Prognostic potential of serum CA 125 levels in danazol-treated patients with external endometriosis: a preliminary study.

Serum levels of CA 125 in 33 patients with progressive external endometriosis who were treated with 400 mg/day of Danazol for 16 weeks were assayed for an extended period (24-40 weeks), and changes in the CA 125 pattern were analyzed. Patterns of hormonal response were classified into four types. Prognosis for one type was good, whereas that for the other three types was poor. By making use of these patterns, we were able to determine more accurately the proper dose of Danazol, to alter the duration of treatment, and to predict relapse.