Frailty as a Key Clinical Indicator in Older Patients with Advanced Lung Cancer: A Systematic Review and...

Frailty is a core geriatric syndrome with significant implications for palliative care, affecting prognosis and quality of life in older patients with advanced lung cancer, yet comprehensive evidence on its prevalence and influencing factors is limited. This study aims to estimate the prevalence of frailty in older patients with advanced lung cancer receiving nonsurgical treatment and to identify associated factors.

Following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we systematically searched 10 databases (including PubMed, Embase, and Web of Science) from inception to August 2025. Observational studies and clinical trials reporting frailty prevalence were included. A random-effects model using the Freeman-Tukey double arcsine transformation was used to calculate the pooled prevalence. Subgroup analyses and sensitivity analyses were conducted. Quality was assessed using the NOS, Joanna Briggs Institute, Cochrane, and Methodological Index for Non-Randomized Studies (MINORS) scales, and the certainty of evidence was evaluated using the Grading of Recommendations Assessment, Development, and Evaluation approach.

Twenty-five studies, encompassing 8643 patients, were included. The pooled frailty prevalence was 41.0% (95% confidence interval: 32.3%-50.0%), but heterogeneity was extremely high (I² = 98.8%; 95% prediction interval: 5.7%-83.1%). Subgroup analysis indicated that the type of frailty assessment tool, age stratification, and study design were major sources of heterogeneity. Malnutrition, pain, depression, treatment toxicity, and poor functional status were closely associated with frailty.

The frailty burden in older patients with advanced lung cancer receiving nonsurgical treatment is high, but the prevalence varies significantly depending on the population and assessment method. Frailty assessment should be individualized and embedded into routine palliative care, and individualized intervention strategies should be developed targeting modifiable risk factors.