Glottic tumours involving the anterior vs posterior paraglottic space have different prognosis. Opportunity for refinement of the TNM 8th Edition

Involvement of the paraglottic space (PGS) in laryngeal cancer has been considered the hallmark of T3 category since the 6th Edition of the TNM Staging System in 2002 (6TNM). Recent evidence has emerged, mainly in the surgical literature, supporting the value of distinguishing the inferior (glottic and subglottic) part of the PGS (iPGS) into anterior and posterior compartments divided by a line tangential to the arytenoid process and perpendicular to the thyroid lamina. The aim of this review was to collect all existing evidence from both the surgical and non-surgical literature supporting the prognostic significance of such a compartmentalisation, in order to propose an amendment to the current 8TNM by distinguishing T3a (glottic tumours with anterior iPGS involvement endoscopically characterised by vocal fold fixation with normal arytenoid movement and radiologically by involvement of the iPGS in front of the above mentioned line) from T3b (glottic tumours endoscopically characterised by impaired arytenoid movement and radiologically by involvement of the iPGS beyond the same line).