Impact of gene expression profiling in lymphoma diagnosis and prognosis.

Lymphoma classification has changed several times over time as our understanding of normal and malignant lymphocyte biology has advanced. This has improved prognostication, but there remain large diagnostic groups with diverse outcomes. In an attempt to refine diagnosis and prognostic power in these, global gene expression profiling (GEP) has been used to further improve our understanding of lymphoma. This review will cover the impact of GEP on the diagnosis, prognosis, biological understanding and identification of novel treatments for the main types of lymphoma, as well its translation to clinical practice. Specifically, it will cover the use of GEP to identify prognostic subgroups within existing diagnostic categories, in an attempt to improve prognostication in those subgroups with wide variation in outcome. Many of these studies have given additional novel insights into the biology of lymphoma, including the role of the immune system and the stromal environment. The improved understanding that these studies have given have suggested possible new treatments, linking diagnosis, prognosis, biological understanding and improved treatment.