Survival in advanced-staged ovarian cancer treated without cytoreductive surgery—a systematic review and exploratory meta-analysis

Objective Cytoreductive surgery is the cornerstone of ovarian cancer treatment. However, a substantial proportion of patients do not undergo surgery, and for this clinically relevant subgroup, survival outcomes are not well defined and treatment strategies differ considerably. This study evaluates overall survival in women with non-surgically treated ovarian cancer and provides a comprehensive overview of their further treatment. Methods Studies reporting survival in non-surgically treated patients with ovarian cancer were included. Those lacking relevant data, involving successful surgery only or other malignancies were excluded. Risk of bias was assessed with ROBINS-I. Survival and treatment data were extracted and pooled to evaluate overall survival and compare treatment strategies. This systematic review followed PRISMA guidelines and was registered in PROSPERO. Results Out of 5759 records screened, 15 observational studies were included. Most studies had moderate to serious risk of bias; four were excluded from quantitative analysis due to critical bias. Reasons for non-surgical management included poor performance status, disease progression, and patient preference. Median overall survival for patients treated with chemotherapy alone ranged from 7.8 to 19.5 months, with a pooled survival of 13.18 months(95%CI:4.83–21.53; I 2 =87.2%). For patients who did not receive systemic therapy, median overall survival ranged from 1.2 to 5.0 months. Hazard ratios comparing chemotherapy alone to chemotherapy plus cytoreductive surgery yielded a pooled hazard rate of 1.95(95%CI:1.67–2.27; I 2 =58.9%). Treatment regimens varied widely but mainly included platinum-based chemotherapy with paclitaxel. Only two studies analyzed treatment regimens in relation to overall survival, showing inconsistent results. Conclusions Patients with advanced ovarian cancer who do not undergo cytoreductive surgery had better survival when they received chemotherapy, though outcomes remain poorer than chemotherapy with surgery. Serious risk of bias and heterogeneity underscore the need for focused, prospective research in this population.