Risk factors of central lymph node metastasis of papillary thyroid carcinoma: A single-center retrospective analysis of 3273 cases
Due to the lack of an accurate preoperative diagnostic method of central lymph node metastasis (CLNM) of papillary thyroid cancer (PTC), the prophylaxis of central lymph node dissection remains controversial. The present study investigated the clinicopathological features of PTC patients and the risk factors of CLNM. The clinicopathological features of PTC patients with respect to sex, age, initial symptoms, observation, tumor diameter, multifocality, extrathyroidal invasion, and pathological data combined with other thyroid diseases, were analyzed retrospectively. The risk factors of CLNM were analyzed by Chi-squared test and multivariate logistic regression model. The CLNM rate of PTC was 40.6% (1331/3273). On average, 7.0 (4.0, 12.0) central lymph nodes were dissected, and 3.70 (±3.8) lymph nodes were proved to be metastatic. Univariate analysis showed that sex (P < .001), age (P < .001), tumor diameter (P < .001), extrathyroid invasion (P < .001), multifocality (P = .001), concurrent nodular goiter (P < .001), initial symptoms (P < .001), and observation or not (P < .001) were related to CLNM. The observation time was neither related to CLNM (P = .469) nor extrathyroidal invasion (P = .137). Tumors localized in the lower part of the thyroid were the risk factors for CLNM (P < .001) while multifocality was unrelated (P = .68). The metastasis rate of bilateral multiple regions > unilateral multiple regions > single region (P = .003). Multivariate logistic regression analysis showed that sex, age, tumor diameter, extrathyroidal invasion, and observation were independent risk factors of CLNM. Male, younger age, large tumor size, and extrathyroidal invasion were independent risk factors for CLNM. CLNM was related to multiple regions occupied by tumors in the thyroid but unrelated to multifocality. The tumor occupying a single region and localized in the lower part of thyroid could be used as a predictive factor for CLNM. For tumors that could not be diagnosed as benign or malignant, observation may be an option, since no evidence of disease progression was presented during observation.