Gene Technology Spots Burkitt's Lymphoma
WEDNESDAY, June 7 (HealthDay News) -- A new gene-based technology is helping doctors distinguish between people who have a rare blood cancer called Burkitt's lymphoma and those who have a more common form of lymphoma, researchers report.
That's important, because Burkitt's lymphoma can be cured in many cases by intensive chemotherapy but not by drug treatments used for the other lymphoma.
One expert cautioned that the new technology is prohibitively expensive.
However, "if this turns out to be the best way to identify Burkitt's lymphoma, then someone will make it practical to do in practice," said Dr. Nancy Lee Harris, professor of pathology at Harvard Medical School.
Harris is co-author of an accompanying editorial on the study, which appears in the June 8 New England Journal of Medicine.
Burkitt's lymphoma is a type of non-Hodgkin's lymphoma that originates in the blood's B cells, a type of white blood cell. It's more common in children but can also affect adults.
The disease carries clinical characteristics that are very similar to another common non-Hodgkin's lymphoma, called diffuse large B-cell lymphoma, making a definite diagnosis difficult. The traditional way of diagnosing Burkitt's lymphoma -- an examination of cells under a microscope -- can often prove wrong.
Now, a study led by experts at the U.S. National Cancer Institute has found that 19 of the 71 cases diagnosed by the traditional method were, in fact, misdiagnosed. And nine of the Burkitt's lymphoma diagnoses turned out to be wrong, subjecting the patients to unnecessary treatments.
That study, and another one done in Berlin, also used different versions of a new technique. With this new technology, tissue samples were profiled for expression of genes thought to be involved in Burkitt's lymphoma.
The American report said the genetic technique verified the diagnosis of Burkitt's lymphoma in 25 patients out of a group of 303 people with lymphoma. But the genetic technique also found that eight cases diagnosed as typical lymphoma had the genetic profile of Burkitt's.
In their study, the German researchers used the new gene-profiling technique on 220 cases of lymphoma. It identified 44 cases of Burkitt's lymphoma, 11 of which had been missed by the traditional method.
While the results were impressive, the technique is not yet ready for widespread use, Harris said.
"It is very expensive, and it is not yet entirely clear what to do with the information you have for an individual patient," Harris said.
The gene-analyzing technology is "too cumbersome and costly to use for individual diagnosis right now," she added.
The machinery to do the genetic analysis isn't widely available, Harris said, and the tissue samples must immediately be frozen at 70 degrees below zero. "Snap-freezing the material is fairly laborious," she said.
But accurate diagnosis is crucial to proper treatment, so, if this new technique proves useful, then simpler, cheaper technologies might be developed, Harris said. For example, it's possible that only a few genes among the hundreds analyzed by the current method might be important, getting around the need for a broader genetic scan.
A different path toward making the technique more usable is already being tried in Berlin, said Dr. Harald Stein, a professor of pathology at the Charity Universitatsmedizin Berlin's Institute of Pathology at Campus Benjamin Franklin.
"We have now achieved a method of obtaining tissue samples that is easier to apply," he said. Instead of being flash-frozen, the specimens are placed in a solution that allows them to be restored at refrigerator temperatures, Stein said.
But, he cautioned, the results obtained in both studies must be verified before widespread use of the technique can be advised.
"We have to use all the information we gather in prospective trials to make sure that our assumptions are correct," Stein said.
If the assumptions are correct, children will be the main beneficiaries. Burkitt's accounts for only about 1 percent of adult lymphomas but 30 percent to 50 percent of childhood lymphomas, Harris said.
Find out more about Burkitt's lymphoma at the Lymphoma Information Network.