Abstract
PURPOSE
The 8th edition of the TNM Cancer Staging Manual incorporates depth of invasion (DOI) into the pathologic tumor classification for oral squamous cell carcinoma (OSSC). While deep invading tumors with small tumor diameters (TD) have been categorized as early stage tumors in the 7th edition, they are now upstaged, potentially influencing the decision to initiate adjuvant radiotherapy (RT).
METHODS
OSCC patients surgically treated with curative intent between 2010 and 2019 were consecutively included. Tumors were staged based on TD only (according to the 7th edition TNM Cancer Staging Manual), then restaged based solely on DOI.
RESULTS
Of the 133 included patients, 58 patients (43.6%) had a different pT-stage when using DOI instead of TD for staging (upstaging in 23.3%). Overall survival (OS) was significantly worse in patients who were upstaged with DOI. In addition, stratification by adjuvant RT showed significant worse OS in upstaged patients without receiving adjuvant RT.
CONCLUSIONS
DOI seems to be an import indicator for adjuvant RT in OSCC-patients.