Endometriosis is endometrium-like tissue outside uterus with similar response towards steroid hormone.[1–4] Several chronic symptoms such as dyspareunia, dys-menorrhea, poly-menorrhea, oligo-menorrhea, pelvic pain and infertility are related to the disease. Endometriosis prevalence is approximately 5–10% of general population and it reached up to 50% in infertile women. The point prevalence of endometriosis (n = 6146, mean age 40.4 ± 8.0 years) was 10.8 per 1000 (95% CI 10.5–11.0). Women aged 40–44 years had the highest prevalence rate of 18.6 per 1000 (95% CI 17.7–19.5). Infertility was documented in 37% of patients. A total of 6045 patients were included in the cohort of newly-diagnosed endometriosis (mean age 34.0 ± 8.1 years), corresponding to an average annual incidence rate of 7.2 per 10.000 (95% CI 6.5–8.0).[5] Another issue of endometriosis is the occurrence of several disturbances that can disturb the quality of life and fertility caused by accession, change of peritoneum function, hormonal, immunology and high relapse occurrence.[6]
It has been long agreed that the growth of endometriosis is hormone dependent. This is supported by the evidence of estrogen and progesterone receptor in endometriosis epistle and stromal.[7] Based on these, it is reasonable if the detection is addressed to cellular change assessment due to hormonal influences. Recently, aromatase enzyme occurrence in endometriosis implantation which affects estrogen biosynthesis which takes part in the development of endometriosis. In this case, estrogen is recognized as endometrial mitogen; therefore, the existence of estrogen production in ectopic endometrial itself is able to explain the failure of hormonal medication to some patients with endometriosis. Moreover, the appearance of aromatase in endometriosis implantation supports the assumption that the production of local estrogen will develop the growth of endometriosis.[6]
Aromatase was discovered by Noble, Simpson, Johns and Bulun[8] in eutopic endometrium and endometriosis implantation in patients with endometriosis, whereas normal endometrium and peritoneum in women without endometriosis do not show the appearance of aromatase. It was also biochemically proven that eutopic endometrium and endometriosis implantation in patients with endometriosis is different from women without endometriosis.
Aromatase is found in eutopic endometrium tissue of endometriosis patients, adenomyosis and uterus myoma using immunohistochemistry technique and is not found in endometrium of cervical carcinoma patients without other gynecologic diseases. Aromatase found in endometriosis implantation and adenomyosis tissue. It is evident that this examination is very sensitive and specific. Our previous study shown endometrium cells that survive in menstrual blood can be isolated and analyzed for several proteins using immunocytochemistry technique. Immunohistochemistry and immunocytochemistry analyses are conducted based on histo score (H-score) through intensity and distribution of colored endometrium cells which is called semi quantitative examination.
The finding of aromatase enzyme in eutopic endometrium in women proven to suffer with endometriosis brought up the question whether aromatase activity can be found and assessed through the examination of menstrual blood of patients with endometriosis and whether there is significant difference in the appearance of aromatase between patients with and without endometriosis. If there is a significant difference and meaningful sensitivity, specificity values, positive and negative predictive values are found, then the appearance of aromatase in endometrium cells in menstrual blood can be used as an alternative diagnosis; we can conclude a theme of the main problem as follows: The growth of endometriosis depends on hormone especially estrogen as endometrium mitogen. Estrogen is not only produced in ovary but also produced locally in endometriosis implantation which plays a role in the growth and development of endometriosis and is assisted with the occurrence of aromatase activity.[9] The appearance of aromatase is also found not only in endometriosis implantation but also in eutopic endometrium of patients with endometriosis.[8, 10]
The available method of diagnosing endometriosis is by laparoscopic surgery. However, the procedure still faces problems since it is invasive and not all patients are willing to do it.[1] Other non-invasive methods have been brought up with detection of the appearance of P450 aromatase in endometrium cells that survive in menstrual blood of endometriosis patients. The aim of this study was to analyze the appearance of P450 aromatase based on the intensity and distribution in menstrual blood between patients with endometriosis and control. We hypothesized that there were significant differences in aromatase expression in menstrual blood in endometriosis patient compared to controls. If it expression has a diagnostic or predictive value, it can be used to detect endometriosis non-invasively in the early stages, so that the management of endometriosis can be done better. Furthermore, better management can also prevent further complications.