The new research, to be presented Tuesday at the 2nd CHILDREN with LEUKAEMIA Causes and Prevention of Childhood Leukaemia Conference in London, is the first comprehensive analysis of studies investigating the association between social contact and childhood leukaemia.
“Combining the results from these studies together provided us with more confidence that the protective effect is real. Analysing the evidence in this way gives a more reliable answer to the question and a more precise estimate of the magnitude of the effect,” said the study’s leader, Dr. Patricia Buffler, professor of epidemiology at the School of Public Health of the University of California, Berkeley.
While the analysis does not reveal how intense social contact might ward off childhood leukaemia, it bolsters the theory that children exposed to common infections early in life gain protection from the disease. It is known that environments such as day care centres increase the chance of infections spreading. Some proponents of the theory believe that if the immune system is not challenged early in life and does not develop normally it may mount an inappropriate response to infections encountered later in childhood and that this could provoke the development of leukaemia.
Leukaemia is the most common cancer found in children in the industrialised world, affecting about one in 2,000 children. Incidence of the disease has been on the increase for decades. Acute lymphoblastic leukaemia, or ALL, the type of leukaemia the studies focused on, accounts for more than 80% of cases and most often occurs in children aged between 2 and 5 years. Scientists believe that for most types of childhood leukaemia to develop, there first must be a genetic mutation in the womb, followed by a second trigger during childhood that results in 1% of those children developing the disease. Infection – or the timing of infection - is one of the suspected triggers.
Buffler’s analysis included 14 published studies comprising a total of 6,108 children with leukaemia and 13,704 without the disease. Parents were asked about day care and playgroup attendance, as well as other forms of social interaction with other children. The studies varied in the timing, duration and extent of social contact investigated and in the age groups and types of leukaemia studied. Twelve of the studies found some indication of a protective effect of social interaction with other children, while two found no effect. No study found that social contact increased the risk of childhood leukaemia.
“Our analysis concluded that children who attended day care or play groups had about a 30% lower risk of developing leukaemia than those who did not. Combined results for studies of day care attendance specifically before the age of 1 or 2 showed a similarly reduced risk,” Buffler said.
The protective effect became even stronger when the researchers omitted from the analysis 5 studies in which the selection of healthy children for the comparison group relied on methods not considered optimal. In that analysis, children exposed to social contact were almost 40% less likely to go on to develop leukaemia than their counterparts.
In a separate report released at the conference on Tuesday by CHILDREN with LEUKAEMIA, scientists reviewed the evidence from studies that have investigated a link between infection and childhood leukaemia. They examined not only the idea that early life infections protect against the disease but also whether vaccination plays a role. In addition, they examined two other related areas of research: the role of infection during pregnancy and whether infection might be a factor influencing childhood leukaemia risk in situations where the population mix changes.
The report concluded that the evidence regarding whether infection during pregnancy or in situations of unusual patterns of population mixing influences the risk is inconclusive at present and that further research is necessary.
“On the question of whether infection early in life protects against leukaemia, the best evidence comes from studies of indirect measures of infection - which eliminates many of the problems common in trying to study infections directly - as well as from studies on immune system stimulation and on the genetics of immune responses,” said one of the report’s authors, Dr. Adrienne Morgan, staff scientist at CHILDREN with LEUKAEMIA.
“Putting our review together with the new analysis on social interaction, we can say pretty confidently that childcare, breastfeeding and vaccination are good things. This gives a steer to the biologists looking for what mechanisms might be at play,” she said.
Emma Ross | EurekAlert!
Researchers show p300 protein may suppress leukemia in MDS patients
28.03.2017 | University of Miami Miller School of Medicine
When writing interferes with hearing
28.03.2017 | Université de Genève
The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.
To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...
Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.
The results will be published on March 22 in the journal „Astronomy & Astrophysics“.
Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...
Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.
Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...
In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.
Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...
20.03.2017 | Event News
14.03.2017 | Event News
07.03.2017 | Event News
28.03.2017 | Physics and Astronomy
28.03.2017 | Health and Medicine
28.03.2017 | Life Sciences