Cancer cachexia syndrome and clinical outcome in patients with metastatic non-small cell lung cancer treated with PD-1/PD-L1 inhibitors: results from a prospective, observational study

Background: Cancer cachexia syndrome (CCS) is an adverse prognostic factor in cancer patients undergoing chemotherapy or surgical procedures. We performed a prospective study to investigate the effect of CCS on treatment outcomes in patients with non-oncogene driven metastatic non-small cell lung cancer (NSCLC) undergoing therapy with programmed cell death protein 1 (PD-1)/programmed death ligand 1 (PD-L1) inhibitors. Methods: Patients were categorized as having cancer cachexia if they had weight loss >5% in the last 6 months prior to immunotherapy (I-O) initiation or any degree of weight loss >2% and body mass index (BMI) <20 kg/m2 or skeletal muscle index at the level of third lumbar vertebra (LSMI) <55 cm2/m2 for males and <39 cm2/m2 for females. LSMI was calculated using computed tomography (CT) scans of the abdomen at the beginning of I-O and every 3 months thereafter. Results: Eighty-three patients were included in the analysis and the prevalence of cancer cachexia at the beginning of I-O was 51.8%. The presence of CCS was associated with inferior response rates to ICIs (P<0.001) and consisted an independent predictor of increased probability for developing disease progression as best response to treatment, OR =8.11 (95% CI: 2.95-22.40, P<0.001). In the multivariate analysis, the presence of baseline cancer cachexia consisted an independent predictor for inferior survival, HR =2.52 (95% CI: 1.40-2.55, P=0.002). Reduction of LSMI >5% during treatment did not affect overall survival (OS; P=0.40). Conclusions: CCS is associated with reduced PD-1/PD-L1 inhibitor efficacy in NSCLC patients and should constitute an additional stratification factor in future I-O clinical trials. Further research at a translational and molecular level is required to decipher the mechanisms of interrelation of metabolic deregulation and suppression of antitumor immunity.