Effect of Age at Diagnosis on the Prognosis of Gastric Cancer Patients: A Population-Based Study in Georgia

Abstract

Introduction: The national burden of gastric cancer (GC) is high in Georgia, which is determined by its high mortality and low survival. The study aimed to estimate the effect of age at diagnosis on the prognosis of GC patients diagnosed between 2015 and 2020 in Georgia. Materials and methods: We obtained data for the study from the national population-based cancer registry. All patients 15 years of age or older, diagnosed during 2015-2020 with invasive GC (site codes C16.0 to C16.9, International Classification of Diseases for Oncology), were eligible for inclusion in the analysis. We produced survival curves using the Kaplan-Meier method, and the log-rank test was used to compare survival between groups. Hazard ratios (HR) were estimated using univariate Cox proportional models and multivariate Cox proportional hazard models. The endpoint of the study was overall survival (OS). The level of statistical significance of the study findings was estimated using p-values and 95% confidence intervals (CI). A p-value<0.05 was considered statistically significant. Results: A total of 1,828 gastric cancer cases were included in the statistical analysis. The average age of patients was 65 years. The bivariate Cox’s regression analysis demonstrated that the risk of gastric cancer mortality increased gradually with the age of cancer patients. The HR and 95% CI were as follows: 1.5 (1.1-1.8) and 2.1 (1.5-2.5) in the 46-65 years and >65 years groups, respectively, with the <46 years group as a reference. Moreover, multivariable Cox’s regression analysis proved that age is an independent risk factor for GC mortality (HR = 1.4; 95% CI = 1.2-1.8; p<.001). Conclusion: We found that age at diagnosis was a significant predictor of the worse survival of GC patients diagnosed between 2015 and 2020 in Georgia.