Clinicopathological landscape and management trends of thyroid carcinoma over two decades: a single-institution study and risk stratification of central lymph node metastasis in T1 papillary thyroid carcinoma

PurposeThis study aimed to describe the clinicopathological landscape of thyroid disease, summarize long-term management trends of thyroid carcinoma (TC) and lymph node metastasis (LNM) from 1999 to 2018, and develop a nomogram to predict central lymph node metastasis (CLNM) in patients with T1-stage papillary thyroid carcinoma (PTC).MethodsA total of 34,420 patients with thyroid disease were included for landscape analysis, among whom 18,917 patients with TC were analyzed for management trends. Subsequently, 11,760 patients with T1-stage PTC were enrolled to identify risk factors for CLNM. A predictive nomogram was constructed using multivariable logistic regression and internally validated.ResultsAmong all patients, 22,919 were diagnosed with thyroid cancer and 11,501 with benign nodules. The proportion of TC increased steadily, reaching 99.3% in 2018. PTC accounted for 99.3% of TC cases, while the proportion of papillary thyroid microcarcinoma showed a slight decline. The rate of central lymph node dissection increased from 34.4% to 97%, whereas the CLNM rate decreased from 81.8% to 55%. In contrast, lateral lymph node dissection declined from 58.3% to 28.8%, with a corresponding reduction in lateral lymph node metastasis. Younger age, male sex, larger maximum tumor diameter (MTD), multifocality, lymphovascular invasion, and capsule invasion were identified as independent risk factors for CLNM (all p<0.05). The optimal MTD cutoff was 0.75 cm. The nomogram showed good discrimination (C-index 0.715) and satisfactory calibration.ConclusionsThis study demonstrates evolving patterns and increasing standardization in thyroid cancer management over two decades. The proposed nomogram may serve as a postoperative pathology-based risk stratification tool to support individualized management and follow-up in patients with T1-stage PTC.