Retrospective Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Oncol. Jan 24, 2020; 11(1): 11-19
Published online Jan 24, 2020. doi: 10.5306/wjco.v11.i1.11
Predictors of distant metastasis in acinic cell carcinoma of the parotid gland
Syed Ahmed Ali, Kevin J Kovatch, Jonah Yousif, Sonali Gupta, Andrew J Rosko, Matthew E Spector
Syed Ahmed Ali, Kevin J Kovatch, Jonah Yousif, Sonali Gupta, Andrew J Rosko, Matthew E Spector, Department of Otolaryngology - Head and Neck Surgery, Michigan Medicine, Ann Arbor, MI 48104, United States
Author contributions: Ali SA, Spector ME, and Rosko AJ designed the study; Spector ME and Rosko AJ supervised the report; Ali SA, Gupta S, and Yousif J performed the research and assisted with analysis; Ali SA, Kovatch KJ, Gupta S and Yousif J wrote the paper; Kovatch KJ, Rosko AJ and Spector ME provided clinical advice.
Institutional review board statement: This work is approved under IRB HUM00036763.
Informed consent statement: Patients were not required to give informed consent to the study because the analysis used anonymous clinical data that were obtained after each patient agreed to treatment by written consent.
Conflict-of-interest statement: The authors declare no potential conflicts of interest.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Matthew E Spector, MD, Associate Professor, Department of Otolaryngology - Head and Neck Surgery, Michigan Medicine, 1500 East Medical Center Drive, Ann Arbor, MI 48104, United States. ahmedali@med.umich.edu
Received: March 8, 2019
Peer-review started: March 11, 2019
First decision: April 15, 2019
Revised: October 14, 2019
Accepted: November 5, 2019
Article in press: November 5, 2019
Published online: January 24, 2020
Abstract
BACKGROUND

AiCC is a primarily indolent disease process. Our aim with this study is to determine characteristics consistent with rapidly progressive AiCC of the parotid gland.

AIM

To report on patients with metastatic lung disease from AiCC and potential correlative factors.

METHODS

Single-institution retrospective review of patients treated at the University of Michigan between 2000 and 2017. Univariate analyses were performed.

RESULTS

A total of 55 patients were identified. There were 6 patients (10.9%) with primary AiCC of the parotid gland who developed lung metastases. The mean age at diagnosis for patients with lung metastases was 57.8 years of age, in comparison to 40.2 years for those without metastases (P = 0.064). All 6 of the patients with lung metastases demonstrated gross perineural invasion intraoperatively, in comparison to none of those in the non-lung metastases cohort. Worse disease-free and overall survival were significantly associated with gross perineural invasion, high-grade differentiation, and T4 classification (P < 0.001).

CONCLUSION

AiCC of the parotid gland is viewed as a low-grade neoplasm with good curative outcomes and low likelihood of metastasis. With metastasis, however, it does exhibit a tendency to spread to the lungs. These patients thereby comprise a unique and understudied patient population. In this retrospective study, factors that have been shown to be statistically significant in association with worse disease-free survival and overall survival include presence of gross facial nerve invasion, higher T-classification, and high-grade disease.

Keywords: Acinic cell carcinoma, Parotid gland, Distant metastases, Facial nerve, Perineural invasion

Core tip: This is a retrospective study to evaluate clinical outcomes in patients with primary acinic cell carcinoma of the parotid gland treated at a tertiary care medical center. Among 55 primary cases, 6 patients developed lung metastases. These patients uniformly demonstrated gross facial nerve invasion intraoperatively. Additional factors that were associated with worse disease-free survival and overall survival included higher T-classification and high-grade disease on pathology.