Two Types Of HRT Raise Risk Of Womb Cancer

Hormone replacement therapy (HRT) with estrogen only or with tibolone increases the risk of endometrial cancer, while the addition of progestagens counteracts that effect, results of the British "Million Women Study" suggest. Tibolone is a synthetic steroid with estrogenic, progestagenic and androgenic properties that is prescribed is many countries outside of the US to treat menopausal symptoms. Dr. Valerie Beral, at the University of Oxford, and study collaborators enrolled approximately 720,000 postmenopausal women without prior cancer or hysterectomy between 1996 and 2001, collecting information on their HRT use. During an average of 3.4 years follow-up, there were 1320 incident cases of invasive endometrial cancer.