International Session 21　　Dysphagia 1

To investigate the prognostic significance of classifying extranodal extension(ENE)into minor ENE(miENE, up to 2 mm)and major ENE(maENE, over 2 mm)in non-HPV squamous cell carcinoma of the head and neck, we retrospectively reviewed microscopic slides from neck dissection specimens of ENE-positive patients and subcategorised them into minor ENE and major ENE.We then compared the two categories in terms of overall survival(OS) , disease-specific survival(DSS) , and disease-free survival(DFS) .Forty-four patients with pathologically positive necks had ENE in the histological report.Twenty-six had minor ENE and eighteen has major ENE.The three-year OS was 46％ in the miENE group and 38． 9％ in the maENE group.DSS and DFS were 80． 8％ and 80． 8％, respectively, in the miENE group and 61． 1％ and 77． 8％, respectively, in the maENE group.None of the comparisons revealed any statistically significant difference.The results of our survival analysis seem to show a trend towards better survival rates in the miENE group, particularly regarding OS.