Day Care at Early Age May Cut Leukemia Risk
Exposure to common infections seems to protect against disease, study finds
FRIDAY, April 22, 2005 (HealthDayNews) -- Children who attend day-care centers regularly during their first few months of life are less likely to develop leukemia than children who don't, British researchers report.
The scientists believe their finding bolsters the theory that increasing exposure to common infections during the first year of life may decrease the risk of developing acute lymphoblastic leukemia.
"Our results provide further support that social activity with other infants and children during the first few months of life protects against subsequent risk of acute lymphoblastic leukemia," the researchers state in the April 22 online issue of the British Medical Journal.
One expert finds the study intriguing but of potentially limited value. "These are interesting and provocative findings," said Dr. Stephen Earl Sallan, a pediatric oncologist at Children's Hospital Dana Farber Cancer Institute, in Boston.
But Sallan also noted that parents whose children are not in these settings might think their children have an increased risk of developing leukemia. "This is not so," he said.
The overwhelming majority of children will never develop leukemia or any other malignancy, Sallan said. "It is only that they have a statistically significantly increased risk of developing leukemia compared to those in 'the right' social setting," he said.
"My guess is that this [study] will allay the guilt of some families who are ambivalent about sending their young children to busy day-care settings, and initiate the guilt of those who choose not to do so. Such is life," Sallan added.
In the study, the team collected data on 6,305 children without cancer, and 3,140 with cancer (1,286 had acute lymphoblastic leukemia). The children were between 2 and 14 years of age.
The investigators found that as levels of social activity increased, the risk of acute lymphoblastic leukemia decreased. The greatest reduction in risk was 69 percent, seen among children who went to day care during the first three months of life.
"Whether early exposure to one or more specific infections, or to a spectrum of non-specific agents, protects against diseases remains to be clarified," the researchers wrote. "Nevertheless, we conclude that some degree of early exposure to infection seems to be important for child health."
Another expert is also not sure if the data is useful. "When I read this, I say, 'What are we going to do with this information?' " said Dr. Herman Kattlove, a medical oncologist and spokesman for the American Cancer Society.
Kattlove said that maybe one can find a specific infection that is protective. It might be possible to identify that infection and then find ways of preventing acute lymphoblastic leukemia, he noted.
"Although we focus a lot on childhood leukemia, there aren't a lot of cases," Kattlove said. In the United States, there are some 2,000 new cases of acute lymphoblastic leukemia each year.
"Most of these cases are cured," Kattlove said. Given that the five-year survival rate is at 85 percent, he wondered, "Would anyone want to spend the research time and money to follow up [this study] for very little gain? The answer would probably be no."
The American Cancer Society can tell you more about leukemia.