Urinary hCG beta-core fragment as a tumor marker for bladder cancer

Abstract

Human chorionic gonadotropin (hCG) is a highly specific tumor marker or trophoblastic neoplasms. Also in patients with non-trophoblastic tumors, hCG beta-related material has been frequently demonstrated in their urine. This material was termed beta-core fragment (beta-CF) since it is recognized by hCG beta-core directed antisera but not by hCG beta-carboxyterminal peptide (CTP) directed antisera. We measured the concentration of beta-CF in the urinary samples from patients with urothelial tumors and studied its clinical usefulness as a tumor marker. The concentration of beta-CF was expressed as ng/mg of creatinine in the urine and the cut-off value was 0.1 ng/mg.Cr. Thirty (61.2%) of 49 patients with bladder carcinoma had raised beta-CF levels and the positive rates were dependent upon pathological grade (25.0, 33.3 and 82.8% at G1, G2 and G3, respectively). The elevated urinary beta-CF were also detected in 5 of 7 patients with upper urinary tract carcinoma. However, there was no elevated urinary beta-CF level in prostate carcinoma. Serial determination in 13 patients with elevated beta-CF level prior to therapy showed that 12 patients had decreased concentrations after successful treatment, but 1 patient with persistently elevated urinary beta-CF level after treatment subsequently relapsed. The determination of urinary beta-CF may provide a useful tool in identifying and monitoring the response to treatment in patients with carcinomas of the bladder and the upper urinary tract.