The impact of frailty on health outcomes in older adults with lung cancer: A systematic review

•Frailty is associated with adverse outcomes in older adults with lung cancer.•Traditional clinical trial endpoints are the most frequently measured outcomes.•The impact of frailty on quality of life and function remains poorly understood. : Frailty is prevalent in older adults with lung cancer, however the impact of frailty in this population is not well understood. The aim of this review was to evaluate the outcomes that are measured in frail older adults with lung cancer, and to determine the associations between frailty and these outcomes. : A systematic online search of PubMed, EMBASE, and Cochrane databases was conducted to identify all English-language studies between January 2015 and May 2022 prospectively evaluating frailty and outcomes in older adults (median age > 65 years) with lung cancer. Studies were excluded if frailty was defined by a single domain assessment or not clearly defined. Quality was assessed using the Newcastle-Ottawa Scale. : Of 1891 studies screened, 16 met inclusion criteria. The median number of patients was 96 (range 26–494) and the mean age was 76.6 years. Eight different frailty assessments were used, and frailty definitions varied widely. The most frequently assessed outcomes were overall survival (n = 13,81%), treatment-related toxicity (n = 8,50%), hospitalisation (n = 5,31%), and treatment completion/discontinuation (n = 4,25%). Quality of life (n = 3,19%), function (n = 1,6%), frailty trajectory (n = 1,6%), and emergency visits (n = 1,6%) were infrequently assessed. Frailty had a strong and consistent association with mortality (Hazard Ratio range: 3.5–11.91). It was also associated with treatment-related toxicity and treatment selection. The remaining outcomes were not statistically significant. : These data support frailty as an important predictor of mortality in older adults with lung cancer, however further research is warranted to determine the association between frailty and other meaningful endpoints for this vulnerable population.