Estimation of the width of free margin with a significant impact on local recurrence in surgical resection of oral squamous cell carcinoma

The purpose of this study was to estimate the width of free margin with a significant impact on local recurrence in surgical resection of oral squamous cell carcinoma (OSCC). Clinical and pathological data of 127 consecutive patients who underwent radical resection of OSCC were analyzed retrospectively. The local control rate was compared between patients with clear, close, and involved surgical margins, changing the required width of free margin for the definition of ‘close surgical margin’ (from 1 to 5 mm). If a free margin of within 1, 2, or 4 mm was judged a close margin, the risk of local recurrence was significantly different among the patients with clear, close, and involved surgical margins. If the definition of close margin was within 5 mm of the resection margin, the difference between clear and close margin did not reach statistical significance. The results of this study suggest that 5 mm of clearance at the surgical resection margin should be the index of oncological surgery. More than 5 mm of histological free margin around OSCC is not justified in terms of the risk management of local recurrence and the resultant morbidity.