To analyze the prognostic significance of the extent of extranodal extension (ENE) and assess the impact of chemoradiation (CRT) on overall survival (OS) in patients with oral cavity squamous cell carcinoma (OCSCC).
Materials and Methods: Utilizing the National Cancer Database (NCDB), we performed a retrospective cohort study of 7,975 patients with OCSCC and microscopic ENE (miENE) or macroscopic ENE (maENE) who underwent primary surgical intervention. We used cox regressions to evaluate the association of the extent of ENE with OS. Additionally, a propensity score matching allowed us to assess the impact of adjuvant radiation alone vs. adjuvant chemoradiation (CRT) on OS in patients with miENE and maENE.
Results: 7,975 patients with OCSCC were included in the final analysis. Within this cohort, 25.4% had miENE and 5.2% had maENE. On univariate analysis, we found that miENE and maENE were associated with decreased OS (HR=1.67; 95% CI 1.56, 1.79 and HR=1.88; 95% CI 1.66, 2.14, respectively). On multivariate analysis with propensity score matching, we found that there was no significant treatment effect in OS between patients who received adjuvant radiation alone vs. adjuvant CRT for patients with miENE, and for those with maENE.
Conclusion: The results of this study suggest that the addition of chemotherapy to adjuvant radiation may not provide a significant survival benefit in patients with OCSCC with miENE and maENE. Comprehensive assessment of the benefits of adjuvant CRT in the setting of miENE vs. maENE will need to be studied in a randomized controlled trial.