Specimen-Based Resection Margins and Local Control during Transoral Robotic Surgery for Oropharyngeal HPV-Mediated Squamous Cell Carcinoma.

Abstract

Objectives: The aim of the study was to investigate the association of surgical margin conditions, including positive specimen margins revised to negative relative to local recurrence, disease-free survival, and overall survival (OS) within a cohort of HPV-mediated oropharyngeal squamous cell carcinoma (OPSCC) who underwent en bloc resection via transoral robotic surgery (TORS).

Materials and methods: Retrospective cohort of patients with untreated HPV-mediated OPSCC cT1 or T2 undergoing TORS resection between October 2014 and March 2020. The methodologic description of our interdisciplinary institutional approach, number of cut-through margins (CTMs) during intraoperative consultation, percentage of final positive margin cases, and disease-free survival and OS stratified by margin status and margin tumor-free distance is identified.

Results: 135 patients with primary cT1/T2 HPV-mediated OPSCC met inclusion criteria. Twenty-eight of 135 (20.7%) specimens revealed CTM and were revised during the same operative setting. Three of 135 (2.2%) surgical cases had positive final margin status. Local control rate was 97%. On univariate analysis, margin distance did not impact OS. CTM and final positive margins had lower OS than initially negative margins (p = 0.044). Pathologic N-stage significantly impacted OS (p < 0.001).

Conclusions: High local control rate and low final positive margin status confound the study of specimen margin-based techniques in HPV-mediated OPSCC resected en bloc with TORS. Pathologic N-stage may impact OS more than margin status. Larger numbers are needed to confirm differences.