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Most Common Lymphoma Found to Be Two
Diseases
A team of scientists has discovered that diffuse large B-cell
lymphoma, the most common type of non-Hodgkin lymphoma, is actually two
distinct diseases.
Louis Staudt, MD, PhD, a scientist at the National Cancer
Institute (NCI) and lead investigator on the project, says this finding helps
explain why about 40 percent of patients with this type of lymphoma can be
cured with standard chemotherapy, while other patients relapse. “It’s
a case of mistaken identity,” said Staudt. “The tumor cells might
look very similar, but this study offers strong evidence that their molecular
engines work very differently.”
Using a technology called DNA microarray, researchers were able to
observe how genes were arranged in the tumor cells and how they behave through
the stages of the tumor’s development. They then created a genetic profile
for the two distinct types of B-cell lymphoma.
In a pilot study involving 42 patients with diffuse large B-cell
lymphoma, researchers found significant differences in survival rates,
depending on the genetic profile of their lymphoma. Three-fourths of those
whose lymphoma matched one genetic profile were alive five years after
chemotherapy. For those whose lymphoma matched the second genetic profile,
fewer than one-fourth were alive five years after treatment.
“As this study shows, genetic profiling of tumors will offer
extra power in predicting which patients will do well and which will do
poorly,” says Ronald Levy, MD, of Stanford University Medical Center and
an author of the paper. “This more precise diagnosis of a developing
cancer should help, in the future, to more accurately guide a patient’s
treatment decisions.” |
