(389) Postoperative Radiotherapy in Advanced Stage Squamous Cell Carcinoma Requiring Maxillectomy

Monday, October 2, 2023

2:45 PM – 3:45 PM East Coast USA Time

Presenting Author(s)

Randall J. Harley, MD, MS

Medical Resident
University of Pennsylvania
Philadelphia, PA, United States

Co-Author(s)

UD

Umamaheswar Duvvuri, MD, PhD

Professor of Otolaryngology
Department of Otolaryngology - Head and Neck Surgery, NYU Grossman School of Medicine
New York, New York, United States
Jose P. Zevallos, MD, MPH

Eugene N. Myers, M.D. Professor and Chair
Department of Otolaryngology - Head and Neck Surgery, University of Pittsburgh School of Medicine
Pittsburgh, Pennsylvania, United States
RF

Robert L. Ferris, MD, PhD

UPMC Endowed Professor and Vice Chair
Department of Otolaryngology - Head and Neck Surgery, University of Pittsburgh School of Medicine
Pittsburgh, Pennsylvania, USA
Mark W. Kubik, MD

Assistant Professory
Department of Otolaryngology - Head and Neck Surgery, University of Pittsburgh School of Medicine
McMurray, Pennsylvania, United States
HS

Heath D. Skinner, MD, PhD

Department of Radiation Oncology, UPMC Hillman Cancer Center and University of Pittsburgh, USA

Senior Author(s)

Shaum S. Sridharan, MD

Assistant Professor, Department of Otolaryngology and Plastic & Reconstructive Surgery
Department of Otolaryngology - Head and Neck Surgery, University of Pittsburgh Medical Center
Pittsburgh, PA, USA

Disclosure(s):

Mark W. Kubik, MD: No relevant relationships to disclose.

Introduction: This study aims to evaluate the therapeutic impact of postoperative radiotherapy (PORT) in patients receiving maxillectomy for pT4N0 maxillary gingival or hard palate squamous cell carcinoma based on tumor size.

Methods: This is a retrospective analysis of the National Cancer Data Base from 2004 through 2019. All adult patients receiving maxillectomy (partial, subtotal, or total) and neck dissection for treatment naive margin negative pT4N0 squamous cell carcinoma (SCC) of the maxillary gingiva or hard palate were included in this study. We adjusted for age, sex, race, insurance status, income, education, urban/rural, facility type, region, comorbidity index, tumor grade, and tumor extension. Inverse probability weighting was used to reweight observations in regression models such that there was covariate balance between treatment groups. Doubly robust estimation was achieved by incorporating weights within the multivariable cox proportional hazards model. Planned a priori post hoc subgroup analysis was performed to evaluate impact of PORT on survival according to tumor size.

Results: We included 452 patients who underwent maxillectomy for pT4N0 SCC in this study (Age, mean 71.3 [SD 11.4]; Male, 203 [44.9%]; Tumor size >2cm, 370 [81.9%]). Overall, 48.9% of patients received PORT (221 patients). In our doubly robust estimation, PORT was associated with a 51% reduction in risk of death among patients with pT4 tumors compared to those not receiving adjuvant therapy (adjusted Hazard Ratio [aHR], 0.49; 95% Confidence Interval [95% CI], 0.31-0.78). On subgroup analysis, we found that PORT was associated with improved survival for tumors >2cm (aHR, 0.6; 95% CI, 0.4-0.89) and tumor 0-2cm (aHR, 0.26; 95% CI, 0.07-.94).

Conclusions: We found that PORT is associated with improved survival for patients receiving maxillectomy for margin negative pT4N0 maxillary gingival or hard palate squamous cell carcinoma. Our subgroup analysis revealed that PORT even provides a survival benefit for smaller tumors 0-2cm in largest diameter.