New Diagnostic Tool Means Better Treatment for Pediatric Leukemia

St. Jude Children's Research Hospital (ALSAC)
Wednesday, 27 March 2002

St. Jude Children's Research Hospital study shows genetic testing can save lives

(Memphis, Tennessee, March 27, 2002) One of the most encouraging success stories of cancer treatment just got better. Scientists from St. Jude Children's Research Hospital suggest that a new genetic screening technique may lead to dramatic improvement in the diagnosis and treatment of acute lymphoblastic leukemia (ALL).

The research is presented in the March issue of the journal Cancer Cell.

The screening technique, called gene expression profiling, is more than 95 percent accurate in diagnosing the correct form of ALL. The test's high rate of accuracy will allow doctors to maximize the risk-benefit ratio of treatment and save the most intensive treatments for those patients determined to be at a high risk for relapse.

ALL, the most common type of childhood cancer, responds well to appropriate treatment. However, there are many subtypes of ALL, and different forms of the disease are sensitive to different treatment strategies. Therefore, selecting the appropriate treatment is critical. Previously, identifying the correct ALL subtype was a difficult and costly ordeal requiring many time-consuming screening procedures as well as the expertise of numerous professionals.

"In the near future, development of custom diagnostics will significantly advance our ability to individualize therapy, so that each patient has the highest chance for cure," said James Downing, M.D., leader of the St. Jude research team.

Gene expression profiling allows leukemia cells from an individual patient to be screened for thousands of genes at one time. The study examined cells from 360 ALL patients and found that each ALL subtype had an individual genetic fingerprint.

"Moreover, we identified a new ALL subtype that had not previously been recognized," Downing said. "Whether this turns out to be a clinically important subgroup remains to be determined."

The expression profiling was performed at St. Jude's Hartwell Center for Bioinformatics and Biotechnology, a state-of-the-art facility that can combine the use of high-speed computers with modern analytical tools of biomedicine.

"The study provides another clear example of how the human genome project will result in a tangible improvement in how cancer is diagnosed and treated in patients," said Clayton Naeve, Ph.D., director of the Hartwell Center.

In addition to the obvious clinical benefits of gene expression profiling, the scientists also reported that the expression profiles of individual leukemia cells provide important clues to the underlying biology of this disease. Such findings will likely provide novel targets for developing new drugs and other therapeutic strategies.

St. Jude Children's Research Hospital, in Memphis, Tennessee, was founded by the late entertainer Danny Thomas. The hospital is an internationally recognized biomedical research center dedicated to finding cures for catastrophic diseases of childhood. The hospital's work is supported through funds raised by ALSAC. ALSAC covers all costs not covered by insurance for medical treatment rendered at St. Jude Children's Research Hospital. Families without insurance are never asked to pay.

For more information, or to contact St. Jude Children's Research Hospital (ALSAC), see their website at: www.stjude.org