Gene expression profiling, a molecular technique that analyzes many genes simultaneously, can accurately distinguish between two types of immune cell tumors — Burkitt’s lymphoma and diffuse large B-cell lymphoma (DLBCL) — according to a team of researchers. Burkitt’s lymphoma and DLBCL cells appear similar when viewed under a microscope but correct diagnosis is critical because each cancer requires very different treatments. Study results appear in the June 8, 2006, issue of the New England Journal of Medicine.
"This is an example of how genetic profiling is emerging as a powerful new tool for determining treatment choices," said US NIH Director Elias A. Zerhouni, M.D. "In the future, many tumors will be classified using genetic profiling, and treatments will be tailored to meet the needs of each patient, another example of a more predictive and personalized era of medicine."
"For the first time, we are beginning to have the ability to take microscopically identical tumors from different patients and demonstrate that they are genetically distinct, in order to provide greater certainty about diagnosis and prognosis," said US NCI Acting Director John E. Niederhuber, M.D. "A complete genetic analysis of human cancers will provide us with the ability to match the patient with a highly specific regimen of targeted therapies."
Burkitt’s lymphoma and DLBCL are types of non-Hodgkin’s lymphoma (NHL), a cancer of B lymphocytes, a type of white blood cell. Healthy lymphocytes help destroy bacteria, viruses and other infectious agents invading the body. Burkitt’s lymphoma is seen primarily in children, but can affect adults ages 30 to 50. DLBCL can affect people of any age; it is most often observed in adults 60 years or older. Because both lymphomas can occur in the same age group and patients present similar clinical symptoms, it is often difficult to distinguish these two types of NHL.
"The value of molecular profiling to accurately diagnosis Burkitt’s lymphoma versus DLBCL will have a major impact on patients because the treatment for these two lymphomas is very different," said Louis Staudt, M.D., Ph.D., deputy chief of the Metabolism Branch and head of the Molecular Biology of Lymphoid Malignancies Section in the US NCI’s Center of Cancer Research, as well as research team co-leader. "If Burkitt’s patients are treated with intensive therapy, there is roughly an 80 percent survival rate. However, if they are misdiagnosed and treated with the therapy recommended for DLBCL, lower intensity chemotherapy, the survival rate is reversed to 20 percent or even less."
To carry out their study, investigators collected samples of Burkitt’s lymphoma from institutions in the United States, Canada and Europe. These organizations are part of the Lymphoma/Leukemia