Higher positive lymph node ratio indicates poorer distant metastasis-free survival in adenoid cystic carcinoma patients with nodal involvement.

OBJECTIVE: Extensive studies have been conducted to analyze adenoid cystic carcinoma (ACC) in the head and neck region. No research has been published focusing on ACC patients with cervical lymph node (LN) metastasis. The aims of current investigation were to summarize the clinical characteristics of ACC patients with LN metastasis (ACC-LNM) and to identify prognostic factors for tumor-related outcomes.

MATERIAL AND METHODS: A retrospective review was conducted with respect to ACC patients with nodal involvement between 2000 and 2013. The clinical variables and outcomes of these special cases were recorded and further analyzed. Metastasis-free survival and overall survival rate were calculated using the Kaplan-Meier method, and the log-rank test and Cox regression analysis were applied to identify the prognostic factors.

RESULTS: A total of 47 patients (34 male and 13 female) 32-77 years of age (mean: 54.6 years; median: 54 years) were analyzed in the current protocol. The recurrence-free survival (RFS), distant metastasis-free survival (MFS), and overall survival (OS) rate in all patients were 90.1%, 55.6%, and 60.1%, respectively. In univariate analysis, T stage, positive LN ratio, LN-involved section, and extracapsular spread were strongly associated with poorer MFS rate. The predictive roles of LN-involved section and surgical margin on the OS rate were also identified. In multivariate analysis, positive LN ratio and surgical margin were predictors for MFS and OS rate, respectively.

CONCLUSIONS: Positive LN ratio was strongly associated with distant metastasis. Comprehensive treatment should be performed in ACC patients with higher positive LN ratios. In addition, ideal surgical margin should be achieved to acquire better overall survival rate.