β-Core Fragment (β-Core/UGF/UGP), a Tumor Marker: A 7-Year Report

Abstract

In 1988 we published three papers describing immunoassay results for urine β-core fragment as a marker of gynecological cancers. Many other papers have been published since, and three commercial immunoassays have been established. β-Core fragment is called β-core, UGF, or UGP by different commercial vendors. To avoid confusion we call it β-core/UGF/UGP here. In this 7-year report, we compare the three commercial assays, establish cutoff limits, and use the Ciba-Corning kit for two large studies. The first was a retrospective study, measuring β-core/UGF/UGP in gynecological cancer and control urines accumulated in our freezers (n= 486). The second is a first prospective study, testing over a 16-month period β-core/UGF/UGP levels in urines of all new patients attending the Gynecology Oncology Clinic (n= 548). In the retrospective study, elevated β-core/UGF/UGP levels (>1.9 ng/ml) were detected in 11% of urines from healthy individuals (n= 132), in 11% from women with benign gynecological disease (n= 196), in 44% from cervical cancer (n= 68), 56% from ovarian cancer (n= 54), and 47% from endometrial cancer (n= 38). Altogether, β-core/UGF/UGP levels were elevated in 50% of 170 samples from gynecological cancers. Overall, sensitivity increased with advancing stage of malignancy. Sensitivity was 28% for stage I, 50% for stage II, 47% for stage III, and 68% for stage IV malignancies. In the prospective study very similar results were recorded. Elevated β-core/UGF/UGP levels (>1.9 ng/ml) were detected in 11% of urines from healthy individuals (n= 99), 11% from individuals with benign gynecological disease (n= 196), 7% from women with carcinomain situ(n= 28), in 42% of samples from cervical cancer (n= 69), 56% from ovarian cancer (n= 59), and 52% from endometrial cancer. Altogether, β-core/UGF/UGP levels were elevated in 48% of 225 gynecological cancer samples. Overall, sensitivity increased with advancing stage of malignancy. Sensitivity was 29% for stage I, 66% for stage II, 60% for stage III, and 77% for stage IV malignancies. In both studies sensitivity for β-core/UGF/UGP increased with advancing stage of disease. Sensitivity for cervical and endometrial cancers was slightly lower than that for ovarian malignancies. This difference may be due to the preponderance of advanced-stage-disease patients in the ovarian cancer group. β-Core/UGF/UGP may be a general stage-dependent marker for all gynecological cancers. The same false-positive results and very similar sensitivity values were found in a retrospective and a prospective study. They confirm each other, and suggest a definitive false-positive rate and sensitivity of this tumor marker for gynecological cancers.