930P - Real-world data analysis of oncological outcomes in patients with pathological extranodal extension (ENE) in OSCC: A proposal to refine the pathological nodal staging system

Background

Nodal involvement significantly influences prognostic outcomes in oral squamous cell carcinoma (OSCC). Current staging systems classify pathological extranodal extension (pENE) as N2a and N3b. This study assesses the prognostic efficacy of redefining nodal stages based on quantitative lymph node involvement.

Methods

A single centre retrospective analysis of 3864 patients with oral cancer from 2015 to 2023 was evaluated, and 825 patients with (pENE) OSCC patients were found. The final study analysis included 640 patients examining clinical and pathological variables influencing the DFS and OS. The primary outcome measures were disease-free survival (DFS) and overall survival (OS), analyzed through Cox regression and Kaplan-Meier survival curves.

Results

Of 640 patients, 79.4% were males with a median age of 48. 50% of patients had primary lesions in the buccal mucosa, and 46% had lesions on the tongue and floor of the mouth. Patients with ≤ 4 positive lymph nodes exhibited significantly better DFS (HR 0.53, 95% CI 0.4-0.6, p<0.001) and OS (HR 0.6, 95% CI 0.58-0.79, p<0.001) compared to those with four or more nodes. The mean DFS for patients with ≤ four nodes was 41.4 months, vs 20.5 months in the >4 group. Similarly, the mean OS was 62.3 months in the ≤ lymph node group versus 26.4 months in the >4 group. Multivariate analysis confirmed lymph node count as a robust predictor of survival, outperforming traditional ENE-based classification.

Conclusions

Extranodal extension is a bad prognostic factor in OSCC; however, the number of positive lymph nodes in patients with extranodal extension showed a significant difference in DFS and OS. A further classification in patients with ENE based on positive lymph nodes can give better prognostication; hence, it should be considered to refine the pathological nodal staging system for better prognostication.

Clinical trial identification

Editorial acknowledgement

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.