Poor prognosis of 56 follicular thyroid carcinomas with distant metastases at the time of diagnosis

Background - There is limited clinical information about the prognostic factors of follicular thyroid carcinoma with distant metastases at the time of diagnosis. In order to determine these factors, we retrospectively analyzed the data of 1,013 thyroid cancer patients. Methods - There were 168 follicular thyroid carcinomas (18.5%). Fifty-six (33.3%) of them presented with distant metastases at the time of diagnosis. The subjects included 45 female patients with a mean age of 55.4 ± 12.4 years, and 11 male patients with a mean age of 56.8 ± 12.6 years (p=0.73). Fourteen clinical parameters were coded into the Computer for univariate analyses. Results - Among 56 follicular thyroid carcinomas, 19 patients had a history of previous thyroid operations, and benign thyroid nodules were found. Only 46.4% of these cases received a total thyroidectomy treatment after the diagnosis was confirmed by a frozen section during the operation. During the follow-up period, 20 (35.7%) patients died of metastatic thyroid cancer. When the tumor was larger than 3 cm, the tumor size was a significant factor in predicting survival (p=0.0273). The survival analysis showed that 31.1% of the females and 54.6% of the males died. Survival was significantly associated with gender and tumor size. Conclusions - A poor prognosis was demonstrated in follicular thyroid cancer with distant metastases at the time of diagnosis. Male sex and larger tumor size were associated with poor prognosis. Failure in diagnosis is one of the main reasons for delaying treatment of follicular thyroid carcinoma.