CA 125 in the follow-up of patients with ovarian cancer.

The value of CA 125 measurement in the diagnosis and follow-up of ovarian cancer was studied in 102 patients. The CA 125 levels were elevated in 88% (322/365) of samples from 82 patients with clinical evidence of disease and in 14% (56/403) of samples from 58 patients without clinical evidence. Preoperative levels were elevated in 84% (44/52) of the patients, and in 100% of those with stage III and IV disease. In patients with non-mucinous tumors the preoperative levels were elevated in 95% of cases (38/40). CA 125 levels were significantly correlated with the course of disease in 88% (36/41) of patients whose tumor regressed, and in 87% (20/23) of those whose tumor progressed. Before second-look surgery of 48 patients, the sensitivity of the CA 125 test was 35% and the specificity was 86%. The results suggest that, although far from infallible, CA 125 is a useful marker for ovarian cancer. It is useful for monitoring the course of chemotherapy, but normal levels do not rule out the possibility of persistent or recurrent disease.