The doctors and clinics putting leukaemia on trial

Survival rates for young children diagnosed with leukaemia are increasing all the time thanks to an ongoing clinical trial, writes RONAN McGREEVY

FINDING OUT that your child has cancer is a nightmare that fills every parent with dread.

Sadly, the dread became a reality for the Sherlock family in September this year. Three-year-old Ella Sherlock had a sore throat and a raging temperature of more than 40 degrees.

After a visit to Tallaght hospital and a course of antibiotics, the fever went away only to return worse than ever two weeks later, this time with a nasty red rash.

“I was still thinking it was a throat infection and that I wasn’t giving her enough iron,” says her mother Dawn. The family is from Knocklyon in Dublin.

Immediately they were taken to Our Lady’s Children’s Hospital, Crumlin, where Ella had a lumbar puncture to be told that there was a 90 per cent chance that Ella had childhood leukaemia. “The 10 per cent was not a lot to be holding on to,” Dawn recalls.

Ella was diagnosed with acute myeloid leukaemia (AML), the rarer of the two main types of childhood leukaemia, the other being acute lymphoblastic leukaemia (ALL). The difference between the two is in the type of white blood cells that become cancerous.

“It was a living nightmare and it still is,” says Dawn. Luckily, Ella has responded well to treatment which began two days after diagnosis.

“She is more than halfway through and she is doing very well,” says consultant paediatric haematologist, Dr Aengus O’Marcaigh.

Ella has been a beneficiary of a continuous medical trial that has halved the number of children dying from leukaemia in a generation.

“Through sequential clinical trials over the past 20 years the outcomes have improved hugely,” O’Marcaigh explains.

“The big difference with myeloid leukaemia is to take the two or three years of acute lymphoblastic leukaemia treatment and deliver it all over six months.”

The outcomes for children with leukaemia have been getting better with every passing year. In the 1960s, only 20 per cent of children survived, 20 years ago the figure was 65 per cent, now it is closer to 90 per cent.

The increases in survival rates are down to the constant trialling of new drugs, a process that has brought about impressive results in recent years.

Thankfully, childhood leukaemia is rarer than many people think. About 50 children every year are diagnosed with it in Ireland, accounting for a quarter of all children who get cancer in the country.

Since 2003, Our Lady’s Hospital has been involved in a continuing drugs trial with 22 other cancer centres in the UK.

The Ukall (UK acute lymphoblastic leukaemia) trial has ensured the survival rates of children have increased from 85 per cent to 90 per cent in the seven years since it was introduced.

O’Marcaigh explains how the sequential drugs trials are refined all the time until the correct drug is found.

“With that approach, you find out very quickly if drug A cured 87 per cent of kids or if drug B cured 88 per cent of kids,” he says.

“If you see that message you switch everybody on to drug B. Drug B becomes the standard treatment then.”

Such an approach is used in the treatment of other childhood cancers leading to similar success rates.

“The big success story of children’s cancer treatment over the past 40 years have been the fact that about 80 per cent with cancer have been treated on a clinical trial and all a clinical trial is, is a recipe book that tells you what to do and when,” he says.

O’Marcaigh says the remaining 10 per cent of children who sadly do not survive leukaemia are proving much harder to cure. New drugs will be needed and some children do not respond to any form of chemotherapy.

“That last 10 per cent will be much difficult than the ‘easy’ 90 per cent. It will take a lot more effort to cure the rest.”

The patient population in Our Lady’s Hospital is too small to justify a drug trial on its own, but the hospital has carried out valuable research in conjunction with Trinity College Dublin into the types of treatment that children should receive.

Using DNA technology, it is now possible to detect cancer cells down to one in 10,000 cells. Those with the mildest form of the disease can be spared the trauma of chemotherapy.

The successes at Crumlin are part of the Stand Up to Cancer campaign, which has sought to highlight all the good news stories in relation to cancer treatment in Ireland.

Modelled on a similar initiative in the United States, the campaign has endeavoured to get the message out that most forms of cancer are not the death sentence they used to be and advances are being made all the time.

DEFINING LEUKAEMIA

The term leukaemia refers to cancers of the white blood cells which are a critical part of the body’s immune system. When a child has leukaemia, large numbers of abnormal white blood cells are produced in the bone marrow. Symptoms include shortness of breath, children being pale or bruising easily. Tiredness and bone pain are other symptoms. There is no known cause for childhood leukaemia other than the kind of massive radiation exposure by children after incidents such as the Chernobyl disaster.