Endocrine Abstracts

Introduction: Systemic treatment of advanced progressing thyroid cancer (TC) is based on molecularly targeted therapy with tyrosine kinase inhibitors (TKIs), mainly inhibitors targeting vascular endothelial growth factor receptors (VEGFR). Such treatment is related to numerous side effects. However, the relationship between TKIs and renal adverse events (RAEs) is unclear. VEGFR inhibitors are associated with proteinuria. In some patients, increased serum creatinine level and the development of chronic kidney failure is observed. However, so far, it has not been determined whether these events are directly caused by TKIs or are more closely linked to iodinated contrast media used in computed tomography (CT), a well-known factor of kidney damage, to follow treatment response.

Aim: The aim of the study is to compare kidney function between TC patients with advanced disease treated and not treated with TKIs. Patients in both groups are followed by repeated contrast-enhanced CT scans. This comparison will consider the number of CT scans performed with iodine contrast media and their impact on the development of chronic kidney disease in both groups.

Methods: A retrospective analysis involves 328 TC patients with advanced inoperable or metastatic disease, including 96 patients treated with TKIs. The remaining 234 patients did not receive any systematic treatment. All patients received at least one VEGFR inhibitor (sorafenib, lenvatinib, cabozantinib, or vandetanib). The maximum number of contrast-enhanced CT scans performed in the TKIs group was 34, while the maximum number in the non-treated group was 16. The data analysis uses the glomerular filtration rate (GFR) as an indicator of kidney function, as per the KDIGO 212 scale. GFR changes over time in patients who received and did not receive VEGFR-TKIs are analyzed.

Results: Among 234 patients who did not receive any systematic treatment, 66.2% did not show any change in kidney function, while 26% experienced worsening of kidney function or developed chronic kidney disease. On the contrary, in 46,8% among 96 patients receiving VEGFR-TKI inhibitors kidney function worsened. Only in 47,9% of them kidney function remained unchanged. The use of TKIs was related with 2,48-fold higher risk of kidney damage compared to non-treated patients. The difference between the groups was statistically significant (P < 0,001).

Conclusion: TKIs may be associated with a higher risk of renal damage and the development of chronic kidney failure in patients with advanced TC. It should be considered when planning the follow-up schedule and the frequency of contrast-enhanced CT scans.