The value of tumor markers in testicular seminomas. Results of a prospective multicenter study.

OBJECTIVES In the course of a prospective multicenter trial, the value of tumor markers in seminomas was assessed. METHODS Human chorionic gonadotropin (HCG), lactate dehydrogenase (LDH) and placental alkaline phosphatase (PlAP) were determined before and after orchidectomy and in the follow-up. Patients with elevated alpha-fetoprotein were considered to have nonseminomas. The half-lives were 24-36 h for HCG and 1 day for LDH and PlAP. RESULTS The incidence of HCG, LDH and PlAP was 35, 34 and 56%, respectively. In 84% of the patients at least one of the three markers was elevated. PlAP had the highest sensitivity to detect metastatic disease (51%), with a specificity of 91%. HCG and LDH were elevated in 42 and 46% of patients in stage II-III with specificities of 95 and 96%. PlAP was the best method to indicate a relapse, but the specificity was low, especially in smokers. For nonsmokers it was in the same range as HCG and LDH. CONCLUSIONS Eighty-four percent of seminomas are marker-positive. PlAP has the highest incidence and sensitivity. Specificity is impaired in smokers. All three markers should be determined in seminomas.