Predictive factors for central lymph node and lateral cervical lymph node metastases in papillary thyroid carcinoma

Central lymph node metastasis (LNM) in papillary thyroid carcinoma (PTC) is common. But the association between primary tumor characteristics and specific features of metastatic lymph nodes in PTC has not been fully identified. Determining risk factors for LNM may help surgeons determine rational extent of lymph node dissection.

Data from 432 patients who underwent thyroidectomy with cervical lymph node dissection for PTC were retrospectively analyzed. The relationships between LNM to central compartment or lateral compartment and clinicopathologic factors were analyzed. Cox regression model was used to determine the risk factors for recurrence-free survival (RFS).

Central lymph node metastasis (CLNM) and lateral lymph node metastasis (LLNM) were found in 216 (50.0%) and 65 (15.0%) patients, respectively. In the multivariate analysis for CLNM, patients < 45 years of age (OR 2.037, 95% CI 1.388-2.988, P < 0.001), extrathyroidal invasion (OR: 2.144, 95% CI 0.824-5.457, P = 0.011), vascular invasion (OR 13.817, 95% CI 1.694-112.693, P = 0.014), LLNM (OR 2.851, 95% CI 1.196-6.797, P = 0.014) and TNM Stage III-IV (OR 465.307, 95% CI 113.903-1900.826, P < 0.001) were independent predictors for high prevalence of CLNM. In the multivariate analysis for LLNM, tumor size more than 1cm (OR 3.474, 95% CI 1.728-6.985, P < 0.001) and CLNM (OR 5.532, 95% CI 2.679-11.425, P < 0.001) were independent predictors for high prevalence of LLNM. Moreover, tumor with T3-T4 stage, extrathyroidal invasion and CLNM were the significant factors related to the RFS.

For patients with pre-operative risk factors of LNM, an accurate preoperative evaluation of central compartment or lateral compartment is needed to find suspicious lymph nodes. And prophylactic lymph node dissection should be performed in patients with high risk of CLNM. Moreover, we suggest performing close follow-up for patients with high risk of RFS.