[Risk factors analysis and prediction model establishment of contralateral central lymph node metastasis in intermediate-to-high risk unilateral papillary thyroid carcinoma].

Objective: To explore the risk factors of contralateral central lymph nodes (Cont-CLNs) metastasis in intermediate-to-high risk unilateral papillary thyroid carcinoma and establish a prediction model. Methods: The clinical data of 206 patients receiving thyroid cancer surgery at Nantong University Affiliated Hospital between January 2021 and June 2023 were retrospectively analyzed, including 50 males and 156 females, with an age of [M(Q₁, Q₃)] 49.0(33.8, 57.0) years old. The risk factors of Cont-CLNs metastasis were screened by univariate analysis and multivariate logistic regression analysis. A nomogram was constructed for predicting Cont-CLNs metastasis in intermediate-to-high risk uPTC. The area under the receiver operating characteristic (ROC) curve(AUC), calibration curve, and decision curve analysis (DCA) were used to evaluate the model's predictive ability, accuracy, and clinical applicability, respectively. R language was used to randomly select 70% of the patients to establish a validation group for internal validation of the model. Results: Patients were divided into a metastasis group (n=56) and a non-metastasis group (n=150) based on the occurrence of Cont-CLNs metastasis. The ages of the two groups were 39.0 (28.0, 56.8) years and 51.0 (38.8, 57.0) years, respectively. There were statistically significant differences in gender, maximum tumor diameter (>1 cm), ipsilateral central lymph nodes (Ipsi-CLNs) metastasis, number of Ipsi-CLNs metastases (≥4), and lateral lymph node metastasis and Cont-CLNs metastasis between the two groups (all P<0.05). The results of multivariate logistic regression analyses showed that males(OR=2.926, 95%CI: 1.063-8.051), maximum tumor diameter>1 cm(OR=4.471, 95%CI: 1.344-14.877), and number of Ipsi-CLNs metastases≥4 (OR=5.011, 95%CI: 1.815-13.834) were risk factors for Cont-CLNs metastasis (all P<0.05). The AUC of the ROC curve, sensitivity, and specificity for predicting Cont-CLNs metastasis in intermediate-to-high risk uPTC by the prediction model in the modeling group were 0.821 (95%CI: 0.744-0.898), 82.5%, and 63.4%, respectively. In the internal validation group, the AUC of the ROC curve, sensitivity, and specificity for predicting Cont-CLNs metastasis in intermediate-to-high risk uPTC by the prediction model were 0.810 (95%CI: 0.717-0.902), 63.3%, and 83.7%, respectively. The calibration curves of the modeling group and the validation group showed that the model had good calibration ability. The DCA curves of the modeling group and the validation group indicated that the prediction model had good clinical adaptability. Conclusions: The prediction model constructed in this study has good predictive performance for Cont-CLNs metastasis in intermediate-to-high uPTC. When patient with intermediate-to-high risk uPTC is male, with maximum tumor diameter>1 cm, and the number of Ipsi-CLNs metastases≥4 should be alert to Cont-CLNs metastasis, and bilateral central lymph node dissection may be considered.