Immunohistochemical expression of CD44s in renal cell carcinoma lacks independent prognostic significance

purpose: to analyze the immunohistochemical expression of the standard isoform of cd44 (cd44s) adhesion molecule in clear cell renal cell carcinoma (ccrcc) and its impact on clinical outcomes. materials and methods: ninety-nine consecutive patients treated surgically for rcc between 1992 and 2009 were selected. a single pathologist reviewed all cases to effect a uniform reclassification and determine the most representative tumor areas for construction of a tissue microarray. the same pathologist, who was blinded to the outcome of the cases, semi-quantitatively scored the staining intensity of cd44s in all specimens. the counting was done using the h-score algorithm. results: of the 99 immunostained rcc specimens, 57(57.7%) showed low expression, and 42(42.4%) showed high expression levels of cd44s. the expression of cd44s was directly associated with tumor size (p = 0.03), clinical stage (p = 0.02) and fuhrman grade (p = 0.02). disease specific survival (dss) rates for patients whose specimens expressed low and high levels of cd44s was 88.1% and 67.5%, respectively (p = 0.009). progression free survival (pfs) rates in patients with low and high expression of cd44s were 78.8% and 61.7%, respectively (p = 0.05). classical features such as the presence of metastasis and clinical stage remained isolated predictors of survival. conclusions: immunohistochemical expression of cd44s was associated with important clinical variables such as stage and fuhrman grade. however, it was not an independent predictor of survival. therefore, we believe it has a limited role as a prognostic marker in patients with ccrcc.