Surgical margin in oral squamous cell carcinoma and its relationship with histopathological risk parameters.

There is controversy surrounding the concept of an adequate tissue margin and its prognostic value in oral squamous cell carcinoma (OSCC) surgical treatment. Therefore, this study investigated the suitability of various distance thresholds for a safe margin and evaluated their relationship with prognosis as well as with other histopathological variables, mainly the depth of invasion. A retrospective cohort of 179 OSCC patients undergoing primary surgical treatment was studied. Involved margins were significantly associated with poor outcomes, but close margins showed no significant difference with clear and positive margins in terms of survival and recurrence. Specifically, a margin >2 mm was significantly associated with higher survival and fewer recurrences in univariate analysis. However, multivariate analysis revealed that histological grade (P = 0.02) and treatment (P < 0.001) were the only variables associated with tumour recurrence. Depth of invasion was significantly associated with lymph node metastasis (P = 0.004), and surgical margin status was significantly associated with depth of invasion (P = 0.001). In this study, a surgical margin ≤2 mm was significantly associated with poorer outcomes and higher recurrence rates in oral cancers, compared to >2 mm, but only in univariate analysis. This association was not observed in multivariate analysis.