Tyrosine kinase inhibitors induced thyroid dysfunction: myth or reality?

BACKGROUND: Chronic myelogenous leukemia (CML) is a hematopoietic stem cell disorder. It is associated with acquired genetic changes in the hematopoietic stem cells in the form of BCR-ABL fusion gene also known as Philadelphia chromosome. MATERIALS AND METHODS: We prospectively studied thyroid function at baseline and at 6 months of imatinib treatment in 26 newly diagnosed BCR-ABL positive CML patients. RESULT: The thyroid-stimulating hormone (TSH) levels increased significantly from baseline (3.20 ± 0.978 mIU/L vs. 3.724 ± 1.726 mIU/L, p < 0.05) after 6 months of treatment, 88.4% of the patients remained euthyroid. Only 2 patients had subclinical hypothyroidism, 1 had hypothyroidism after 6 months of tyrosine kinase inhibitors (TKI) therapy. CONCLUSION: Imatinib did not have any significant effect on thyroid function in CML patients in this study.