P-584 Treatment of benign uterine bleeding in morbidly obese postmenopausal women with an aromatase inhibitor
Authors: Stovall D 
Published: June 2023

Abstract

Study question
Can morbidly obese women with postmenopausal bleeding, a benign endometrial biopsy, and no response to an oral progestin be successfully treated using an aromatase inhibitor?

Summary answer
Postmenopausal uterine bleeding in morbidly obese women with benign endometrial histology and an elevated serum estrone level do respond to treated with an aromatase inhibitor.

What is known already
Morbidly obese postmenopausal women who have uterine bleeding and a benign endometrial biopsy are commonly not good surgical candidates, and need good medical treatment options especially when treatment with an oral progestin has failed. The etiology for uterine bleeding in these individuals can stem from elevated estrogen production from peripheral sources.

Study design, size, duration
This was a prospective, proof of concept study with no placebo control group. Ten morbidly obese postmenopausal women with elevated serum estrone levels and uterine bleeding for &gt; eight weeks who had failed oral progestin therapy were treated with letrozole 2.5 mg/d and evaluated monthly for 3 months duration. At the first monthly follow-up visit, serum estrone levels were re-assessed. Vaginal bleeding was re-assessed at each monthly follow-up visit.

Participants/materials, setting, methods
This study was performed in an outpatient setting at a private health system. Inclusion criteria included postmenopausal uterine bleeding (not spotting), age &gt; 50, postmenopausal status (based on an FSH level of &gt; 40 mIU/mL and an estradiol &lt; 25 pg/mL), an estrone level &gt; 30 pg/mL, a BMI &gt; 40 kg/m2, a benign endometrial biopsy, a normal pelvic ultrasound, and failure of progestin therapy. All women received letrozole 2.5 mg/d and were evaluated monthly.

Main results and the role of chance
Ten women were enrolled in the study. Their ages ranged from 51 to 68. Their mean BMI was 50.75 kg/m2. All of the women in the study had daily vaginal bleeding for &gt; 8 weeks that was greater than spotting, and had additional co-morbidities that made them poor surgical candidates. Serum estrone levels pre-treatment ranged from 63 pg/mL to 550 pg/mL with a mean of 216 pg/mL. After 4 weeks of treatment with letrozole, 8 women had complete cessation of their vaginal bleeding which was sustained for the complete 3 months of follow-up. The two other women in the study had significantly reduced vaginal bleeding from treatment month one to 3 based on self-reporting. Serum estrone levels after 4 weeks of treatment with letrozole dropped by an average of 71% with a range of 50% to 93%. There were no serious adverse events, and no treatment tolerability complaints. Since there was no control group for comparison, the reductions in both vaginal bleeding and serum estrone levels could be from chance alone, including regression to the mean, and not treatment related.

Limitations, reasons for caution
This was a small, proof of concept study that was performed in a select population of patients. Although a very favorable outcome was obtained in our study population, a much larger study might show both a reduced success rate in regards to vaginal bleeding and some significant adverse events.

Wider implications of the findings
The data from this study suggests that morbidly obese postmenopausal women with uterine bleeding and benign endometrial histology who have failed oral progestin therapy, are poor surgical candidates, and in whom IUD placement may be very difficult, may have another good treatment option.

Trial registration number
N/A