Supraomohyoid neck dissection in the management of oral squamous cell carcinoma: special consideration for skip metastases at level IV or V.

PURPOSE: The aim of this study was to evaluate the therapeutic safety and prognosis of supraomohyoid neck dissections for oral squamous cell carcinoma, with a special focus on the risk of skip metastases in level IV or V. MATERIALS AND METHODS: A retrospective study was conducted of 637 patients with oral squamous cell carcinoma who were admitted to the department of oral and maxillofacial surgery from September 1995 through July 2010. After completing a diagnostic evaluation, all patients underwent surgery (wide primary excision with supraomohyoid neck dissection, extended supraomohyoid neck dissection, or modified radical or radical neck dissection) and were followed periodically. RESULTS: Levels I, II, and III were the most common sites of occult metastasis. Skip metastases alone at level IV or V and any neck recurrence at level IV or V were not found. Three-year neck recurrence-free survival and disease-specific survival were not significantly different among the patients who underwent supraomohyoid neck dissection, extended supraomohyoid neck dissection, or modified radical or radical neck dissection owing to cN0 to cN(+) disease. CONCLUSIONS: The rate of skip metastasis at level IV or V is very rare and is very difficult to diagnose accurately. The results of this retrospective study show that supraomohyoid neck dissection for oral squamous cell carcinoma is an appropriate treatment.