KJOG Korean Journal of Obstetrics and GynecologyKorean J Obstet Gynecol 1738-5628 Korean Society of Obstetrics and Gynecology 10.5468/kjog.2010.53.4.346 kjog-2010-53-4-346 Original Article Expression of aromatase in endometiosis and its relation to clinical laboratory and surgical parameters LeeIl-Han 1 KimDong-Ho 2 NohJi Hyun 3 KohJae Whoan 3 KimYong Bong 3 Mire-I OB & GY Women’s Clinic, Seoul, Korea Department of Obstetrics and Gynecology, Chung-Ang University Hospital, Seoul, Korea Department of Obstetrics and Gynecology, Paik Hospital, Inje University College of Medicine, Seoul, Korea Corresponding author : E-mail kimyb2@unitel.co.kr 04 2010 30 4 2010 53 4 346 353 16 11 2009 09 03 2010 Copyright © 2010 Korean Society of Obstetrics and Gynecology 2010 This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/4.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. Objective

Aromatase is the key enzyme for the conversion of C19 steroids into estrogen in certain human tissues. We studied to evaluate the aromatase expression in eutopic endometirum and endometriotic lesion and its relationship to clinical and laboratory parameters.

 Methods

The study included 78 cases of endometriotic lesion and 14 cases of eutopic endometrium and 30 cases of normal uterine endometrium obtained through laparoscopic surgery and curettage. The frozen tissue specimens were examined by immunohistochemistry using aromatase. Clinical symptoms, laboratory findings, and operative findings were analyzed and compared in according to aromatase expression.

 Results

We observed positive immunohistochemical expression for aromatase in endometriotic lesion from 46/78 patients (59.0%). Aromatase expression was elevated in comparison to eutopic endometrium (5/14 patients, P=0.032) and the difference was more pronounced when eutopic endometriums from patients with endometriosis were compared with those of healthy controls (2/30 patients, P<0.001). Aromatase-positive patients had more moderate-to-severe chronic pelvic pain, higher CA-125 level significantly. Also in operative findings, severe grade endometriosis, bilateral endometriomas, and associated leiomyoma and adenomyosis were more frequent in aromatase positive patients. High values of white blood cell count, erythrocyte sedimentation rate, CA 19-9 were more frequent in aromatase positive patients notwithstanding insignificant differences.

 Conclusion

Unopposed local biosynthesis of estrogens by increased expression of aromatase in eutopic endometrium and endometrial tissue could be involved in the development or maintenance of endometriosis and other uterine estrogen-triggered diseases. Our findings suggest increased expression of aromatase may be related with severity, activity, and chronic pelvic pain in patients with endometriosis.

 Aromatase Endometrioma Tumor markers Endometriosis

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Endometrial specimen from healthy control lacking aromatase expression (H&E stain, ×400).

Eutopic uterine endometrium from an endometriotic patient exhibiting moderate glandular expression of aromatase in the cytoplasm of respective cells (H&E stain, ×400).

Representative tissue biopsy from a peritoneal endometriotic lesion with strong aromatase expression in glandular and stromal components (A, H&E stain, ×200; B, H&E stain, ×400).

Expression of aromatase in normal, eutopic endometrium and endometriotic lesion of patients with endometriosis

Endometriotic lesion, No. (%) (n=78) Eutopic endometrium, No. (%) (n=14) Normal endometrium, No. (%) (n=30)
Gland 39 (50.0) 5 (35.7) 2 (6.7)
Stroma 37 (47.4) 0 0
Gland+Stroma 30 (38.5) 0 0
Total 46 (59.0)† 5 (35.7)*,† 2 (6.7)*

P<0.05 in eutopic vs normal endometrium.

P<0.05 in endometriotic tissue vs eutopic endometrium.

Clinical findings in patients with endometriosis according to immunohistochemical expression for aromatase

Clinical findings Aromatase expression with endometriosis (n=78)
 No endometriosis (n=30) P-value
Positive (n=46) Negative (n=32)
Age (yr) 34.2±9.6 35.1±7.9 37.4±6.6 NS
BMI (kg/m2) 22.3±2.16 21.4±3.18 22.5±3.63 NS
Infertility (%) 11 (23.9) 6 (18.8) 0 >0.05
Patient with previous pregnancy (%) 17 (37.0) 13 (40.6) 23 (76.7) NS
Severe symptoms (%) Dysmenorrhea 17 (40.5) 13 (40.6) NS
Chronic pelvic pain 28 (60.9) 14 (43.8) <0.05
Dyspareunea 5 (10.9) 3 (9.4) NS
VAS >4 27 (58.7) 24 (75.0) NS

BMI: body mass index, VAS: visual analogical scale.

Laboratory and operative findings in patients with endometriosis according to aromatase expression

Aromatase expression with endometriosis (n=78)
 No endometriosis (n=30) P-value
Positive (n=46) Negative (n=32)
WBC (106/L) 6.483±3.008 6.271±2.901 5.896±2.749 NS
ESR (mm/hr) 25.3±19.3 22.6±17 21.7±17.5 NS
CA 19-9 (U/mL) 37.5±52.4 30.2±33.1 31.1±24.3 NS
CA-125 (U/mL) 80.1±78.5 56.5±52.1 21.3±14.6 <0.001
Grade 3,4 endometriosis (%) 41 (89.1) 10 (31.2) <0.001
Presence of endometrioma (%) 39 (84.8) 26 (81.3) >0.05
Bilateral endometrioma (%) 24 (54.2) 5 (15.6) <0.05
Combined leiomyoma or adenomyosis (%) 18 (39.1) 9 (28.1) <0.05

WBC: white blood cell, ESR: erythrocyte sedimentation rate.