Serum CA 125 in epithelial ovarian cancer. A longitudinal study.

Plasma levels of CA 125 were determined in 113 patients with ovarian cancer of epithelial origin. Of these, 69 patients had CA 125 measured before the first laparotomy and 84.6% of them had a CA 125 level greater than 35 U/ml. In 87 of the 113 patients whose tumour was producing CA 125, a good correlation was observed between the CA 125 levels and the clinical follow-up: 95.7% of the patients in remission had levels less than 35 U/ml, whereas all the patients with no change or with a progressive disease had levels greater than 35 U/ml. Furthermore in recurrent disease the levels of CA 125 were also increased (greater than 35 U/ml) in 92.3% of the patients. Thus, CA 125 measurements at regular intervals are of great clinical value in following the evolution of a tumour or the success of a therapy, but unfortunately do not allow detection of an ovarian tumour at an early stage.