Tibolone reduces risk of fracture and breast cancer but doubles stroke risk

Tibolone reduces the risk of fracture, breast cancer and possibly colon cancer in postmenopausal women, but more than doubles  the risk for stroke, according to findings from the LIFT trial.  The Long-Term Intervention on Fractures with Tibolone (LIFT) trial randomised 4,538 women (aged 60 and 85 years) to receive 1.25 mg daily of tibolone or placebo. All participants had a bone-mineral density T score of -2.5 or less at the hip or spine or a T score of -2.0 or less and radiologic evidence of a vertebral fracture. Annual spine radiographs were used to assess for vertebral fracture. The study was discontinued early on by the advisory board when the increased risk for stroke became clear. During a median of almost three years of treatment, women who were taking tibolone had a reduced risk of both vertebral fracture (p<0.001) and non-vertebral fracture (p=0.01) a decreased risk of invasive breast cancer (p=0.02) and colon cancer (p=0.04). However, women receiving tibolone also had an increase in the absolute risk for stroke of 2.3 per 1000 person-years and a more than doubling in the relative hazard of stroke (2.19; CI, 1.14 to 4.23; p=0.02). There was also a trend to a higher incidence of endometrial cancer in women with a uterus. The authors note that whilst the study was not sufficiently powered to look at the relative risk of coronary heart disease or venous thromboembolism there was no significant differences between the two groups. In an accompanying editorial Dr Ghada El-Hajj Fuleihan recommends that tibolone be avoided in "older women, those at a high risk for stroke, and those who have breast cancer or are at high risk for the disease".   Reference Cummings, S. Ettinger, B. Delmas, P. et al. 2008, ‘The Effects of Tibolone in Older Postmenopausal Women’ New England Journal of Medicine, vol. 359, pp. 697-708....