Symposium: Management of endometriosis-associated pain

Danazol treatment of endometriosis-associated pain

Currently, medical and surgical treatment options for endometriosis are limited due to suboptimal efficacy, and also safety and tolerance issues. Long-term use of gonadotrophin-releasing hormone analogs, androgenes, and the danazol, which are widely used drugs for endometriosis, is usually not possible due to their suboptimal safety and tolerance profile. The lack of an effective, tolerable and safe treatment option for endometriosis makes animal models of experimental endometriosis necessary to study candidate drugs. The aim of this study was to investigate the efficacy of imatinib on the experimental endometriosis in a rat model.

Endometriosis was induced by autotransplantation of uterine tissue into the peritoneal cavity. Twenty-four rats, which had visually confirmed endometriotic implants on subsequent laparotomy, were randomized into three groups to receive imatinib (25 mg/kg/day, p.o.), anastrozole (0.004 mg/day, p.o.), or normal saline (0.1 mL, i.p.) for 14 days. After removal of endometriotic tissue and H & E staining, endometriosis score was determined according to a semiquantitative histological classification. Also, immunostaining with primary antibodies including VEGF, CD117, and Bax were used for immunohistochemical (IHC) examination.

Both anastrozole and imatinib suppressed the growth of endometriotic tissue and reduced the number of ovarian follicles. Although the difference was not statistically significant, imatinib was less effective than anastrozole for treatment of endometriosis.

Imatinib effectively treats experimental endometriosis by its inhibitor effects on angiogenesis and cell proliferation.

Endometriosis remains a diagnostic and therapeutic challenge despite decades of clinical experience and research. The multiple treatment options for endometriosis described in this symposium clearly indicate how difficult it can be to diagnose and effectively treat endometriosis with our current understanding of the disease. At least 3 major challenges to our understanding can be identified: (1) endometriosis does not always cause pain; (2) other causes of pelvic pain often coexists in patients with endometriosis; and (3) common medical and surgical treatments for endometriosis are relatively nonspecific. Insights from the articles in this symposium can help clinicians reach a new level of understanding of endometriosis and perhaps lead to more effective methods for diagnosing and treating this perplexing condition.