Marked increase of the growth factors pleiotrophin and fibroblast growth factor-2 in serum of testicular cancer patients

Background: Malignant tumors of the testis are among the most common cancers in men between the ages of 15 and 30 years. The sensitivity of detection of known tumor markers depends upon the tumor histology and stage. In other cancers, increased serum concentrations of various angiogenic growth factors have been described as potential markers for tumor progression and metastasis. One main histological feature of testicular cancer is profound angiogenesis. Design: In this study, we investigated by sensitive enzyme-linked immunosorbent assays (ELISAs) the levels of various growth and angiogenesis factors in the serum of testicular cancer patients as compared with normal control subjects. For the most profoundly increased growth factors, pleiotrophin (PTN) and fibroblast growth factor-2 (FGF-2), we furthermore analyzed tumor lysates by northern blotting, RT-PCR and ELISA. Results: We demonstrate a marked elevation of average serum levels of PTN (∼20-fold) and of FGF-2 (∼7-fold) in patients and expression of both growth factors in tumor biopsies. To a lesser extent, vascular endothelial growth factor (VEGF) and epidermal growth factor (EGF) serum levels were increased, whereas FGF-4 and transforming growth factor-β levels were similar to those in normal control subjects. Elevation of PTN, FGF-2, EGF and VEGF was detected in seminomatous as well as non-seminatous tumors, and even in early stages. Conclusions: PTN and FGF-2 may represent promising new diagnostic markers for testicular cancer with high sensitivity even in early-stage testicular cancer. Further studies are warranted to extend our analyses.