Abstract
Papillary thyroid carcinoma and follicular thyroid carcinoma both are collectively referred as well-differentiated thyroid carcinomas (WDTC). Both carcinoma types carry an excellent prognosis except in cases with aggressive backgrounds or clinicopathological features. We herein investigated survival rates and various prognostic factors in patients with WDTC. In this retrospective study, a total of 602 patients diagnosed as having WDTC, who had undergone total thyroidectomy with or without neck dissection and had received adequate radioactive iodine treatment from January, 2006, to December, 2008 were included. Data were collected by medical record review. Size of the tumor (p < 0.001) and extrathyroidal extension (p < 0.001) were factors for developing regional lymph node metastasis. Nodal metastasis N0 (central compartment) and N1 (lateral compartment) did not adversely affect 7-year overall survival (p < 0.8). For both regional metastasis (p = 0.001) and distant metastasis (p = 0.025), age > 55 years adversely affected overall survival. No significant difference was found in 7-year overall survival between patients with gross and microscopic extrathyroidal extension (77.6% vs. 74.5%, p = 0.18), 10-year overall survival with gross and microscopic extrathyroidal extension was also non-significant (71.1% vs. 81.3%, p = 0.509). There was no role of prophylactic central compartment neck dissection in treating patients with WDTC. Overall survival at 3, 5, 7 years, and 10 years were 94.2%, 88.8%, 85.2%, and 82.7%, respectively. It can be concluded that the survival was adversely influenced by advanced age (> 55 years). Moreover, poor long-term overall survival and disease-free survival were observed in our study population owing to advanced stage carcinoma (extrathyroidal extension and lymph node metastasis) at presentation.