Mechanism of LHRH analogue action in uterine fibroids. Comparison of ovarian cyst formation in women using the levonorgestrel-releasing intrauterine system vs. hysterectomy. Role of goserelin-depot in the clinical management of uterine fibroids.
Luteinising hormone-releasing hormone analogues have been found to reduce the size of uterine fibroids. Further studies are required to determine their exact mechanism of action. However, they are known to induce hypo-oestrogenism, which leads to reduction in uterine arterial blood flow, one mechanism by which reduction of fibroid size is thought to occur. To analyze the effect of the levonorgestrel-releasing intrauterine system (LNG-IUS) on ovarian cyst formation, endometrial thickness and the size of uterus and uterine fibroids by ultrasonography.
                This was a prospective, randomized trial comparing the LNG-IUS and hysterectomy in 236 women (age range 35-49 years) referred for menorrhagia. Transvaginal ultrasound examination was used to study the presence of ovarian cysts, uterine size, endometrial thickness, and the size of the uterus and uterine fibroids during a 12-month follow-up period.
                At baseline examination, 12 ovarian cysts were detected, eight in the LNG-IUS group and four in the hysterectomy group. During the follow-up period, 14 new cysts had emerged at 6 months and 14 new cysts had emerged at 12 months in the LNG-IUS group, whereas the corresponding figures in the hysterectomy group were three and eight, respectively. All but one of the 14 new cysts (94.1%) detected at 6 months in the LNG-IUS group resolved spontaneously, whereas two out of the eight cysts detected at the baseline examination persisted for 12 months. Three cysts were removed at operation. The relative risk of the occurrence of ovarian cysts was significantly higher in women with LNG-IUS, compared with women who underwent hysterectomy. LNG-IUS did not affect the size of the uterus or uterine fibroids, but it was associated with a decrease in endometrial thickness. The occurrence of cysts did not correlate with age or follicle stimulating hormone levels, but a weak positive correlation between the occurrence of cysts and the presence of irregular bleeding was observed.
                LNG-IUS use in the treatment of menorrhagia was associated with the development of ovarian cysts, but these were symptomless and showed a high rate of spontaneous resolution. LNG-IUS did not affect the size of the uterus or the size of uterine fibroids, but decreased the thickness of the endometrium. On 30 women suffering from uterine fibroids, the monthly subcutaneous administration of goserelin depot (3.6 mg) for 6 (n = 22) or 12 months (n = 8) induced an about 50% shrinkage of uterus and fibroid volume, and within 3 months, an increase in the haematocrit value, with no metabolic side effects or detectable bone demineralization, evaluated by single photon absortiometry at distal radius. Both uterine and fibroid volumes reversed to pretreatment values after 3 months of goserelin depot withdrawal. In comparison with untreated subjects, on another 10 patients a three month administration of goserelin depot reduced the loss of blood during the surgical removal of the uterus or fibroids. Present data indicate that goserelin depot is effective and relatively safe in the medical management of uterine fibroids. Although, goserelin depot cannot yet be proposed as a definite medical therapy, it may represent a useful instrument in the presurgical management of uterine fibroids.
There is no consistent evidence from the limited number of studies that SERMs reduce the size of fibroids or improve clinical outcomes. Further studies are required to establish evidence of benefit of SERMs in treating women with uterine fibroids. This updated review did not find any new study for inclusion.