Influence of Performance Status on the Effectiveness of Pembrolizumab Monotherapy in First-Line for Advanced Non-Small-Cell Lung Cancer: Results in a Real-World Population

Simple Summary Monotherapy with pembrolizumab is the standard of first-line treatment for patients with advanced non-small-cell lung cancer (NSCLC) and a programmed Death ligand-1 (PD-L1) tumor proportion score (TPS) >= 50%. However, pembrolizumab outcomes in real-world settings seem to be lower than those obtained in randomized clinical trials (RCTs). In this study, we analyzed a cohort of 88 patients with advanced NSCLC and PD-L1 TPS >= 50% treated in first-line with pembrolizumab and we investigated the influence of the Eastern Cooperative Oncology Group Stage Performance Status (ECOG PS) as a possible prognostic factor of survival. Our study showed that patients with PS >= 2 had poorer pembrolizumab outcomes with a significantly lower rate of response, progression-free survival (PFS) and overall survival (OS). ECOG PS was the only prognostic factor of PFS and OS identified. To confirm these results, patients with PS >= 2, should be studied in RCTs and include other tools to evaluate patients' PS more objectively. The KEYNOTE-024 clinical trial showed promising results for pembrolizumab in the first-line of treatment of advanced non-small-cell lung cancer (NSCLC). However, the profile of patients in real-world practice differs from those included in this clinical trial. Here, an observational single-center retrospective study was performed through a comparative analysis of clinical outcomes after pembrolizumab therapy according to the Eastern Cooperative Oncology Group Stage Performance Status (ECOG PS). Moreover, univariate and multivariate analyses were carried out to detect prognostic factors. In our cohort, 63.7% of patients had an ECOG PS of 0-1. Regarding response rate, 31.8% of patients had a partial response (PR), 19.3% had stable disease (SD) and 23.9% had progression disease. On the other hand, patients with ECOG PS >= 2 showed a significantly lower rate of PR and SD to pembrolizumab than patients with a PS of 0-1. The rate of response, median overall survival (OS) and progression-free survival (PFS) were significantly higher in patients with ECOG PS 0-1 than in those with ECOG PS >= 2. In the current study, we found ECOG PS as the only independent predictor of OS and PFS. Due to the ECOG PS scale being a subjective parameter, other tools are needed to identify treatment effectiveness to each patient.