Clinical evaluation of new cancer-associated antigen CA125 II in epithelial ovarian cancers: comparison with CA125.
With use of monoclonal antibodies (moABs) M 11 and OC125, a sensitive sandwich immunoradiometric assay (IRMA) for CA125 II was developed. CA125 antigen was adsorbed by moAB OC125 and M 11, but horseradish peroxidase-labelled OC125 did not compete with M 11, indicating that although these two moABs recognized CA125 antigen, they reacted with separate antigenic determinants. We also demonstrate that the dual capture technique with OC125 and M 11 antibodies has a larger dynamic range than OC125 alone. This could potentially increase the sensitivity in terms of low CA125 levels. Forty-six patients with ovarian cancer before therapy and a further 20 cases during follow-up were evaluated for the presence of two serum tumor markers: CA125 II and CA125. The overall positive rate for CA125 II was 97.8%, compared with 91.3% with CA125. Serum CA125 II levels were closely correlated with serum CA125 levels (r = 0.918). The mean CA125 II levels before treatment, at response, and at recurrence were 194.3, 19.6, and 103.5 U/mL, respectively. Normalization of serum CA125 II levels at response does not imply absence of microscopic residual disease. CA125 II changes during follow-up suggest recurrence and can be used to monitor individual patients.
Kobayashi
H
H
Department of Obstetrics and Gynecology, Hamamatsu University School of Medicine, Shizuoka, Japan.
Tamura
M
M
Satoh
T
T
Terao
T
T
D000328:Adult; D000368:Aged; D000911:Antibodies, Monoclonal; D015295:Antigens, Tumor-Associated, Carbohydrate / Q000097:blood*; D001667:Binding, Competitive; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D015592:Immunoradiometric Assay; D008875:Middle Aged; D010051:Ovarian Neoplasms / Q000276:immunology* / Q000628:therapy; D012680:Sensitivity and Specificity
D000911:Antibodies, Monoclonal; D015295:Antigens, Tumor-Associated, Carbohydrate