Prognostic role of surgical margins in patients undergoing transoral robotic surgery after neo-adjuvant chemotherapy

Purpose: To define if positive and close surgical margins are associated to worse prognosis in patients who underwent transoral robotic surgery (TORS) after neoadjuvant chemotherapy (NCT). Methods: A retrospective cohort study was carried out at a tertiary referral center. The primary outcome was local-regional control (LRC), and the results were summarized with hazard ratios (HR) and 95% confidence intervals (CIs). Results: A total of 308 patients (median age: 62.0, IQR: 55.0–68.2) were included. Univariable analysis showed a significant reduced LRC for patients with positive margins (HR = 1.82, 95% CI: 1.02–3.24). However, they were not associated with worse LRC after adjusting for adverse tumor variables (HR = 0.81, 95% CI: 0.40–1.65). ROC analysis was performed on 123 patients with negative margins (AUC: 0.54) measuring an optimal threshold of 1.25 mm (sensitivity = 60.0%; specificity = 50.5%). Univariable analysis showed non-significant differences between close and wide negative margins (HR = 1.44, 95% CI: 0.59–3.54). Conclusions: A positive surgical margin is not an independent predictor of tumor control and survival. A threshold of 1.25 mm was identified as the most appropriate to define close margins, but no difference was measured after distinguishing negative margins in close and wide margins.