laryngeal cancers represent about 30% of head and neck cancers with a high incidence for the glottic location ( from 25 to 85% ) [ 1 , 2 ] . there is currently no recommendation from the uicc ( international union against cancer ) for pre - therapeutic assessment ( endoscopy , computed tomography , and magnetic resonance imaging ) specifying in particular the need to involve them . now the evaluation of the cartilaginous extension , especially thyroid , is an important element in the pre - therapeutic assessment of the endolaryngeal cancer . in case of infiltration the tumor is classified ct4a , and the patient is amenable to an aggressive therapy given the high risk of local recurrence and low radiosensitivity . the purpose of this study is to evaluate , by comparing , the existing correlation between preoperative radiological classification of endolaryngeal tumors involving the anterior commissure ( endoscopy , ct scan ) and postoperative classification ( pt pathology ) . this is a single - center retrospective study ( 19982005 ) conducted at the croix - rousse hospital on 127 patients with endolarynx cancer involving the anterior commissure . all these patients were surgically treated and 32 of them with a total laryngectomy , the 95 other patients with a partial laryngectomy . squamous - cell carcinoma represented the main pathology ( 124 patients ) with a case of adenosquamous carcinoma , a case of pseudosarcomatous carcinoma , and a last case of verrucous carcinoma . all patients underwent a nasofiberscopy ( including a verification of chordal mobility ) followed by panendoscopy using optical at 0 and 30. radiological examinations were performed in seven different centers in 2  mm maximum sections , in all cases after injections of contrast . the tumor extension should be clarified to the following areas : sub glottis , paraglottic area , preepiglottic area , and cartilages ( thyroid , cricoid ) . the patients were 58 years old in average , 93% of them were smokers , and more than half had a regular alcohol consumption . table 1 summarizes the comparison of ct and pt stages for all tumors in the study . only 76% of tumors have been classified correctly with the endoscopy and ct scan combination . it is more likely to correctly classify tumors with a limited size since only 64% of t3 and t4 tumors were correctly classified preoperatively . 24.6% of ct2 and 33.3% of ct3 tumors are actually reclassified pt4 after histopathological examination . this shows that the cartilage invasion is frequently under - estimated by the radiological assessment with endoscopy and cervical ct scan . this underestimation of the cartilage infiltration is more common than on the assessment of the subglottis , paraglottic areasc and preepiglottic extension . only 2% of ct2 tumors were reclassified pt3 , and 5% of the ct3 tumors were reclassified pt2 after pathological examination of the specimen . a decrease in the survival rates of laryngeal cancer in the united states , the terms of support , especially for the advanced stages , are currently controversial . if no conclusion of this study can be drawn in a formal and dogmatic manner , the proliferation of treatment options ( radical surgery , partial surgery , transoral surgery , and laryngeal preservation protocols ) requires more accurate and right pretreatment staging . one of the major means of all these studies , randomized or not , is the selection mean with the inclusion of patients with faulty pretreatment radiological staging . the underestimation of the thyroid cartilage invasion by cervical ct is found in many studies with variable rates . in a prospective study related to the cartilage invasion , realized on 40 patients , zbren et al . found a 67% sensitivity and a 87% specificity of ct . when studies involve all endolaryngeal tumors , it appears that the anterior commissure of the underestimation is greatest . thus , on nakayama and brandenburg 's cases , 50% of t3 tumors were subclassified by breach of a micro - cartilage invasion . 90% of this situation involved tumors of the anterior commissure .   the special case of the thyroid cartilage invasion via the anterior commissure was also clearly demonstrated . barbosa et al . then found a 25% overall underestimation of the ct stage of the anterior commissure tumors by the combination ct / endoscopy . however , reports show a stronger underestimation for smaller tumors classified as t1 and t2 ( respectively 50% and 62% of correct estimation ) . showed that the redefinition of radiological criteria allowed the increase in accuracy of radiological conclusions in two successive audit cycles by increasing the accuracy rate of 45% to 71% . this also shows that our balance sheet allows us to achieve correct figures and that theses are not related to poor quality of the examinations . table 2 summarizes the various studies on the reclassification of endolaryngeal tumors after postoperative pathologic examination ( initial radiological staging ct / endoscopy ) . some scan signs to look for can increase the relevance of this paper . for the thyroid cartilage , specificity ( ability to correctly identify individuals who are not affected by the disease ) would be about 93% for erosion or lysis the combination of these signs causes a high sensitivity ( ability to detect cases of a disease ) and reinforces the negative predictive value ( probability of being healthy if negative ) . zbren et al . also studied retrospectively the reclassification of the endolaryngeal recurrent lesions . in these cases , it appears that the combination ct / endoscopy is even less accurate to correct a tnm stage assessment . they report indeed a 48% sensitivity on the study of the thyroid cartilage invasion and 47% for the cricoid invasion . our study did not use any mri as an examination to detect the cartilage infiltration . with a 8994% sensitivity and a 7488% specificity , its negative predictive value ( npv ) is around 9496% , but its positive predictive value ( ppv ) reaches only about 71% ( probability of getting sick if positive ) . they are then many false positives with a significant risk of inadequate treatment by overestimation [ 1215 ] .   this difficult pretreatment evaluation of the cartilaginous extension of endolaryngeal tumors leads us to suggest a surgical approach with resection of exposed cartilaginous portions as soon as the anterior commissure and the anterior portion of the subglottis are getting invaded . our study shows that radiological pretreatment classification ( ct ) of laryngeal cancer involving the anterior commissure is often inaccurate when compared with postoperative pathology ( pt ) . the mri appears to offer a more effective accuracy but still below the pt . this finding should lead to a transdisciplinary consideration from the moment the treatment choice is not directed towards a first surgical resection .
background . 
 the objective of this study is to assess the accuracy of pre- and posttherapeutic staging of endolaryngeal cancer involving anterior commissure . 
 materials and methods . 
 127 patients were included in this retrospective study , and laryngectomy ( partial or radical ) was achieved in all of them . 
 initial radioclinical evaluation ( ct ) was performed ( endoscopy - ct scan ) and compared with postoperative histopathological findings . results . 
 24,6% of ct2 and 33,3% of ct3 laryngeal tumors were reclassified pt4 after the histopathological examination . 
 conclusion . 
 pre - therapeutic staging ( combining endoscopy - ct scan ) of endolaryngeal cancer involving anterior commissure is inadequate and sometimes underestimates thyroid cartilaginous invasion . 
 nethertheless , a precise diagnostic assessment by surgery with postoperative histological findings is possible . 
 cartilage and/or paraglottic structures are involved , or not , on the laryngectomy specimen exam . 
 so surgery should always be discussed in first line in transdisciplinary meeting for endolaryngeal cancer management .