Immune Checkpoint Inhibitor-induced Thyroid Dysfunction Is Associated with Higher Body Mass Index

Area of Science:

• Oncology
• Immunology
• Endocrinology

Background:

• Obesity is a proinflammatory state potentially influencing immune-related adverse events (irAEs).
• Immune checkpoint inhibitors (ICIs) like anti-PD-1/L1 therapies can trigger irAEs, including thyroid dysfunction.
• The relationship between body mass index (BMI) and thyroid irAEs in patients receiving ICIs requires further characterization.

Purpose of the Study:

• To investigate the association between BMI and the development of thyroid irAEs in cancer patients treated with anti-PD-1/L1 therapy.
• To determine if BMI influences the incidence, type, or timing of thyroid dysfunction following ICI treatment.

Main Methods:

• Retrospective analysis of 185 cancer patients treated with anti-PD-1/L1 therapy.
• Inclusion criteria: normal baseline thyroid function and available BMI data.
• Primary endpoint: BMI difference between patients with overt thyroid dysfunction and euthyroid patients; secondary endpoints included any thyroid dysfunction, overt thyrotoxicosis/hypothyroidism, and time to dysfunction.

Main Results:

• Any thyroid dysfunction occurred in 38.9% of patients, with overt dysfunction in 22.1%.
• Mean BMI was significantly higher in patients with overt thyroid dysfunction (27.3 vs 24.9, P=.03).
• Higher BMI correlated with overt thyrotoxicosis (P<.01) and earlier onset in obese patients (23 days) compared to leaner patients.

Conclusions:

• Increasing BMI is associated with a higher likelihood of developing thyroid irAEs, particularly overt thyrotoxicosis, in patients receiving PD-1/L1 inhibitors.
• Obese patients experienced earlier onset of overt thyrotoxicosis.
• Findings underscore the complex interaction between obesity, immune response, and irAEs in the context of ICI therapy.