Long-term efficacy of lenvatinib for recurrent papillary thyroid carcinoma after multimodal treatment and management of complications: a case report

BACKGROUND: The advent of tyrosine kinase inhibitors (TKIs) has changed the treatment of RAI refractory, unresectable recurrent differentiated thyroid cancer (DTC), which was formerly treated with multidisciplinary remedies. CASE PRESENTATION: Here we describe the case of a 64-year-old woman who underwent total thyroidectomy with tracheal resection and suffered from a recurrent tumor in the neck and multiple lung and bone metastases 3 and 11 months, respectively, after the operation. Multimodal therapies, RI (I-131), EBRT, and taxane-based chemotherapy were ineffective, and sorafenib was started as a TKI. However, because of disease progression, sorafenib was replaced by lenvatinib after 9 months. The effect of lenvatinib has continued for more than 1 year and 9 months, and the patient has well survived. During the treatment period, a tracheal pin-hole fistula suddenly emerged, which was naturally cured by the temporary cessation of lenvatinib. Adverse events such as hypertension, proteinuria, and diabetes as innate complications have been successfully managed until the present according to our institute regulations. CONCLUSIONS: Even where multimodal treatment was ineffective, lenvatinib was suggested to be an alternative treatment option for RAI refractory recurrent DTC and patient could have a chance to be controlled successfully.