Interactions of lung cancer with adipose and muscle tissue in the development of cancer cachexia

Introduction: Cancer cachexia (CC) is often experienced by lung cancer patients (LCP). It is associated with shrinkage of skeletal muscle mass, immobility, reduced quality of life, and shorter patient survival. Brown (BAT) and white adipose tissue (WAT), plus abdominal muscle mass play a role in the development of CC. Aims: We aimed to find out whether and how adipose and muscle tissue interacts with LC in CC. Methods: Retrospectively, 200 LCP and 30 healthy controls (HC) were analysed for BAT activation via fluorine-18 deoxyglucose positron emission tomography/computed tomography. Mean standardized uptake values (SUVmean) of predefined regions of interest (ROI) in the retroclavicular fat were measured, normalized to liver uptake and reported as SUV ratio (SUVR). ROIs from transversal CT images were used to quantify visceral adipose (VAT) and abdominal muscle mass. Prospectively, 50 LCP were likewise analysed for BAT activation and additionally underwent bioelectrical impedance analysis to assess body composition and analysis of circulating adipokines via enzyme-linked immunosorbent assay. Results: LCP showed higher SUVR in BAT than the HC. Higher SUVR in BAT was associated with lower BMI (r=-0.38) and reduced VAT (r=-0.44). LCP with higher SUVR in BAT were associated with significant weight loss (odds ratio 2.3, P Conclusions: LCP express higher BAT activity than HC, which is correlated with CC. Adiponectin is associated with BAT activation and leaner body composition.