Urinary gonadotropin fragment, a new tumor marker. I. Assay development and cancer specificity

Urinary gonadotropin fragment (synonyms: UGF and human chorionic gonadotropin beta-subunit core fragment) is a small peptide which is present in the urines of pregnant women, of those with trophoblast disease and of those with certain nontrophoblastic malignancies. We developed a new UGF assay with improved specificity and then investigated levels in urines of 493 women: 155 healthy and postmenopause, 79 healthy and premenopause, 89 with benign gynecologic disease, and 170 with active gynecological cancer. A UGF cutoff level of greater than 3 fmole/ml was chosen to monitor the progress of patients during and after cancer therapy. Using this cutoff value, UGF specificity and sensitivity for active cancer were 90 and 66%, respectively. Levels exceeded this cutoff in 74% of women with recurrent disease. For screening purposes and for differentiating benign and malignant disease a cut-off of 8 fmol/ml, was indicated. At this higher cutoff specificity and sensitivity for active cancer were 99 and 46%, respectively.