Biomarkers of endometriosis: How far have we come and where are we going?

Endometriosis is a common gynaecological disease that is characterized by endometrium-like tissue outside the uterine cavity. Endometriosis significantly compromises the quality of life of women and is a major cause of infertility. The gold standard for diagnosis of endometriosis is visual inspection by laparoscopy, which significantly prolongs the time to final diagnosis. This lack of non-invasive diagnostic approaches is why the discovery of biomarkers for endometriosis has been defined as a research priority. In this report, we describe hypothesis-driven and hypothesis-generating approaches for biomarker discovery, along with some important potential biomarkers of endometriosis and their diagnostic characteristics, sensitivities, and specificities. Finally, we present our perspective on the discovery of biomarkers for endometriosis, and discuss some results from our previous and more recent studies. Future studies must focus on improving patient quality of life rather than on discovering significant differences, and therefore close collaboration between clinicians and pre-clinical researchers is essential.