On the origin and significance of serum CA-125 concentrations in 97 patients with endometriosis before, during, and after buserelin acetate, nafarelin, or danazol

OBJECTIVE: To further elucidate the origin and significance of serum CA-125 in pelvic endometriosis. DESIGN: Retrospective. PATIENTS: Ninety-seven women with endometriosis who participated in two trials: (1) open-label study on buserelin acetate (n = 51) and (2) comparative, placebo-controlled study on nafarelin (n = 31) versus danazol (n = 15) (2:1 ratio). INTERVENTIONS: (1) Buserelin acetate 900 micrograms/d intranasally (IN); (2) nafarelin 400 micrograms/d IN versus danazol 400 mg/d orally during 6 months. MAIN OUTCOME MEASURE(S): Serum CA-125 and estradiol concentrations; severity of endometriosis-related symptoms; scores according to The American Fertility Society (AFS) classification for endometriosis and/or adhesions (before and on last day of therapy). RESULTS: Menstruation and adhesions appeared major factors influencing pretreatment serum CA-125 concentrations. Compared with nonmenstruating women without adhesions, both menses and adhesions induced a slight increase tending to significancy, whereas the elevating effect of adhesions and menses together was highly significant and more than expected. All three treatment regimens reduced CA-125 concentrations to the same extent; cessation of therapy was followed by restoration to pretreatment concentrations. Of the AFS scores for implants and/or adhesions, only pretreatment scores for adhesions correlated significantly with CA-125 concentrations. Severity scores for endometriosis-related complaints did not correlate. CONCLUSIONS: The findings indicate that adhesions play a major role in the presence of CA-125 in the systemic circulation and suggest that reductions of serum CA-125 concentrations during gonadotropin-releasing hormone agonist and danazol therapy are hormonally determined.