Salivary microRNA testing for endometriosis: clinical evaluation in an endometriosis center

Endometriosis is challenging to diagnose due to its nonspecific symptoms and the lack of reliable non-invasive methods. This study evaluates the diagnostic accuracy of Endotest©, a salivary microRNA test, by comparing its performance to laparoscopy. Additionally, it examines its ability to detect deep infiltrating endometriosis. In an exploratory attempt, we also conducted postoperative Endotest© to evaluate the consistency of results after surgery.

A prospective study was carried out in women undergoing laparoscopy for suspected endometriosis. Preoperative saliva samples were collected and analyzed using Endotest©. A second Endotest© was performed postoperatively in patients with confirmed endometriosis. Accuracy, sensitivity, specificity, positive predictive value, and negative predictive value were calculated in this off-label setting and compared to radiologic methods in case of deep infiltrating endometriosis. Misclassification factors and potential changes in microRNA expression after surgery were also analyzed.

Among 134 participants, 120 had endometriosis confirmed by laparoscopy. Compared to laparoscopy, preoperative Endotest© showed an accuracy of 73%, with sensitivity of 78% and specificity of 33% in this highly preselected patient cohort. For deep infiltrating endometriosis, the diagnostic accuracy of 49% for Endotest© was inferior to radiologic methods. Postoperative Endotest results were inconsistent, with 18 of 84 cases showing discordant findings between pre- and post-surgical testing.

Endotest demonstrated high sensitivity but low specificity in this off-label analysis, limiting its use as a standalone diagnostic tool in this highly preselected patient cohort. The variability in postoperative Endotest© results suggests that microRNA expression may change after surgery. Further studies are needed to determine its role in clinical practice.