Clinicopathological study on diameter of extranodal extension of cervical metastatic lymph nodes in the prognosis of oral cancer

Objectives

To investigate the relationship between the degree of destruction of the cervical lymph node capsule, extranodal invasion distance, and the prognosis of extranodal extension (ENE)-positive patients

Study design

We retrospectively examined microscopic slides from neck dissection specimens of ENE-positive patients of our hospital. The ENE distance was measured by a pathologist who set up a virtual lymph node and measured the maximum extranodal invasion distance. The maximum distance was used for multiple ENEs. Forty patients with ENE were enrolled in this study. The Kaplan–Meier method was used to estimate survival.

Results

Among the ENE-positive cases, the capsule was completely destroyed and partially destroyed in seven and 33 cases, respectively. Disease-specific survival (DSS) was 1251 days (range 156–3009 days). The median distance of extranodal invasion was 2500 µm (392–8500 µm) in the 33 ENE-positive cases in which the capsule was not completely destroyed. Receiver operating characteristic curve analysis of these 33 cases showed that the cutoff value of extranodal invasion distance for progression-free survival was 2241 µm.

Conclusions

ENE is a prognostic predictor of oral cancer; ENE was an independent prognostic factor; and ENE size cutoff of 2241 µm was a significant prognostic factor.