Publication

Abstract : pAccording to the eighth edition of the AJCC Cancer Staging Manual (AJCC8), a depth of invasion (DOI) gt;10 mm is classified as pT3, representing a locally advanced tumour requiring postoperative radiotherapy (PORT). When node-negative, however, evidence regarding whether PORT improves loco-regional control or survival is unclear. To clarify this, two cohorts of patients were studied: (1) patients classified as pT3N0 by the seventh edition of the AJCC manual (AJCC7), with DOI gt;10 mm and a tumour diameter gt;4 cm (17 patients who received PORT), and (2) patients classified as pT1N0 and pT2N0 by AJCC7, with DOI gt;10 mm and a tumour diameter lt;4 cm (55 patients who did not receive PORT). Loco-regional control and survival were analysed. PORT was found not to impact overall survival or disease-free survival. It was also found not to impact local, regional, or distant recurrence. Although the two subsets of patients considered here (DOI gt;10 mm with tumour diameter below or above 4 cm) were previously distinct, they are both considered pT3 in AJCC8. Data from this study indicate that the routine administration of PORT to patients with a DOI gt;10 mm may not be warranted in the absence of other risk features such as nodal disease or close margins. © 2018 International Association of Oral and Maxillofacial Surgeons/p