Identifying risk factors for metastasis to the level VII lymph node in papillary thyroid carcinoma patients

The level VI lymph nodes are anatomically connected to the level VII lymph nodes and papillary thyroid carcinoma (PTC) can metastasis to both regions. The aim of this study was to identify clinicopathologic factors associated with level VII lymph node metastasis.

Between March 2015 and September 2016, a total of 275 consecutive patients were operated on for PTC with prophylactic level VII dissection at the Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, ZheJiang, China. Patients with PTC were performed via video-assisted approach. Multivariate logistic regression analysis was performed to evaluate the associations between clinicopathologic factors.

Of the 275 subjects enrolled in this study, 79 patients (28.73%) showed lymph node metastasis to the level VII. The multivariate logistic regression analysis showed ultrasonography-positive lymph nodes (p < 0.001), the location of primary carcinoma (p = 0.002) and hashimoto thyroiditis (HT) (p = 0.04) were associated with level VII lymph node metastasis.

Based on the results of our study, we considered central-compartment lymph node dissection (CLND) as an integral strategy. On the basis of surgery safety, transcervical level VII lymph node dissection could be considered for PTC patients with high risk factors such as ultrasonography-positive lymph nodes, tumor located in middle and lower thirds of the thyroid lobe and the patients without HT. In future, prognostic significance of level VII lymph node dissection should be evaluated through long-term surveillance.