Takaaki Shirai

Clinical usefulness and false-positive results of CA 125 as a tumor marker of ovarian cancer —A study on 674 patients—

To study the clinical usefulness and false-positive results of CA 125 as a tumor marker of ovarian cancer, we measured serum CA 125 levels in 197 patients with gynecological diseases, 274 normal, pregnant and postpartum women, 14 patients with abnormal pregnancy, 82 healthy women with a normal ovulatory menstrual cycle and 107 healthy non-pregnant subjects, using RIA kits. A level below 34 U/ml was considered the normal CA 125 range. The positive ratio of serum CA 125 in patients with malignant ovarian tumor was 81.3 per cent, and in those with serous cystadenocarcinoma the rate was 100 per cent. On the other hand, only one patient with benign ovarian tumor had a positive CA 125 value. Therefore, we suggest that CA 125 is useful for differentiation between benign ovarian tumor and ovarian cancer. However, because the positive ratio of CA 125 level is high in patients with recurrences of uterine cervical adenocarcinoma, those with tubal cancer, endometriosis, early pregnancy, abnormal pregnancy plus intrauterine fetal death and menstruating women, such situations must be given due attention when CA 125 is used as a tumor marker of ovarian cancer.

Clinical Usefulness of Determination of CA 125 Levels in the Serum and Menstrual Blood

We measured CA 125 levels in sera and menstrual blood of subjects with a normal ovulatory cycle and in those with endometriosis. Serum CA 125 levels were higher in the latter, in each phase of the menstrual cycle. The CA 125 levels in patients with endometriosis, particularly those with adenomyosis, tend to be higher than in those with a normal ovulatory cycle. We propose that measurement of CA 125 in the menstrual blood may be able to help distinguishing adenomyosis from myoma uteri and may also help in assessing clinical endometriosis.