In this study, we sought to explore the importance of selected myokines in a homogenous population of patients with gastric cancer characterized by high rates of Cancer-Associated Cachexia [CAC]. Myokine levels in peripheral blood were compared between patients with and without cachexia to identify mediators potentially involved in the pathogenesis of CAC. Moreover, we compared myokine concentrations in paired samples of portal and peripheral blood to verify whether they are released by the primary tumour. Finally, a label-free quantitative proteomics was applied to explore other potential circulating mediators of CAC and to analyse their interactions with myokines.