LAUSR

We appreciate very much the questions raised by the author and pay much attention to this issue. First, the article was constructed in the beginning of 2017. The histology of tumors presented in our article should be based on 2017, not 2005. This is our omission. Compare with the 2005 edition (28 types), the new WHO classification from 2017 describes less malignant tumor entities (20 types) [1]. All pathological types involved in our study were included in 2017 edition, except polymorphous adenocarcinoma which was changed from polymorphous low-grade adenocarcinoma (as the author had pointed out). However, the name variation could not impact the results and conclusion of our article. The relationship between the prognosis of parotid malignancies and clinical parameters (TNM stage, tumor grade) has been discussed in numerous previous articles [2, 3]. This paper focused on the impact of different histological types on overall survival or disease-free survival of parotid carcinoma. Based on the observation presented in our article, fine-needle aspiration cytology (FNAC) or intraoperative frozen section might be used to define histological types and risk group through the predictive grading scheme discussed in the paper. This would provide another opportunity to refine or clarify the surgical decision. (e.g., the region of neck dissection and safe resection margin). 11 patients of polymorphous adenocarcinoma were reported in our article. There was regional difference in incidence of polymorphous adenocarcinoma. Meanwhile, Roberto et al. had review 126 patients of malignant parotid gland tumors, and 11 patients with polymorphous adenocarcinoma were reported (11/126, 8.7%) [3]. Maybe the proportion of polymorphous adenocarcinoma in the parotid gland is not that rare. All patients included in this study were primary parotid malignant tumors. The five patients of malignant lymphoma involved were initially originated from parotid, so they were not excluded from our study. These five patients were all received systemic treatment after surgery. Two “other types” in Pathology type involved in our article was chondrosarcoma.