Usefulness of CA125 in the differential diagnosis of uterine adenomyosis and myoma.

Objectives: To evaluate the usefulness of CA125 levels in the differential diagnosis of adenomyosis and myoma. This has been addressed by few, if any, previous studies.

Study Design: Preoperative serum CA125 levels were measured in 2149 women who were diagnosed at total hysterectomy as having adenomyosis, myoma, endometriosis, and/or normal pelvis. Their medical records were retrieved and reviewed.

Results: The mean serum CA125 level in the adenomyosis patients was significantly greater than that in the patients diagnosed with myoma (65.21±96.60 U/mL vs.12.86±14.23 U/mL, respectively; P<0.001). In the differential diagnosis of adenomyosis and myoma, the cut-off serum CA125 level with the highest accuracy (78.8%) and highest diagnostic value (61.2%) was 19 U/mL. Using this cut-off value, the negative predictive value was 69.5%, and the positive predictive value was 76.5%. These results are clearly superior to those of the empirical single cut-off value of 35 U/mL. Receiver operating characteristic curve analysis revealed the area under the curve for differentiating adenomyosis from myoma was 0.776, indicating good diagnostic performance.

Conclusion: In the differential diagnosis of adenomyosis and myoma, cut-off values for CA125, particularly the cut-off value of 19 U/mL, provide improved diagnostic performance. Serum CA125 testing can be performed during the initial screening of women with possible adenomyosis to differentiate this condition from myoma, although the diagnostic accuracy of using CA125 testing alone is limited.