Outcomes of Non-High Grade Serous Carcinoma after Neoadjuvant Chemotherapy for Advanced-Stage Ovarian Cancer: Single-Institution Experience

Purpose: Outcomes in patients with ovarian high-grade serous carcinoma (HGSC) treated with neoadjuvant chemotherapy (NAC) have been widely studied; however, there is limited information on responses to chemotherapy among patients with non-HGSC. The aim of this study was to compare the survival outcomes of patients with advanced-stage non-HGSC and HGSC treated with NAC. Materials and Methods: This study was a retrospective analysis of patients with advanced-stage ovarian cancer treated at Yonsei Cancer Hospital between 2006 and 2017. The demographics, chemotherapy response, and survival rates were compared between patients with non-HGSC and those with HGSC. Results: Among 220 patients who underwent NAC, 25 (11.4%) patients had non-HGSC histologic subtypes, and all received a taxane-platinum combination regimen for NAC. Patients with non-HGSC had lower baseline cancer antigen-125 levels (p<0.001), poorer response rates (p<0.001), lower rates of optimal cytoreduction (p=0.003), and poorer progression-free survival (PFS) (median PFS 10.3 months vs. 18.3 months; p=0.009) and overall survival (OS) (median OS 25.5 months vs. 60.6 months; p<0.001), compared to those with HGSC. In multivariate analysis, non-HGSC was a negative prognostic factor for both PFS [hazard ratio (HR), 3.19; 95% confidence interval (CI), 1.73-5.88] and OS (HR, 4.22; 95% CI, 2.07-8.58). Conclusion: In this study, poorer survival outcomes were observed in patients who underwent NAC for treatment of non-HGSC versus those treated for HGSC. Different treatment strategies are urgently required to improve survival outcomes for patients with non-HGSC undergoing NAC.