Impact of surgical resection margins less than 5 mm in oral cavity squamous cell carcinoma: a systematic review.

The width of the surgical resection margin impacts recurrence and survival in oral cavity squamous cell carcinoma (OSCC). The most commonly used definition of a clear margin is one larger than 5 mm, although due to anatomical restrictions to e.g. bone or vessels, this size is not always feasible. Margins less than 5 mm affect postsurgical strategies and prognoses, and further knowledge of margins smaller than 5 mm is needed. We aimed to systematically review the literature on the impact of surgical resection margins less than 5 mm addressing recurrence and survival in OSCC. A systematic literature search was performed in the PubMed and EMBASE databases identifying studies regardless of publication date that examined margin less than 5 mm, with or without a comparison to size of 5 mm or greater, in patients with OSCC. We assessed the impact on recurrence and survival. We identified six studies ( = 1514 patients); all studies, investigated recurrence, and three ( = 768 patients) evaluated survival. The studies had noteworthy variability in, e.g. follow-up times, anatomical sublocations, T- and N-stage classifications, and outcome measures. Five studies ( = 1387 patients) reported that margins smaller than 5 mm would be safe and would not affect survival or recurrence negatively compared to their own data on larger margins. One study reported that a clear resection margin greater than five mm was necessary to ensure optimal outcomes. The literature showed significant bias and risk issues. In five of the included studies with 1387 patients, we found in selected cases, where margins larger than 5 mm are not possible, a tendency regarding resection margins less than 5 mm to be sufficient for the surgical treatment of patients with primary OSCC. However, the data is insufficient to enable altered recommendations of resection margins in patients with primary OSCC.