Abstract
BACKGROUND: Standard of care for adjuvant treatment of stage III endometrial cancer includes chemotherapy and radiation. In addition to stage, tumor molecular profiles may predict treatment outcomes, and prospective clinical trials are ongoing. However, tumor molecular testing is costly and time-consuming. Our objective was to evaluate the cost-effectiveness of tumor molecular testing in stage III endometrial cancer. METHODS: A Markov decision model compared two strategies for stage III endometrial cancer: Tumor Molecular Testing (TMT) versus No TMT. TMT included sequential POLE next generation sequencing, mismatch repair immunohistochemistry (IHC), and p53 IHC. POLE-mutated patients were assigned to adjuvant radiation therapy; all others including controls were assigned to adjuvant chemoradiation. First recurrences were treated with 6 cycles of carboplatin and paclitaxel. Second recurrences were treated with pembrolizumab alone for mismatch repair deficient patients and both pembrolizumab and lenvatinib for other patients. Sensitivity analyses were performed to test model robustness. RESULTS: Compared to No TMT, TMT was cost saving with equivalent effectiveness. On one-way sensitivity analysis, TMT remained cost saving over all parameter ranges. TMT was also favored on probabilistic sensitivity analysis in 80% of iterations at a willingness-to-pay threshold of $100,000/quality adjusted life-year (QALY) gained. However, when TMT was compared to mismatch repair IHC alone, TMT cost $182,798/QALY gained. CONCLUSIONS: In this model of patients with stage III endometrial cancer, TMT was cost saving compared to No TMT. However, when compared to mismatch repair IHC alone, TMT was economically unfavorable.