Extranodal extension in resected oral cavity squamous cell carcinoma: more to it than meets the eye

Abstract

Objective/hypothesis: Extranodal extension (ENE) is an independent prognosticator in head-neck Squamous cell carcinoma (SCC). All patients with ENE, however, do not behave the same, and there is a need for further risk stratification. This study evaluates the prognostic significance of various grades of ENE and the number of nodes with ENE on overall survival (OS) in oral cavity SCC (OCSCC).

Study design: Retrospective cohort study.

Methods: Ninety-four patients with node-positive OCSCC treated with primary surgery and appropriate adjuvant therapy during the year 2011 were evaluated. Surgical histopathology slides of all patients were reviewed, and ENE was graded according to the grading system proposed by Lewis Jr et al. RESULTS: On univariate analysis, lymph node density (LND) greater than or equal to 0.12 (P = 0.013), the presence of ENE in more than two nodes (P = 0.006), and ENE grade 3 through 4 (P = 0.035) were associated with worse (OS). Conventional prognostic factors such as tumor (T) stage, nodal (N) stage, stage grouping, depth of invasion, and pattern of invasion did not have a significant impact on OS. On multivariate analysis, the presence of ENE in more than two nodes (P = 0.018) independently predicted a worse OS. Extranodal extension grade 3 through 4 showed a trend toward significance (P = 0.08). A combination of LND greater than or equal to 0.12, ENE grade 3 through 4, and ENE in more than two lymph nodes conferred the poorest prognosis (3-year OS: 18%; P = 0.000).

Conclusion: In patients with ENE and advanced nodal disease, T stage, N stage, stage group, depth, and pattern of invasion lose their impact on OS. In patients with ENE, nodal characteristics such as LND, the number of nodes with ENE, and grade of ENE serve as important prognosticators and aid in further risk stratification.

Level of evidence: 4 Laryngoscope, 129:1130-1136, 2019.

Keywords: Head and neck cancer; extranodal extension; lymphatic metastasis; oral cancer; prognosis; squamous cell carcinoma; survival.