Extracapsular extension in oral cavity cancers-predictive factors and impact on recurrence pattern and survival

Extracapsular extension (ECE) has long been considered a poor prognostic factor in oral cavity cancer, the presence of which warrants intensification of adjuvant therapy. This study was done to analyze the survival of patients with ECE who received adjuvant chemoradiation. Patients with pathologically confirmed squamous cell carcinoma of the oral cavity, with a minimum of 2 years of follow-up, who were treated at a tertiary cancer centre in New Delhi, India during the years 2009-2017, were included. On multivariate analysis, ECE was significantly associated with depth of invasion >10 mm and tumour deposit size >5 mm. Among the node-positive group, patients without ECE had a 5-year disease-free survival (DFS) and 5-year overall survival (OS) advantage over ECE-positive patients of 7.8% (63.8% vs. 56.0%) and 16.5% (87.2% vs. 70.7%), respectively. For patients with ECE, the hazard ratio for DFS and OS was 1.3 (95% confidence interval 0.97-1.75, P = 0.078) and 2.30 (95% confidence interval 1.35-3.92, P = 0.002), respectively. ECE remains one of the strongest predictors of recurrence and survival in oral cancer patients, and despite aggressive adjuvant therapy, distant recurrence is still significantly high.