[Hormones and cancer: risk-benefit].

The influence which female sexual steroids, especially estrogen, have on the development of cancer has not only been shown epidemiologically, but also by experimental findings. Hormones, in spite of a known marginal increase in the risk of thrombosis and endometrial cancer, play an important role in the preventive cancer medication (oral contraceptives: ovarian and endometrial cancer; chemoprevention: high-risk breast cancer patients). Basically, hormone replacement therapy should be administered to all patients suffering from gynecological malignomas. In the case of patients suffering from breast cancer, the advantages of hormone replacement therapy (e.g., less risk of cardiovascular complications) need to be weighed against the disadvantages.