Extranodal extension in head and neck squamous cell cancer: is there a role for further stratification?

To investigate the prognostic significance of the stratification of extranodal extension (ENE) into ENE minor (ENEmi, up to 2mm) and ENE major (ENEma, over 2mm) in non-HPV-related squamous cell cancers of the head and neck, we retrospectively reviewed microscopic slides from neck dissection specimens of ENE-positive patients and subcategorised them into ENEmi and ENEma. We then compared the two groups 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 ENEmi and 18 ENEma. The three-year OS was 46% in the ENEmi group and 38.9% in the ENEma group. DSS and DFS were 80.8% and 80.8%, respectively, in the ENEmi group and 61.1% and 77.8%, respectively, in the ENEma 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 ENEmi group, particularly regarding OS. Nonetheless, extension of the tumour outside the lymph node capsule by more than 2mm was not found to be significantly associated with any of the explored survival outcomes.