An update on the biological markers of endometriosis

Endometriosis is a disease that affects 7-10% of reproductive-age women. When its diagnosis is delayed, its management becomes more difficult. Both for earlier detection and for therapeutic follow-up, discovering noninvasive biological markers with good specificity for this disease is a promising aspect of its research. We analyzed the recent data in the literature regarding these markers to determine which were worth following.

This literature review focused on medical data reported in the last 6 years (2011-2016). After identifying articles in PubMed, an analysis of the type of data and level of evidence provided was performed. The selected articles were compared and conclusions regarding the specific markers addressed.

Of the 255 articles identified that reported human studies, we had access to the full text for 169 of them. We selected 71 prospective studies to include in our analysis. The studies were divided based on the primary marker studied: 22 analyzed inflammatory and immunological markers, 9 adhesivity and migration markers, 18 genetic polymorphisms, 7 oxidative stress, 4 micro-RNA circulating fragments, and 11 other biological markers (hormonal receptors, leukocytes, and others).

CA 125 remains the most recommended marker for suspicion of endometriosis and follow-up. Other markers, such as CA 19-9, CA 72-4, and endometrial cells in peripheral blood, have more value for differentiating endometriosis from other pathologies, while circulating micro-RNA could help clarify the endometrial stem cell's implication in its pathogeny. Finally, other new urinary markers could be used in early diagnostic and screening strategies.