Purpose
Immune checkpoint inhibitors (ICIs) have significantly improved the outcomes of patients with cancer; however, these agents may initiate immune-related adverse events (irAEs). Previous studies have demonstrated a robust correlation between disease prognosis and the occurrence of irAEs, specifically skin or endocrine irAEs. Herein, we aimed to evaluate the correlation between irAE-related adrenal insufficiency (AI) and ICI treatment efficacy.
Patients and methods
Patients diagnosed with gastrointestinal, respiratory, head and neck, urological, skin and gynecologic cancers treated with anti-programmed cell death 1 (PD-1)/anti-programmed cell death ligand 1 (PD-L1) antibody as monotherapy or combined therapy (combined with chemotherapy or targeted therapy) were divided into irAE-A (patients with irAE-related AI), irAE-B (patients with other irAEs) and non-irAE groups. Immunotherapy efficacy was assessed based on the disease control rate (DCR), progression-free survival (PFS), and overall survival (OS). Survival probabilities were estimated using the Kaplan–Meier method with the log–rank test.
Results
Of the 192 patients enrolled in our study, 17 developed irAE-related AI and 83 developed other irAEs. The DCR of the irAE-A and irAE-B groups were higher than that of the non-irAE group (
P
<0.05). Multiple extended Cox regression analyses showed that irAE status (irAE-A vs non-irAE,
P
=0.008; irAE-B vs non-irAE,
P
=0.020), Eastern Cooperative Oncology Group (ECOG) status (
P
=0.045), tumor-node-metastasis (TNM) stage (
P
=0.000), and treatment line (
P
=0.002) were independent predictors of PFS. Contrarily, irAE status (irAE-A vs non-irAE,
P
=0.009; irAE-B vs non-irAE,
P
=0.013), ECOG status (
P
=0.007), TNM stage (
P
=0.035), treatment line (
P
=0.001) and treatment modality (
P
=0.008) were independent predictors for OS.
Conclusion
IrAE-related AI was significantly associated with ICI treatment efficacy in patients with cancer, which could be a potentially predictable marker. Due to the destruction of adrenal tissue by T cells with enhanced activity, AI reflects enhanced T cell activity to some extent.