Cancer is a deeply complex disease, made even more so when it affects children and young people. Thanks to research, survival has dramatically increased over the past 50 years, but the nature of cancer means recovery outcomes can vary between different kinds and even within the same group of cancers, such as leukaemias.
Though cancers in under 25s are generally less common than in those who are older, there are still 4,200 children and young people diagnosed in the UK each year. Great strides have been made, but there is still much more to be done to secure the futures of children and young people affected by cancer.
Cancers in children and young people are “intrinsically different diseases” from those that affect adults, says Prof Richard Gilbertson, director of the Cancer Research UK Cambridge Centre and a renowned expert on childhood cancers. “Cancer in children almost invariably arises within tissues in the embryo or in the very early developing tissues,” he explains, “which means that those tissues and those cancers are very different [from those seen in adults].”
Whereas children’s cancers are dominated by those of the blood or of immature brain, nerve or soft tissues, he says, cancers in adults most commonly develop from mature epithelial tissues, such as lung, prostate and breast – and so the cancers themselves are very, very different. On top of that, children’s cancers are caused by different genetic changes than those in adult cancers, and are rarely caused by the lifestyle factors often linked to adult cancers. So, whereas four in 10 adult cancers can be avoided with lifestyle changes, finding a preventive strategy is far more challenging when it comes to cancers that affect children and young people.
Innovation in the treatment of children’s and young people’s cancers is not where it could be, held back by unique challenges facing researchers in this field. The fact that cancer in children is much less common means there are simply fewer samples to study, and it can be difficult to recruit enough patients to run clinical trials – which are essential to test and develop new treatments. Plus, there are fewer researchers working on childhood cancers with fewer funding options available to them, and not enough industry support. Ultimately, this has limited the treatment options available to children who are diagnosed.
“Essentially, what we’re doing is treating childhood cancers with treatments that were developed for adults,” Gilbertson says. “The reason this works is because most of the treatments for adult cancers that we’re used to, like radiotherapy or chemotherapy, basically destroy cells that are dividing rapidly,” he says. And while this is an effective way of killing rapidly dividing cancer cells for many people – reflected in the fact that more than eight in 10 children diagnosed with cancer in the UK now survive for at least 10 years – more than double the survival rate of 50 years ago – such treatments often leave lasting damage.
“Many of those children who do survive have some form of life-changing side-effect from their cancer treatment,” he says. As an example, irradiating a brain tumour can cause a lot of damage to the surrounding normal brain, which is a serious problem, particularly in someone young. “We know that many of those children will grow up with intellectual and endocrine growth problems, which persist for the rest of their lives, meaning that many of them will not become independent, face challenges forming long-term relationships and have reduced intellectual capacity,” he says. And in other cases, the impact of treatment is life-shortening. “Children who are successfully treated may not die of cancer, but they may still die prematurely.”
The good news is that a community of researchers worldwide, including those funded by Cancer Research UK, is committed to changing this. “What we are trying to do now is to invent totally new treatments that are designed specifically for children,” Gilbertson says. “Over the past two decades, we’ve worked very closely with labs in North America and Germany, and made many more strides in our research than perhaps have been made in the more common adult cancers.”
Researchers now know the embryonic cellular origins of some childhood cancers, and can use this information to differentiate between very different types of cancers arising in the same body part or organ, which sets the stage to develop completely new, life-transforming treatments. They are also making use of cutting-edge technology to further their understanding of these potential treatments. For instance, a project to build a computer model of childhood development and cancer using artificial intelligence is exciting Gilbertson – not least because of the almost limitless potential such technology brings to advance knowledge of these cancers, and therefore research into treatment. “This project brings the vision of what we might be treating tomorrow and puts it on our desk today,” he says. It also makes the possibility of screening children for cancer before they are symptomatic more of a realistic goal than a pipe dream.
Ultimately, Gilbertson says, the goal of the research is to give children and young people affected by cancer a “full life”. “It’s not just the length of life we think about,” he explains. “We want a world in which someone can shut the door on cancer at the age of six, and never be affected by it again.” It is clear that the work of Gilbertson and funders such as Cancer Research UK are edging us ever closer to this ideal.
This Childhood Cancer Awareness Month, find out more about cancers that affect children and young people, and Cancer Research UK’s work in this area at cruk.org/childrenandyoungpeople
