ABSTRACT
<p><b>OBJECTIVE</b>To investigate prognostic factors of medullary thyroid carcinoma.</p><p><b>METHODS</b>By using univariate analysis and multivariate analysis, the prognostic factors were investigated in 102 patients with medullary thyroid carcinoma treated at this hospital.</p><p><b>RESULTS</b>Overall survival rates of 5-year, 10-year and 15-year were 87.4%, 74.6% and 54.2% respectively by Kaplan-Meier method analysis. In univariate analysis, gender, age, bilateral thyroid lobe tumors, tumor size > 4 cm, invasion of thyroid capsule, distant metastasis, and non-radical tumor resection were significant poor prognostic factors. In multivariate analysis, tumor size > 4 cm (chi(2) = 7.43, P = 0.0035), distant metastasis (chi(2) = 23.50, P = 0.0000), and non-radical tumor resection (chi(2) = 25.90, P = 0.0000) remained as independent prognostic factors.</p><p><b>CONCLUSIONS</b>Tumor size > 4 cm, distant metastasis, and non-radical tumor resection are the independent predictors of patients survival. Early diagnosis and early therapy can improve significantly the prognosis of medullary thyroid carcinoma.</p>