Reply: Biochemical markers for endometriosis: a long way to go

Sir, There is definitely a long way to go regarding biochemical markers for endometriosis. We completely agree with that and appreciate the comments and suggestions raised by Galazis et al. in their recent Letter to the Editor. They have pointed out and suggested a very interesting proposal for further analysis and validation studies, such as the mathematical modeling already used in ovarian cancer—the risk of malignant index (RMI). This is something very important and should be considered and discussed in our field. During the past years we developed a very accurate transvaginal ultrasound (TUS) examination for endometriosis (Abrão et al., 2007; Gonçalves et al., 2009) with bowel preparation before the procedure in Brazil, which seems to have high sensitivity and specificity for the diagnosis of endometriosis, especially in deep endometriosis (including different affected sites like the rectum and retrocervical area) or endometriomas. This examination could be helpful in such a model. We also agree that the possibility of validation of a mathematical model as they have suggested, gathering clinical parameters (chronic pelvic pain, dysmenorrhea, dyspareunia, cyclic dyschezia or dysuria, and infertility), a panel of biochemical markers, which could include the chemokines that we showed to be more relevant as well as other markers known to be raised in endometriosis, such as annexin V, VEGF, CA125 and sICAM-I (Vodolazkaia et al., 2012), and finally adding radiological findings from TUS and/or magnetic resonance imaging could really improve the accuracy of a noninvasive test for endometriosis—the ‘endometriosis clinical test’. This may improve screening, diagnosis and even staging of the disease. Hence, we believe that our systematic review (Borrelli et al., 2014) and the points raised by Galazis et al. should stimulate further collaborative multi-center research in this matter.