Bone Metastases from Differentiated Thyroid Carcinomas

Purpose: Only limited information exists on the clinicopathological profiles and the treatment outcomes of bone metastases from differentiated thyroid carcinomas. Therefore the impact of treatment strategies has been inadequately investigated. The aims of this study were to evaluate the proper management and the prognostic factors that influence the long-term outcomes of patients treated for bone metastasis from differentiated thyroid carcinoma. Methods: Twenty-two cases of bone metastases out of 3,775 differentiated thyroid carcinomas treated at Yonsei University Medical Center between Jan. 1986 and Dec. 2004 were analyzed. The overall incidence of bone metastases from differentiated thyroid carcinomas in our series was 0.6%. There were 11 women and 11 men, with a mean age at the time of primary diagnosis of 51 years (25∼71 years). The mean follow-up after diagnosis of bone metastases was 83 months (1∼358 months). Results: The histological diagnoses of primary tumor were 21 and 1 papillary and follicular cancers, respectively. Metastases restricted to the skeleton alone were found in 13 patients, whereas 9 patients showed associated extraskeletal distant metastases. Seventeen patients had multiple bone metastases. In 6 patients, the bone metastases were surgically removed with intention of cure. The overall survival rates at 10 years was 44.4%. From univariate log-rank survival rates analyses, capsular invasion (P=0.0014), preoperative vocal cord palsy (P=0.0097), multiple organ involvement (P=0.024) and the impossibility of surgical treatment for skeletal metastaisis (P=0.0471) were related with a poor prognosis. Conclusion: From the results, the survival rate was shown no significantly decline in the patients with poor prognostic factors. Therefore the therapeutic options should be individualized according to the initial clinical state and the prognostic factors. Our data also suggest that surgical resection for metastatic bone lesions and postoperative adjuvant therapy should be performed to obtain better survival rates.ope