New therapies for lymphoid neoplasms

The lymphoid neoplasms represent some of the most heterogeneous and diverse malignancies known to medicine. The spectrum of clinical diseases ranges from rapidly growing diseases like Burkitt and lymphoblastic lymphoma to some of the slowest and most indolent cancers known to science, like small lymphocytic lymphoma and follicular lymphoma. This diversity in clinical behavior reflects the molecular heterogeneity that often defines these complex neoplasms which, based on the World Health Organization (WHO) classification, can be subdivided into at least 40 different subtypes.¹ Important advances in immunohistochemistry and cytogenetics, coupled with our historical skills in basic morphology, have now allowed the delineation of each non-Hodgkin lymphoma (NHL) subtype as a distinct clinical entity - each with its own unique clinical behavior and treatment paradigms. Recent advances in gene expression profiling (GEP) have led to an entirely new way to think about lymphoma classification based on individual gene clusters that correlate with prognosis and clinical behavior. These types of classification models offer an opportunity to think about designing rational and specific therapeutic regimens targeted against the unique biological basis of the disease. Chapter 84 provides a more extensive update on gene expression profiling of lymphomas.