Most patients with lung cancer experience cancer cachexia (CC), a syndrome of skeletal muscle and adipose tissue wasting. Knowledge of body composition changes in patients is limited, however, because most studies have been cross-sectional, comparing patients with non-cancer controls or patients with and without CC.

Few studies, in contrast, have evaluated body composition in patients with lung cancer over time. This review examines our current understanding of longitudinal body composition changes in patients with lung cancer and identifies modifying factors contributing to variation in muscle and adipose tissue wasting, focusing on biological sex.

We identified 32 studies conducting longitudinal measurements of body composition by computed tomography, bioelectrical impedance, dual x-ray absorptiometry or total body nitrogen, with a total of n=3,951 patients (35% female). All studies evaluated changes following diagnosis while patients were receiving treatment.

Most studies reporting muscle-specific outcomes show decreased skeletal muscle mass, with more pronounced muscle wasting in males and male-enriched populations. In a small number of studies reporting muscle density, the majority show increased myosteatosis.

Adiposity changes are less frequently reported, although wasting appears more prevalent in late-stage disease. Further studies are needed to define adipose changes along the lung cancer continuum.

Our review emphasizes the need for balanced recruitment based on biological sex and sex-based analyses. Additionally, consensus reporting of relevant patient data and outcomes in future studies will allow for meta-analysis and assist in the development of effective treatments for lung CC.