BACKGROUND
Recent advancements in cancer treatment include the introduction of immunotherapy and kinase inhibitors, which have significantly improved cancer prognosis among patients. However, these compounds are responsible for several adverse events that affect the endocrine glands. Endocrine-related adverse events, and specifically thyroid abnormalities, are now acknowledged as frequent side effects of classes of drugs known as immune checkpoint inhibitors (ICIs) and tyrosine kinase inhibitors (TKIs). Interestingly, thyroid abnormalities during treatment with ICIs has been shown to be a positive prognostic sign.
The favorable outcome achieved with ICI and TKI drugs individually have prompted clinical trials assessing combined ICI+TKI regimens. Initial reports indicate a potential increase in rates of thyroid abnormalities during combined ICI+TKI therapy. This study examines the effect of ICI+TKI therapy on thyroid function in cancer patients with normal thyroid function as determined by pretreatment TSH levels.
THE FULL ARTICLE TITLE
Tsai K et al. The combined effect of immune checkpoint inhibitors and tyrosine kinase inhibitors on thyroid function. Thyroid 2024;34(2):158-166; doi: 10.1089/ thy.2023.0542. PMID: 38069567.
SUMMARY OF THE STUDY
This study included adult patients treated with a combination of ICI and TKI therapy for solid cancers. ICIs used were pembrolizumab, nivolumab, and ipilimumab, and the TKIs used were lenvatinib, axitinib, sunitinib, pazopanib, cabozantinib, tivozanib, and imatinib. After receiving ICI+TKI, patients were identified as having no thyroid abnormalities if they had no changes in thyroid hormone levels. Thyroid disturbances were defined as follows: 1) hypothyroidism as elevated TSH and low FT4 levels; 2) subclinical hypothyroidism as elevated TSH with normal FT4 levels; 3) hyperthyroidism as a low TSH and elevated FT4 levels; and 4) subclinical hyperthyroidism as low TSH with normal FT4 levels. Patients who needed an increase in thyroid hormone therapy after initiation of ICI+TKI were defined as having worsening of hypothyroidism.