Limited clinical information is specified in the presentations, results of treatment and prognostic factors of
follicular thyroid carcinoma with lung
metastases. In order to better characterize the information, we retrospectively analyzed the data of 2,003
thyroid cancer patients who received treatment and follow-up at the Chang Gung Memorial Hospital during the period from January 1979 to December 2002. There were 1,516 cases of papillary and 272 cases of
follicular thyroid carcinomas. In the study, lung
metastases of the
follicular thyroid carcinomas were defined as post-operative or follow-up chest X-ray, diagnostic or therapeutic (131)I scan with positive finding of lung
metastases. Serum
thyroglobulin (Tg) levels under
thyroxine treatment of patients with lung
metastases had to be over 1.5 ng/mL. Of the
follicular thyroid carcinomas, there were 70 (25.7%) with lung
metastases including 50 females (mean age 54.1 +/- 12.6 years old) and 20 males (mean age 59.4 +/- 12.0 years old). Of the 70 patients, there were 53 patients (75.7%) who presented with lung
metastases at the time of diagnosis. Of the 70 patients of
follicular thyroid carcinoma with lung
metastases, 30 patients (42.9%) died at the end of the follow-up, and only 4 patients improved to disease free status. The 5, 10, 15, and 20 year survival rates in these patients were 68.5%, 54.0%, 41.6%, 27.7%, respectively. Age, post-operative Tg level and
tumor size are important prognostic factors which are demonstrated to be significantly different statistically between lung
metastases group and the group of the patients without distant
metastasis. Otherwise, only the
tumor size and accumulative dose of (131)I
therapy demonstrate a significant difference between survival and mortality groups. Seventeen of the 70 patients developed lung
metastases during the follow-up period. Mean period between diagnosis and recurrence of these patients was 3.6 +/- 0.9 years. Over 75% of
follicular thyroid carcinoma with lung
metastases was diagnosed at the time of presentation. Forty percent (28/70 cases) of the
follicular thyroid carcinoma with lung
metastases had history of thyroid surgery in this study. If lung
metastases are diagnosed in
follicular thyroid carcinoma, it will be followed by a poor prognosis. Older patients, higher postoperative Tg, and larger
tumor size in
follicular thyroid carcinoma need aggressive postoperative treatment.