DIFFERENT HCG ASSAYS TO MEASURE ECTOPIC HCG SECRETION IN BLADDER-CARCINOMA PATIENTS

We evaluated the clinical performance of assays measuring intact human chorionic gonadotropin alone (i-hCG), intact and nicked human chorion ic gonadotropin (i-hCG and hCGn), free beta-subunit (free beta-hCG) an d total beta-human chorionic gonadotropin (t-hCG) using different comm ercial kits, in a group of bladder carcinoma patients with ectopic hum an chorionic gonadotropin (hCG) secretion, at diagnosis and during tre atment. The diagnostic sensitivity obtained ranged between 63.6% and 7 5.7% (t-hCG assays), 72.7% (free beta-hCG assay), 18.2% (i-hCG and hCG n) and 6% (i-hCG assay). Median increases of hCG during treatment in p atients with chemotherapy resistance ranged from 4.9 to 6.9 for t-hCG and free beta-hCG assays and from 1.4 to 3.2 for i-hCG and i-hCG plus hCGn assays. Median decreases when chemotherapy was efficient ranged f rom 2.8 to 3.3 (t-hCG and free beta-hCG assays) and from 1.1 to 1.5 (i -hCG and i-hCG plus hCGn assays). We conclude that t-hCG and free beta -hCG are the most suitable assays for the management of bladder carcin oma patients as the ectopic secretion of chorionic gonadotropin is mai nly due to the free beta-subunit.