Prophylactic lymph node dissection in papillary thyroid carcinoma: is there a place for lateral neck dissection?

BACKGROUND: Cervical lymph node (LN) metastases are common in patients with papillary thyroid carcinoma (PTC), and they have a negative impact on recurrence. The management of preoperatively node-negative (N0) PTC is still controversial. The aim of our study was to describe the results of a prophylactic bilateral lymph node dissection (LND) and to investigate its impact on recurrence.

METHODS: From 2003 to 2011, we analyzed 603 consecutive preoperatively N0 PTC patients. For each patient, we reviewed demographics data, tumor characteristics, pattern and risk factors of LN metastasis, and outcome.

RESULTS: Lymph node metastases were found in 23 % of patients: 19 % in the central compartment and 8 % in the lateral compartment, including 1 % in the lateral compartment on the opposite side from the tumor. Multivariate analysis showed that hyperthyroidism and extrathyroidal invasion of the tumor were significantly associated with LN metastasis. Further analysis showed that localization of the tumor in the upper third of the thyroid lobe and metastatic LN in the central compartment were independent risk factors for lateral LN metastasis. During the 4.3-year follow-up, 23 recurrences were observed (4 %), including 5 in the central compartment. Recurrence rates were 2 % in the N0 group, 5 % in N1a patients, and 22 % in N1b patients (p < 0.001).

CONCLUSIONS: In preoperatively N0 PTC patients, LN metastases are frequent in central and ipsilateral lateral compartments. Prophylactic LND in the central and ipsilateral lateral compartments should therefore be recommended in the presence of PTC to identify high-risk patients.