Serum and tissue syndecan-1 levels in renal cell carcinoma

Background: The proteoglycan syndecan-1 is involved in cell proliferation, adhesion and angiogenesis. It was shown to be involved in cancer progression in different tumor entities. So far, the role of syndecan-1 in renal cell carcinoma (RCC), one of the most common diseases in urologic oncology, was little described. Purpose of the present study was to obtain serum concentrations and tissue expression levels of syndecan-1 in a cohort of patients diagnosed with RCC. Methods: Clinical and follow-up data were obtained from 413 RCC patients. SDC1 levels were determined in serum samples of 100 patients by enzyme-linked immunosorbent assay and tissue SDC1 expression was measured by immunohistochemistry (IHC) in 343 cases. Results were correlated with clinicopathological and follow-up data. Results: Five and ten years overall and cancer specific survival were 67% and 56% [overall survival (OS)] and 79% and 76% [cancer-specific survival (CSS)]. In female patients and locally advanced disease (>= T3), tissue SDC1 expression was decreased (female 85.6% vs. male 71.1% low tissue SDC1 expression, P=0.0153 and <= T2 70.0% vs. >= T3 87.2% low tissue SDC1 expression, P=0.0055) compared to male patients and organ confined disease. Locally advanced tumor stage, presence of lymph node or distant metastases, high Fuhrman grading and clear cell carcinoma as histopathological subtype were independent prognostic factors for reduced CSS and OS. There was no impact of serum SDC1 (sSDC1) serum concentration or SDC1 tissue protein expression on OS, CSS or recurrence free survival (RFS) in uni- or multivariable analysis. Conclusions: sSDC1 concentration or SDC1 tissue protein expression levels had no influence on patients' prognosis in the present cohort of patients diagnosed with RCC.