This retrospective, multicenter cohort study aimed to determine whether cancer cachexia serves as a biomarker for determining the most effective treatment for patients having non-small-cell lung cancer (NSCLC) with high programmed death ligand 1 (PD-L1) expression treated with immune checkpoint inhibitors (ICIs) alone or combined with chemotherapy (ICI/chemotherapy). We included 411 patients with advanced NSCLC with a PD-L1 tumor proportion score of ≥50%. The patients were treated with pembrolizumab monotherapy or ICI/chemotherapy. Cancer cachexia was defined as a weight loss of >5% of the total body weight or a body mass index of <20 kg/m2 coupled with an additional weight loss of >2% within 6 months before starting treatment. Eighty-five (21%) patients met the cancer cachexia criteria. Overall survival (OS) was significantly shorter in patients with cachexia than in those without cachexia in both the pembrolizumab monotherapy group (17.2 vs. 35.8 months, p < 0.001) and the ICI/chemotherapy group (27.0 months vs. not reached, p = 0.044). However, after stratifying by cancer cachexia status, no significant difference in OS was observed between the pembrolizumab monotherapy and chemoimmunotherapy groups, regardless of cachexia. In conclusion, ICI/chemotherapy offers limited benefits for NSCLC patients with high PD-L1 expression and concurrent cancer cachexia. Considering the frailty associated with cachexia, ICI monotherapy may be preferred to ICI/chemotherapy for these patients. New interventions that can better address the negative prognostic impact of cachexia in patients treated using ICIs with or without chemotherapy remain warranted.
Keywords: Cancer cachexia; combination therapy; immune checkpoint inhibitor; non-small cell lung cancer; treatment outcome.