Monoclonal antibody assays for measuring ovarian tumor antigen in blood. Detection of NB/70K in patients with ovarian cancer and nongynecologic diseases.

Blood levels of human ovarian tumor antigen NB/70K were measured using four different monoclonal anti-NB/70K antibody radioimmunoassays (NB12123, NB12913, NB13834, and NB13831 assays). Four hundred thirty-two blood samples were obtained from apparently disease-free controls, from patients with benign and malignant ovarian tumors, and from patients with benign nontumorous and malignant diseases of the breast, lung, and gastrointestinal systems. The means, medians, and percent of samples that had elevated levels of NB/70K were calculated for each group of patients or controls for each assay. For all control versus malignant disease comparisons, there were statistically significant differences in all assays. For all benign versus malignant disease comparisons in the ovary, breast, lung, and gastrointestinal systems, there were statistically significant differences in all assays with the exception of the benign versus malignant gastrointestinal disease comparison in the NB12123 assay. Elevated NB/70K levels were detected in blood from ovarian cancer patients, almost all of whom had adenocarcinomas. Elevated NB/70K levels were also detected in blood samples from patients with adenocarcinoma, squamous, and clear cell carcinomas of the lung as well as in adenocarcinoma and ductal carcinoma of the breast. These results indicate that NB/70K is a marker for different pathologic types of malignancies.