Serum CA 125 concentrations in women with endometriosis or uterine fibroids treated with gonadotrophin-releasing hormone agonist analogues.

We assessed the possible role of CA 125 in the monitoring of gonadotrophin-releasing hormone (GnRH) agonist analogue therapy in women with endometriosis and uterine fibroids. Serum concentrations of this cell surface antigen did not correlate with uterine volume and appeared to have no value in the assessment of shrinkage of uterine fibroids during GnRH agonist treatment. While CA 125 levels were not always elevated in subjects with endometriosis, they fell during treatment in all patients. The change accurately reflected therapeutic progress in these women and was of particular value in those patients who had commenced therapy with elevated levels. It is suggested that CA 125 may be useful in the monitoring of therapeutic progress in selected patients with endometriosis treated with GnRH agonists; the need for surgical follow-up may be obviated.