Prognosis After Brain Metastasis from Differentiated Thyroid Carcinoma

Background In patients with differentiated thyroid carcinoma (DTC), lung and bone metastasis sometimes occur. However, brain metastasis (BM) is extremely rare. Because most previous reports about BM from DTC included a relatively small number of cases, the clinical characteristics and outcomes of BM are still unclear. Patients and methods Between 1965 and 2013, among 961 patients who had died because of DTC, 24 patients were diagnosed with BM from DTC. One patient with BM from DTC is still alive. To identify the prognostic factors for longer survival after BM, the medical records of these 25 patients were retrospectively reviewed. Results The median age at BM diagnosis was 66 years. Typical symptoms associated with BM had appeared in 20 patients (80 %). The Karnofsky Performance Status (KPS) was good (>= 70) in 10 patients and poor (<= 60) in 15 patients. Seven patients had a single intracranial lesion of BM, 6 patients had 2 or 3 lesions, and 9 patients had 4 or more. Eleven patients did not receive any treatment for BM, and 14 patients underwent surgical resection, radiation therapy, or both. One-year and 5-year disease-specific survival rates were 28 and 10.6 %, respectively. Good KPS (>= 70), small number of intracranial lesions (<= 3), and treatment for BM were prognostic factors for long survival on univariate analysis (p < 0.05). On multivariate analysis, only treatment for BM was significant. Conclusion Treatment of BM from DTC is indicated in patients who have a good KPS and fewer intracranial lesions, and some of them may achieve long survival.