A very close margin of ≤1mm predicts a poor outcome in resected buccal cancer patients with a pathological margin of ≤3mm

Objectives: A close margin of ≤3mm results in a high risk for locoregional recurrence, but still is not an independent factor that helps to guide the use of aggressive postoperative therapies in patients with resected buccal mucosa carcinoma. This suggests there is a diversity of clinical outcomes in this group of patients. The present study explores the predictors among this clinically debated group of patients. Materials and Methods: From 2000 to 2008, 30 resected buccal mucosa carcinoma patients with a close margin of ≤3mm were retrospectively included in this study. All patients were treated with radical surgery together with postoperative radiotherapy (RT) or chemoradiotherapy (CCRT). Locoregional/local/regional control, disease-free status, disease-specific survival and overall survival were the study end points. Results: Two factors were observed that were able to predict 5-year locoregional control. These were a pathological N classification (pN0 vs. pN1-2, 71.5% vs. 30.0%, p=0.044) and a very close margin (>1mm vs ≤1mm, 81.8% vs. 50.7%, p=0.040). Remarkably, the predicting effect of a very close margin was well translated into disease-free status (81.8% vs. 47.1%, p=0.024) and disease-specific survival (100% vs. 70.6%, p=0.037). After multivariate analysis, a very close margin of ≤1mm was found to independently predict a high risk of locoregional recurrence (HR, 9.528; 95% CI, 1.326-18.481; p=0.025) and disease failure at any site (HR, 12.778; 95% CI, 1.934-25.217; p=0.013). Conclusion: More aggressive postoperative treatments should be considered for resected buccal mucosa carcinoma patients with a very close margin of ≤1mm.