Primary tumour characteristics predict the invasiveness of lymph node metastases in papillary thyroid carcinoma patients

Objective: This study evaluated whether primary tumour characteristics are associated with specific features of metastatic lymph nodes in papillary thyroid carcinoma patients. Method: A retrospective review of 411 patients with pathologically diagnosed cervical lymph node metastasis was conducted. Results: A metastatic lymph node focus size of at least 2 mm was independently associated with a primary tumour size of at least 1 cm (hazard ratio 1.962) and with male sex (hazard ratio 1.947). A number of at least five lymph node metastases was independently associated with a primary tumour size of at least 1 cm (hazard ratio 2.863), extrathyroidal extension (hazard ratio 1.737) and male sex (hazard ratio 1.689). Extranodal extension was independently associated with a primary tumour size of at least 1 cm (hazard ratio 2.288), extrathyroidal extension (2.201) and male sex (hazard ratio 1.733). Conclusion: Primary papillary thyroid carcinoma characteristics are related to the pathological features of lymph node metastases.