Survival and therapeutic modalities in patients with bone metastases of differentiated thyroid carcinomas

Data for patients with bone metastases (BMs) of differentiated thyroid carc inoma (DTC) were retrospectively studied to identify factors associated wit h survival. We especially studied the impact of therapies. Among the 1977 p atients followed for DTC in our department from 1958 to 1999. 109 (77 femal es and 32 males; age range, 20-87 yr) presented BMs. All patients except 1 underwent total thyroidectomy, followed by radioiodine therapy (greater tha n or equal to3.7 gigabecquerels) in 95 cases. Survival rates at 5 and 10 yr were 41% and 15%, respectively. Univariate analyses indicated that a young age at BM discovery (P < 0.005) and the discovery of BM as a revealing sym ptom of DTC (P < 0.05) were features significantly associated with improved survival as well as radioiodine therapy (P < 10(-4)) and BM complete surge ry (P < 0.02). Using multivariate analysis, the detection of BMs as a revea ling symptom of thyroid carcinoma (P < 0.0005), the absence of metastasis a ppearance in other organs than bones during the follow-up (P < 0.03), the c umulative dose of radioiodine therapy (P < 0.0001), and complete BM surgery in young patients (P < 0.04) appeared as independent prognostic features a ssociated with an improved survival.