Changing concepts of medical treatment of endometriosis

Studies on the natural history of endometriosis have demonstrated that the majority of endometriosis implants tend to progress, a finding that indicates eradication of the lesions by medical and/or surgical approaches. Infertility and dysmenorrhea are other indications for medical therapy in this disease. In recent prospective and controlled studies, progestin (at high doses), gestrinone and GnRH agonist analogues have been equally effective as regards elimination of endometriosis and relief of endometriosis-associated symptoms, compared to danazol, a standard treatment in endometriosis. These four classes of drugs differ, however, in their adverse effects and as regards compliance. Danazol is a steroid with androgenic and anabolic effects and it adversely affects lipid metabolism. Gestrinone and 17-OH progestins are weaker, and GnRH agonist analogues and some progestins neutral in these respects. GnRH agonist analogues induce a hypo-estrogenic state with associated climacteric symptoms and mineral loss from the bones. The clinical value of combinations of GnRH analogue and steroid(s), used to prevent these side-effects, is so far unclear. Laparoscopic microsurgery has revolutionized the treatment of endometriosis lesions. Hence, hormone treatment as a supplement to microsurgical approaches may become a dominant form of medical therapy in endometriosis. The definitive value of pre- or post-operative hormonal treatment in this disease should, however, be tested in controlled trials. Such studies have proved antiprostaglandins to be useful in the treatment of dysmenorrhea secondary to endometriosis. Because each of the four drugs was ineffective in the treatment of infertility associated with endometriosis it is a waste of time to expose patients desiring pregnancy to long-term hormonal therapy. Ovarian hyperstimulation with IVF and other methods of assisted fertilisation are promising alternatives, but their definitive value is so far unproven in this disease. Conclusively, the significance of medical therapy in endometriosis is only partly resolved, and therefore, many therapeutic problems await prospective randomised trials and new innovations.