Leukemia, the most common cancer in children, adolescents and young adults, represented 26.4 percent of all of the types of cancer occurring in those under 20 years of age between 2010 to 2014. Last year, 4,824 children, adolescents and young adults were diagnosed with leukemia.
Between 1969 and 2014, the death rate from leukemia for children, adolescents and young adults declined by 78.6 percent from 2.8 per 100,000 population to 0.6 per 100,000 population, yet despite these advances, the disease is still the second leading cause of cancer death among young people.
Now, however, there is new hope. Cancer researcher Mel Greaves, who works at the Institute of Cancer Research in London and has been studying childhood leukemia for three decades, recently announced that he may have discovered the root cause of leukemia in children.
ICYMI: Research at the ICR has transformed our understanding of #ChildhoodLeukaemia and how it is treated. Now, research from Professor Sir Mel Greaves, could once more revolutionise the way we view the disease. Read more in @conor_mckeever's feature: https://t.co/qLAim3HBCe pic.twitter.com/8nZbe56wN0— The ICR (@ICR_London) January 7, 2019
Acute lymphoblastic leukemia is generally triggered by a genetic mutation that occurs in one out of every 20 children. “That mutation is caused by some kind of accident in the womb. It is not inherited but leaves a child at risk of getting leukemia in later life,” Greaves says. Yet for a child to fully develop leukemia, the immune system must be compromised. “For an immune system to work properly, it needs to be confronted by an infection in the first year of life. Without that confrontation with an infection, the system is left unprimed and will not work properly,” Greaves says.
Given that parents nowadays go out of their way to keep their children isolated from germs, their immune systems are often incapable of properly fighting infection due to lack of exposure. If a baby’s immune system is unprimed, their bodies will overreact to common infections, which can trigger chronic inflammation.
As the inflammation advances, chemicals called cytokines are released into the bloodstream, which can spark a second mutation that results in leukemia in children that have the first mutation. “The disease needs two hits to get going. The second comes from the chronic inflammation set off by an unprimed immune system,” Greaves says.
BREAKING: Professor Mel Greaves has been knighted in the New Year Honours List for his pioneering and hugely influential research into #ChildhoodLeukaemia: https://t.co/V6rc5APkl5#NewYearsHonours 🏅 pic.twitter.com/Mb6hg0gpTj— The ICR (@ICR_London) December 28, 2018
In the past, power lines and nuclear fuel reprocessing plants were blamed for childhood cancers, yet the problem seems to be closer to home. Though Greaves is not sure how to prevent the initial prenatal mutation during pregnancy, he hopes to find ways to block future chronic inflammation.
In an effort to fortify children’s immune systems, Greaves and his team are working on the bacteria, viruses and other microbes found in the digestive system, which can indicate the bugs children have been exposed to in life. “We need to find ways of reconstituting their microbiomes – as we term this community of microbes. We also need to find which are the most important species of bacteria for priming a child’s immune system,” Greaves says.
The researcher is currently experimenting on mice to uncover which bugs best stimulate rodent immune systems. He hopes to follow up with human trials in the next two or three years.
“The aim is to find six or maybe 10 species of microbes that are best able to restore a child’s microbiome to a healthy level. This cocktail of microbes would be given, not as a pill, but perhaps as yogurt-like drink to very young children,” Greaves says. “And it would not just help prevent them getting childhood leukemia. Cases of conditions such as type 1 diabetes and allergies are also rising in the west and have also been linked to our failure to expose babies to bacteria to prime children’s immune systems. So, such a drink would help cut numbers of cases of these conditions as well.”