Investigation of thyroid profiles in oncology patients treated with tyrosin kinase inhibitors

Objective: Tyrosine Kinase Inhibitors (TKIs) are among the therapeutic agents commonly used in cancer patients in the presence of appropriate targets. Hypothyroidism is not uncommonly observed in oncology patients using TKIs. The aim of this study is to evaluate the thyroid function tests of cancer patients receiving TKI therapy and to investigate the relationship of these tests with other laboratory changes and response evaluations with radiological imaging. Material-method: 173 patients who were diagnosed with cancer and used TKI treatment at Çukurova University Oncology Clinic between 2010 and 2021 were included in the study retrospectively. The correlation between the thyroid function tests, laboratory and radiological evaluations of the patients was examined. CML (Chronic Myeloid Leukemia) patients were excluded and the inflammatory indices of the patients with and without hypothyroidism were compared with the radiological responses of the patients to the treatment. Results: Hypothyroidism was found in 16,7% of 173 patients diagnosed with cancer. Hypothyroidism was observed most frequently in the group that received pazopanib (47,4%) and sunitinib (30,7%). The prognostic nutritional index (PNI) measured at the 3rd month was found to be significantly higher in the patients. There was a significant decrease in calcium and phosphorus levels. Although the treatment responses were higher in the group with hypothyroidism, it was not statistically significant. It was associated with the limited number of patients.Conclusion: Hypothyroidism is an important side effect in patients receiving TKI therapy, and care should be taken especially in patients receiving pazopanib and sunitinib. Calcium and phosphorus levels should be checked before treatment and necessary replacements should be made. Higher response to treatment in patients with hypothyroidism may be a guide for future studies on larger patients. Keywords: Cancer, Hypothyroidism, FT3, FT4, TSH, TKI