The risk factors for thyroid immune-related adverse events requiring medical intervention

Abstract

Introduction: Immune-related adverse events (irAEs) are frequently observed in patients undergoing immune checkpoint inhibitor (ICI) therapy, with thyroid irAEs being the most common among endocrine irAEs. According to the Common Terminology Criteria for Adverse Events, irAEs greater than Grade 1 typically require medical intervention. However, the risk factors associated with developing thyroid irAEs beyond Grade 1 remain unclear. Methods: A retrospective study was conducted in a community hospital. Medical records from the past ten years were extracted, and a multivariable analysis was performed comparing Grade 1 thyroid irAEs to those exceeding Grade 1. Results: Of the 384 patients who underwent ICI therapy, 134 (34.9%) developed thyroid irAEs, with 78 (20.3%) experiencing Grade 1 and 56 (14.6%) experiencing Grade 2. A total of 83 (21.6%) patients were diagnosed with hypothyroidism and 51 (13.3%) with hyperthyroidism. Multivariable analysis revealed that age and ICI combination therapy were risk factors for Grade 2 hypothyroidism irAE, with an Odds Ratio (OR) of 1.06 (95% Confidence Interval (CI): 1.01–1.13, p = 0.019) and OR 1.70 (95% CI: 1.08–2.75, p = 0.022), respectively. For hyperthyroidism, compared to digestive, lung, and urology cancers, breast cancer and mesothelioma showed an OR of 3.86 (95% CI: 1.61–9.25, p < 0.001). Conclusion: The management of hypothyroidism and hyperthyroidism during cancer treatment presents unique challenges. Chemotherapy regimen selection requires careful consideration of patient-specific factors such as age and type of cancer.