Purpose: There are three kind of assays related to human chorionic gonadotropin (hCG) : free beta hCG (fbetahCG), which is the standard assay for the management of testicular cancer in Japan, intact hCG (ihCG), which detects hCG only, and total hCG (thCG), which detects hCG free-betahCG and possibly other degradation products. We examined the efficacy of thCG assay for the management of testicular cancer.
Materials and methods: The simultaneous determination of serum thCG (DPC IMMULYZE hCG), ihCG (hCG [SRL] or (ECLusys hCG STAT)) and fbetahCG (BALL ELSA F-betahCG) was performed in 21 patients with germ-cell tumor (18 gonadal tumors and 3 extra-gonadal tumors; 8 seminomatous germ-cell tumors [SGCTs] and 13 non-seminomatous germ-cell tumors [NSGCTs]) during treatment. We examined the correlation, diagnostic sensitivity and efficacy of management with three assays.
Results: There was no correlation between fbetahCG and the other two assays in SGCTs, while there was good correlation among the three assays in NSGCTs. In SGCTs, diagnostic sensitivity was higher in thCG, whereas in NSGCTs diagnostic sensitivity was higher in thCG and ihCG. In 7 patients whose hCG assays were positive at diagnosis, serum fbetahCG became negative first during treatment in all patients, but serum thCG and ihCG became negative after about 4 weeks.
Conclusions: In this study, thCG assay was significant for the diagnosis and management of patients with testicular cancer especially NSGCTs compared with fbetahCG assay. This study revealed that thCG assay is appropriate as the standard assay in NSGCTs.