Extranodal extension is a strong prognosticator in HPV-positive oropharyngeal squamous cell carcinoma

To comprehensively examine the prognostic significance of extranodal extension (ENE) in human papillomavirus-positive oropharyngeal squamous cell carcinoma (HPV-positive OPSCC).

Retrospective cohort of cases diagnosed with HPV-positive OPSCC from 2010 to 2015 in the National Cancer Database. Inclusion of all OPSCC HPV-positive cases with appropriate International Classification of Diseases-0-3 codes that received surgery with a neck dissection. Univariate and multivariable analyses were conducted. Hazard ratios (HR) for the independent effects of ENE and N stage on overall survival were estimated by Cox proportional hazards regression.

Cases that were ENE-negative had the highest 5-year survival (92.6%; 95% confidence interval [CI]: 90.5%-94.7%). ENE-positive cases had the lowest 5-year survival (84.0%; 95% CI: 80.7%-87.4%). After adjusting for confounding variables, ENE-positivity was associated with almost twice the hazard of death (HR = 1.90; 95% CI: 1.35-2.67) compared to ENE-negative cases. Nodal (N) category 1, ENE-positive status was associated with an increased risk of death (HR = 1.88; 95% CI: 1.26-2.80) compared with N1, ENE-negative status. Compared to N1/ENE-negative cases, N2/ENE-positive cases had the poorest survival (HR: 2.93; 95% CI: 1.94-4.43). Both microscopic and macroscopic ENE were associated with worse outcomes compared to node-positive/ENE-negative status.

The implementation of the American Joint Committee on Cancer 8th edition staging system provides a much-improved framework to develop and discuss treatment plans for HPV-positive OPSCC. We feel that careful consideration should be given to the importance of ENE in patients with HPV-positive OPSCC.

4 Laryngoscope, 130:939-945, 2020.