Soluble CD44 variants in the serum of patients with urological malignancies.

In patients with malignant diseases, characteristic alterations in the expression of CD44 protein and their variants were found. For the present study, the serum concentrations of the standard isoform CD44 std and the two variant isoforms CD44 v5 amd CD44 v6 were measured by ELISA in patients with prostate cancer (n = 49), benign prostatic hyperplasia (n = 30), renal cell carcinoma (n = 31) and bladder cancer (n = 29). The data were compared with the results of 30 healthy men and 30 healthy women. The sCD44 v5 concentrations in patients with prostate cancer (p < 0.01), benign prostatic hyperplasia (p < 0.01) and men with renal cell cancer (p < 0.01) were significantly lower than those measured in the male control group. The sCD44 v5 concentrations observed in male patients with bladder cancer were lower than in the male control group (p < 0.05). Only in one group the concentration of sCD44 std differed significantly from the others. The sCD44 std concentration in male patients with renal cell cancer was significantly lower than in the male control group (p < 0.01). Other significant differences were not found. In contrast to results observed in other carcinomas, the determination of soluble CD44 proteins in serum cannot be recommended as a marker for urological malignancies.