Intraoperative margins in oral and oropharyngeal cancer transoral surgery benefit from sampling method modifications.

Objectives: To investigate the impact on local relapse rate (LRR) and disease specific survival (DSS) of intraoperative margins (FS) obtained by circumferential sampling method, corresponding to the lesion shape and marked using clock-face orientation combined with narrow band imaging (NBI) in head and neck squamous cell carcinoma Materials and Methods: 147 consecutive patients who underwent primary surgery with radical intent for oral and oropharyngeal cancer between 2011 and 2016 were prospectively enrolled. Patients were assigned to 3 groups with different sampling methods. In group A (n=44) a classical FS sampling method was used. In group B (n=73), the clock-face orientation sampling method (FS oclock) was used, whereas in group C (n=30), the FS oclock method combined with NBI. The primary outcome measure was the interdependence between FS sampling methods and oncological outcomes measured by LRR and DSS.

Results: In total, 1534 FS samples were obtained with range of 3-24 FS taken per case, median 7.25 in group A, 8.15 in group B and 7.52 in group C. When compared FS histology and final histology in all groups the sensitivity, specificity and accuracy were 61.54%, 98.51% and 95.24%, respectively. The overall LRR equaled 8.8%. The lowest LRR was observed in FS oclock method combined with NBI (6.67%) followed by FS oclock (6.85%) and FS classic (13.64%). For all patients, DSS achieved 95.92% - 95.45% in FS classic, 95.89% in FS oclock and 96.67%. in FS oclock combined with NBI.

Conclusion: The FS oclock sampling method combined with NBI increases the chance of achieving tumor-negative margins and in result improves the treatment outcome reflected by LRR and DSS.