Prevalence of respiratory complications in long-term survivors of childhood and adolescent cancer: a systematic review and meta-analysis.

Background: Improved survival after childhood and adolescent cancer has led to a growing population of long-term survivors, yet the burden of late respiratory complications remains poorly quantified. In this study, the prevalence of respiratory complications in long-term survivors was quantified, and associated risk factors were identified. Methods: A systematic review and meta-analysis were performed. PubMed, Embase, Web of Science, Cochrane Central Register of Controlled Trials (CENTRAL), China National Knowledge Infrastructure (CNKI), Wanfang, and China Science and Technology Journal Database (VIP) were searched from inception to December 30, 2025, for studies reporting respiratory outcomes in 5-year survivors diagnosed with malignancy before age 21 years. The primary outcome was prevalence, defined as the proportion of survivors affected at the time of assessment. Two reviewers independently screened studies, extracted data, and assessed risk of bias using the Newcastle-Ottawa Scale (NOS). Pooled prevalence was estimated using random-effects models. Results: A total of 11 studies involving 128,509 survivors were included. Study quality was generally high (NOS scores 7-9). The pooled prevalence of any respiratory complication was 35% [95% confidence interval (CI): 30-40%], though limited by extreme heterogeneity (I Conclusions: Respiratory complications affect approximately one-third of long-term survivors. Higher prevalence was associated with greater treatment intensity and longer follow-up. Lower prevalence among more recently diagnosed survivors suggests evolving treatment strategies may be reducing long-term pulmonary toxicity.