Modeling treatment outcomes for patients with advanced ovarian cancer: Projected benefits of a test to optimize treatment selection

Objective For patients with advanced stage epithelial ovarian cancer (EOC), substantial emphasis has been placed on diagnostic tests that can discern which of two treatment options – primary cytoreductive surgery (PCS) or neoadjuvant chemotherapy followed by interval cytoreductive surgery (NACT+ICS) – optimizes patient-level outcomes. Our goal was to project potential life expectancy (LE) gains that could be achieved by use of such a test. Methods We developed a microsimulation model to project LE for patients with stage IIIC EOC. We compared: a "standard-of-care" strategy, in which patients were triaged to PCS vs. NACT+ICS based on current clinical practice; and a "test" strategy, in which patients were triaged based on results of a hypothetical test. We identified those test performance characteristics for which the test strategy outperformed the standard-of-care strategy, from a LE standpoint. Effects of parameter uncertainty were evaluated in sensitivity analysis. Results Even with a perfect test, the LE gain was modest (LE with test vs. standard-of-care strategy=67.6 vs. 66.4months; LE gain=1.2months). In order to outperform the standard-of-care, the test had to have a high probability of correctly identifying "resectable" patients at PCS (i.e. those for whom complete or optimal cytoreduction would be possible); this test property was more important than correct triage of unresectable patients to NACT+ICS. Results were sensitive to the proportion of patients whose underlying disease was resectable at PCS. Conclusion Diagnostic tests that are designed to triage patients with advanced stage EOC will likely have only a modest effect on LE.