Hidehiko Akashi

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.

SLFN11 is a BRCA Independent Biomarker for the Response to Platinum-Based Chemotherapy in High-Grade Serous Ovarian Cancer and Clear Cell Ovarian Carcinoma

Abstract BRCA1/2 mutations are robust biomarkers for platinum-based chemotherapy in epithelial ovarian cancers. However, BRCA1/2 mutations in clear cell ovarian carcinoma (CCC) are less frequent compared with high-grade serous ovarian cancer (HGSC). The discovery of biomarkers that can be applied to CCC is an unmet need in chemotherapy. Schlafen 11 (SLFN11) has attracted attention as a novel sensitizer for DNA-damaging agents including platinum. In this study, we investigated the utility of SLFN11 in HGSC and CCC for platinum-based chemotherapy. SLFN11 expression was analyzed retrospectively by IHC across 326 ovarian cancer samples. The clinicopathologic significance of SLFN11 expression was analyzed across 57 advanced HGSC as a discovery set, 96 advanced HGSC as a validation set, and 57 advanced CCC cases, all of whom received platinum-based chemotherapy. BRCA1/2 mutation was analyzed using targeted-gene sequencing. In the HGSC cohort, the SLFN11-positive and BRCA mutation group showed significantly longer whereas the SLFN11-negative and BRCA wild-type group showed significantly shorter progression-free survival and overall survival. Moreover, SLFN11-positive HGSC shrunk significantly better than SLFN11-negative HGSC after neoadjuvant chemotherapy. Comparable results were obtained with CCC but without consideration of BRCA1/2 mutation due to a small population. Multivariate analysis identified SLFN11 as an independent factor for better survival in HGSC and CCC. The SLFN11-dependent sensitivity to platinum and PARP inhibitors were validated with genetically modified non-HGSC ovarian cancer cell lines. Our study reveals that SLFN11 predicts platinum sensitivity in HGSC and CCC independently of BRCA1/2 mutation status, indicating that SLFN11 assessment can guide treatment selection in HGSC and CCC.