Bone metastases of differentiated thyroid cancer: Clinical outcome

Objectives The aim of the study is to evaluate therapy response and clinical outcome in patients with bone metastases of differentiated thyroid cancer (DTC).

Methods 38 patients with bone metastases of DTC were followed in our department from 1990 to2010 (27 females and 11 males; mean age 54 yrs). The mean follow up time was 56 months (12 to 174 months).

Results Histopathology types were papillar in 18, follicular in 16 patients,poorly differentiated in 3 patients and hurtle-cell in 1. Bone metastases were present at the initial diagnosis in 29% of pts(n:11).Bone metastases were in multiple sites in 27 (71%) pts and associated with other distant metastases (especially lung)in 9(23%).Metastatic sites were pelvic (31%),vertebral(21%) and other sites (48%.RAI treatment was administered to all pts one to six times (total 200-1800 mCi). All of the pts had elevated tyroglobulin levels in initial stage. 28 (74%)of all pts had underwent RT. After RAI therapy and/or RT, tyroglobulin(Tg)levels decreased in 16 pts(42%).Seven out of 16 Tg levels decreased below 1 ng/ml. On the other hand Tg levels increased progresively in 17 pts.Five(13%)of them died after initial diagnosis time range from 12 to 174 months.There were no therapy response in five pts.2 pts had no uptake on posttherapy scan. Only one patient with metastesectomy is cured.

Conclusions In patients with bone metastasis of DTC, there can still be a chance for therapy response and even for cure. After initial diagnosis of DTC, early RAI therapy, surgery if possible and/or RT in patients with bone metastases contribute to good clinical outcome and quality of life