Status of current research on endometriosis.

Endometriosis, a benign gynecologic disorder, occurs in about 10% of women of reproductive age and in up to 50% of women with infertility. Endometriosis is defined as the presence of endometrial glandular and stromal cells outside their normal location in the uterus. Commonly affected areas in the abdominopelvic cavity include the ovaries, the cul-desac and other kinds of pelvic peritoneum, bowel and diaphragm. Rarely is it found in extraabdominal sites, including the pleura and pericardium. While it is not a malignant disorder, endometriosis exhibits cellular proliferation, cellular invasion and neoangiogenesis. The steroid hormone dependence of endometriosis is underscored by its appearance during the reproductive years. Furthermore, the progress of this enigmatic disease can be tempered by administration of antiestrogens, inhibitors of endogenous estradiol production, and hormonal and surgical castration. It is a disorder that markedly affects well-being and physical and emotional health in women. Research on the pathogenesis of endometriosis currently interfaces with four areas of basic research, including the fields of genetics, environmental science, cancer biology and immunology. Here we focus on current research in the latter two disciplines and their relevance to endometriosis research.