Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Study refines breast cancer risks

13.02.2002


Increasing age is the strongest risk factor for breast cancer
© SPL


Large scale study spells out links with pregnancy and miscarriage.

Childless women are at a higher risk of developing breast cancer, confirms one of the largest studies on reproductive factors and the disease, but those who suffer miscarriages are not. Researchers are pinning down key risk factors in the hope of working out exactly how they increase susceptibility.

How pregnancy and abortion alter women’s chance of developing breast cancer has been the subject of conflicting reports. A new French study has tracked 90,000 women, aged 40-65, since 1990 and goes some way to clarifying these risks.



Unlike previous work, the report separately calculates how each factor alters risk in both pre- and post-menopausal women. Most significantly, the team found no link between miscarriage and risk of the cancer in pre- or post-menopausal women. This contrasts with previous surveys suggesting a link with induced abortion.

Specialists no longer accept the proposed link to abortion, says breast cancer researcher Mads Medley of the Statens Serum Institut in Denmark. Older studies asked women to recall their abortion history at the time of their diagnosis, which influenced how likely they were to recall such incidents: "You introduce a bias," he explains.

Clavel-Chapelon’s study was prospective - detailed questionnaires were sent out before the onset of cancer and without knowing who would develop the disease. This means that women’s answers were more likely to be unbiased. Eliminating spontaneous abortion as a risk factor "is nice to know," says Medley.

The new study offers "far stronger data in terms of blowing that theory away", agrees Gordon McVie, joint director-general of Cancer Research UK. The study’s three other main findings support previous evidence: that overall breast cancer risk increases the later a woman has her first child, the fewer children she bears and the earlier she starts her periods1.

A woman whose periods began at age 15 is at two-thirds the risk of one who started at 11 or earlier, find Francoise Clavel-Chapelon of the Gustave-Roussy Institute in Villejuif and her team.

But all the variations in risk are small, points out cancer researcher Robin Weiss of University College London and editor of the British Journal of Cancer, which is publishing the work. "They’re very powerful data, but they’re not huge differences," he says.

Increasing age is the strongest risk factor for breast cancer: the older a woman, the more likely she is to develop the disease. Overall, 1 in 8 women in the United States will develop the cancer in their lives; 1 in 9 in Britain.

Immediate impact?

The study is likely to have little immediate impact: women cannot change their reproductive cycle and are unlikely to alter decisions about whether to have children. "It’s difficult to turn it into prevention," admits Clavel-Chapelon.

Instead, scientists hope to work out exactly what happens in the breast during puberty, pregnancy and menopause. When breast tissue prepares for milk production, it may switch on certain genes that are protective; so identifying these genes might lead to treatments. "We can go all the way from looking at populations to looking at molecules in cells," says Weiss.

With this in mind, DNA samples from many of the women in the project have already been collected and stored. The study is part of a bigger international effort to identify other lifestyle factors - such as diet and use of hormone replacement therapy - that may affect risk. "Large studies have the power to dissect these out," says McVie.

References

  1. Clavel-Chapelon, F. and the E3N-EPIC Group Differential effects of reproductive factors on the risk of pre- and postmenopausal breast cancer. Results from a large cohort of French women. British Journal of Cancer, DOI 10.1038/sj/bjc/6600124, (2002).


HELEN PEARSON | © Nature News Service
Further information:
http://www.nature.com/nsu/020211/020211-8.html

More articles from Health and Medicine:

nachricht World first: Massive thrombosis removed during early pregnancy
20.07.2017 | Universitätsspital Bern

nachricht Therapy of preterm birth in sight?
19.07.2017 | Universitätsspital Bern

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: Manipulating Electron Spins Without Loss of Information

Physicists have developed a new technique that uses electrical voltages to control the electron spin on a chip. The newly-developed method provides protection from spin decay, meaning that the contained information can be maintained and transmitted over comparatively large distances, as has been demonstrated by a team from the University of Basel’s Department of Physics and the Swiss Nanoscience Institute. The results have been published in Physical Review X.

For several years, researchers have been trying to use the spin of an electron to store and transmit information. The spin of each electron is always coupled...

Im Focus: The proton precisely weighted

What is the mass of a proton? Scientists from Germany and Japan successfully did an important step towards the most exact knowledge of this fundamental constant. By means of precision measurements on a single proton, they could improve the precision by a factor of three and also correct the existing value.

To determine the mass of a single proton still more accurate – a group of physicists led by Klaus Blaum and Sven Sturm of the Max Planck Institute for Nuclear...

Im Focus: On the way to a biological alternative

A bacterial enzyme enables reactions that open up alternatives to key industrial chemical processes

The research team of Prof. Dr. Oliver Einsle at the University of Freiburg's Institute of Biochemistry has long been exploring the functioning of nitrogenase....

Im Focus: The 1 trillion tonne iceberg

Larsen C Ice Shelf rift finally breaks through

A one trillion tonne iceberg - one of the biggest ever recorded -- has calved away from the Larsen C Ice Shelf in Antarctica, after a rift in the ice,...

Im Focus: Laser-cooled ions contribute to better understanding of friction

Physics supports biology: Researchers from PTB have developed a model system to investigate friction phenomena with atomic precision

Friction: what you want from car brakes, otherwise rather a nuisance. In any case, it is useful to know as precisely as possible how friction phenomena arise –...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Closing the Sustainability Circle: Protection of Food with Biobased Materials

21.07.2017 | Event News

»We are bringing Additive Manufacturing to SMEs«

19.07.2017 | Event News

The technology with a feel for feelings

12.07.2017 | Event News

 
Latest News

NASA looks to solar eclipse to help understand Earth's energy system

21.07.2017 | Earth Sciences

Stanford researchers develop a new type of soft, growing robot

21.07.2017 | Power and Electrical Engineering

Vortex photons from electrons in circular motion

21.07.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>