Oral Cavity Cancer: Depth of Invasion (DOI) AJCC 8th ed. 2017

AfHNS Clinical Practice Guidelines Tongue FOM

  • Distance from adjacent normal basement membrane to deepest point of cancer (Blue plumb lines)
  • Correlates with prognosis and occult nodal metastases
  • Preoperative assessment
    • Palpation +/- imaging
    • Must distinguish exophytic from invasive cancers (see adjacent figures)
  • T-stage increases with every 5mm
    • T1: Less invasive (≤5 mm)
    • T2: Moderate depth (>5 to ≤10mm)
    • T3: Deeply invasive (>10 mm)
  • Extrinsic muscle infiltration no longer a staging criterion for T4 because
    • Superseded by DOI
    • Limited extrinsic muscle invasion difficult to assess

Index: Clinical Practice Guidelines for Oral Cancer

Resource Appropriate Oral Cancer Guideline Scenarios