N-RAS expression in patients with salivary adenoid cystic carcinoma: association with clinicopathologic features and prognosis

ObjectiveThe aim of this study was to investigate N-RAS expression in patients with salivary adenoid cystic carcinoma (SACC) and to analyze its association with clinicopathologic features and prognosis.Study DesignWe determined N-RAS expression in SACC tumors via immunohistochemistry and evaluated the association between N-RAS expression and clinicopathologic variables. The disease-free survival (DFS) curves were plotted by using the Kaplan-Meier method. The parameters of prognostic significance found by univariate analysis were tested by a multivariate Cox regression model.ResultsN-RAS expression was detected in 61 of 72 SACC tumor samples (84.7%). In univariate analyses, N-RAS expression was associated with clinical stage, tumor size, adjacent tissue invasion, and distant metastasis. N-RAS expression was associated with DFS in univariate analysis; however, in multivariate analysis, N-RAS was not an independent prognostic indicator, but clinical stage (0.04) and histologic subtype (0.02) were statistically significant.ConclusionsOur data suggest that N-RAS was overexpressed in SACC tissues, but was not an independent prognostic indicator of DFS. Only clinical stage and histologic subtype were prognostic indicators of DFS.