[The clinical value of mdm-2 (proto-oncogene) expression in testicular cancer, Correlation with tumor progression]

To determine whether mdm-2 protein level is aberrant in germ cell testicular tumors (GCTT) and if so, what is the relationship between mdm-2 overexpression and other disease parameter including histologic subtypes, p53 status, metastatic potential, and clinical stage, 81 testicular germ-cell tumors were screened for their mdm-2 expression at the protein levels using immunohistochemistry (IHC) and Western blot (WB) analysis. Overall, in this study 45 (55.6%) tumors showed positive mdm-2 nuclear immunoreactivity. The incidence of mdm-2 immunostaining was significantly higher (p = 0.0007) in non-seminomas (NSGCT) than in seminomas (S). The frequency of positive tumor was higher in tumors from metastatic patients than in tumors of patients free from metastasis (p = 0.011). Mdm-2 expression was detected significantly more frequently in tumors of advanced stages, i.e. II/B, II/C, and III versus tumors of early stages (I and II/A) (p = 0.0098). A significant difference could be established between the three stages of disease and the expression of mdm-2 (chi 2 = 0.0386), namely the incidence of mdm-2 expression increased with an advanced stage. Using Western blotting 22 (68.8%) out of 32 tumors overexpressed the mdm-2 oncoprotein of 90 kd (p90). Mdm-2 expression as detected by immunostaining may provide a reliable prognostic tool to subgroup of patients with more aggressive GCTT.