Treatment of symptomatic uterine leiomyoma with letrozole

Abstract

Uterine leiomyomas are the most common benign tumours of the female genital tract, often necessitating hysterectomy. The most common symptoms are dysmenorrhoea, menorrhagia, infertility and abortion. Ovarian hormones seem to play an essential role in pathogenesis, and deprivation of ovarian oestrogen causes leiomyomas to shrink significantly. The purpose of this study was to evaluate the effects of the non-steroidal aromatase inhibitor letrozole on uterine leiomyomas and on bone metabolism. A prospective, open clinical trial was conducted in a university-based hospital. Sixteen premenopausal women with symptomatic uterine leiomyomas were treated with letrozole 5 mg/day orally for 3 months. The main outcome measures of uterine and uterine leiomyoma sizes, serum FSH, LH, oestradiol concentrations, ovarian volumes and myoma-related symptoms were noted at baselines and once a month during treatment. Lumbar spine bone mineral density and biochemical markers of bone metabolism were studied at the beginning and at the end of 3 months. Letrozole significantly decreased uterine leiomyoma sizes (P < 0.01) and promptly benefited women with heavy menstrual bleeding associated with leiomyomas without changing bone mineral density. Aromatase inhibitors may represent a new generation of medications for the treatment of leiomyoma and associated symptoms. Larger clinical trials are needed, however, to fully evaluate their safety and efficacy.

Effects of letrozole on patients with symptomatic leiomyoma in the reproductive age women

“…17 Gurates et al reported that at the end of 3 month, letrozole resulted in a mean 46.72% reduction of original uterine leiomyoma volume and mean reduction of original uterine volume by 21.67% whereas Hilario SG et al reported that there was average reduction of uterine volume of 9.32% attaining up to 30% with the use of anastrazole 1 mg/day over 12 weeks. 8,12 This study also demonstrated an increase in the haemoglobin concentration which may be due to an improved menstrual pattern. Baseline mean value of haemoglobin concentration was 9.59±1.26 g/dl and at the end of treatment it was 10.76±0.85 g/dl and hence statistically significant (p <0.01).…”

“…Deprivation of ovarian oestrogen causes leiomyoma to shrink. 8 Some investigators have shown that leiomyoma tissues are a source of oestrogen. Oestrogen secreted by leiomyomatous tissue may reach a sufficient concentration within the local compartment to support its own growth.…”

Three-month treatment with triptorelin, letrozole and ulipristal acetate before hysteroscopic resection of uterine myomas: prospective comparative pilot study

“…Letrozole, a selective, competitive, reversible non-steroidal aromatase inhibitor decreases the volume of myomas and the intensity of associated symptoms [7][8][9][10][11]. Ulipristal acetate (UPA), a selective progesteronereceptor modulator, decreases the volume of uterine myomas and controls uterine bleeding [12][13][14][15].…”

Contemporary management of uterine fibroids: focus on emerging medical treatments

“…Aromatase inhibitors, including letrozole, anastrozole, and fadrozole, are a class of agents that block the synthesis of estrogen. Aromatase inhibitors have been shown to readily reduce UF size (up to 71% in 2 months) 82 and ameliorate UF symptoms, including a reduction in menstrual volume and duration of menstruation, and urinary retention [82][83][84] . The most common side effects of aromatase inhibitors include hot flashes, vaginal dryness, and musculoskeletal pain 14 .…”