Lymph node status of lateral neck compartment in patients with N1b papillary thyroid carcinoma

Conclusion Loco-regional recurrence-free survival was significantly decreased in the papillary thyroid cancer patients with >6 metastatic lymph nodes and a lymph node ratio >0.22. Also, the risk of lung metastasis was significantly increased in cases with bilateral neck node metastases. Objective This study focused on the metastatic lymph node status of the lateral neck compartment to understand its prognostic significance for loco-regional recurrence and distant metastasis. Methods Between January 2004 and December 2009, 1040 patients were diagnosed with papillary thyroid cancer and underwent treatment. Results In a multivariate analysis, sex, the number of metastatic lymph nodes, and the lymph node ratio was significantly associated with loco-regional recurrence. The sensitivity/specificity of 46 metastatic lymph nodes for predicting recurrence was 64.0%/69.7%. The 5-year loco-regional recurrence-free survival of patients with 0-6 metastatic lymph nodes and >6 metastatic lymph nodes were 93.4% and 79.2%, respectively. The 5-year loco-regional recurrence-free survival of patients with a lymph node ratio <= 0.22 and a lymph node ratio >0.22 were 97.1% and 78.8%, respectively. In the multivariate analysis, only bilateral neck node metastases were significantly associated with lung metastasis.