Objective: Surgery, radiation, and observation are the practical N0 neck management. Among these modalities, the most promising management has not been concluded yet. We aimed to evaluate oncologic outcomes comparing among the modalities in clinically N0 early stage oral cancer.

Material and Method: Clinicopathological data of 236 patients, who were diagnosed as T1 or T2, N0 squamous cell carcinoma of the oral cavity, were retrospectively reviewed. The eligible patients were classified into three groups regarding to the neck management whether elective neck dissection, elective neck radiation, or observation. Oncologic outcomes were evaluated at 5 years.

Results: Five-year overall survival rates were 77.7% for neck dissection group, 58.8% for the radiation group and 76.5 % for the observation group (p=0.197). Five-year disease specific survival rates for the same three groups were 77.7%, 70.3% and 80.9%, respectively (p=0.339), while the 5-year regional disease free survival rates were 84.6%, 79.4% and 61.3% (p=0.062), respectively. The occult regional metastasis rate was 24.4%. In subgroup analysis regarding to T stage, the occult regional metastasis rate of T1 stage was 15.38 %, and the occult regional metastasis rate of T2 stage was 28.57%.

Conclusion: The differences of oncologic outcomes of clinical N0 in early stage oral cancer undergoing elective neck dissection, radiation, and observation are not statistically significant.