WASHINGTON (Reuters) - People who have survived childhood leukemia are much more prone to develop other types of cancer in the decades after their original cancer treatment, a study published on Tuesday found.
Researchers tracked 2,169 people treated as children and adolescents between 1962 and 1998 at St. Jude Children’s Research Hospital in Memphis, Tennessee, for acute lymphoblastic leukemia. It is a form of cancer in which the bone marrow makes too many of a kind of white blood cell.
Their cancer had gone into complete remission, and their health was monitored for an average of 19 years.
The researchers, writing in the Journal of the American Medical Association, found that the childhood leukemia survivors were 13.5 times more likely than the general population to develop the most serious types of cancer.
In addition, the incidence of new cancers increased steadily for these cancer survivors over the 30 years after their leukemia treatment, the study found.
“More and more patients survive longer and longer these days because of the improvement in the therapy for the initial cancer,” St. Jude’s Dr. Nobuko Hijiya, who led the study, said in a telephone interview.
The findings underscore the need to closely monitor the health of these childhood cancer survivors for decades after their original treatment, Hijiya said. They also add to studies showing that pediatric cancer survivors have other serious health risks.
Acute lymphoblastic leukemia is the most commonly diagnosed pediatric cancer, and is considered one of the most curable. More than 80 percent of patients survive.
The researchers said previous studies had looked at the risk of developing other types of cancer among childhood leukemia survivors, but they followed them for only about 15 years and did not give a longer-term assessment.
For the 1,290 patients whose leukemia stayed in remission (879 had a leukemia relapse), about 10 percent developed another cancer, with a relatively rapid increase cases starting 20 years after the original treatment.
The majority of the cancers they developed were types that respond well to treatment such as meningioma, a tumor near the brain and spinal cord, and basal cell carcinoma, a type of skin cancer, but some were very serious, the researchers said.
Chemotherapy and radiation treatments used on childhood leukemia patients may have been harsher than current treatments, and this in part accounts for the increased risk, the researchers said. But they said genetic factors also may be in play.