Immunological and nutritional predictive factors in patients receiving pembrolizumab for the first-line treatment of non-small cell lung cancer

Immune checkpoint inhibitors (ICIs) have prolonged the survival of patients with various carcinomas, including non-small cell lung cancer (NSCLC), and have caused a paradigm shift in cancer treatment. Although programmed death-ligand 1 (PD-L1) expression in tumor cells is a predictive marker of therapeutic efficacy, additional predictive markers are required. This study aimed to explore the role of immunological and nutritional parameters in the prediction of treatment response.Patients diagnosed with NSCLC and treated with pembrolizumab were examined retrospectively. Body weight was measured 4-6 weeks before the start of the first treatment, immediately before treatment, and 4-6 weeks after the start of the first treatment. Progression-free survival (PFS) was defined as the time from the start of pembrolizumab treatment to the last follow-up date or until disease progression. Statistical analyses were performed to confirm the association between various factors and association between these factors and PFS.Thirty-eight patients with advanced NSCLC were included. We observed a significant association of weight loss and PD-L1 expression with PFS in the multivariate analysis. A significant correlation was found between the advanced lung cancer inflammation index and neutrophil-to-lymphocyte ratio. A weight loss of > 5% after the start of treatment was significantly associated with worse PFS.Weight loss is an important negative prognostic factor in patients with NSCLC receiving immunotherapy. Weight maintenance may be important for good ICI treatment efficacy, and future interventions in cancer cachexia are expected to further enhance the treatment efficacy of ICIs.