Management of clinically negative nodes (N0) in supraglottic laryngeal carcinoma: A systematic review

The purpose of this study was to evaluate the treatment of clinically negative cervical lymph nodes in supraglottic carcinoma by a meta-analysis. The search words were "supraglottic carcinoma", "cervical lymph nodes negative/cN0", "radical neck dissection", and "radiotherapy". The databases included the Chinese biomedical literature database, Medline, Cochrane library, EMBASE database, journals, and theses, etc. from 1989 onwards. Using the 5-year overall survival, disease-free survival, and disease-specific survival rates, and the recurrence and distant metastasis rates as observation indexes, the proper model and method were selected after a heterogeneity test to allow combined statistic tests, sensitivity analysis, and publication bias analysis to be conducted. Four studies (807 cases) were included in the analysis. Comparisons of the 5-year overall survival, disease-free survival, and disease-specific survival rates as well as lymph node metastasis and the recurrence rate for radical neck dissection and radiotherapy showed no significant differences. There was no advantage of radical neck dissection in supraglottic carcinoma with clinically negative cervical lymph nodes compared to radiotherapy. However, owing to the lack of a prospective study and large number of cases, selection bias and measurement bias may still exist.