A break for kids with leukemia

Although the good news is we cure a lot of children with leukemia, the treatment can cause many problems that show up later. These can be a second leukemia, heart problems, bone problems, growth retardation and even a drop in intelligence.

A lot of effort has been directed toward avoiding these problems. Sometimes the treatments that cause these long term issues can’t be avoided. Better a smaller child than a dead one. And many of the other problems, except another leukemia, can be dealt with.

But what if there are children with acute leukemia who can avoid the harsher treatments? Can we identify them? That is what investigators from the Pediatric Oncology Group (POG) set out to do. POG is the major pediatric oncology research group in the U.S.

They studied 653 children with acute leukemia who were expected to have a good outcome because of certain characteristics of their leukemia. Instead of the harsher drugs, the researchers gave them only drugs that did not cause leukemia, heart problems and bone problems. These are a class of drugs called antimetabolites that have been in use for at least 50 years. They work mainly by interfering with DNA synthesis but they don’t damage existing DNA or anything else.

The investigators also withheld brain radiation, which is a common treatment to kill leukemia cells that can hide from chemotherapy in the brain. Instead, they relied on injecting chemotherapy into the spinal fluid, which is standard treatment for all children with leukemia.

To be absolutely sure this approach worked, the children were followed for at least 8 or 9 years after the treatment. So far, 79 children have relapsed which is not too different from what would be expected with more severe treatments. And, most of these responded to a second course of treatment, so by the end of 6 years only about 2-3% of the children had died.

And it is reassuring to know that the nearly 600 children who were cured by the first course of treatment are likely to live normal healthy lives.