Clinical significance of panendoscopy in initial staging of oral squamous cell carcinoma and detection of synchronous second malignancies of the upper aerodigestive tract - Insights from a retrospective population-based cohort study.

The aim of this study was to examine the prevalence of synchronous upper aerodigestive tract (UAT) tumors within oral squamous cell carcinoma (OSCC) patients, and to specify distinct risk groups who benefit from panendoscopy. Definite clinical and pathohistological characteristics, as well as overall and recurrence-free survival (OAS and RFS, respectively) of OSCC patients with and without synchronous second UAT tumors, carcinomas in situ, or higher-grade dysplasia/metaplasia, were evaluated based on a retrospective population-based cohort study, including alignment with cancer registry data. Out of 727 included OSCC patients, 465 cases (64.0%) received panendoscopy. Among these, 18 UAT tumors were detected, all of which were linked to patients with a positive history of nicotine abuse. Every synchronous UAT tumor was revealed by panendoscopy, which, analyzed as an independent staging procedure, was accompanied by a low complication rate (1.7%). When illuminating the impact of a second UAT tumor in OSCC patients, survival analysis revealed reduced 5-year OAS (63.9% vs 43.5%, p = 0.010) and RFS (57.1% vs 32.4%, p = 0.016) for patients with a second oncology diagnosis of the UAT. Within the limitations of the study, it seems that panendoscopy should be performed in the majority of patients suffering from OSCC, because most of them have a history of smoking and drinking, which correlates with an increased risk of developing synchronous UAT tumors.