Real-World Evaluation of the Efficacy of Third-Line Treatment Regimens for Advanced Gastric Cancer: A Single-Center Retrospective Study.

AIMS/BACKGROUND: The optimal regimens of third-line treatments for advanced gastric cancer have yet to be identified. This study aimed to evaluate the therapeutic efficacy of different third-line treatment regimens and to identify prognostic factors affecting patient outcomes following third-line therapy. Additionally, it sought to evaluate treatment-related adverse events and economic costs associated with different regimens, thereby providing a theoretical basis to guide the selection of third-line treatment regimens.

METHODS: In this real-world retrospective study, data were collected from patients diagnosed with advanced gastric cancer who fulfilled predetermined inclusion criteria. Survival outcomes between different groups were compared using Kaplan-Meier survival curves and the log-rank test. Cox proportional hazards regression analysis was employed to identify prognostic factors of patients with advanced gastric cancer after receiving third-line treatment.

RESULTS: A total of 145 patients were included and divided into three groups: 45 patients in the chemotherapy-alone group, 58 patients in the immunotherapy/targeted therapy group, and 42 patients in the chemotherapy + immunotherapy/targeted therapy group. Survival analysis revealed a median survival time (MST) of 7.7 months (95% confidence interval [CI]: 6.8-8.5) for the overall cohort, while the chemotherapy + immunotherapy/targeted therapy group demonstrated the longest MST (MST: 10.5 months; 95% CI: 8.9-12.1), followed by the immunotherapy/targeted therapy group (MST: 8.5 months; 95% CI: 7.1-9.9). Regression analysis showed that a history of gastric surgery was an independent prognostic factor (hazard ratio [HR] = 0.639; 95% CI: 0.431-0.948; p = 0.026) for gastric cancer patients following third-line treatment. Regarding adverse events, the chemotherapy + immunotherapy/targeted therapy group exhibited the highest incidence (90.5%), followed by the chemotherapy-alone group (75.6%). Cost analysis showed that the chemotherapy + immunotherapy/targeted therapy group incurred the highest overall cost, and both total treatment costs and anti-tumor drug-related costs were positively correlated with patient survival (r2 = 0.2656 and 0.3081, respectively).

CONCLUSION: Patients receiving third-line chemotherapy combined with immune or targeted therapy achieve the longest MST; however, this regimen is also associated with a higher incidence of adverse events and overall treatment costs.