Objective:

To describe the clinicopathological landscape of thyroid disease, summarize long-term management trends of thyroid carcinoma and lymph node metastasis from 1999 to 2018, and develop a nomogram to predict central lymph node metastasis in T1-stage papillary thyroid carcinoma, specifically focusing on the differences between thyroid disease and thyroid carcinoma.

Key Findings:

• The proportion of thyroid carcinoma increased to 99.3% by 2018, with papillary thyroid carcinoma accounting for 99.3% of cases, indicating a shift in disease prevalence.
• Central lymph node dissection rates increased from 34.4% to 97%, while central lymph node metastasis rates decreased from 81.8% to 55%, suggesting improved surgical management.
• Identified independent risk factors for central lymph node metastasis: younger age, male sex, larger maximum tumor diameter, multifocality, lymphovascular invasion, and capsule invasion, which can guide clinical decision-making.
• The optimal maximum tumor diameter cutoff for risk assessment was 0.75 cm, providing a specific metric for clinicians.
• The nomogram demonstrated good discrimination (C-index 0.715) and satisfactory calibration, supporting its use in clinical practice.

Interpretation:

The study highlights evolving management practices and risk assessment for thyroid carcinoma, emphasizing the importance of individualized patient care based on clinicopathological features.

Limitations:

• Retrospective design may introduce selection bias, potentially affecting the reliability of the findings.
• Single-institution study may limit generalizability of findings, necessitating further multicenter studies to validate results.

Conclusion:

The evolving patterns in thyroid cancer management over two decades indicate increasing standardization, with the nomogram serving as a valuable tool for postoperative risk stratification in T1-stage papillary thyroid carcinoma.