Predictors of level V metastasis in well-differentiated thyroid cancer

Cervical lymphadenectomy is frequently performed in patients with lateral cervical lymph node metastases to improve regional control of disease. However, there is no consensus regarding the appropriate levels of the neck that need to be dissected. Treatment options that have been advocated include the modified radical neck dissection, limited neck dissections, and selective nodal excisions. In particular, the routine dissection of level V remains controversial due to the attendant morbidity to the spinal accessory nerve. To identify clinical and pathological predictors of cervical node metastases to level V in differentiated thyroid carcinoma, we reviewed our experience at The University of Texas M. D. Anderson Cancer Center for the management of metastatic well-differentiated thyroid cancer.

We retrospectively analyzed 70 patients who underwent thyroidectomy and neck dissection for well-differentiated thyroid cancer at M. D. Anderson Cancer Center.

In our series, 53% of neck specimens harbored metastatic thyroid carcinoma at level V. Additionally, 13 level V contralateral neck dissections were performed, and 57% were found positive for metastases. The presence of ipsilateral level V metastases was significantly associated with multifocal disease (p <.05), ipsilateral level II (p <.05), III (p <.05), or IV (p <.01) metastases. Furthermore, ipsilateral involvement of level V was associated with contralateral lymph node metastases (p <.05). Age, sex, and size of primary tumor were not found to be associated with level V metastases. Additionally, preoperative imaging was not sensitive for detecting the presence of level V metastases.

In our series, cervical metastases from differentiated thyroid carcinoma were commonly present at level V. Patients with multifocal cancer within the thyroid gland, and cervical metastases in the ipsilateral jugular nodes have a higher risk of harboring metastatic disease at level V. We believe that routine dissection of the level V lymph nodes should be performed in the setting of a comprehensive neck dissection for patients with lateral neck metastasis from well-differentiated thyroid cancer.