“…[6][7][8][9][10][11][12] The risk factors studied include grade, pattern of invasion, PNI, LVSI, margins, and depth of invasion among others. A recent study by Brockhoff et al, 24 however, concludes that carcinoma of the tongue and the floor of the mouth is relatively more aggressive than other subsites and 2-mm depth of invasion should be used as an indicator for elective neck dissection, whereas in carcinoma of the retromolar trigone, alveolus, and hard palate, the significant depth of invasion is 4 mm. Close/positive margin is now an established poor prognostic factor 13,14 and recent confirmation of depth of invasion as a poor prognostic factor has raised the relevant question of adjuvant therapy in these patients.…”