Spinal metastases in primary thyroid malignancies: Single center experience of 44 cases

Patients with differentiated thyroid carcinoma have a 10 year survival rate of more than 95%. However, the existence of spinal metastases significantly reduces overall survival. In this study, we review the epidemiology and outcomes of patients with thyroid malignancies with spinal metastases.

A retrospective analysis was conducted on 44 patients with thyroid malignancy and spinal metastases treated at our institution from 2008 to 2021, evaluating the outcome parameters by analyzing demographic, clinical and radiological profiles.

The median age upon presentation was 58 years (range - 35 to 80 years). 54.5% had single-level involvement. The thoracic spine exhibited the highest incidence of involvement, followed by the transitional zones and lumbar spine. The most common presenting features were spinal and radicular pain followed by myelopathy. In 77.3% of cases, the pathology was identified as the follicular variant of papillary thyroid carcinoma. A total of 81.8% of patients underwent total thyroidectomy, with 84% receiving iodine ablation and 61.3% undergoing locoregional radiotherapy. Surgical intervention for spinal metastases was performed in 18 individuals (40.9%). There was significant improvement in the postoperative Visual Analog Scale (VAS) score in the operated group (p-value of 0.000). Overall, no significant difference was observed in the OS and PFS between the operated and non-operated groups except for the subset of patients who underwent postoperative radiation therapy (p-value of 0.013).

Vertebral metastasectomy in primary thyroid malignancies is associated with significant pain relief. Patients who receive postoperative radiotherapy perform better than patients who either undergo metastasectomy or radiation therapy.