Revisiting the prognostic role of extranodal extension in oral cavity squamous cell carcinoma: minor versus major extension matters.

Extranodal extension (ENE) is a well-known adverse feature in head and neck cancer, with a substantial effect on prognosis. However, the extent of ENE (minor vs major), is not a part of the decision-making process for the treatment of head and neck cancers. The aim of this study was to investigate its effect on prognosis in oral cavity squamous cell carcinoma (OCSCC). A retrospective analysis was conducted of adult patients treated surgically for OCSCC at a a university-affiliated tertiary care centre between the years 2002 and 2022, who had ENE on final pathology. Major ENE beyond the lymph node capsule was considered >2 mm. Overall survival (OS), disease-free survival (DFS), and ENE extent association with other factors were analysed. Out of a total of 349 patients treated surgically for OCSCC during the study period, 101 (28.9%) were node-positive: 47 (13.5%) had ENE, of whom 16 (4.6%) had minor ENE, and 31 (8.9%) had major ENE (>2 mm). DFS was significantly longer in the minor ENE group when compared to the major ENE group, (P = 0.016), while OS was not (P = 0.34). On multivariate analysis, the only variable that was significantly associated with DFS was major ENE when compared to minor ENE, with a hazard ratio of 5.47 (95% confidence interval CI 1.19-25.08%, P = 0.02). The extent of ENE seems to be an important prognostic factor in OCSCC. Subject to future prospective studies, deintensification of adjuvant therapy could be considered in patients with minor ENE.