Bevacizumab in frontline chemotherapy improved the survival outcome for advanced ovarian clear cell carcinoma: a multicenter retrospective analysis
Advanced ovarian clear cell carcinoma (OCCC) is associated with poor outcomes owing to chemoresistance. Bevacizumab (Bev) is increasingly being used to treat advanced ovarian cancer; however, its efficacy in OCCC remains unclear. This study evaluated the treatment outcomes of frontline bevacizumab chemotherapy in patients with OCCC. This retrospective multi-institutional study included patients diagnosed with advanced OCCC at eight institutions in Japan between 2008 and 2018. Patients were categorized into pre and post-market groups based on the Bev approval dates. Progression-free survival (PFS) and overall survival (OS) were analyzed using univariate and multivariate methods. Additionally, patients were classified into Bev-treated (Bev+) and non-Bev-treated (Bev-) groups, and their prognoses were compared. A total of 96 patients were in the pre-market group and 82 in the post-market group. The post-market group had a significantly higher proportion of patients with poor performance status and patients who underwent interval debulking surgery (p<0.01 and p<0.01, respectively). Univariate analysis demonstrated a better PFS in the post-market group (p=0.041). In multivariate analysis, better PFS (hazard ratio [HR]=0.52; p=0.002) and OS (HR=0.47; p=0.002) were observed in the post-market group than in the pre-market group. Bev+ patients had significantly better PFS and OS than Bev- patients in univariate (p<0.001 and p<0.001, respectively) and multivariate analyses (PFS: HR=0.36; p<0.001 and OS: HR=0.21; p=0.001, respectively). Incorporating Bev into frontline chemotherapy may improve outcomes in patients with advanced OCCC.