Clinical analysis of lenvatinib therapy for unresectable thyroid cancer at Nagoya City University Hospital and related facilities

Lenvatinib is a molecular targeted drug indicated for unresectable radioiodine refractory thyroid cancer, but predictors of therapeutic prognosis have not been established. In this study, we retrospectively reviewed histopathological features and clinical factors in 30 cases of unresectable thyroid cancer treated with lenvatinib at Nagoya City University Hospital and related facilities, and analyzed the effects on survival. The median follow-up was 20 months, the 1-year overall survival rate was 71.2％, and the 1-year progression-free survival rate was 63.0％. The histological types were papillary carcinoma in 17 cases, undifferentiated carcinoma in 5 cases, follicular carcinoma in 3 cases, medullary carcinoma in 2 cases, poorly differentiated carcinoma in 2 cases, and squamous cell carcinoma in 1 case. The progression-free survival rate was significantly better in cases in which tumor shrinkage was observed at 8 weeks after administration, cases with differentiated carcinoma, cases in which the neutrophil-lymphocyte ratio （NLR） was ≤ 3, and cases in which the Glasgow prognostic score （GPS） was 0. It is suggested that NLR and GPS may be new predictors of prognosis.