Author(s)
Pablo Llerena
Kevin Wang, BA
CraigCraig A. Bollig, MD
Affiliation(s)
Rutgers Robert Wood Johnson Medical School;
Abstract:
Introduction: Minor salivary gland carcinomas (MSGCs) are rare oropharyngeal malignancies that are primarily treated surgically, with or without adjuvant radiation therapy. Positive surgical margins are associated with worse outcomes, but existing literature is limited mainly to small series. Our objectives were to perform a national analysis of risk factors associated with positive margins in this population, including a transoral robotic surgical approach (TORS).
Methods: The National Cancer Database (NCDB) was queried for patients with T1-T4a oropharyngeal MSGC undergoing surgical treatment between 2010-2017. Clinical risk factors for positive surgical margins were determined using univariate and multivariate testing. Overall survival (OS) was analyzed based on patient demographics and clinical factors using Kaplan-Meier and Cox proportional hazards models.
Results: 785 patients were identified, of which 165 (21.0%) had positive margins. On multivariate analysis, T4a tumor stage (OR 2.00, 95% Confidence Interval [CI]: 1.03-3.88) and adenoid cystic carcinoma (OR 2.02, 95% CI: 1.29-3.18) were both independently associated with positive margins. TORS versus a non-robotic approach was not associated with positive margins (OR 1.05, 95% CI: 0.69-1.59). Positive margins were independently associated with a worse OS than negative margins (HR 1.63, 95% CI: 1.03-2.59) on multivariate analysis.
Conclusions: This study currently represents the largest, national review assessing positive margins in oropharyngeal MSGC. Histologic type (adenoid cystic carcinoma) and T4a tumor stage were both predictive of positive margins. With increasing use of TORS over the last decade, there does not appear to be a greater risk of positive margins compared to non-robotic approaches.