Nilotinib-Associated Destructive Thyroiditis

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.

Thyroid autoimmunity and hypothyroidism are associated with deep molecular response in patients with chronic myeloid leukemia on tyrosine kinase inhibitors

PURPOSE

Thyroid alterations including de novo appearance of thyroid autoimmunity are adverse effects of tyrosine kinase inhibitors, used in solid and hematologic cancer therapy, but the relationship between thyroid alterations during this treatment and the outcome of chronic myeloid leukemia remains unclear. Aim of this study was to investigate whether the presence of thyroid alterations may affect the clinical outcome of chronic myeloid leukemia on tyrosine kinase inhibitors.

METHODS

We evaluated thyroid function and autoimmunity in 69 chronic myeloid leukemia patients on long-term therapy looking at the association between thyroid abnormalities and disease molecular response.

RESULTS

Overall, 24 of 69 (34.8%) had one or more thyroid abnormalities during therapy. A high percentage of patients (21/69, 30.4%) showed thyroid autoimmunity (positive thyroid autoantibodies with ultrasound hypoechogenicity), while clinical and subclinical hypothyroidism and subclinical hyperthyroidism were, respectively, found in 4 of 69 (5.8%) and 3 of 69 (4.3%) of cases. Second-generation tyrosine kinase inhibitors resulted significantly associated (14/32, 43.7%) with Hashimoto's thyroiditis, compared to first generation (7/37, 18.9%; p = 0.03). Interestingly, we also found a significant association between euthyroid (14/26, 53.8%) and hypothyroid Hashimoto's thyroiditis (4/26, 15.4%) in patients with deep molecular response, as compared to euthyroid (3/43, 7%; p = 0.0001) and hypothyroid (0/43, 0%; p = 0.02) Hashimoto's thyroiditis patients with major molecular response.

CONCLUSIONS

Our study confirms and extends our knowledge on the tyrosine kinase inhibitors effects on thyroid, showing that thyroid autoimmunity is frequently observed in chronic myeloid leukemia patients on long-term therapy and is associated with a better oncological response.