ASO Author Reflections: Depth of Invasion in Oral Cavity Squamous Cell Carcinoma—Past, Present, and Future

Excerpt

The International Consortium for Outcome Research in Oral Cavity Squamous Cell Carcinoma (OCSCC)—established in 2012—has collected data from 11 head and neck cancer centers in 9 different countries.1 The initial consensus was that OCSCC aggressiveness was chiefly reflected by depth of invasion (DOI) rather than tumor thickness.1 Compared with the previous third to seventh editions (1988–2010), the eight edition (2017) of the American Joint Committee on Cancer (AJCC) Staging Manual has been updated T-status with the goal of improving its clinical utility and prognostic ability. The major reason for DOI being a criterion for disease upstage to T2-3 is to be found in the results of the above-mentioned international collaborative effort.1 However, specific data on T4 tumors were lacking. Moreover, it was unclear how many patients were staged as pT4 based on DOI versus other criteria (e.g., evidence of extrinsic muscle invasion or through cortex/skin invasion), and most of the subjects were from betel chewing endemic areas.1 …