Can anti-oestrogens prevent breast cancer? We'll know in five years says cancer specialist

September 28, 2000

Five years from now European cancer specialists should finally know whether anti-oestrogen drugs such as tamoxifen and raloxifene can prevent breast cancer and save the lives of women at high risk of the disease.

Professor Trevor Powles from the UK's Royal Marsden Hospital in Surrey told a news conference at the European Breast Cancer Conference in Brussels that an overview of all the current trials of tamoxifen and raloxifene will be possible in 2005.

This will allow full evaluation of the long-term effects of tamoxifen and the newer drug raloxifene on breast cancer incidence and mortality, and of the drugs' side-effects. It should also be possible to identify which sub-groups of healthy women can gain clinical benefit from these drugs.

"Until this is known, the general opinion of cancer specialists in Europe is that it is not possible to identify any risk groups of healthy women in whom use of tamoxifen or raloxifene prophylaxis is justified at this time outside of clinical trials. That's why it has not yet been licensed in Europe for use in a preventive setting."

He said that in the United States, tamoxifen has been approved by the Food and Drugs Administration for risk reduction in healthy women at high risk - the criteria in the US being women who had two-thirds increased risk over ten years. The FDA had come to this decision after the 13,000-women US trial was stopped early when an interim analysis in 1998 showed a 49% reduction in the incidence of early breast cancer in those who took tamoxifen compared with those who took the placebo.

But European experts are more cautious as the interim analysis of trials at the Royal Marsden and in Italy failed to show a similar effect - probably because there were differences in the risk factors and characteristics of the women in the three trials.

"The US results are very encouraging and indicate that there is a real chance that tamoxifen can prevent cancer and hopefully give rise to long-term clinical benefit. But lack of mortality data from the US trial and any data pointing to clinical benefit from the reduced incidence, together with indications we have from the Italian and Royal Marsden trial that there may be groups of women who are tamoxifen-resistant, raises concerns about its widespread use in healthy women at present. That's why we need to continue to recruit to the European trials and follow-up the participants over time."

Professor Powles said that whatever the outcome of these two trials prospects for eventual chemoprevention of breast cancer using designer drugs looked bright.

"We already have clinical evidence that raloxifene does not have the side effect of increasing the risk of endometrial cancer, which is one of the drawbacks of tamoxifen. In addition it has been shown to reduce fractures arising from osteoporosis: so the time is approaching when we will have drugs that can prevent breast cancer but without unwanted side-effects.

"Up to now there has been very little we can offer women at high risk except more frequent checks and screening - and for those at very high risk - the drastic step of preventive mastectomy. I'm confident that situation will change within the next few years," said Professor Powles.
-end-
Note: after 30 September Mary and Kay will be available at 32-2-775-0203

ECCO-the European CanCer Organisation

Related Breast Cancer Articles from Brightsurf:

Oncotarget: IGF2 expression in breast cancer tumors and in breast cancer cells
The Oncotarget authors propose that methylation of DVDMR represents a novel epigenetic biomarker that determines the levels of IGF2 protein expression in breast cancer.

Breast cancer: AI predicts which pre-malignant breast lesions will progress to advanced cancer
New research at Case Western Reserve University in Cleveland, Ohio, could help better determine which patients diagnosed with the pre-malignant breast cancer commonly as stage 0 are likely to progress to invasive breast cancer and therefore might benefit from additional therapy over and above surgery alone.

Partial breast irradiation effective treatment option for low-risk breast cancer
Partial breast irradiation produces similar long-term survival rates and risk for recurrence compared with whole breast irradiation for many women with low-risk, early stage breast cancer, according to new clinical data from a national clinical trial involving researchers from The Ohio State University Comprehensive Cancer Center - Arthur G.

Breast screening linked to 60 per cent lower risk of breast cancer death in first 10 years
Women who take part in breast screening have a significantly greater benefit from treatments than those who are not screened, according to a study of more than 50,000 women.

More clues revealed in link between normal breast changes and invasive breast cancer
A research team, led by investigators from Georgetown Lombardi Comprehensive Cancer Center, details how a natural and dramatic process -- changes in mammary glands to accommodate breastfeeding -- uses a molecular process believed to contribute to survival of pre-malignant breast cells.

Breast tissue tumor suppressor PTEN: A potential Achilles heel for breast cancer cells
A highly collaborative team of researchers at the Medical University of South Carolina and Ohio State University report in Nature Communications that they have identified a novel pathway for connective tissue PTEN in breast cancer cell response to radiotherapy.

Computers equal radiologists in assessing breast density and associated breast cancer risk
Automated breast-density evaluation was just as accurate in predicting women's risk of breast cancer, found and not found by mammography, as subjective evaluation done by radiologists, in a study led by researchers at UC San Francisco and Mayo Clinic.

Blood test can effectively rule out breast cancer, regardless of breast density
A new study published in PLOS ONE demonstrates that Videssa® Breast, a multi-protein biomarker blood test for breast cancer, is unaffected by breast density and can reliably rule out breast cancer in women with both dense and non-dense breast tissue.

Study shows influence of surgeons on likelihood of removal of healthy breast after breast cancer dia
Attending surgeons can have a strong influence on whether a patient undergoes contralateral prophylactic mastectomy after a diagnosis of breast cancer, according to a study published by JAMA Surgery.

Young breast cancer patients undergoing breast conserving surgery see improved prognosis
A new analysis indicates that breast cancer prognoses have improved over time in young women treated with breast conserving surgery.

Read More: Breast Cancer News and Breast Cancer Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.