%0 Journal Article %T The updated AJCC/TNM staging system (8 th edition) for oral tongue cancer %A Dong Jin Lee %A Kyubo Kim %J SCIE-indexed Journal %D 2019 %R 10.21037/26416 %X An increasing amount of literature shows solid evidence that the depth of invasion (DOI) of oral cavity squamous cell carcinoma is an independent predictor for occult metastasis, recurrence, and survival (1-3). Furthermore, the DOI of the primary tumor has been a major criterion when deciding to perform elective neck dissection on oral cavity squamous cell carcinoma patients since as early as the mid-1990s (4). A cut-off value of 4 mm has conventionally been used when determining the need for elective neck dissection, based on a study by Kligerman et al. (4). Thereafter, several reports have proposed a range of cut-off points for improving survival, detection of occult nodal metastases, and decreasing risk of locoregional recurrence (5,6) %U http://tcr.amegroups.com/article/view/26416/html