Cervical Lymph Node Metastases In Salivary Gland Adenoid Cystic Carcinoma: A Systematic Review And Meta-analysis

Objective: The purpose of this research was to determine whether neck dissection is necessary for the adenoid cystic carcinoma of head and neck.Methods: This article screened the abstract and full-text papers that investigated salivary gland primary adenoid cystic carcinoma of head and neck.Two independent reviewers searched for articles published form January 1998 to August 2018 in four databases(Web of Science,Pub Med,Ovid and China National Knowledge Infrastructure),having no limits in languages.Statistical data were analyzed statistically by Review Manager 5.3.Results: In total,18 studies involving 2993 patients were included in the analysis.Of the 2993 patients,473 patients had cervical lymph node metastasis,with a merge frequency of 16%(95% CI: 13–19).Among included articles,only 4 involved cervical lymph node occult metastases,with a merge frequency of 14%(95% CI: 9–20).There were 5 articles containing minor salivary glands involving 370 patients of which 92 patients had cervical lymph node metastases and the merge frequency was 25%(95% CI: 11–38).Moreover,there were 4 studies on major salivary glands involving 904 patients of which 158 patients had cervical lymph node metastases and the merge frequency was 17%(95% CI: 15–20).Conclusions: Elective neck dissection is unnecessary for all patients with salivary gland adenoid cystic carcinoma of head and neck.Moreover,compared with major salivary glands,minor salivary glands have a higher cervical lymph node metastases rate in adenoid cystic carcinoma.The overall cervical lymph node metastases rate of minor salivary glands is 25%,which is enough to attract our attention.Therefore,we suggest that neck dissection might be applied to adenoid cystic carcinoma of minor salivary glands.