Modern non-invasive diagnosis of endometriosis

Introduction. Endometriosis is a disease characterized by an overgrowth of morphologically and functionally endometrium-like tissue outside the uterine cavity. Early diagnosis of endometriosis is very difficult. The gold standard for diagnosis is the surgical method − laparoscopy, performed for infertility, pelvic pain or the presence of pelvic masses. However, this approach is currently being reconsidered, and the search for endometriosis markers for earlier diagnosis of this disease is relevant. The purpose of the literature review was to summarize the current data on promising noninvasive markers of endometriosis determined in various biological media. Materials and methods. Scientific literature was searched in PubMed, ResearchGate, and Elibrary databases for 2017−2022 using a combination of Russian and English keywords: endometriosis, endometrioma, endometriosis pathogenesis, peritoneal fluid, biomarkers, serum markers. Results. We evaluated more than 30 putative biomarkers in peritoneal fluid, serum, urine, and saliva, as well as their combinations in publications that met the selection criteria. Studies have evaluated the diagnostic value and efficacy of endometriosis biomarkers, but the results of these studies have sometimes been inconsistent. We were unable to identify a single biomarker or combination of biomarkers that was unequivocally clinically useful. The most significant changes in biochemical composition were observed in peritoneal fluid, but it requires invasive intervention to obtain it. Discussion. Saliva and urine studies have shown promising results in terms of diagnostic accuracy, but the evidence was of low quality for introduction into clinical guidelines. A number of serum biomarkers may be useful either for detecting endometriosis at early stages or for differentiating ovarian endometrioma from other benign ovarian masses, but the evidence for meaningful conclusions is insufficient. Conclusion None of the biomarkers have shown sufficient accuracy for clinical use outside of the research environment, yet research in this area remains promising.