Combination Assay of Urinary β‐Core Fragment of Human Chorionic Gonadotropin with Serum Tumor Markers in Gynecologic Cancers

Abstract

Ectopic production of the immunoreactive β‐subunit of human chorionic gonadotropin (IR‐hCGβ) by gynecologic malignancies has been well recognized, but IR‐hCGβ has not yet been established as a clinically useful tumor marker, except for germ cell tumors. We measured the concentrations of IR‐hCGβ‐related molecules, intact hCG, free hCGβ, and β‐CF, in the sera and urine of patients with various gynecologic cancers (cervical, endometrial, and ovarian cancers) to assess their clinical usefulness as a tumor marker in comparison with serum tumor markers such as CEA, SCC, CA125, and CA19‐9. The highest incidence of IR‐hCGβ was obtained in tbe assay for β‐CF in the urine, with positive rates of 47.7% (94 of 197) for cervical, 37.8% (14 of 37) for endometrial, and 84.4% (38 of 45) for ovarian cancers with a cut‐off value of 0.2 ng/mg of creatinine. In cervical cancer, there was no significant correlation between the concentrations of urinary β‐CF and serum SCC, and 57.9% (114 of 197) of the patients were detected by the combination assay of these tumor markers. Serial determination in 22 cervical cancer patients with elevated urinary β‐CF level prior to therapy showed that its level decreased after successful treatment, but 4 of 5 patients with persistent or recurrent disease had elevated levels of urinary β‐CF. All of the ovarian cancer patients examined were detected by the combination assay of urinary β‐CF and serum CA125. The levels of urinary β‐CF showed little correlation with those of the serum tumor markers, indicating the usefulness of the combination assay of urinary β‐CF with serum tumor markers for detecting cervical and ovarian cancers.