Immune Checkpoint Inhibitor-induced Thyroid Disorders: A Single Center Experience

Area of Science:

• Oncology
• Immunology
• Endocrinology

Background:

• Immune checkpoint inhibitors (ICI) activate T lymphocytes against cancer but can cause immune-related adverse events (irAE).
• Thyroid dysfunction, including hyperthyroidism and hypothyroidism, is a known irAE of ICI therapy.
• This study investigates the incidence and characteristics of thyroid irAE in patients receiving oncological immunotherapy.

Purpose of the Study:

• To evaluate the impact of oncological immunotherapy on thyroid function.
• To identify patterns and outcomes of thyroid dysfunction in patients treated with ICI.
• To assess the utility of biochemical and ultrasound monitoring for thyroid irAE.

Main Methods:

• Retrospective analysis of 120 patients treated with ICI between December 2016 and March 2020.
• Detailed collection of 10 cases with confirmed thyroid irAE.
• Monitoring included biochemical assessments (TSH) and neck ultrasound for thyroid volume.

Main Results:

• Thyroid irAEs occurred in 10 out of 120 patients, predominantly in females, with a median onset of 9 weeks after ICI initiation.
• All patients eventually developed persistent hypothyroidism requiring levothyroxine replacement.
• A statistically significant increase in TSH and a reduction in thyroid volume (indicating destructive thyroiditis) were observed.

Conclusions:

• Patients undergoing immunotherapy require vigilant monitoring for thyroid dysfunction.
• Biochemical assessments and ultrasound-measured changes in thyroid volume are valuable tools for diagnosing and managing thyroid irAEs.
• Early detection and management of ICI-induced thyroid dysfunction are essential for patient outcomes.