Assessment of Health-Related Quality of Life in Gastric Cancer Patients: A Cross-Sectional Study in North-Eastern Kazakhstan

Background/Objectives: Gastric cancer severely affects health-related quality of life (HRQoL). This study evaluated HRQoL profiles and identified clinical, functional, and symptom correlates among gastric cancer patients in Kazakhstan. Methods: A cross-sectional study was conducted in a single-center cohort (n = 387) using validated Russian-language European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire-Core 30 (EORTC QLQ-C30) (Kazakh verbal clarification provided when needed, n = 12). Hierarchical multivariable linear regression was performed to identify factors independently associated with Global Health Status/QoL (GHS). Results: Mean GHS score was 51.9 ± 24.3. Major reported symptom burdens included stomach area pain, fatigue, and anxiety. In the final adjusted regression model (Step 3), GHS was significantly predicted by older age (ß = −0.21, p < 0.001), pain (ß = −0.37, p < 0.001), body image (ß = −0.12, p = 0.035), and functional domains: physical (ß = −0.20, p = 0.022), role (ß = 0.14, p = 0.026), emotional (ß = 0.32, p < 0.001), and cognitive functioning (ß = −0.14, p = 0.018). Employment categories also remained significant predictors: white-collar (ß = 0.09, p = 0.044), service sector (ß = 0.20, p < 0.001), blue-collar (ß = 0.19, p < 0.001), and retired (ß = 0.16, p = 0.022). Anxiety showed a positive association with GHS (ß = 0.24, p < 0.001), reflecting a statistical suppression effect, whereas fatigue (ß = −0.02, p = 0.745) was not significant after controlling for covariates. Conclusions: HRQoL in gastric cancer patients is strongly associated with physical symptom burden, age, and functional status. Targeted pain management, psychological support, and holistic care should be prioritized in routine oncology practice.