The present study retrospectively reviewed the treatment courses and results of patients with follicular thyroid
tumors, including
carcinomas. In the 5 year study period from April 2015 to March 2020, 797 patients with differentiated
thyroid carcinoma and 128 patients with follicular
tumors (FTs) received surgery or treatment for distant
metastases and recurrence at the Kanagawa
Cancer Center (Japan). Of these patients, 73 that were diagnosed with
follicular thyroid carcinoma (
FTC) were included in the present study. An algorithm used for the application of treatment strategies was assessed. The aim of the present study was to examine patients with FT or
FTC who were treated at the Kanagawa
Cancer Center to devise appropriate treatment strategies and to evaluate the various treatment outcomes of
FTC. Pre-diagnostic serum
thyroglobulin and
thyroid stimulating hormone levels, follow-up and overall survival (OS) were investigated in the present study. The results revealed that OS was significantly increased in patients with minimally invasive
follicular thyroid cancer (MIFTC) compared with widely invasive
follicular thyroid cancer (WIFTC) (log-rank test, P=0.017). Additionally, OS was significantly higher in patients without distant
metastasis at the first consultation compared with those initially diagnosed with distant
metastasis (log-rank test, P=0.023). Although all patients without distant
metastasis at the first consultation and those with MIFTC are alive, the 10-year survival rates were 75.3% for patients with WIFTC and 75.6% for those with distant
metastasis at the first consultation. The results of the present study suggested that the prognosis of WIFTC was the worst among patients with
FTC and distant
metastasis, and that total
thyroidectomy surgery and radioactive
iodine treatment are essential. Additionally, if the disease progresses, prompt inclusion of
tyrosine kinase inhibitor therapy is necessary.