Prognostic factors in patients with recurrent differentiated thyroid carcinoma

BACKGROUND: Approximately 20% of patients with thyroid carcinoma have relapse. To evaluate the factors affecting their disease-free survival and prognosis, we studied 68 patients with recurrent differentiated thyroid carcinoma, ranging in age from 5 to 73 years (mean: 47.6 years). Three-fourths of patients were followed for >10 years. Thirty-nine patients were treated with total or subtotal thyroidectomy at first operation; the remainder underwent lesser operations. Fifty-six patients had local recurrence, mostly lymph node infiltration. Twenty-six patients died. METHODS: Survival curves were constructed using the Kaplan-Meier method. Factors affecting relapse and survival were tested by univariate or multivariate analysis. RESULTS: Univariate analysis identified age at diagnosis, local tumor extension, and surgical method as significant factors for disease-free survival. These three factors and histology were significant prognostic factors. Multivariate analysis showed age, histology, and disease-free interval as significant and independent variables. CONCLUSIONS: In high-risk patients, complete resection of thyroid tissue and cervical lymph nodes is critical.