A Single-Center, 10-Year Retrospective Study on Surgical Treatment and Prognosis Analysis of Differentiated Thyroid Carcinoma with Spinal Metastasis

OBJECTIVE: Metastatic spinal differentiated thyroid carcinoma (MSDTC) is relatively rare in the clinic and often overlooked. The objective of the current study is to analyze the clinical characteristics and prognosis of patients with MSDTC who underwent surgical treatment to determine the prognostic factors that affect survival. METHODS: This study retrospectively analyzed the clinical data and postoperative follow-up results of MSDTC patients who underwent spinal surgery at the Orthopedic Department of Peking Union Medical College Hospital from January 2010 to January 2020. Clinical data and survival time were analyzed by Kaplan–Meier analysis. RESULTS: Eleven patients were included, and the average age was 58.3 years (range 37‒74). The average time from the initial surgery to the discovery of spinal metastasis was 42.9 months (range 0‒132), and the average follow-up time was 21.8 months (range 3‒80). Progression was identified in seven patients, and 10 patients (90.9%) died during the follow-up period. Kaplan–Meier analysis showed that extraosseous visceral metastasis (p=0.012), revised Tokuhashi score (p=0.035), Tomita score (p=0.038), and surgical method (p=0.028) were associated with overall survival (OS). In addition, skeletal visceral metastasis (p=0.017), revised Tokuhashi score (p=0.028), Tomita score (p=0.038), and surgical method (p=0.049) were associated with progression-free survival (PFS). CONCLUSION: Surgical treatment is an effective method for treating MSDTC and leads to pain relief, restored function and increased spinal stability. Based on our single-center experience, extraosseous visceral metastasis, revised Tokuhashi score, Tomita score, and surgical methods may be potential prognostic factors for OS whilst visceral metastasis, revised Tokuhashi score, Tomita score, and surgical methods may be potential prognostic factors for PFS.