Mel Greaves (now Sir Mel) was knighted last Friday for his 35-year contribution to research into the causes of childhood leukemia with The Institute of Cancer Research in London, UK.
Greaves' career began in the seventies, when he was inspired by the plight of young cancer patients in Italy and at Great Ormand Street Hospital, London. He was particularly struck by the way leukemia develops in children who are – in all other ways – healthy and has, since then, been instrumental to the theory that cancer evolves to become more malignant and resistant to drugs in a process akin to natural selection. His ultimate goal is to create a yogurt-like drink that can stop children developing the disease in the first place. A medicinal Yakult, if you will.
Greaves has called leukemia a "paradox" of progress in modern societies, where it is increasing in incidence by roughly 1 percent every year. It is, he says, a lack of exposure to microbes in early life that triggers an immune system malfunction, which can (in some cases) lead to acute lymphoblastic leukemia (ALL) – the most common type of leukemia.
Greaves' knighthood comes the same year as a major new analysis investigating ALL, published in Nature Reviews Cancer. The paper was authored by Greaves and involved a staggering amount of research. (More than 30 years' worth, to be precise.) In it, he lays out a two-step process of genetic mutation and exposure to infection, which combined can trigger childhood leukemia.
The first step is a genetic mutation that occurs in the womb and predisposes the child to leukemia. While this increases the chance of developing the disease, it isn't enough to cause it by itself. In fact, just 1 percent of children born with this particular genetic mutation will go on to develop leukemia. For this to happen, the child needs to be exposed to one or more common infections. Which, Greaves says, is more likely to happen to children who have less interaction with other kids as infants and a so-called "clean" upbringing. The irony here is that our militaristic use of anti-bac and phobia-like obsession with germs and dirt is actually exacerbating the problem, possibly even causing it in the first place.
Perhaps the most exciting takeaway from this research is the idea that childhood leukemia may be preventable. Greaves compares it to conditions like Type 1 diabetes and allergies, which can, at least partly, be prevented by certain lifestyle factors. In the case of leukemia, this may mean "priming" a child's immune system during the first year of life.
So how exactly does one go about this? Previous studies have linked day care attendance and breastfeeding to a lower incidence of ALL. However, Greaves wants to develop a more direct approach – which takes us back to yogurt.
He is currently working on a project to see whether or not direct exposure to harmless "bugs" in early life can prevent childhood leukemia. Right now, he is testing this hypothesis on mice but the hope is that one day a similar process can be used to stop leukemia developing in children.
Speaking of his knighthood, delivered during the annual New Year's honors list, Greaves said he is "honored" if "somewhat bewildered".
"It has been a wonderful journey over the last 40 years since I first started studying leukemia, and I feel very privileged to have been able to contribute towards the unpicking of this once mysterious and lethal disease," he said.