Hispanic children are more likely than those from other racial and ethnic backgrounds to be diagnosed with acute lymphoblastic leukemia (ALL) and are more likely to die of their disease, found a study conducted by the Children’s Oncology Group and St Jude Children’s Hospital.

Researchers studying a gene called ARID5B linked eight common variants of the gene to an increased risk of not only developing pediatric ALL, but of having the cancer return after treatment. Two more ARID5B variants were tied to higher odds of developing the disease. Investigators found that Hispanic children were up to twice as likely as their white counterparts to inherit a high risk-version of ARID5B.

"For years we have known about ethnic and racial disparities in ALL risk and outcome, but the biology behind it has been elusive. Therefore, it is truly exciting to be able to not only pin down the biological basis, but find that the same gene might be responsible for both differences,” said Jun Yang, Ph.D., of St. Jude and the paper's corresponding author. “Children who inherit high-risk versions of ARID5B are more likely to develop ALL in the first place and then more likely to fail therapy.”

Multiple factors contribute to cancer development, and inheriting a high-risk version of ARID5B is not enough to cause the disease, Yang said.

These findings set the stage for exciting research in understanding how genetic, environmental and other factors combine in ALL, especially in the context of racial and ethnic disparity, he said.

"These and other genomic studies suggest we are poised to finally make significant progress in eliminating racial disparities in this catastrophic disease," Yang said. Additional work is needed to translate these findings into new clinical tools, he added.

Although the work of St. Jude researchers and others is helping to close the survival gap, Hispanic children are still less likely than children from other racial or ethnic backgrounds to be alive five years after diagnosis.

The study appears in the Jan. 30, 2012 online edition of the Journal of Clinical Oncology.