PERSEVERE: longitudinal assessment of quality of life and treatment toxicities in Chinese breast cancer patients – a multicentre cohort study protocol

Introduction Survival outcomes for early-stage breast cancer have improved substantially; however, many survivors experience persistent treatment-related toxicities that adversely affect long-term quality of life (QoL) and functional recovery. Prospective survivorship data from China remain limited. The PERSEVERE study aims to characterise longitudinal trajectories of QoL and treatment-related toxicities among Chinese women treated for stage I–III breast cancer and to identify factors associated with suboptimal recovery. Methods and analysis PERSEVERE is a prospective, multicentre, observational cohort study enrolling approximately 3000 women with newly diagnosed stage I–III invasive breast cancer across cancer centres in China. Data are collected at baseline and serially for up to 5 years, including clinical variables, a validated suite of patient-reported outcome measures collected via a centralised REDCap electronic platform and baseline biospecimens. The primary outcome is the change in the European Organisation for Research and Treatment of Cancer (EORTC) QLQ-C30 global health status/QoL score from baseline to 12 months. Longitudinal and time-to-event analytical approaches appropriate for observational cohort studies will be applied, with exploratory analyses planned to investigate symptom trajectories and biological correlates. Ethics and dissemination The study protocol (ID: NCC25/629-5575) has been approved by the Independent Ethics Committee of the National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences. Written informed consent will be obtained from all participants. Study findings will be disseminated through peer-reviewed open-access publications and presentations at national and international conferences, with summaries shared with clinicians and patient advocacy groups. Trial registration number NCT07010939 .