Quality of Life Measures in Advanced Endometrial Cancer: A Systematic Review of Reporting Practices in Phase III Clinical Trials

<b>Background:</b> Advanced endometrial cancer is associated with poor survival. With the advent of molecular classification and novel systemic therapies-including immunotherapy and targeted agents-treatment regimens have become increasingly complex. While these approaches aim to improve survival, they also potentially introduce long-term toxicities and treatment burden, reinforcing the importance of incorporating health-related quality of life (HRQoL) and patient-reported outcomes (PROs) into clinical trials. <b>Methods:</b> A systematic review was conducted of phase III randomized controlled trials (RCTs) in advanced, recurrent, or metastatic endometrial cancer evaluating systemic treatment registered on ClinicalTrials.gov and published up to 30 November 2025. Extracted data included study characteristics, HRQoL instruments, reporting formats, adherence to CONSORT-PRO, and timing of HRQoL dissemination (relative to primary efficacy reports). <b>Results:</b> Eight phase III RCTs published between 2020 and 2024 were included. Although HRQoL was consistently designated as a secondary endpoint, reporting within pivotal efficacy publications was limited. Most reports presented mean changes from baseline using the EORTC QLQ-C30, QLQ-EN24, and EQ-5D-5L. None of the primary reports reported time-to-deterioration analyses or the proportions of patients improving/deteriorating. Adherence to CONSORT-PRO was low, with only a minority of items addressed. Dedicated QoL publications were delayed by up to 25 months after primary efficacy reports and typically appeared in journals with lower impact factors. <b>Conclusions:</b> Despite routine inclusion of HRQoL measures in trial protocols, reporting remains inconsistent, limited in scope, and often delayed. Strengthening adherence to established frameworks is essential to ensure that HRQoL endpoints are predefined, analytically robust, and disseminated alongside efficacy data-particularly in a rapidly evolving therapeutic landscape.