Abstract
The Union for International Cancer Control-American Joint Committee on Cancer TNM staging system for glottic squamous cell carcinoma (SCC) includes different types of lesions defined by the involvement of specific subsites in each T category. Our study aims to identify different subcategories according to tumor local extension and determine oncologic outcomes after treatment by transoral laser microsurgery (TLM) alone. We retrospectively evaluated 410 patients affected by previously untreated pT1-pT3 glottic SCC treated by TLM alone from January 2005 to December 2015 at the Departments of Otorhinolaryngology-Head and Neck Surgery, Universities of Genoa and Brescia, Italy. All patients had at least 2 years of follow-up. Clinical, radiological, surgical, and histopathological data were reviewed and tumors divided into six subcategories: I, pT1a not involving the anterior commissure (AC); II, pT1b involving the AC; III, pT2 extending superficially to the supraglottis or the subglottis; IV, pT2 infiltrating the vocal muscle; V, pT3 involving the anterior paraglottic space; VI, pT2 or pT3 with vertical extension across the AC with/without involvement of the pre-epiglottic space. Recurrence-free survival (RFS), local control with laser alone (LCL), and organ preservation (OP) were defined as the primary oncologic outcomes. The 2, 5, and 10-year RFS for the entire series were 85.7, 80.3, and 73.8%, LCL rates 93.8, 92.1, and 89.6%, and OP rates 96.8, 95.9, and 93.5%, respectively. However, when comparing the rates of RFS, LCL, and OP for each subcategory, important differences emerged. In particular, subcategories V and VI showed a significantly increased risk of local recurrence [hazard ratio (HR) = 9.2 and 13.3, respectively]. These subcategories also had a significantly reduced probability to achieve LCL (HR: 73.6 and 93.5, respectively) and OP (HR: 6.4 and 8.1, respectively). The present classification in subcategories allows introducing the concept of a three-dimensional map of isoprognostic zones in glottic SCC treated by TLM alone as a useful tool in its management by a multidisciplinary tumor board.
Highlights
The Union for International Cancer Control–American Joint Committee on Cancer TNM staging system for glottic squamous cell carcinoma (SCC) includes different types of lesions defined by the involvement of specific subsites in each T category
The present study introduces a new conceptual tool that we have defined “three-dimensional (3D) map of isoprognostic zones,” which allows for the definition, for each therapeutic strategy, of the oncologic outcomes that are reasonably obtainable for each specific T subcategory, more precisely than previously obtained by the simple use of TNM stratification alone
The aim of the present study is to retrospectively stratify in 6 subcategories, defining an equal number of isoprognostic zones, a cohort of 410 T1, T2, and selected T3 glottic SCCs according to location and extension, describe different patterns of growth and possible pathways of recurrence, and define the role and limits of transoral laser microsurgery (TLM) as a single treatment modality in terms of recurrence-free survival (RFS), local control with laser alone (LCL), and organ preservation (OP) rates for each subcategory
Summary
The Union for International Cancer Control–American Joint Committee on Cancer TNM staging system for glottic squamous cell carcinoma (SCC) includes different types of lesions defined by the involvement of specific subsites in each T category. Even the 8th Edition of the TNM staging system [15] is definitively too simplistic to precisely define the different possible extensions of glottic tumors (especially when dealing with T2 and T3 lesions), limiting a proper patient and interdisciplinary counseling. These T categories may differ according to the involvement of various glottic subsites, superficial spreading to the supraglottis or subglottis, deep extension toward visceral compartments [paraglottic (PGS) and pre-epiglottic spaces (PES)], vocal cord/arytenoid mobility, and infiltration of the cartilaginous framework. The process of subdividing each T category in a number of more homogeneous subgroup of lesions should help in communicating and sharing therapeutic outcomes to be achieved in every single case scenario, making a custom tailored approach for evaluation and treatment of a specific tumor more feasible
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
