Research presented in this thesis was driven by the need to inform our current knowledge on Quality of life (QoL) of patients undergoing extensive surgery for advanced ovarian cancer. National Institute for Health and Care Excellence (NICE) commissioned this multicentre prospective observational research to update Interventional Procedure Guideline. Existing evidence supports the utilisation of extensive surgery to achieve complete debulking to improve survival outcomes. The systematic review found no good quality studies to inform QoL outcomes for extensive surgery. The observational study showed significant variation in case selection and surgical intervention across participating centres and patients undergoing extensive surgeries did not report a worse QoL compared to patients having less extensive surgeries. A specific investigation into incidence of acute kidney injury (AKI) as a parallel project showed overall incidence of AKI during treatment of advanced ovarian cancer is high (30%), however, most of these incidences were transient, related to patient’s pre-existing co-morbidities and did not cause major deleterious effect on health within the study period. The result will inform the policy makers, organisations, clinicians and patients and should reassure them regarding use of extensive surgery in advanced ovarian cancer.