RANK and RANKL Expression in Salivary Gland Tumors

Objectives: The pathogenesis and molecular basis of salivary gland tumors (SGT) are not well understood. We investigated the expression of receptor activator of nuclear factor kappa B (RANK) and RANK ligand (RANKL) in benign and malignant SGTs and their relationship with clinicopathological features. Methods: Fifty malignant and 38 benign SGTs were analyzed in this study. We evaluated the correlation between RANK and RANKL expression and benign and malignant tumors, as well as the correlation between clinicopathological prognostic parameters and RANK and RANKL expression. Results: Receptor activator of nuclear factor kappa B was positive in 82% (41) malignant SGTs and in 34.2% (13) benign SGTs. Receptor activator of nuclear factor kappa B ligand was expressed in 28% (14) malignant and 5.3% (2) benign tumors. Receptor activator of nuclear factor kappa B and RANKL expression were significantly different between benign and malignant SGTs (P< .001,P= .006, respectively). However, a relationship was not found between positive expression of RANK or RANKL and clinicopathological features. Conclusions: In our study, RANK and RANKL expression was found to be higher in malignant SGTs compared to benign SGTs and RANK was more sensitive than RANKL. In addition, RANK and RANKL expression was higher in some malignant histological subtypes. Based on these results, we think that RANK and RANKL expression in SGTs and its potential as a target for treatment should continue to be investigated.