Clinical features of lenvatinib treatment in elderly patients with advanced thyroid cancer.

Until recently, there had not been an effective systemic chemotherapy for advanced differentiated thyroid carcinoma (DTC); lenvatinib, a multi-tyrosine kinase inhibitor, has been proven effective for DTC, but has also been revealed to have adverse side effects including hypertension, hand-foot syndrome (HFS) and diarrhea. There have been few clinical studies focused on the characteristics, safety concerns or precautions for lenvatinib treatment in elderly patients. The present study administered lenvatinib to 18 patients with DTC in Kumamoto University Hospital (Kumamoto, Japan), with 9 patients in both the younger group (<75 years old) and elderly group (≥75 years old). The median maximum systolic blood pressure (sBP) was significantly different between the two groups (158 mmHg in the younger group vs. 173 mmHg in the elderly group; P=0.042). There were no significant differences in median maximum diastolic blood pressure (94 vs. 95 mmHg; P=1.00), median degree of sBP elevation (43 vs. 55 mmHg; P=0.199) or median days until hypertension diagnosis (2.11 vs. 2.33 days; P=0.436). There were also no significant differences in other toxicities (HFS, proteinuria or diarrhea). In conclusion, lenvatinib should be introduced carefully to elderly patients with DTC, as they tend to present with hypertension during treatment. However, there were no differences in other toxicities between the younger and elderly groups; lenvatinib was fully tolerated in patients with DTC >75 years old.