Immune checkpoint inhibitors (ICIs) therapy has revolutionized the treatment patterns of non-small cell lung cancer (NSCLC). However, patients treated with ICIs may experience immune-related adverse events (irAEs). Markers that could predict the onset of irAEs are still unclear. Here, we report the possible correlation of baseline peripheral lymphocytes with irAEs and clinical outcomes in advanced NSCLC patients receiving ICIs. A total of 109 advanced NSCLC patients treated with ICIs from April 2017 to January 2021 were analyzed retrospectively. Logistic and Cox regression analyses was applied to evaluate independent risk factors for irAEs, progression-free survival (PFS), and overall survival (OS). Among these patients, 55 (50.5%) patients experienced irAEs. The level of CD8+ T lymphocytes at baseline was the independent risk factor for the onset of irAEs (p = 0.008). A higher level of CD8+ T lymphocytes was associated with longer PFS (11.0 months vs. 3.0 months, p < 0.001) and OS (27.9 months vs. 11.7 months, p = 0.014). Furthermore, patients who had higher baseline CD8+ T lymphocytes and experienced irAEs had a longer PFS (18.4 months vs. 2.2 months, p < 0.001) and OS (32.8 months vs. 9.0 months, p = 0.001) than those who had lower CD8+ T lymphocytes and no irAEs. Our study highlights the value of baseline peripheral CD8+ T lymphocytes as a predictive factor for irAEs in advanced NSCLC patients receiving ICIs. In addition, patients who have higher baseline CD8+ T lymphocytes and experience irAEs would have a superior PFS and OS.
Keywords: baseline peripheral CD8+ T lymphocytes; immune-related adverse events; non-small cell lung cancer; prognostic.