Background
Kinase inhibitors are recommended for treating radioactive iodine (RAI)-refractory differentiated thyroid cancer patients with metastatic, rapidly progressive, symptomatic, and/or imminently threatening disease that is not otherwise amenable to local control using alternative approaches. Although associated with a significant progression-free survival improvement, the benefit of TKIs needs to be proved in the context of associated moderate to severe toxicities that require frequent dose reduction and delays.
Methods
Retrospective cohort study of medical records of 71 patients treated with tyrosine kinase inhibitors lenvatinib and sorafenib for thyroid cancer at Gangnam Severance Hospital from July 2016 to December 2017 was conducted. Baseline clinical parameters, dosage and adverse effects from initiation of treatment were collected.
Results
Sorafenib (N=48) and lenvatinib (N=23) was used. Initial starting dose for lenvatinib was 20mg/per day in all of the 20 patients. Adverse effects occurred in 19 patients (82.6%), requiring dose reduction in 8 (34.8%) of patients and drug cessation in 1 patient (4.3%). For patients using sorafenib, the initial starting dose was £400mg daily in 12 patients (25.0%), 600mg in 16 patients (33.3%) and 800mg daily in 20 patients (41.7%). Dose reduction was needed for adverse effects in 27 patients (56.3%), and drug cessation was necessary in 4 patients (8.3%). When most common adverse effect was compared, hand-foot-syndrome was significantly more frequent in patient using sorafenib (42 (87.5%) vs 13 (56.2%), p=0.003).
Conclusion
Both of the TKIs showed high rate of adverse effect. Adverse effect was more observed in sorafenib patients, which needed more often drug cessation.