Significance of S100A8, S100A9 and calprotectin levels in bladder cancer

Objectives: Members of the S100 protein family, S100A8, S100A9 and their heterodimer complex known as calprotectin are thought to be involved not only in inflammatory pathways but also in tumorigenesis and cancer progression. Therefore, they have been widely studied in various types of cancer; however, there is limited knowledge about their role in bladder cancer. In this study, our aim was to determine the levels of S100A8 and S100A9 in the sera, and calprotectin levels in the sera and urines of bladder cancer patients and compare it to urinary BTA, a tumor marker that can be used in the diagnosis of bladder cancer.Materials and methods: The study was comprised of two major groups: 52 healthy controls and 82 patients with bladder cancer. The patient group was also divided into subgroups according to tumor stage and grade. Urine BTA levels, serum S100A8 and S100A9 levels, and serum and urine calprotectin levels in healthy controls and patients were determined using commercially available ELISA kits.Results: While serum S100A8 and S100A9 levels did not differ between the controls and patients significantly, serum and urine calprotectin levels and urine BTA levels were significantly elevated in patients compared to controls. Serum calprotectin or urine BTA levels did not differ significantly among the patient subgroups. However, urine calprotectin levels were significantly elevated in muscle-invasive tumors (T2-4) compared to lower stages (Ta and T1).Conclusions: Urine calprotectin levels can be used in the diagnosis and staging of bladder cancer as a marker for muscle invasion.