Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New treatment improves long-term outlook for breast cancer survivors

10.10.2003


A Canadian-led international clinical trial has found that post-menopausal survivors of early-stage breast cancer who took the drug letrozole after completing an initial five years of tamoxifen therapy had a significantly reduced risk of cancer recurrence compared to women taking a placebo. The results of the study appear in today’s advance on-line edition of the New England Journal of Medicine.



The clinical trial has been halted early because of the positive results and researchers are notifying the 5,187 women worldwide who have participated in the study. Women on letrozole will continue taking the drug and those on the placebo can begin taking letrozole, if they wish.

"This very important advance in breast cancer treatment will improve the outlook for many thousands of women," said Andrew von Eschenbach, M.D., director of the National Cancer Institute which led the study in the United States. "This is one more example of the ability to interrupt the progression of a cancer using a drug that blocks a crucial metabolic pathway in the tumor cell."


Study researchers found that letrozole, when taken after five years of tamoxifen therapy, substantially increased the chance of remaining cancer free. In total, 132 women taking the placebo had their disease recur compared to 75 on letrozole. Overall, letrozole reduced the risk of recurrence by 43 percent, so that after four years of participating in the trial, 13 percent of the women on the placebo, but only seven percent, of those on letrozole had recurred. Deaths from breast cancer were also reduced. Seventeen women taking the placebo died of breast cancer compared to nine taking letrozole.

While tamoxifen is widely used to prevent breast cancer recurrence in post-menopausal women, it stops being effective after five years because, researchers believe, tumours become resistant to it.

"More than half of women who develop recurrent breast cancer do so more than five years after their original diagnosis," says Paul Goss, M.D., of Princess Margaret Hospital in Toronto. "For years, we have thought that we had reached the limit of what we could do to reduce the risk of recurrence with five years of tamoxifen. Our study ushers in a new era of hope by cutting these ongoing recurrences and deaths from breast cancer after tamoxifen by almost one half." Goss, a leading expert in novel hormone therapies for the treatment and prevention of breast cancer, conceived and chaired the international trial with letrozole.

A form of hormone therapy for the treatment of breast cancer, letrozole works by limiting the ability of an enzyme called aromatase to produce estrogen, a major growth stimulant in many breast cancers.

Mayo Clinic medical oncologist James Ingle, M.D., says, "Based on our findings, all post-menopausal women with hormone-receptor positive tumours completing about five years of tamoxifen should discuss taking letrozole with their doctors to reduce their risk of breast cancer recurrence." Ingle, from Rochester, Minn., led the research study in the United States.

With Canadian Cancer Society funding, the clinical trial was coordinated by the National Cancer Institute of Canada Clinical Trials Group at Queen’s University, in partnership with the U.S. National Cancer Institute and its Clinical Trials Cooperative Groups. Novartis, which manufactures letrozole, also known as Femara®, provided the drug for the trial.

Women participated in the study for an average of 2.4 years and for as long as five years. The study found that women taking letrozole had a reduction in the number of recurrences of cancer in their previously affected breast, a reduction in the number of new cancers in their opposite breast, and a reduction in the spread of the cancer outside their breast.

The side effects of letrozole, a pill which is taken once a day, are very similar to those experienced by women undergoing menopause. They were generally mild in study participants. Women in the study will continue to be followed to more thoroughly assess any effects of long-term use of letrozole on bone strength or other organs. Until these are known, patients should be monitored closely.

"The Canadian Cancer Society is pleased to have made a key contribution to this study," says Barbara Whylie, M.D., director of Cancer Control Policy for the Canadian Cancer Society. "We estimate that more than 20,000 Canadian women will be diagnosed with breast cancer this year and just over half of those are going to be eligible for this drug. That means these women will have a significantly improved hope for a future without cancer."

"This large trial only began in 1998 and we already have important results that will change clinical practice," says Jeffrey Abrams, M.D., coordinator of the U.S. National Cancer Institute’s Cooperative Group breast cancer treatment trials. "This is a tribute to the patients and physicians who participated since their efforts will now have a positive impact on so many lives."

Participants in the clinical trial were enrolled through hospitals, cancer centers and institutes throughout Canada, the United States, England, Belgium, Ireland, Italy, Poland, Portugal and Switzerland. The European Organization for Research and Treatment of Cancer and the International Breast Cancer Study Group coordinated the European component of the trial.


The Canadian Cancer Society is the largest charitable funder of cancer research in Canada. It funds clinical trials research through its support of the National Cancer Institute of Canada Clinical Trials Group.

The National Cancer Institute is the primary U.S. agency for cancer research

NCI Press Officers | EurekAlert!
Further information:
http://cancer.gov/newscenter/pressreleases/letrozoleQandA
http://cancer.gov/clinicaltrials/developments/aromatase-inhibitors-digest

More articles from Health and Medicine:

nachricht One gene closer to regenerative therapy for muscular disorders
01.06.2017 | Cincinnati Children's Hospital Medical Center

nachricht The gut microbiota plays a key role in treatment with classic diabetes medication
01.06.2017 | University of Gothenburg

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>