Impact of Routine Follow-Up Examinations on Life Expectancy in Ovarian Cancer Patients: A Simulation Study

Abstract
Objective The clinical benefit of routine follow-up in patients treated for ovarian cancer is subject to debate. In this study, the magnitude of the potential survival benefit of routine examinations was evaluated by Markov modeling. Methods The clinical course of ovarian cancer was simulated using a 4-state nonstationary Markov model. Risk of recurrence and mortality probabilities were derived from individual patient data and Statistics Netherlands. The life expectancy was simulated for 3 follow-up scenarios: a current, withholding (all recurrences detected symptomatically), and perfect follow-up program (all recurrences detected asymptomatically). The impact of effective recurrence treatment in the future was modeled by varying the mortality ratio between patients with asymptomatically versus symptomatically detected recurrences. The model was validated using empirical data. Results The mean life expectancy of patients, aged 58 years and in complete clinical remission after primary treatment, was 10.8 years. Varying the transition probabilities with ±25% changed the life expectancy by up to 1.1 years. The modeled life expectancy for the withholding and perfect follow-up scenarios was also 10.8 years and insensitive to model assumptions. In patients with stages IIB to IV, the life expectancy was 7.0 years, irrespective of follow-up strategy. A mortality ratio of 0.8 for patients with asymptomatically versus symptomatically detected recurrences resulted in a gain in life expectancy of 5 months for withholding versus perfect follow-up. Conclusions Routine follow-up in ovarian cancer patients is not expected to improve the life expectancy. The timing of detection of recurrent ovarian cancer is immaterial until markedly improved treatment options become available.