Experience of human chorionic gonadotropin assays in gestational trophoblastic tumors

From May 1979 through December 1988, 146 patients with gestational trophoblastic tumors (71 hydatidiform mole, 3 partial mole, 15 choriocarcinoma and 57 persistent trophoblastic tumors) were studied. A total of 1178 daily urine samples were collected before and/or after treatment, and in the course of follow-up. H93 RIA (an HCG specific assay), H80 RIA (an assay detecting hCG and hLH) and a hCG alpha assay measured levels in the urine specimens. Three hCG declining patterns (pattern D, P and R) based on the H93 RIA assay were noted. Patients showing pattern D had the most favorable outcome (no mortality at all). However, pattern P and R had a 10% and 14.3% mortality rate, respectively. The ratios of H80/H93, hCG alpha/H93, hCG alpha/H80 in the urine specimens were similar in both pattern D and R (excluding samples from a patient who expired later). However, the ratios of H80/H93, hCG alpha/H93, hCG alpha/H80 of samples from the patient (CK) who expired later were significantly different from those of the pattern D and R. This was suggestive of a marked unbalanced secretion of hCG and its subunit in the urine specimens of patient CK. The molecular forms in pattern D were similar to the standard hCG. However, the molecular form in pattern R of 3 fatal choriocarcinomas showed a great variation, from smaller to larger than the standard hCG. The isoelectric points of hCG in pattern D and R were all acidic. In clinical practice, we can measure the ratios of H80/H93, hCG alpha/H93 and hCG alpha/H80, molecular forms, and isoelectric points of hCG.(ABSTRACT TRUNCATED AT 250 WORDS)