Abortions do not increase risk of breast cancer
It is known that previous pregnancy decreases the risk of breast cancer. But a new dissertation from the Karolinska Institutet in Sweden shows that even brief pregnancies terminated prior to full term can have a certain preventive effect. The results could not confirm several earlier studies showing that the risk of developing breast cancer increases among individuals who have had an abortion.
It has long been known that pregnancy has a preventive effect against breast cancer, but it is not known why. At the same time, several studies have indicated that abortions or miscarriages seem to increase the risk of breast cancer. This is refuted by a new dissertation from the Department of Medical Epidemiology and Biostatistics at the Karolinska Institutet.
We have looked a some 4,000 journals from maternity centers in which women have responded to standardized questions about abortions, among other things, and have not found any correlation between abortions and increased risk of breast cancer. In fact aborted pregnancies had some preventive effect in our study, says Gunnar Larfors, author of the newly defended dissertation.
Abortion is still a taboo subject in our society and also entails a trauma, so I believe that many women choose not to report an abortion if they are asked out on the street. But on the other hand, if you ask a person who has been afflicted with breast cancer about previous abortions, the probability is great that they will answer the question truthfully. This can skew the results to make it seem as if breast cancer is tied to abortion. In our study all women had answered the same question before developing breast cancer, says Gunnar Larfors.
A study from Denmark based on the Danish abortion register also found no correlation between abortions and increased risk of breast cancer.
Preventive effect unclear
The dissertation also rejects an earlier hypothesis about how pregnancy protects against breast cancer. A hormone that occurs in high levels during pregnancy, hCG, has evinced a preventive effect against breast cancer in experiments on rats and is already in use in clinical studies in the US.
But in several studies we have looked at women who have had extremely high levels of hCG, for example women with severe morning sickness, and have not been able to find any further risk reduction in them. This indicates that hCG is not the hormone to explain the reduced risk of breast cancer after pregnancy in humans, says Gunnar Larfors.
Title of dissertation: Pregnancy-related Risk Factors for Breast Cancer
Ulla Bredberg-Rådén | alfa
The most recent press releases about innovation >>>
Die letzten 5 Focus-News des innovations-reports im Überblick:
Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.
Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....
Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).
When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...
Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.
How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...
Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.
It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...
Hybrid material converts more sunlight and can weather seawater's harsh conditions
It's possible to produce hydrogen to power fuel cells by extracting the gas from seawater, but the electricity required to do it makes the process costly. UCF...