Endocrine Abstracts

Multi kinase inhibitors (MKIs) constitute a new therapeutic option in advanced RAI-refractory differentiated thyroid cancer (DTC) and medullary thyroid carcinoma (MTC). To date four different MKIs demonstrated a beneficial effect on progression free survival in DTC (sorafenib, lenvatinib) and MTC (vandetanib and cabozantinib). However, the treatment related toxicity, which potentially may limit their clinical use and lead to a negative impact on the quality of life, have been widely discussed recently.

Material and methods: The study group involved 81 patients with advanced thyroid cancer, who received different MKIs: 24 patents – lenvatinib, 20-vandetanib, 22-sorafenib, 8-cabozantinib, 4-motesanib and 3-axitinib. All side effects were classified according to the Common Terminology Criteria for Adverse Events (CTCAE), version 4.0. Median treatment duration was 21.3 months (range 0.7–100.0 months).

Results: Among the most common adverse effects were hypertension (73%), skin reactions (70.3%), diarrhea (54.1%), weight loss (54.1%) and stomatitis (43.2%). The majority of side effects fulfilled G1 (mild) and G2 (moderate) criteria except of hypertension mainly classified as G3 (the necessity of the administration of at least 2 antihypertensive drugs). The management of treatment related side effects was based mainly on cautious follow-up (wide panel of laboratory examinations, regular ECG monitoring, echocardiography and other examinations, if necessary), non-pharmacological methods (sun blockers, moisture creams), concomitant pharmacotherapy (antihypertensive drugs, loperamide and other depending on different side effects) and dose modifications: 52.7% of patients needed dose reduction. Multidisciplinary team involving oncologists, internists, dermatologists, cardiologists, nurses and psychologists was also an important part of our successful patients care. Only 14.5% of patients required drug withdrawn due to its poor tolerability.

Conclusion: The proper management of MKI-related side effects is essential to keep patients on therapy as long as the treatment is beneficial without an unfavorable impact on their quality of life.