The pathophysiology of cancer anorexia is complex and serum biomarkers, including growth and differentiation factor(s) (GDF), may be modulated. We explored the association(s) between GDF-15 serum levels and anorexia and, secondarily, with low muscle mass and body weight loss in cancer patients. We considered gastrointestinal and lung cancer patients (CP) and healthy BMI-matched controls. The FAACT-questionnaire was administered to diagnose anorexia and we calculated the L3-SMI by CT scan to assess low muscularity, setting their cutoff values at the lowest tertile. GDF-15 serum levels were assessed by ELISA. We enrolled 59 CP and 30 controls; among CP, 25 were affected by gastrointestinal and 34 by lung cancer. Anorexia was present in 36% of CP. Gastrointestinal CP resulted more anorexic compared to lung CP (p = 0.0067). Low muscle mass was present in 33.9% of CP and L3-SMI was lower in gastrointestinal compared to lung CP (p = 0.049). The GDF-15 levels were higher in CP vs. controls (p = 0.00016), as well as in anorexic vs. non-anorexic CP (p = 0.005) and vs. controls (p < 0.0001). Gastrointestinal CP showed higher GDF-15 levels vs. lung CP (p = 0.0004). No difference was found in GDF-15 between CP with low muscle mass and those with moderate/high muscularity and between patients with body weight loss and those with stable weight. Our data support the involvement of GDF-15 in the pathogenesis of cancer anorexia. The mechanisms of action of GDF-15 in cancer should be further clarified also regarding the changes in muscularity.
Keywords: GDF-15; anorexia; body weight loss; cancer; muscularity; skeletal muscle; tumor-secreted factors; wasting.