Establishment of model to predict lateral neck recurrence of central lymph node metastasis in papillary thyroid carcinoma

Objective: To explore the risk factors for lateral neck recurrence of central lymph node metastasis (CLMN) in papillary thyroid cancer (PTC), and to construct a model to predict the recurrence. Methods: The records of 245 consecutive PTC patients with CLMN underwent surgical treatment from 1996 to 2009 in our department were retrospectively reviewed. The threshold value of CLNM number is determined by ROC curve. The risk factors for lateral neck recurrence were determined by using Cox regression model. The identified risk factors were incorporated into a nomogram model to predict the risk of lateral neck recurrence. Results: A total of 245 patients were enrolled in the study, among them, 32 cases occurred lateral neck lymph node recurrence and 4 cases were dead of thyroid carcinoma. Multivariate analysis revealed that primary tumor size, extrathyroidal extension, the number of metastatic CLNM >3 were independent risk factors of lateral neck recurrence (P<0.05), lateral neck recurrence was a risk factor of disease-free survival(P<0.05). The nomogram model of predicting the lateral neck recurrence was further established based on the above 3 independent risk factors, the area under the receiver operating characteristic (ROC) curve of which was 0.790. Conclusions: The nomogram model based on the independent risk factors of LN recurrence can be helpful to screen the papillary thyroid carcinoma patients with high risk of lateral neck recurrence, and provide more guidance for clinical treatment.