Influencing factors and prediction model of ultrasound-based false-negative central lymph node metastasis in localized papillary thyroid carcinoma.

BACKGROUND: Patients with papillary thyroid cancer (PTC) exhibited a high false-negative rate for central lymph nodes (CLNs), with unknown influencing factors and predictive models. This study aimed to identify risk factors for false-negative CLN findings in a cohort study and to develop a predictive model to support clinical decision-making. METHODS: This cohort study included patients admitted to the Breast and Thyroid Surgery Department of Shandong Provincial Hospital, China, between January 2013 and December 2023. All patients included in the study were confirmed to papillary thyroid cancer (TC) based on postoperative paraffin-embedded pathology. False-negative CLNs refers to metastasis undetected by preoperative ultrasound but confirmed postoperatively by pathology. Logistic regression, forest graph and nomogram were used to calculate and display statistical difference between influencing factors and the false-negative rate of CLNs. RESULTS: A total of 5,614 patients with papillary TC [44.19±11.14 years, 4,469 women (79.6%)] were analyzed. Logistic regression analysis showed that gender [odds ratio (OR): 1.832, 95% confidence interval (CI): 1.570-2.137, P<0.001], chronic disease (OR: 0.655, 95% CI: 0.552-0.778, P<0.001), diameter of malignant thyroid nodules under ultrasound (OR: 1.816, 95% CI: 1.511-2.182, P<0.001), diameter of CLNs under ultrasound (OR: 1.404, 95% CI: 1.074-1.836, P=0.01), enlargement of lateral lymph nodes (LLNs) under ultrasound (OR: 1.550, 95% CI: 1.213-1.980, P<0.001), diameter of LLN under ultrasound (OR: 0.645, 95% CI: 0.435-0.956, P=0.03) were statistically significant preoperative influencing factors. CONCLUSIONS: This cohort study indicated that the false-negative rate of CLNs was quite common. Personalized preventive CLN dissection was suggested.