In the largest breast cancer trial undertaken, researchers have found a more effective treatment for early stage breast cancer in post menopausal women.
The drug Anastrozole (Aramidex) was compared with Tamoxifen - the present standard therapy - in a trial of 9,366 women from 21 countries. The results show a 17 per cent reduction in the rate of relapse and better overall survival rates in patients taking Anastrozole compared with those taking tamoxifen.
Results from the ATAC (Aramidex, Tamoxifen, Alone or in Combination) trial were announced in Dublin yesterday via a live web cast from the 24th Annual San Antonio Breast Cancer Symposium in the United States.
Professor Tom Gorey, consultant surgeon at the Mater Hospital and professor of surgery at UCD, who was the lead investigator for the study in the Republic, welcomed the trial results.
"All drug therapy is a balance between efficacy and side effects. Long term tolerability is a key issue for a treatment which women will usually have to take for at least five years.
The ATAC study results show clear advantages for Aramidex over the current gold standard." Tamoxifen, which has been used for 20 years , carries a risk of deep vein thrombosis [DVT]. The latest research shows a lower incidence of the serious blood clotting disease with Anastrozole.
Cancer of the womb, another side effect of Tamoxifen, occurred five times less often in patients taking Anastrozole compared with those taking Tamoxifen. Hot flushes and weight gain were also more common among women treated with the established therapy.
Aramidex was first marketed in the Republic in 1996, but only for the treatment of advanced breast cancer in women who had gone through the menopause. It is not yet licensed for the treatment of early - stage breast cancers, although Professor Gorey told The Irish Times he expects it to complete the regulatory process in about six months time.
Anastrozole works by blocking the production of oestrogen from a pathway which is the primary source of the female hormone in women after the menopause.
Breast cancer is an oestrogen-sensitive disease. Tamoxifen works in a different way by blocking oestrogen receptors at tumour sites and has been effective at prolonging the lives of many women who have developed breast cancer.
The current treatment strategy for early-stage breast cancer (cancer that has not spread beyond the breast) in post menopausal women consists of surgery to remove the tumour, followed by a course of radiotherapy or chemotherapy or both. Women then receive hormonal treatment - such as tamoxifen - for approximately five years to reduce the risk of the cancer recurring.
Women in the Republic have a one-in-13 chance of developing breast cancer during their lifetime. According to the National Cancer Registery there were 634 deaths from breast cancer here in 1997.
