Predictors of level II and Vb neck disease in metastatic papillary thyroid cancer.

OBJECTIVE To identify predictors of levels II and Vb involvement in papillary thyroid cancer (PTC) with lateral neck metastasis. DESIGN Large case series. SETTING High-volume tertiary care hospital. PATIENTS Consecutive sample of 185 patients who underwent 248 selective neck dissections of at least levels II to V for pathologically proven PTC. MAIN OUTCOME MEASURES Significant independent predictors of level II and Vb metastasis, including age and pathologic variables (tumor diameter, dominant nodule cellular pathology, multifocality, extracapsular invasion, positive margins, and lymphovascular invasion). RESULTS Levels II and Vb were involved in 49.3% and 29.2% of our cohort, respectively. Age and lymphovascular invasion were independent predictors of level Vb involvement with metastasis (logistic regression: odds ratio for age = 0.92, SE = 0.03, P = .02; and odds ratio for lymphovascular invasion = 5.52, SE = 0.80, P = .03). No significant predictors were identified for level II involvement. CONCLUSIONS Levels II and Vb were involved in a significant number of patients with PTC and lateral neck disease. Younger age and lymphovascular involvement were independent risk factors for level Vb involvement in patients with PTC and lateral neck metastasis. The increased risk might be of marginal clinical significance. No significant predictors were identified for level II involvement. Our findings do not favor a limited neck dissection on the basis of any of the study's clinical or pathologic variables, and we therefore recommend the routine excision of levels IIa to Vb in all patients with PTC presenting with lateral neck disease.