Bone metastases from thyroid carcinoma: Clinical characteristics and prognostic variables in one hundred forty-six patients

To describe the clinical characteristics and define the indicators that bes t predict survival in patients with bone metastases from thyroid carcinomas . We collected data from medical records of 146 patients with documented bo ne metastases from thyroid carcinoma seen at our medical center over a 38-y ear period. Univariate and multivariate analyses of prognostic indicators f or survival were performed. Bone metastases were present at the initial dia gnosis in 47% of patients. Vertebrae (29%), pelvis (22%), ribs (17%), and f emur (11%) were the most common sites of metastases. Multiple lesions were present in 53% of the cases. The overall 10-year survival rate from the tim e of diagnosis of thyroid cancer was 35%, and from diagnosis of initial bon e metastasis was 13%. By univariate analysis from the time of the initial b one metastasis, radioiodine uptake by skeletal metastases, the absence of n onosseous metastases and treatment with radioiodine were significant progno stic factors. By multivariate analysis, radioiodine uptake by skeletal meta stases and the absence of nonosseous metastases were independent favorable prognostic variables for survival. In a subgroup of patients in which histo logic specimens were available and were reviewed, Hurthle cell carcinoma wa s the most favorable histologic subtype for survival with the undifferentia ted subtype being the worst. The spread of thyroid carcinoma to bone is mor e common in patients over 45 years of age, is usually symptomatic, and is o ften multicentric. Overall survival is best in those whose lesions concentr ate radioactive iodine and those who have no nonosseous metastases.