The use of serum CA-125 as a marker for endometriosis in patients with dysmenorrhea for monitoring therapy and for recurrence of endometriosis

Acta Obstet Gynecol Scand. 1998 Jul;77(6):665-70. doi: 10.1034/j.1600-0412.1998.770615.x.


Background: To estimate the value of CA-125 for the diagnosis of endometriosis in women with dysmenorrhea, as well as its significance in monitoring therapy and follow-up.

Methods: One hundred and fifty-seven women undergoing laparoscopy for dysmenorrhea were prospectively studied for serum CA-125 concentration. For those with advanced endometriosis receiving danazol treatment after conservative surgery, CA-125 was also determined every month during medication and once every 12 months after treatment.

Results: The sensitivity and specificity of serum CA-125 for the diagnosis of endometriosis were 61.1% and 87.5% respectively. Elevated CA-125 (>35 U/ml) was noted in 65/75 cases (86.70%) with advanced endometriosis, but in only 15/56 patients (26.8%) with minimal and mild endometriosis. Although there were significantly higher CA-125 levels in unmarried women, and a negative correlation (r=-0.1970, p=0.0284) between CA-125 and parity, there was no statistical difference in incidence of endometriosis by the status of marriage or parity. Ten women with advanced endometriosis were found with persistent endometriosis by laparoscopy during danazol treatment, even though they tested with normal CA-125 levels (<35 U/ml) at that time. Fifteen patients had elevated CA-125 levels before and one year after therapy, and were confirmed with recurrence of endometriosis by laparoscopy. Nine women with elevated CA-125 levels before treatment, were found without recurrence of endometriosis and had normal CA-125 levels one year after therapy.

Conclusion: For endometriosis, CA-125 is a valuable adjuvant in the follow-up of recurrence in patients with advanced endometriosis and initially elevated CA-125 levels. It is not an effective screening tool for patients with dysmenorrhea, or for monitoring therapy. There was no significant correlation between the development of endometriosis and reproductive factors.

MeSH terms

  • Adolescent
  • Adult
  • Biomarkers / blood*
  • CA-125 Antigen / blood*
  • Diagnosis, Differential
  • Dysmenorrhea / immunology*
  • Endometriosis / diagnosis*
  • Endometriosis / immunology*
  • Endometriosis / surgery
  • Female
  • Humans
  • Laparoscopy
  • Middle Aged
  • Predictive Value of Tests
  • Prospective Studies
  • Recurrence
  • Sensitivity and Specificity
  • Severity of Illness Index


  • Biomarkers
  • CA-125 Antigen