Oncologic Safety of Close Margins in Patients With Low- to Intermediate-Grade Major Salivary Gland Carcinoma
Creators: name: Luu, Bao K.
name: Bowmaster, Vanessa B.
name: Moore, Michael G.
name: Sajisevi, Mirabelle
name: Dundar, Yusuf
name: Callas, Peter
name: Holcomb, Andrew J.
name: Stein, John S.
name: Sulibhavi, Anita
name: Vinh, Daniel B.
name: Coffey, Charles S.
name: Khaja, Sobia F.
name: Cooper, Dylan J.
name: Hinni, Michael L.
name: Noroozi, Hesameddin
name: Blasco, Michael A.
name: Donovan, John
name: Chung, Jeffson
name: Nguyen, Kenny
name: Kejner, Alexandra E.
name: Aulet, Ricardo
name: Virgen, Celina G.
name: Grasl, Stefan
name: Sadeghi, Nader
name: Habib, Andy M.
name: Hara, Jared H.
name: Chan, Kimberly
name: Goldstein, David P.
name: Young, Geoffrey D.
name: Stoeckli, Sandro J.
name: Mukdad, Laith
name: Shapiro, Justin
name: Goodman, Joseph F.
name: Cordero, Joehassin
name: Ryan, William R.
name: dos Santos, Luiz R. Medina
name: Asarkar, Ameya A.
name: Kalman, Noah S.
name: Paydarfar, Joseph A.
name: Schmitt, Nicole C.
name: Juloori, Aditya
name: Vural, Emre
name: Davis, Kyle P.
name: Vendra, Varun
name: Garvey, Emily A.
name: Wooten, Christian
name: Feinberg, Philip A.
name: Chang, Brent A.
name: Stokes, William Alvo
name: Henson, Christina
name: Magliocca, Kelly R.
name: Hier, Michael P.
name: Johnson-Obaseki, Stephanie
name: Goyal, Neerav
name: Bell, Rebecca K.
name: Michael, Cara
name: Enepekides, Danny J.
name: Giurintano, Jonathan P.
name: de Melo, Giulianno Molina
name: Eskander, Antoine
name: Ku, Jamie A.
name: Hackman, Trevor G.
name: Moura, Kauê
name: Erovic, Boban M.
name: Gupta, Nikita
name: Patel, Rusha
name: Lambert, Arnaud
name: Woody, Neil M.
name: Goulart, Rafael N.
name: Savaria, Fabrice N.
name: Miles, Brett A.
name: Plonowska-Hirschfeld, Karolina A.
name: Morand, Gregoire B.
name: Burruss, Clayton P.
name: Edwards, Heather A.
name: Dedivitis, Rogerio A.
name: Hua, Nadia
name: Cognetti, David M.
name: Kakarala, Kiran
name: Tasoulas, Jason
name: Shaver, Timothy B.
name: Du, Yue
name: Thomas, Carissa M.
name: St. John, Maie
Publisher: name: American Medical Association (AMA)
Year: 2024

description: 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.