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

INTRODUCTION: 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. METHODS: 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. RESULTS: 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. DISCUSSION: 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.