Survival in stage IV ovarian cancer with increased use of debulking surgery and bevacizumab

Abstract

Objectives: Advanced ovarian cancer has a poor prognosis, with a 5 year survival probability of <30%. Attempts to improve survival have focused on debulking surgery and systemic therapy. We assessed the evolution of treatment patterns and survival of patients with advanced epithelial ovarian cancer with specific attention to changes in survival after introducing bevacizumab.

Methods: Population based data from the Belgian Cancer Registry were coupled with administrative reimbursement data from the compulsory health insurance organizations and the national database where date of death is registered, based on the patient's unique national number. Patients with epithelial ovarian cancer stage IV diagnosed in 2004-17 were included. The proportion of patients who underwent debulking surgery and received bevacizumab was calculated per incidence year. Survival was compared for the three incidence periods (2004-08, 2009-13, 2014-17) and before and after the introduction of bevacizumab.

Results: 2034 patients with stage IV epitheial ovarian cancer were included. From 2012 onwards, uptake of bevacizumab increased, with 50% of patients with stage IV ovarian cancer diagnosed in 2017 receiving bevacizumab. The proportion of stage IV patients who underwent debulking surgery also increased over time, from 21.1% in 2004-08 to 50.4% and 45.4% in 2009-13 and 2014-17, respectively. The 3 year observed survival probability fluctuated between 27% and 42% without a trend over time. The increase in debulking surgery was associated with improved survival (hazard ratio (HR) 0.88, 95% confidence interval (CI) 0.79 to 0.98) but the introduction of bevacizumab was not (HR 0.94, 95% CI 0.85 to 1.03). For patients diagnosed in 2004, the mean cost per patient treated with oncological drugs was about €12 500, which doubled to about €25 000 for patients diagnosed in 2014 or later.

Conclusions: Despite a rise in the use of debulking surgery and the introduction of bevacizumab into clinical practice, no improvement in 3 year survival probability was observed for patients with advanced ovarian cancer in Belgium.

Keywords: Medical Oncology; Ovarian Cancer; Surgery.