Children's Health: Childhood leukemia survivors remain at risk for second cancers

Children who are successfully treated for leukemia will need regular checkups for decades because of an elevated risk for other forms of cancer.

Fortunately, researchers have found that the majority of these late-occurring secondary cancers are low-grade and curable.

"These patients need to be followed by their physicians very closely for their lifetimes and then we may be able to find those cancers early," says Dr. Nobuko Hijiya, lead author of the study and an oncologist at St. Jude Children's Research Hospital in Memphis, Tenn.

Until now, she says, doctors didn't know whether the incidence of secondary cancers persisted in childhood leukemia survivors 15 to 20 years after treatment for their disease. "But now we showed it does."

With the latest treatments, 80 per cent of children who develop leukemia -- a cancer of the blood or bone marrow -- survive. And most do not develop new cancers for at least 10 years.

To find out how the survivors fare over the longer term, Hijiya and her colleagues studied more than 2,100 people who were treated for childhood leukemia between 1962 and 1998 and achieved complete remission. Nearly 10 per cent developed second cancers, including brain tumours, skin cancers and bone marrow cancers. As the decades went by, the percentage of leukemia survivors who had developed second cancers kept increasing, from four per cent at 15 years to 11 per cent at 30 years.

Although the majority of late-occurring secondary cancers were more treatable low-grade tumours, the risk for high-grade tumours still exceeded the risk in the general population, the researchers found.