[Association between metastatic lymph node ratio and recurrence after radical resection of thyroid cancer]

Objective:To investigate the relationship between the metastatic lymph node ratio（LNR） and recurrence in patients receiving radical surgery for thyroid cancer. Methods:A total of 890 patients who underwent radical thyroidectomy at the Department of Head and Neck Surgery, Tangshan Workers' Hospital, between January, 2014, and December, 2024, were included in this study. Based on postoperative recurrence status, the patients were divided into a recurrence group（n=77） and a non-recurrence group（n=813）. Clinicopathological data were collected for all patients, and factors associated with recurrence were analyzed to evaluate their predictive value. Results:The recurrence group exhibited significantly higher proportions of tumor diameters（2-4 cm and >4 cm）, calcification, postoperative pathological lymph node metastasis, lymph node diameter ≥3 cm, and LNR compared to the non-recurrence group. Additionally, recurrence-free survival（RFS） was significantly shorter in the recurrence group than in the non-recurrence group（all P<0.05）. Multivariate Cox regression analysis identified LNR as an independent risk factor for recurrence in patients after radical thyroidectomy（HR: 3.976, 95%CI 1.535-10.301, P=0.004）. Receiver operating characteristic（ROC） curve analysis demonstrated that the area under the curve（AUC） for LNR in predicting postoperative recurrence was 0.652, with a sensitivity of 53.25% and specificity of 76.75%, and the optimal cutoff value was 0.197. The high-LNR group（≥0.197） had a significantly lower RFS rate compared to the low-LNR group（<0.197）（82.2% vs. 94.5%, P<0.05）. Conclusion:LNR is a risk factor for recurrence in patients after radical thyroidectomy and holds certain predictive value for postoperative recurrence, which may provide reference for prognostic assessment in thyroid cancer patients.