Risk Stratification for Extranodal Extension in Head and Neck Cancers-Implication for Treatment Intensification.

Area of Science:

• Oncology
• Pathology

Background:

• Extranodal extension (ENE) is a key adverse prognostic factor in head and neck cancers.
• Current risk stratification for ENE requires refinement regarding optimal cutoff values and interactions with other risk factors.

Purpose of the Study:

• To evaluate the prognostic significance of different extranodal extension (ENE) cutoffs in head and neck cancers.
• To determine the optimal ENE extent cutoff for predicting survival and response to adjuvant therapy.

Main Methods:

• Retrospective analysis of treatment-naïve head and neck cancer patients with confirmed ENE on histology.
• Comparison of survival outcomes (OS and DFS) using 2mm and 4mm ENE cutoffs.
• Receiver-operator curve (ROC) analysis to determine the optimal ENE cutoff.
• Assessment of adjuvant chemoradiation (CRT) benefit based on ENE extent.

Main Results:

• The standard 2mm cutoff for ENE did not show significant differences in overall survival (OS) or disease-free survival (DFS).
• ROC analysis identified a 4mm cutoff as having the best predictive ability for DFS.
• Patients with macroscopic ENE (Ma-ENE) demonstrated a significant survival benefit from adjuvant CRT, unlike those with microscopic ENE (Mi-ENE).
• The 4mm cutoff was predictive of therapeutic benefit from adjuvant CRT.
• Tumor location, T-stage, depth of invasion, nodal metastasis burden, and male sex were significant clinicopathological factors interacting with ENE.

Conclusions:

• The 2mm cutoff for ENE extent lacks sufficient hazard discrimination for OS and DFS in head and neck cancers.
• A 4mm cutoff for ENE extent, identified via ROC analysis, shows superior predictive ability for DFS.
• The 4mm cutoff is valuable for predicting treatment response to adjuvant CRT, particularly for Ma-ENE.