Follicular lymphoma is the second most common form of non-Hodgkin's lymphoma and accounts for more than 20% of all cases. Follicular lymphoma is cancer of the lymph nodes, which are an important part of the immune system, the body's natural defense system against infection.
But the survival time of people with follicular lymphoma varies greatly and may range from one year to more than 20 years after the cancer is diagnosed. That wide variation has prompted researchers to search for ways to predict how follicular lymphoma may progress.
In this study, researchers found that a test that screens for particular genetic patterns was able to accurately predict survival time for people with follicular lymphoma.
The study showed that two genetic signatures of this type of cancer allowed researchers to group patients into four groups whose average survival times ranged from about 13 years to less than four years.
The results appear in the Nov. 18 issue of The New England Journal of Medicine.
Genetic Profiling May Predict Lymphoma Survival
In the study, researchers profiled the genetic makeup of 95 samples from people with untreated follicular lymphoma.
Based on these findings, researchers grouped genes that predicted the length of survival into two genetic signatures and evaluated these survival predictors in another test of 96 samples.
Researchers found the two genetic signatures associated with survival allowed them to divide patients into four groups with very different average survival times. For example, those in the top group had an average survival time after diagnosis of 13.6 years while those in the bottom group averaged 3.9 years.
The study showed that these genetic signatures accurately estimated follicular lymphoma survival times regardless of other traditional variables, such as the progression of the tumor.
Surprisingly, researchers say the genetic patterns that predicted survival were actually associated not with the cancerous cells within the tumor but with the noncancerous, healthy ones.
In an editorial that accompanies the study, Ralf Küppers, PhD, of the Institute for Cell Biology at the University of Duisburg-Essen Medical School in Essen, Germany, says the findings represent an important advance in risk stratification for people with follicular lymphoma.
In addition, the results suggest that the aggressiveness of the follicular lymphoma is mainly determined by the environment in which the tumor occurs, rather than genetic differences within the tumor itself.