Papillary thyroid carcinomas with lung metastases

Abstract

Background: Limited information is available on the presentation, treatment outcomes, and prognostic factors of papillary thyroid carcinoma with lung metastases.

Methods: This study retrospectively analyzed the data of 2003 patients with thyroid cancer who were treated and followed up at Chang Gung Memorial Hospital from January 1979 to December 2002. In total, 1516 papillary thyroid carcinomas were enrolled. One hundred two (6.7%) papillary thyroid carcinomas with lung metastases were followed including 57 women with mean age of 41.7 +/- 17.3 years and 45 men with mean age of 49.6 +/- 17.2 years. These patients included 52 patients with papillary thyroid carcinoma who presented with lung metastases at the time of diagnosis. The 102 cases of papillary thyroid carcinomas with lung metastases included 72 cases with lung metastases only, and 30 cases with other organ involvement.

Results: After mean follow-up periods of 8.8 +/- 0.6 years, 28 (27.5%) of the patients with lung metastasis died, while 6 improved to clinical stage I. The 5-, 10-, 15-, and 20-year survival rates in patients with papillary thyroid carcinoma without distant metastasis and in the lung metastases groups were 99.0%, 98.5%, 98.0%, 98.0%, and 91.3%, 75.0%, 64.0%, 51.2%, respectively. Comparing the Kaplan-Meier survival curves between the patients with papillary thyroid carcinomas with lung metastases only and those with multiorgan metastases demonstrates no statistically significant difference in mortality rates. However, age, gender, postoperative thyroglobulin (Tg) level and tumor size displayed statistically significant differences between the lung metastases and no distant metastasis groups. Fifty of the 102 patients with papillary thyroid carcinomas with lung metastases developed lung metastases during follow-up. Larger amounts of remnant thyroid tissues with higher Tg levels were noted in these patients compared to those without distant metastasis.

Conclusions: The prognosis of patients with papillary thyroid carcinoma with lung metastases at time of diagnosis is the same as for those whose lung metastases are discovered later. Survival analysis demonstrates no difference between lung metastases and multiorgan metastases.