Prognostic Factors and Survival Outcomes in Thyroid Cancer Patients With Bone Metastasis: Insights From a Population-Based Cohort Study.

[OBJECTIVES] Thyroid cancer (TC) is the most common endocrine malignancy, and bone metastasis (BM) is the second most common type of metastasis after lung. BM is associated with a poor prognosis; however, relevant research remains limited. This study aims to evaluate the prognostic factors and survival outcomes in patients with thyroid cancer with bone metastasis (TCBM).

[METHODS] Data from patients with TCBM were extracted from the Surveillance, Epidemiology, and End Results (SEER) database. Univariable and multivariable Cox proportional hazards regression models were used to identify survival predictors. Survival outcomes were calculated using the Kaplan-Meier method and compared using the log-rank tests.

[RESULTS] A total of 696 TCBM patients from 2010 to 2021 were included. Among these, patients aged ≥55 years (P < .001); those with anaplastic TC (P < .001); those with brain, liver, and lung metastases (all P < .05); and those with T4 stage disease (P = .011) significantly reduced overall survival. Significant factors for cancer-specific survival included anaplastic TC (P < .001), liver (P = .010) and lung metastases (P < .001), and radioisotope treatment (P < .001).

[CONCLUSION] This study highlights the critical role of age, pathological subtype, metastatic lesions, and radioisotope therapy in determining the prognosis of TCBM. These findings contribute to providing more rational treatment decisions and risk stratification for patients with TCBM.