The internationally recognised symbol for childhood cancer is the gold ribbon. During Childhood Cancer Awareness Month (CCAM) each September, people ‘Go Gold’ and raise awareness of the need for more research that leads to safer treatments and cures. The following are some facts and figures for childhood cancers and some suggestions on what you can do to help raise awareness.
4,000 children and young people are diagnosed with cancer every year in the UK. That’s ten every day. In children under 14, the incidence is rare – around 1,600 new cases are diagnosed every year in the UK. This means that around one child in 500 will develop some form of cancer by the age of 14 years.
Tumours that affect children are in two major groups. The first is the leukaemia, which are cancers of the blood and bone marrow. The second is the ‘solid’ tumours; the most commonly affected area is the child’s central nervous system (brain and spinal cord).
The most common type of childhood cancer is a type of leukaemia, known as acute lymphoblastic leukaemia (ALL). Normally the bone marrow makes stem cells that mature into blood cells over time. In ALL, too many stem cells turn into immature white blood cells (lymphoblasts) that don’t mature into the normal blood cells (lymphocytes) that fight infection by attacking germs and other harmful bacteria.
The most common solid tumours of childhood affect the brain and spinal cord, and they have the highest mortality rate of the childhood cancers. Types include medulloblastoma, PNET, germ cell tumours, low-grade and high-grade gliomas, ependymoma, and astrocytoma.
Choosing optimal chemotherapy is no longer done by the oncologist alone, but by a large team of oncologists, pharmacists, cell biologists, and trial coordinators, who analyse the results from previous attempts to treat cancers and alter regimens accordingly. New developments are tested in large-scale multicentre trials, which most oncology patients are enrolled into. In this way, there has been a dramatic improvement in the outcome for most childhood and adult cancers over the last 20 years.
Fifty years ago, 75% of children diagnosed with cancer died; today the average five-year survival rate across all childhood cancer types is 82%. However, survival rates vary considerably between different types of childhood cancer and by age and gender. For e.g., the survival rate for retinoblastoma (eye cancer) has now reached 100%. For ALL it is 92%. Brain and spinal cord tumours have an overall survival rate of 75%. However, because brain tumours are one of the most common types of cancer, it accounts for more than a third of all childhood cancer deaths.
The causes of most childhood cancers are not known. About 5% of all cancers in children are caused by an inherited genetic mutation (a mutation that can be passed from parents to their children). For e.g., around 30% of cases of retinoblastoma are caused by an inherited mutation in a gene called RB1. But this explains little about the overall aetiology as retinoblastoma accounts for only about 4% of all cancers in children.
Most cancers are thought to develop because of mutations in genes that lead to uncontrolled cell growth. If the mutations are not inherited, they can arise spontaneously in an individual (de novo). These gene mutations can be the result of exposure to environmental factors. But in children, these environmental risk factors have been proven difficult to identify. Several studies have shown that exposure to ionizing radiation can damage DNA, which can lead to cancer. Genetic mutations that initiate cancer development can also arise during the development of a fetus in the womb. Parental exposure to cancer-causing chemicals or x-rays could be a catalyst for this.
Mutations in DNA repair pathways have been implicated in the production of chromosomal translocations. The Philadelphia chromosome is a specific genetic abnormality found in approximately 30% of adult ALL cases and 10% of paediatric ALL cases. It is a mutated form of chromosome 22 resulting from a translocation with chromosome 9. The mix of genetic material causes the ABL1 gene of chromosome 9 to combine with the BCR gene of chromosome 22, resulting in the fusion gene BCR-ABL1. The resulting BCR-ABL1 protein is a tyrosine kinase signalling protein that is constitutively active (i.e. always switched on) and rapidly drives cell proliferation.
Clearly, more work needs to be done to identify the causes of childhood cancers, which would help to develop novel therapeutic modalities.
Be bold and go gold
This article will have hopefully familiarised you with some facts and figures about childhood cancer. There are plenty of resources online if you feel inclined to delve deeper.
One way to show kids with cancer that they are not alone is to do something brave and bold. Shave Your Lid for a Kid and join the growing movement of everyday heroes standing in solidarity with the kids who need it the most.
More modestly, you can help raise awareness by wearing a gold ribbon, which is the official symbol for CCAM. And of course, to help drive research forward you can fundraise. From bike-a-thons to golf tournaments and everything in between, hosting a fundraiser is a great way to raise awareness.