Epidemiological characteristics and I-131 scintigraphic of patients with papillary thyriod carcinoma with distant metastases

One hundred and twenty-nine patients with papillary thyroid carcinoma were treated with radioiodine (I-131) and followed up in our department between the years 1992 and 2000. Thirty-three patients (25.6%) had distant metastases (mean follow-up time was 3.12 +/- 2.9 years). The incidence of distant metastases among patients with papillary carcinoma was higher in our group in comparison with most published studies. The most common sites for distant metastases were the lungs and mediastinum. In 32 of the 33 patients distant metastases were found in those sites. We characterized two main patterns of I-131 uptake in lung metastases: in the first there was diffuse lung uptake and in the second there were focal lesions. Bone metastases were only found in one patient. Distant metastases were found in 38.7% of males as compared to 21.4% of females. The age of the male patients with distant metastases was significantly higher than the age of the other patients (mean age 52.8 years, p = 0.099). There was no significant association between distant metastases and advanced age. Most cases of distant metastases in females (81%) were diagnosed at the time of the primary diagnosis as compared to less than half (42%) in males. Sixteen patients with distant metastases underwent cervical lymph node dissection. In 15 patients (94%) cervical lymph node metastases were found. It was found that 39.4% of the patients with distant metastases were born in Israel and 30.3% were born in the Soviet Union. The percentage of the patients with distant metastases, who came to Israel from the Soviet Union after the nuclear accident in Chernobyl (1986), was found to be significantly higher then their relative number in the Israeli population and higher then their relative number in the hospitalized patient population in the years of the study (24.2% as compared to 9% and 8.1% respectively). The survival rate of patients with distant metastases was 97% and for patients without metastases the rate was 100%.