Leukemia Can Be Cured Without Brain Damage

(USA TODAY) -- Doctors have found a way to cure leukemia in children while sparing them from a toxic treatment that can cause brain damage, a study says.

In a study of 498 children with acute lymphoblastic leukemia - the most common pediatric cancer - doctors from St. Jude Children's Research Hospital treated them only with drugs and did not administer radiation to the brain, according to a study in Thursday's New England Journal of Medicine. Although radiating the skull can help prevent cancer from spreading to the brain, it can also cause leave children with serious learning disabilities.

Most doctors today are scaling back their use of cranial radiation, using it for only for children who are at high risk of relapse, or up to 20% of patients, the study says.

About 3,300 children are diagnosed with acute lymphoblastic leukemia each year.

The study is the first to do away with cranial radiation for everyone, including high-risk children.

Even without the radiation, 94% of children survived at least five years after diagnosis. That's the highest survival rate seen in a major study, says senior author Mary Relling, St. Jude's chair of pharmaceutical sciences. And 86% survived that long without a relapse, the study says.

Because most relapses occur within a few years of diagnosis, these children are probably cured, says Stephen Sallan of Children's Hospital Boston, who was not involved in the study.

And even without radiation, high-risk children in the study had longer remissions than these children usually have, Relling says. These children may have done better because of many small adjustments to their chemotherapy regimens, which last about 2½ years. For example, doctors used a stronger steroid than usual.

But Sallan says it's too soon to know whether the St. Jude regimen will become the new standard of care. It's possible the new drug combinations used in the study could cause problems in the future, he says. For example, the steroid used in the study, dexamethasone, increases the risk of bone decay, which can lead children to have joint replacement surgery.

Dexamethasone and other types of chemo used in the study also can affect the brain, Sallan says.

In addition, Sallan says doctors can't definitively say that the high-risk children in this study do better than others. That's because researchers didn't randomly assign half of the patients in the study to try each treatment.

However, Sallan notes that he's eager for updates on the progress of children in the study. If they continue to thrive, other hospitals eventually may give up cranial radiation as well.