BOSTON Dana-Farber Cancer Institute scientists have discovered that a rare but lethal blood cancer that strikes infants in their first year is a genetically distinct type of leukemia that might someday be treatable with designer drugs specifically targeted to it.
The discovery will help researchers single out the abnormal genes that make the leukemia so difficult to treat, as well as identifying new targets within the cancer cells for drugs that would be more selective than those used today. Nature Genetics will publish the findings on its Web site on Dec. 3 and in its January 2002 print edition.
This finding is very exciting to us because it forces us to think about this as a separate disease and to think about other therapies that could be designed to attack its specific weak points, says Scott Armstrong, MD, PhD, lead author of the paper.
Currently, physicians diagnose and treat the rare cancer as a particularly aggressive form of the more common Acute Lymphoblastic Leukemia, or ALL. The cancer may respond to chemotherapy at first, but tends to recur fatally. Thats why the prognosis is so much worse than for most types of childhood leukemia, which today can usually be treated effectively.
The Dana-Farber scientists and collaborators propose the name Mixed Lineage Leukemia, or MLL, for the newly identified disease, which affects fewer than 100 hundred babies annually in the United States but is typically fatal in about 60 percent of the cases.
Using powerful gene chips, the researchers say theyve found that the genetic abnormalities in the cells of this infant cancer are dramatically different from ALL, and also from AML (Acute Myelogenous Leukemia), the other common type of childhood leukemia. The pattern of gene activity in the infant cancer is so distinct that the disease warrants its own name and might be tamed with drugs designed to hit its unique set of vulnerable points.