Alyssa M Civantos1, Shreya Viswanathan2, Aman Prasad1, Solymar Torres Maldonado1, Robert M Brody3, Steven B Cannady3, Jason G Newman3, Rabie M Shanti3, Jason A Brant3, Karthik Rajasekaran4,5. 1. Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA. 2. School of Engineering and Applied Sciences, University of Pennsylvania, Philadelphia, PA, USA. 3. Department of Otorhinolaryngology-Head and Neck Surgery, University of Pennsylvania, 800 Walnut Street, 18th Floor, Philadelphia, PA, 19107, USA. 4. Department of Otorhinolaryngology-Head and Neck Surgery, University of Pennsylvania, 800 Walnut Street, 18th Floor, Philadelphia, PA, 19107, USA. Karthik.Rajasekaran@pennmedicine.upenn.edu. 5. Leonard Davis Institute of Health Economics, University of Pennsylvania, Philadelphia, PA, USA. Karthik.Rajasekaran@pennmedicine.upenn.edu.
Abstract
PURPOSE: To evaluate the role of elective neck dissection (END) and of adjuvant radiation (aRT) in polymorphous adenocarcinoma (PAC), previously known as polymorphous low-grade adenocarcinoma (PLGA). METHODS: Retrospective cohort study of patients in the National Cancer Database with a histology of PAC (coded as PLGA) at a head and neck site diagnosed between 2004 and 2015. Multivariable Cox proportional hazard modeling was used to assess overall survival in the overall population, and in sub-analyses of clinically N0 disease, positive resection margins, and late stage disease. RESULTS: A total of 922 patients [66.8% female; mean (SD) age, 60.9 (13.9) years] met inclusion criteria. 74.7% of patients received surgery alone, and 18.0% received surgery and aRT. Only 7.6% of patients with clinically N0 disease received an END, with 10.6% of these having at least one positive node. END did not have a survival benefit compared to no END [HR 1.28 (0.61-2.68)]. Compared to surgery alone, aRT did not have significantly increased survival in the overall population or in late stage [HR 0.68 (0.39-1.19) and HR 0.46 (0.18-1.22), respectively]. On sub-analysis of patients with positive resection margins, aRT had a significant survival benefit compared to surgery alone [HR 0.37 (0.14-0.99)]. CONCLUSION: PAC is a rare, slow-growing malignant tumor typically treated with surgical excision, with undefined indications for END or aRT. Our findings show END to not have a benefit to overall survival. In patients with positive resection margins, there was a survival benefit for aRT.
PURPOSE: To evaluate the role of elective neck dissection (END) and of adjuvant radiation (aRT) in polymorphous adenocarcinoma (PAC), previously known as polymorphous low-grade adenocarcinoma (PLGA). METHODS: Retrospective cohort study of patients in the National Cancer Database with a histology of PAC (coded as PLGA) at a head and neck site diagnosed between 2004 and 2015. Multivariable Cox proportional hazard modeling was used to assess overall survival in the overall population, and in sub-analyses of clinically N0 disease, positive resection margins, and late stage disease. RESULTS: A total of 922 patients [66.8% female; mean (SD) age, 60.9 (13.9) years] met inclusion criteria. 74.7% of patients received surgery alone, and 18.0% received surgery and aRT. Only 7.6% of patients with clinically N0 disease received an END, with 10.6% of these having at least one positive node. END did not have a survival benefit compared to no END [HR 1.28 (0.61-2.68)]. Compared to surgery alone, aRT did not have significantly increased survival in the overall population or in late stage [HR 0.68 (0.39-1.19) and HR 0.46 (0.18-1.22), respectively]. On sub-analysis of patients with positive resection margins, aRT had a significant survival benefit compared to surgery alone [HR 0.37 (0.14-0.99)]. CONCLUSION:PAC is a rare, slow-growing malignant tumor typically treated with surgical excision, with undefined indications for END or aRT. Our findings show END to not have a benefit to overall survival. In patients with positive resection margins, there was a survival benefit for aRT.
Authors: Adam J Kimple; Grace K Austin; Rupali N Shah; Chris M Welch; William K Funkhouser; Adam M Zanation; William W Shockley Journal: Laryngoscope Date: 2014-09-17 Impact factor: 3.325