[Serum and tissue levels of placental alkaline phosphatase in patients with testicular tumor].

Placental alkaline phosphatase (PLAP) levels in sera and tissues from 40 patients with testicular tumor were measured using a monoclonal immuno-catalytic assay. The mean value of the PLAP levels of seminoma tissues was found to be 92-fold higher than that of normal testes, being significantly high compared with that of non-seminoma tissues. The mean value of the serum PLAP levels from patient's with seminoma was also significantly higher than that from patients with non-seminoma. In 2 groups of seminoma and mixed type tumor containing seminoma and non-seminoma components, the PLAP levels of tissues from patients who had high levels of the serum PLAP (greater than or equal to 100 mKAU) were significantly higher than those from patients who had normal serum PLAP levels (less than 100 mKAU). In the seminoma or mixed type tumor groups, the serum PLAP levels of all patients who had high levels before treatment decreased to within a normal range after orchiectomy with or without chemotherapy or radiation therapy. We conclude that PLAP seems to be an useful tumor marker for the diagnosis and the monitoring of response to treatment in patients with seminoma.