Clinical significance of lymph node metastasis of thyroid papillary carcinoma located in one lobe

Background: Previous studies have shown that lymph node metastasis can be of prognostic value. In this study, we investigated the clinical significance of node metastasis focusing on metastasis in the central compartment for patients with papillary carcinoma located in one lobe. Patients and Methods: We investigated the frequency of lymph node metastasis in 759 patients with papillary carcinoma to determine whether and how such metastasis affects disease-free survival (DFS). Results: Central node metastasis was observed in 63% of patients, and the frequency was increased in relation to tumor size. The frequency of lateral node metastasis was 62.0%, which was also directly related to tumor size. On multivariate analysis of cases showing tumor larger than 1 cm, central node metastasis was recognized as an independent prognostic factor of DFS. The frequency of metastasis to the paratracheal nodes contralateral to the tumor was drastically elevated for tumors larger than 1 cm, but metastasis to this region did not independently predict worse DFS. Conclusion: Central node metastasis independently predicts a worse DFS for patients with papillary carcinoma larger than 1 cm.