Oncologic Safety of Close Margins in Patients With Low- to Intermediate-Grade Major Salivary Gland Carcinoma

Authors

Mirabelle Sajisevi, Division of Otolaryngology, University of Vermont Medical Center, Burlington.
Kenny Nguyen, Robert Larner College of Medicine, University of Vermont, Burlington.
Peter Callas, Robert Larner College of Medicine, University of Vermont, Burlington.
Andrew J. Holcomb, Department of Head & Neck Surgical Oncology, Estabrook Cancer Center, Nebraska Methodist Hospital, Omaha.
Emre Vural, Department of Otolaryngology, University of Arkansas for Medical Sciences, Little Rock.
Kyle P. Davis, Department of Otolaryngology, St Louis University School of Medicine, St Louis, Missouri.
Carissa M. Thomas, Department of Otolaryngology, University of Alabama at Birmingham.
Karolina A. Plonowska-Hirschfeld, Department of Otolaryngology, University of California, San Francisco.
John S. Stein, Department of Otolaryngology, University of Alabama at Birmingham.
Antoine Eskander, Department of Otolaryngology-Head and Neck Surgery, University of Toronto, Sunnybrook Health Sciences Centre and Michael Garron Hospital, Toronto, Ontario, Canada.
Kiran Kakarala, Department of Otolaryngology, Department of Otolaryngology-Head and Neck Surgery, University of Kansas Medical Center, Kansas City.
Danny J. Enepekides, Department of Otolaryngology-Head and Neck Surgery, University of Toronto, Sunnybrook Health Sciences Centre and Michael Garron Hospital, Toronto, Ontario, Canada.
Michael P. Hier, Otolaryngology-Head and Neck Surgery, Jewish General Hospital, Montreal, Québec, Canada.
William R. Ryan, Department of Otolaryngology, University of California, San Francisco.

Document Type

Journal Article

Publication Date

2-1-2024

Journal

JAMA otolaryngology-- head & neck surgery

Volume

150

Issue

2

DOI

10.1001/jamaoto.2023.3952

Abstract

IMPORTANCE: Postoperative radiation therapy for close surgical margins in low- to intermediate-grade salivary carcinomas lacks multi-institutional supportive evidence. OBJECTIVE: To evaluate the oncologic outcomes for low- and intermediate-grade salivary carcinomas with close and positive margins. DESIGN, SETTING, AND PARTICIPANTS: The American Head and Neck Society Salivary Gland Section conducted a retrospective cohort study from 2010 to 2019 at 41 centers. Margins were classified as R0 (negative), R1 (microscopically positive), or R2 (macroscopically positive). R0 margins were subclassified into clear (>1 mm) or close (≤1 mm). Data analysis was performed from June to October 2023. MAIN OUTCOMES AND MEASURES: Main outcomes were risk factors for local recurrence. RESULTS: A total of 865 patients (median [IQR] age at surgery, 56 [43-66] years; 553 female individuals [64%] and 312 male individuals [36%]) were included. Of these, 801 (93%) had parotid carcinoma and 64 (7%) had submandibular gland carcinoma, and 748 (86%) had low-grade tumors and 117 (14%) had intermediate-grade tumors, with the following surgical margins: R0 in 673 (78%), R1 in 168 (19%), and R2 in 24 (3%). Close margins were found in 395 of 499 patients with R0 margins (79%), for whom margin distances were measured. A total of 305 patients (35%) underwent postoperative radiation therapy. Of all 865 patients, 35 (4%) had local recurrence with a median (IQR) follow-up of 35.3 (13.9-59.1) months. In patients with close margins as the sole risk factor for recurrence, the local recurrence rates were similar between those who underwent postoperative radiation therapy (0 of 46) or observation (4 of 165 [2%]). Patients with clear margins (n = 104) had no recurrences. The local recurrence rate in patients with R1 or R2 margins was better in those irradiated (2 of 128 [2%]) compared to observed (13 of 64 [20%]) (hazard ratio [HR], 0.05; 95% CI, 0.01-0.24). Multivariable analysis for local recurrence found the following independent factors: age at diagnosis (HR for a 10-year increase in age, 1.33; 95% CI, 1.06-1.67), R1 vs R0 (HR, 5.21; 95% CI, 2.58-10.54), lymphovascular invasion (HR, 4.47; 95% CI, 1.43-13.99), and postoperative radiation therapy (HR, 0.10; 95% CI, 0.04-0.29). The 3-year local recurrence-free survivals for the study population were 96% vs 97% in the close margin group. CONCLUSIONS AND RELEVANCE: In this cohort study of patients with low- and intermediate-grade major salivary gland carcinoma, postoperative radiation therapy for positive margins was associated with decreased risk of local recurrence. In isolation from other risk factors for local recurrence, select patients with close surgical margins (≤1 mm) may safely be considered for observation.

Department

Surgery

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