Profiles of epitope-defined markers in sera from patients with testicular germ cell tumors.

Epitope-defined tumor markers of AFP (FA), HCG (PM), PLAP (H7) and CEA (D/AH) were determined by monoclonal antibodies in sera of patients with germ cell tumors of the testis. Characteristic profiles of PLAP (H7) were seen in localized and metastatic seminoma and in sera of patients with mixed tumors with seminoma components. PLAP (H7) levels started to rise 10 months before clinical detection of recurrence in one case. Persisting elevated levels of PLAP (H7) in several cases were indicative of metastatic seminoma. PLAP (H7) occurred rarely in sera of patients with metastasing non-seminomatous tumors. AFP (FA) detected in seminoma sera led to identification of non-seminomatous disease in one case. High AFP (FA) alone occurred in yolk sac tumors, HCG (PM) with AFP (FA) or PLAP (H7) in patients where the tumors had components of teratoma and/or embryonal carcinoma, moderately elevated levels of AFP (FA) and sometimes also HCG (PM) occurred.