Administration of Lenvatinib to patients with anaplastic thyroid cancer

The proportion of anaplastic thyroid cancer is only one to two percent of all thyroid cancers. However, multidisciplinary therapy has little effect on the prognosis of anaplastic thyroid cancer. Lenvatinib has been approved in Japan since 2015 as a treatment for patients with unresectable or metastatic thyroid cancer. We administered lenvatinib to nine patients with anaplastic thyroid cancer from October 2015 through January 2017. Two patients were male and seven were female. The mean age of the patients was 74.6 years (with an age range of 54-84). We investigated the therapeutic effects and adverse events of lenvatinib in these patients with anaplastic thyroid cancer. Six out of the nine patients showed partial response (PR). One patient survived for more than a year after administration of lenvatinib. In the nine patients administered lenvatinib, the most usual adverse events were hypertension (eight patients), followed by gastrointestinal symptoms (seven patients), renal insufficiency (six patients), thrombocytopenia (four patients), and fistula formation (three patients). It is important to continue administering lenvatinib while adjusting the dose depending on the grade of adverse events.