Efficacy of platinum-based chemotherapy in platinum-resistant ovarian cancer: A systematic review with pooled analysis of outcomes.

Abstract

e18076 Background: Current management of recurrent ovarian cancer (OC) is based on the amount of time between the completion of penultimate platinum-based treatment and the detection of relapse. Patients with platinum-free interval (PFI) < 6 mo. are considered to be platinum-resistant (PROC) and to have low response rate (RR) probability to platinum-based chemotherapy. Methods: We searched PubMed database for all prospective and retrospective full-text articles and abstracts on the treatment of patients with PROC for all years between 01/01/2000 and 01/06/2019 in English language. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) tool was used to ensure transparent reporting of the results. Study inclusion criteria were: 1) morphologically confirmed epithelial ovarian cancer; 2) standard definition of PROC as a disease that recurred within 6 months after completion of platinum-based chemotherapy; 3) treatment with platinum- or non-platinum chemotherapy with agents that are routinely used for OC; 4) no concomitant therapy with targeted or investigational agents; 5) clearly defined RR for patients with PROC and criteria used for response assessment. Pooled analysis of outcomes and multiple linear regression analysis was conducted to assess the impact of platinum salts on probability of response. Results: We identified 7156 articles and screened them for title and abstract. After the review process we selected 197 studies for further analysis. Of them, 52 (n = 1320) and 145 (n = 6937) trials assessed efficacy of platinum- and non-platinum based chemotherapy respectively. Among patients treated with platinum-based and non-platinum chemotherapy RR was 36.04% (95% CI 33.45-38.63) and 14.85% (95% CI 14.01-15.68) respectively. Pooled median progression-free survival was 5.8 mo. and 3.75 mo. respectively. In multiple linear regression model administration of platinum-based chemotherapy was the strongest predictor of objective response with B value 0.503 (p < 0.001). Among platinum agents cisplatin (RR 39.9%: 95% CI 35.8-44.0%) and carboplatin (RR 42.3%; 95% CI 37.0-47.6%) were associated with better rates of objective response compared to oxaliplatin (RR 28.1%; 95% CI 23.9-32.3). Conclusions: This systematic review shows that patients with 'platinum-resistant' ovarian carcinoma may derive significant benefit from reintroduction of platinum agents and their value should be evaluated in further randomized trials.