Endometrial Effects of Tibolone

Abstract

The Tibolone Histology of the Endometrium and Breast Endpoints Study results confirm previous findings that tibolone does not induce endometrial hyperplasia or carcinoma in postmenopausal women, and it is associated with a better vaginal bleeding profile than CEE/MPA.

Tibolone reduces osteoporotic fracture risk and breast cancer risk, but increases the risk of stroke

“…On the other hand, nothing could be concluded about endometrial cancer, because there were four cases in the tibolone group and zero in the placebo one. MWS found greater risk of endometrial cancer among tibolone users, [17] but a randomised study observed no cases of this carcinoma [18]; however, the patients were younger than the LIFT study's ones, which could raise question on the possibility of increase of this risk in older women.…”

Role of androgens, progestins and tibolone in the treatment of menopausal symptoms: a review of the clinical evidence

“…Tibolone increases bone density but fracture data are not yet published. Tibolone suppresses the endometrium and is associated with fewer days of bleeding and spotting than combined HRT (Archer 2007).…”

Drugs for the treatment of menopausal symptoms

“…In addition to having weak androgenic effects, tibolone significantly lowers SHBG, and increases circulating free testosterone further adding to its androgenicity [91]. The incidence of breast tenderness after treatment with tibolone is low [90] and mammographic density does not increase with tibolone, unlike with traditional oral HT [92]. In osteoporotic women over the age of 60 years, tibolone significantly reduces the incidence of vertebral and non-vertebral fractures and is associated with a reduced risk of breast cancer (RH 0.32; 95% CI 0.13 --0.80; p = 0.02) and colon cancer (RH 0.31; 95% CI 0.10 --0.96; p = 0.04) [93].…”

“…In osteoporotic women over the age of 60 years, tibolone significantly reduces the incidence of vertebral and non-vertebral fractures and is associated with a reduced risk of breast cancer (RH 0.32; 95% CI 0.13 --0.80; p = 0.02) and colon cancer (RH 0.31; 95% CI 0.10 --0.96; p = 0.04) [93]. Tibolone has been associated with an increased risk of stroke in older women but this has not been observed in multiple RCTs of younger women [94,95]. Tibolone also does not increase the risk of venous thromboembolic disease or coronary heart disease events [93,96].…”

“…There have been conflicting reports in the literature about the endometrial safety of tibolone. In a large RCT comparing tibolone 1.25 and 2.5 mg with CCE/medroxyprogesterone acetate (MPA), tibolone did not induce endometrial hyperplasia or carcinoma in postmenopausal women; it is also associated with a better vaginal bleeding profile than CEE/MPA [94]. In addition, rates of break-through bleeding after commencement of tibolone are low [97].…”