Lenvatinib for Anaplastic Thyroid Cancer and Lenvatinib-Induced Thyroid Dysfunction

Area of Science:

• Oncology
• Pharmacology

Background:

• Lenvatinib is an oral multitargeted tyrosine kinase inhibitor effective for radioiodine-refractory differentiated thyroid cancer.
• Limited data exists on lenvatinib's efficacy and safety in anaplastic thyroid cancer (ATC).
• Hypothyroidism is a known side effect of tyrosine kinase inhibitors, but its incidence with lenvatinib is not well-defined.

Purpose of the Study:

• To investigate the efficacy and safety of lenvatinib in patients with unresectable anaplastic thyroid cancer (ATC).

Main Methods:

• Retrospective analysis of five patients with unresectable ATC treated with lenvatinib 24 mg daily.
• Evaluation of objective response rate (ORR), time to progression (TTP), overall survival, and safety.
• Monitoring for treatment-related adverse effects.

Main Results:

• Objective response rate (ORR) was 60% (3/5 partial response, 2/5 stable disease).
• Median time to progression (TTP) was 88 days; median overall survival was 165 days.
• Common adverse effects included hypothyroidism (80%), hypertension (80%), fatigue (80%), and decreased appetite (80%).

Conclusions:

• Lenvatinib demonstrates efficacy in unresectable ATC, potentially improving prognosis.
• Hypothyroidism occurred in 80% of patients, possibly due to treatment-induced thyroid injury.
• Most treatment-related adverse effects were manageable through dose modification and medical therapy.