Introduction Low-grade serous ovarian cancer (LGSOC) is a rare disease with limited treatment options. The aim of this study was to evaluate the efficacy of bevacizumab in the management of LGSOC, focusing on the impact on progression-free survival (PFS) and overall survival (OS), both in the first-line setting and the recurrent setting.

Methods A single-centre, observational, retrospective cohort study was conducted on 162 patients diagnosed with LGSOC treated at the University Hospitals Leuven, Belgium. Twenty-nine patients received bevacizumab in first-line setting and 16 in recurrent setting. Demographics, treatment modalities and clinical data were collected, and survival analyses were performed. Multivariate Cox regression was employed to assess the impact of surgical outcome and platinum-sensitivity on OS.

Results In the first-line setting, no significant difference in PFS and OS was observed. Multivariate Cox regression analysis accounting for FIGO staging and surgical outcome showed a trend towards improved OS with bevacizumab in the first-line setting (HR: 0.679; p=0.333). Furthermore, the importance of complete cytoreductive surgery was observed (HR: 0.380), either by primary debulking surgery or interval debulking surgery. In the recurrent setting, the bevacizumab group showed a significantly longer median PFS (14 months vs. 11 months, p=0.036) and OS (145 months vs. 72 months, p=0.024) compared to the chemotherapy-alone group.

Conclusion/Implications This study provides evidence supporting the potential benefit of bevacizumab in the management of LGSOC, with improvements observed in PFS and OS, particularly in recurrent disease. Additionally, these results highlight the significance of complete cytoreductive surgery in improving the outcome.