Evidence is accumulating that although chemotherapy and hormonal drugs are both effective for patients with early breast cancer, the greater gains are being found from hormone therapy. The future for fighting cancer using novel hormone treatments is bright, Professor Mitch Dowsett, Professor of Biochemical Endocrinology at the Royal Marsden Hospital and the Institute of Cancer Research, London, UK, told a news briefing at the 3rd European Breast Cancer Conference in Barcelona on Wednesday (20 March)
"It is becoming increasingly clear that whilst chemotherapy and hormonal drugs both improve survival in early breast cancer and that these effects are additive, the gains from hormonal therapy are greater. Recent improvements in hormonal therapy and the understanding of molecular mechanisms promise to extend these gains further in the next few years," he said. "It is particularly exciting to recognise that these agents are sufficiently well tolerated for trial as prophylactics of breast cancer."
Most breast cancer cells feed off the female hormone oestrogen, so the rationale for the most widely used medical endocrine therapies is invariably based around blocking or withdrawing the stimulation that oestrogen provides to oestrogen receptor positive breast cancers. How that is done depends on whether the patient is pre or post-menopausal.
In pre-menopausal women GnRH agonists* are used to block ovarian stimulation, but their disadvantage is that they initially stimulate the ovaries and also do not suppress oestrogen production by the ovary completely. So the challenge is to find drugs that overcome this problem.
"GnRH antagonists, such as antarelix, abarelix and cetrorelix, are under trial in prostate cancer and in vitro fertilisation (IVF). These dont initially stimulate the ovaries and appear to achieve immediate, persistent and complete ovarian suppression. To my knowledge these have not yet been tested in breast cancer, but they clearl
Contact: Margaret Willson
Federation of European Cancer Societies