Leukemia in Down's kids linked to parental factors

By David Douglas

NEW YORK (Reuters Health) - There appears to be a relationship between infertility or infertility treatments in the parents and a risk of developing acute leukemia in children with Down's syndrome, researchers report.

However, as senior investigator Dr. Logan G. Spector told Reuters Health, "these results are very tentative and don't have any immediate clinical implications."

In the medical journal Cancer, Spector of the University of Minnesota, Minneapolis, and colleagues note that Down's syndrome children have a 10- to 20-fold increased risk of developing acute leukemia.

They also point out that previous research has uncovered "mixed evidence for associations between reproductive history or infertility and acute leukemia among children without Down's syndrome."

To investigate these relationships in children with Down's syndrome, the researchers studied 97 Down's syndrome children with acute lymphoblastic leukemia and 61 with acute myeloid leukemia. The researchers also enrolled 173 same-age children with Down's syndrome but without leukemia.

Overall, there was no statistically significant association between leukemia in the children and parental reproductive factors, such as the outcome of previous pregnancies, contraception use or infertility outcomes. However, Down's syndrome children with parents who had tried to become pregnant for 1 year or longer had more than twice the risk of acute myeloid leukemia.

There also were suggestions that fertility treatments and older age of the mother were associated with a greater risk of acute myeloid leukemia risk.

"We wish to do follow-up studies," concluded Spector, "to see if the results can be replicated and, if so, to figure out how the mother's treatment for infertility could contribute to the risk of acute myeloid leukemia in the specific population of children with Down's syndrome."

SOURCE: Cancer, November 1, 2007.