Predictive value of metastatic cervical lymph node ratio in papillary thyroid carcinoma recurrence

BACKGROUND: The purpose of this study was to determine whether the proportion of metastatic cervical lymph nodes resected (metastatic lymph node ratio [MLNR]) predicted papillary thyroid carcinoma (PTC) recurrence, and whether MLNR could alter the predictive ability of TNM nodal classification for recurrence in PTC. METHODS: We conducted a retrospective review of patients with PTC who underwent a total or near-total thyroidectomy with at least 1 lymph node removed at our institution. RESULTS: Of 253 patients, 35 (13.8%) developed recurrent disease. The total MLNR (ratio between total metastatic lymph nodes and total number of lymph nodes resected) independently predicted PTC recurrence (odds ratio [OR], 1.024; 95% confidence interval [CI], 1.010-1.039; p = .001). In receiver operating characteristic (ROC) curve analysis, TNM nodal classification with total MLNR had greater accuracy in predicting PTC recurrence than did TNM nodal classification alone (0.726 and 0.675, respectively). CONCLUSION: MLNR is an independent predictor of PTC recurrence and enhances the predictive value of TNM nodal classification.