[Experiences with CA 125, a tumor marker for malignant epithelial ovarian tumors]

CA 125 (Cancer Antigen 125) is an antigen identified by means of a monoclonal antibody on the surface of epithelial ovarian carcinoma cells. The serum concentration levels of CA 125 were measured in 41 women with benign and 95 patients with malignant tumours of the ovary. Immunoradiometric determination was effected by means of a kit supplied by Centocor. 35 U/ml was assumed as limit values of the standard range. Enhanced serum concentrations of CA 125 were seen in 5 per cent of the healthy volunteers of a standard group of persons, in 17 per cent of women with benign and in 78 per cent of women with malignant ovarian tumours. Patients without recurrence of tumour after successful primary treatment showed values above 35 U/ml in only 3 per cent of the cases. The incidence of pathological CA 125 serum concentration levels depended upon the histological type of the ovarian tumour and was highest in women with epithelial carcinomas, especially those with serous cystadenocarcinomas (87 per cent). In follow-up examinations of 30 patients with ovarian carcinoma over a period of one to 60 months, CA 125 concentrations correlated with the disease pattern in 90 per cent of the cases. The increases in CA 125 values preceded clinical diagnosis of the relapse by 1-8 months in seven out of twelve women. Routine determination of CA 125 appears advisable in the control of patients with ovarian carcinoma on account of the high sensitivity and specificity during follow-up.