Estimating the Effect of Elagolix Treatment for Endometriosis on Postmenopausal Bone Outcomes: A Model Bridging Phase III Trials to an Older Real-World Population

Elagolix, a gonadotrophin‐releasing hormone antagonist, is used in premenopausal women with endometriosis. There is a risk of bone loss with elagolix, but the long‐term effects of BMD loss later in life cannot be directly assessed and has not been quantified. To address this gap in knowledge, this study indirectly estimated the impact of elagolix on postmenopausal fracture risk. BMD change in premenopausal women with endometriosis treated with elagolix was modeled from the phase III program data (elagolix group) and used to simulate treatment effects on (fracture risk assessment tool estimated) 10‐year risks of hip and major osteoporotic fracture in women ages 50 to 79 years from the 2005–2010 National Health and Nutrition Examination Survey (NHANES; N = 2303). Change in the proportion of women reaching risk‐based antiosteoporotic treatment thresholds was also estimated. For elagolix versus NHANES, median 10‐year risk of major osteoporotic fracture was 4.73% versus 4.70% in women ages 50 to 59 years, 7.03% versus 6.97% in women ages 60 to 69 years, and 10.83% versus 10.68% in women ages 70 to 79 years. Median 10‐year risk of hip fracture in these same groups was 0.19% versus 0.18% for women ages 50 to 59 years, 0.51% versus 0.49% for women 60 to 69 years, and 2.22% versus 2.14% for women 70 to 79 years. The proportion of women reaching risk‐based antiosteoporotic treatment thresholds caused by elagolix 150 mg daily for 12 months was 0.36% higher at age 50 to 59 years, 0.23% at age 60 to 69 years, and 1.79% at age 70 to 79 years. The number needed to harm was 643 for one additional hip fracture and 454 for one additional major osteoporotic fracture. Results were similar for elagolix 200 mg twice a day for 3 months. In the modeled scenarios, elagolix had minimal impact on long‐term risk of fracture and reaching risk‐based treatment thresholds. © 2020 The Authors. JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research © 2020 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Should we abstain from treating women with endometriosis using menopausal hormone therapy, for fear of an increased ovarian cancer risk?

Women suffering from endometriosis often have an early menopause, resulting in severe menopausal symptoms and an increased risk of osteoporosis. They are therefore candidates for menopausal hormone therapy (MHT). Unfortunately, MHT may increase the risk of endometriosis recurrence. Moreover, endometriosis patients are at increased risk of ovarian cancer, which may be further enhanced by MHT use. It is unknown, however, whether MHT more frequently increases type I (low-grade serous tumors), which seem to be increased when endometriosis is present, or type II (the more aggressive high-grade serous) tumors. We propose the following decision-making algorithm for endometriosis patients considering MHT. Those who have been treated with bilateral salpingo-oophorectomy, and in whom there is no residual endometriotic disease, can probably be treated using MHT without risk of endometriosis recurrence or fear of ovarian cancer. For women with significant, residual endometriosis lesions, the benefit may outweigh the risks, when menopause is reached before the age of 45 years or when severe symptoms are present.

IATROGENIC ENDOMETRIAL PATTERNS

The histological patterns exhibited in the endometrium due to the newer progestational agents cannot be correlated with the patient's menstrual cycle or the physiological endometrium which follows ovulation. The oral progestational agents which have been produced during the past few years have had wide clinical application. Although the 19-nor-steroids and the derivatives of 17 alphahydroxyprogesterone differ in chemical structure, they produce similar histological appearances in the endometrium. Prolonged use of these compounds produces atrophy of the endometrial glands and a cellular stroma which might be mistaken for endometrial sarcoma. In view of the fact that such compounds are widely used in clinical practice and as contraceptive agents, it is essential that the pathologist should be aware of the bizarre endometrial patterns which they may produce; the more important of these changes are illustrated and discussed.

PELVIC ENDOMETRIOSIS WITH IRREDUCIBLE FEMORAL HERNIA

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