34.2%, ranging from 80.1% in Stage I to 4.9% in Stage IV. Cox regression revealed Stage IV (HR 5.87), mucinous histology (HR 1.42), and low SES (HR 1.36) as independent mortality predictors. Regional disparities in survival and mortality were significant. This national registry-based analysis reveals persistent late-stage diagnoses, limited treatment accessibility, and substantial geographic and socioeconomic disparities in stomach cancer outcomes. The findings underscore the urgent need for early detection strategies, decentralization of oncologic care, and equitable access to multimodal treatment. These insights provide a critical foundation for national gastric cancer control policies and future risk-stratified screening initiatives.