The diagnostic value of human chorionic gonadotrophin in patients with testicular seminoma.

Human chorionic gonadotrophin (HCG) was measured in sera from seminoma patients by an immunoassay which recognised both free beta-chains and intact HCG molecules. This seemed to increase the sensitivity of the assay without affecting its specificity. The HCG values were correlated to the clinical course in 151 patients. Pre-orchiectomy samples were assayed in 57 patients. Elevated pre-operative HCG levels were found in 15 of 38 patients (39%) in stage I and in 13 of 19 patients (68%) in stages II to IV. After orchiectomy the HCG values were normal in 114 of 115 patients in stage I and elevated in 13 of 36 patients (36%) in stages II to IV. Relapses were observed more often in stage II to IV patients who produced HCG at the time of diagnosis than in non-producers (3 of 13 patients versus 1 of 23 patients). In 7 of 11 relapses the serum HCG was elevated. HCG positive relapses were seen in patients both with and without initially elevated serum HCG.