Outcome of treatment with total main tumor resection and supraomohyoid neck dissection in oral squamous cell carcinoma

Background/Purpose: Supraomohyoid neck dissection (SOHND) is commonly used to treat oral squamous cell carcinoma (OSCC) patients with clinical NO or selected N 1 status. The purpose of this study was to evaluate the clinical outcome of OSCC patients treated with SOHND. Methods: This retrospective study reviewed the clinical outcome of 257 patients (247 men, 10 women) with N0, N1 and N2a OSCC treated with wide excision of the main tumor and SOHND between 1992 and 1999. All patients were followed up for at least 5 years. Survival distributions were analyzed using Kaplan-Meier curves. N status was compared using chi(2) and log rank tests. Results: The neck failure rate was 20% for clinically false negative cases, 6.1% for clinically true negative cases, 21.8% for clinically false positive cases, and 40% for clinically true positive cases. The 3- and 5-year overall neck disease-free survival rates were 79.8% and 77.6%, respectively. The 3- and 5-year neck disease-free survival rates were 86.7% and 84.2% for pathologic NO cases, 56.9% and 56.9% for pathologic N1 cases, and 27.5% and 27.5% for pathologic N2 cases, respectively. Log rank test showed that the p value for difference in survival at 3-5 years was 0.064 for pathologic NO vs. N1 cases, < 0.0001 for pathologic NO vs. N2 cases, and 0.008 for pathologic N1 vs. N2 cases. Conclusion: This study showed that SOHND is effective for pathologic NO OSCC, relatively effective for pathologic N1, and less effective for pathologic N2a. These findings also support that when SOHND is used to treat N2a OSCC, postoperative radiotherapy or radical neck dissection may be needed to improve the neck disease-free survival rate.