Abstract: One non-randomised study met our inclusion criteria. It analysed retrospective data for 194 women with stage IIIC advanced epithelial ovarian cancer who underwent either ultra-radical (extensive) or standard surgery and reported disease specific overall survival and perioperative mortality. Multivariate analysis, adjusted for prognostic factors, identified better disease specific survival among women receiving ultra-radical surgery, although this was not statistically significant (Hazard ratio (HR) = 0.64, 95% confidence interval (CI): 0.40 to 1.04). In a subset of 144 women with carcinomatosis, those who underwent ultra-radical surgery had significantly better disease specific survival than women who underwent standard surgery (adjusted HR = 0.64, 95% CI 0.41 to 0.98). Progression-free survival and quality of life (QoL) were not reported and adverse events were incompletely documented. The study was at high risk of bias. We found only low quality evidence comparing ultra-radical and standard surgery in women with advanced ovarian cancer and carcinomatosis. The evidence suggested that ultra-radical surgery may result in better survival.  It was unclear whether there were any differences in progression-free survival, QoL and morbidity between the two groups. The cost-effectiveness of this intervention has not been investigated. We are, therefore, unable to reach definite conclusions about the relative benefits and adverse effects of the two types of surgery. In order to determine the role of ultra-radical surgery in the management of advanced stage ovarian cancer, a sufficiently powered randomised controlled trial comparing ultra-radical and standard surgery or well-designed non-randomised studies would be required.

Plain-language summary: We systematically searched the scientific literature for reports of studies comparing ultra-radical and standard surgery for women with advanced ovarian cancer. We looked for randomised controlled trials, which are regarded as the best type of study, and for non-randomised studies that were analysed using methods that allow for differences between the groups of women receiving different types of surgery. We found only one relevant non-randomised study. It analysed data for 194 women recruited at one centre. Analysis that allowed for the differences in the extent of disease of the women who received the two different types of surgery found better disease specific survival among women receiving ultra-radical surgery. The best estimate was that their risk of death from ovarian cancer was about one third lower than for women who had standard surgery, but it might actually have been anywhere between 60% lower and 4% higher. However, the extent of disease in these women varied a lot so the authors also analysed only the 144 women whose cancer had spread throughout their abdomen. Again, the best estimate was that their risk of death was about one third lower than for women who had standard surgery, but it might have been anywhere between 60% lower and only 2% lower. Although this result seems to suggest that ultra-radical surgery might be better than standard surgery, we need to be cautious as the study was not well designed nor analysed, so it may be over-estimating the real benefits of ultra-radical surgery. The study did not report all deaths, which would have been a more reliable and more important outcome. Neither did it report any differences between the groups in the time before the cancer progressed. It did not report quality of life (QoL) which would be very important to women with this advanced cancer. The cost-effectiveness of this intervention was not investigated. Therefore, we could not reach any definite conclusions about the relative benefits and adverse effects of the two types of surgery. Better designed, large studies are needed in order to compare ultra-radical and standard surgery for women with advanced ovarian cancer.