Around one in five of these cases involves acute myeloid leukaemia (AML) the type Chris was diagnosed with. AML is a cancer of blood-forming cells in the bone marrow. Abnormal immature white blood cells fill the bone marrow and then spill out into the bloodstream. as a result, production of normal blood cells is disrupted, causing symptoms such as anaemia, bleeding problems and infections.
He was told he had to begin gruelling chemotherapy treatment. ?I felt awful. I lost all of my hair and felt really sick.? The treatment worked and his experience inspired him to later attend medical school and look at leukaemia treatments.
One particular milestone in his treatment had a powerful influence on his cancer research interests. Doctors gave Chris and his parents a choice between a bone marrow transplant or no further treatment.
THE TRANSPLANT could cure him but at the time it carried a 50 per cent mortality rate. Worse still, doctors had no way of identifying which children would benefit and which might not. Chris, his parents and the medical team decided on no further treatment.
?I now believe that was the most important decision of my life. Part of the transplant treatment involved total body radiation which would have been a major risk to my fertility.
?If I had gone ahead with it I might not have my three lovely children. I made the right decision but I made it with little or no information to guide me.?
These days the techniques used in bone marrow transplant are far more advanced and doctors can identify which patients are most likely to benefit before they go ahead with the therapy but the treatment of medulloblastoma lags far behind.
?With leukaemia, we are now 20 years further on than when I was treated,? says Chris. ?Thanks to discoveries in genetics research we can tell the difference between types of disease and individualise treatments better.
?We have not got that far with medulloblastoma but the same approach, of drilling down to the genetic basis of the disease, will take us forward and show us good results.?
Medulloblastomas are malignant tumours formed from poorly developed cells at a very early stage of life.
They are more common in children, particularly between the ages of three and eight.
They make up about 20 per cent of all childhood brain tumours and are more common in boys than girls.
Symptoms include headaches, vomiting (often first thing in the morning) and sight problems.
Children often appear tired, weak and irritable and may experience changes in personality and behaviour.
They may also stumble or walk in an awkward or uncoordinated way. Speech can also be affected and words may be slurred or muddled.
Other symptoms include jerky eye movements, stiffness in the neck and muscle weakness.