LIBERATE-Studie: Hormonersatztherapie mit Tibolon erhöht das Rezidivrisiko bei Mammakarzinompatientinnen

The use of hormone replacement therapy in breast cancer patients with climacteric symptoms has been discussed controversially. In 2003, the HABITS study was stopped after accrual of 434 patients, who had received HRT, due to an increased risk of metastases and recurrence. The LIBERATE study included 3148 women with vasomotor symptoms during the adjuvant phase after surgically treated breast cancer. Patients were randomly assigned to treatment with either 2.5 mg tibolone daily or placebo. Most of the patients were ER positive, the mean duration of therapy was 2.1 years. Tibolone-treated patients had significantly less osteoporosis and bone fractures. Especially patients with osteoporosis at start of therapy benefited from tibolone. The relative risk of breast cancer recurrence and metastasis, however, increased by 40 %. In hormone receptor positive patients the relative risk increase was 56 %. The increase in relative risk in ER negative patients was 15 %. In 202 patients who were treated with tibolone and aromatase inhibitors, the hazard ratio was 2.42 compared to placebo. These data demonstrate that tibolone increases the risk of recurrence in breast cancer patients and is therefore contraindicated in this setting.