SP 5.01 Cost-Effectiveness Analysis of Laparoscopic vs. Open Distal Gastrectomy for Locally Advanced Gastric Cancer Based on TNM Stage: A Markov Model
Min Lai, Jianling Zhang, Wenzhen YuanAbstract
Background
Although laparoscopic distal gastrectomy (LDG) and open distal gastrectomy (ODG) show comparable oncological outcomes in locally advanced gastric cancer (LAGC), the long-term cost-effectiveness of LDG remains unclear in China.
Methods
A Markov model with three health states (stable disease, progression, death) was developed using 5-year follow-up data from the CLASS-01 trial. Incremental cost-effectiveness ratio (ICER), quality-adjusted life years (QALYs), incremental QALYs, and costs were calculated from the Chinese healthcare system perspective. Cost-effectiveness was determined using willingness-to-pay (WTP) thresholds. One-way and probabilistic sensitivity analyses assessed model robustness.
Results
In stage I patients, LDG yielded 0.29 additional QALYs at an extra cost of $819.33, resulting in an ICER of $2,829.98/QALY (below WTP threshold), indicating cost-effectiveness. In stage II and III patients, ODG dominated LDG by providing higher QALYs at lower or similar cost (stage II: incremental QALY -0.14, incremental cost +$1,073.62; stage III: incremental QALY -0.22, incremental cost +$913.41). Sensitivity analyses confirmed that LDG cost was the most influential parameter, but base-case conclusions remained robust. Probabilistic sensitivity analysis showed LDG became more cost-effective at higher WTP thresholds in stage I, whereas ODG was consistently preferred in stages II–III.
Conclusion
LDG is cost-effective for stage I LAGC, while ODG is the preferred strategy for stage II and III disease in China. These findings support stage-specific surgical selection and inform clinical decision-making and healthcare resource allocation nationwide.