Noninvasive diagnosis of moderate to severe endometriosis: the platelet-lymphocyte ratio cannot be a neoadjuvant biomarker for serum cancer antigen 125.

STUDY OBJECTIVE

To investigate whether the combined value of the platelet-lymphocyte ratio (PLR) and serum cancer antigen 125 (CA 125) can be used in diagnosing moderate to severe endometriosis.

DESIGN

A retrospective study (Canadian Task Force classification II-2).

SETTING

A single center (Department of Obstetrics and Gynecology, Physical Examination Center of Peking Union Medical College Hospital, Beijing, China).

PATIENTS

Two hundred ninety-nine premenopausal women who underwent laparoscopic surgery, 197 patients with moderate to severe endometriosis, 102 patients with benign tumor, and 112 healthy subjects.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Analyses were performed using 1-way analysis of variance and receiver operating characteristic (ROC) curves.

RESULTS

The mean absolute value of serum CA 125, PLR, and the combination values were significantly increased for patients in the moderate to severe endometriosis group (p = .000, p = .004, p = .009, respectively). The area under the curve (AUC) for CA 125 was 0.943 (95% confidence interval [CI], 0.918-0.967) with a sensitivity and specificity of 71.6% and 99.1%, respectively. The AUC for PLR was 0.587 (95% CI, 0.520-0.653) with a sensitivity of 65.0%, a specificity of 51.8%, and a cutoff value at 117.16. The combination, which was calculated by multiplying CA 125 levels by the PLR, with an AUC of 0.929 (95% CI, 0.900-0.958) and a cutoff value of 2812.40, showed the highest sensitivity of 90.4% but a lower specificity of 84.8%.

CONCLUSION

Serum CA 125 is better than the PLR and the combination biomarkers in diagnosing moderate to severe endometriosis.