Efficacy of non-platinum chemotherapy in platinumresistant ovarian cancer: a meta-analysis

Background: Recurrent ovarian cancer (OC) patients with platinum-free interval (PFI) < 6 mo. are usually consid- ered platinum-resistant and treated with non-platinum based chemotherapy. There is a lack of evidence to compare various non-platinum therapeutic options in patients with platinum-resistant ovarian cancer (PROC). We conducted meta-analysis to assess efficacy of various therapeutic options in PROC patients. This article aimed to compare non-platinum therapeutic regimens. Methods: We queried the PubMed database for full-text articles on the treatment of PROC patients (01/01/2000-01/06/2019 timeframe). Inclusion criteria were: 1) epithelial ovarian cancer; 2) recurrent disease ≤ 6 mo. after platinum-based chemotherapy; 3) standard therapy with platinum- or non-platinum agents; 4) no targeted therapy, investigational agents or non-platinum doublets; 5) reported response rate (RR) and assessment criteria. Proportion meta-analysis (random-effect model) and beta-regression were conducted to assess efficacy of various options. Statistical analysis was dose with meta and betareg packages of R software. Results: We identified 7156 articles and screened them for title , 157 studies were left for further analysis. Efficacy of non-platinum- and platinum-based therapy was assessed in 113 (n = 5272) and 44 (n = 1055) trials respectively, only the latter were included in this analysis. In meta-proportion random-effect model RR among patients treated with taxanes, etoposide, doxorubicin/PLD, topotecan and gemcitabine were 27 % (95 % CI 0.21-0.34), 19 % (95 % ДИ 0.13-0.27), 15 % (95 % CI 0.11-0.19), 13 % (95 % CI 0.10-0.18) and 10 % (95 % CI 0.07-0.14), respectively. Multiple beta-regression model accounting for response assessment method, number of prior therapy lines and other factors confirmed the results. Conclusions: Taxanes monotherapy may be the most effective therapeutic option for patients who are not candidates for platinum-based chemotherapy.