Redefining adequate margins in oral squamous cell carcinoma: outcomes from close and positive margins.

Purpose: Adequacy of surgical margins impacts outcomes in oral cancer. We sought to determine whether close and positive margins have different outcomes in patients with oral cancer. Methods: Retrospective data from 612 patients with oral carcinoma were analyzed for the effect of margin status on locoregional recurrence-free survival (LRFS), disease-free survival (DFS) and overall survival (OS). Results: A total of 90 cases (14.7%) had close margins and 26 patients (4.2%) had positive margins. Recurrences were documented in 173 patients (28%), of which 137 (22% of the study sample) were locoregional, and 164 patients (27%) had died. Among patients with close or positive margins, a cutoff of 1 mm optimally separated LRFS (adjusted p = 0.0190) and OS curves (adjusted p = 0.0168) whereas a cutoff of 2 mm was sufficient to significantly separate DFS curves (adjusted p = 0.0281). Conclusions: Patients with oral carcinoma with positive margins (< 1 mm) had poorer outcomes compared to those with close margins (1–5 mm) in terms of LRFS, DFS and OS. There is a suggestion that a cutoff of < 2 mm might provide slightly more separation for DFS. [ABSTRACT FROM AUTHOR]