Margin distance in oral tongue cancer surgery: A systematic review of survival and recurrence outcomes.

The status of resection margins is a proxy for the completeness of resection in oral tongue cancer surgery and is therefore a useful predictor for post-operative prognosis. Historically, a margin distance of 5 mm or greater has been deemed a negative margin and is believed to yield a benefit in terms of control and survival. To summarize the literature more completely on this topic, we conducted a systematic review that examines radial margin distance and its relationship to disease control and survival in oral tongue cancer. Our review includes 34 studies which reported survival and/or recurrence outcomes for oral tongue cancer patients based on margin status. Most studies reported outcomes for the 5 mm margin, while the minority utilized other margin cutoffs. For the 5 mm cutoff, outcomes were generally favorable regarding survival and recurrence outcomes. Nonetheless, studies using 4 mm, 3.3 mm, and 10 mm cutoffs also found favorable survival and recurrence outcomes; however, these are a minority of the included studies.