Dysplasia at the margin? Investigating the case for subsequent therapy in 'Low-Risk' squamous cell carcinoma of the oral tongue

Purpose: This is a retrospective analysis of the impact of moderate dysplasia at the resection margin for early stage cancer of the oral tongue. Materials and methods: Patients with T1-2N0 oral tongue cancer treated with surgery alone at Fox Chase Cancer Center (FCCC) from 1990 to 2010 were reviewed. Tumor and margin characteristics were abstracted from the pathology report. Overall survival (OS), disease-free survival (DFS) and local control (LC) were calculated using the Kaplan Meier method. Predictors of LC, OS and DFS were analyzed. Results: 126 Patients met the inclusion criteria. Dysplasia was present at the final margin in 36% of the cases (severe: 9%, moderate: 15%, mild: 12%). Median follow-up was 52 months. 3 and 5-year actuarial LC for the entire cohort was 77% and 73%, respectively. Actuarial 5-year LC and DFS were significantly worse for patients with moderate or severe dysplasia at the margin vs. none or mild dysplasia at the margin (49% vs 82%, p = 0.005 and 49% vs 80%, p = 0.008, respectively); 3-year comparisons were not significant. When analyzed separately, the detrimental local effect of moderate dysplasia at the margin persisted (p = 0.02) and the effect of severe dysplasia at the margin was approaching significance (p = 0.1). Mild dysplasia at the margin did not significantly impair LC or DFS. Multivariate analysis demonstrated worse LC (HR: 2.99, p = 0.006) and DFS (HR: 2.84, p = 0.008) associated with severe or moderate dysplasia at the margin. Conclusions: Both severe and moderate dysplasia at the margin appear to be correlated with inferior LC and DFS. Additional therapy may be justified, despite added morbidity.