Results from two studies published in the New England Journal of Medicine suggest that the technique of gene expression profiling may improve the ability of physicians to distinguish Burkitt’s lymphoma from diffuse large B-cell lymphoma. Accurate diagnosis of these two types of non-Hodgkin’s lymphoma is important because they require different treatment.
Non-Hodgkin’s Lymphoma (NHL) is a form of cancer that begins in the cells of the lymph system (spleen, thymus, tonsils, bone marrow, lymph nodes, and circulating immune cells). Lymphocytes are the main cells in the lymph system and exist in two forms: B and T-cells. Each of these cells serves a specific function in aiding the body fight infection.
In NHL an excessive amount of atypical (cancerous) lymphocytes accumulates in the lymph system. These lymphocytes can crowd and suppress the formation and function of other immune and blood cells.
Non-Hodgkin’s lymphoma is categorized by the type of lymphocyte it involves and further defined by the rate at which the cancer grows. The appearance of the cells under a microscope indicates the growth rate. High-grade or aggressive NHL is the fastest growing, whereas low-grade or indolent lymphoma develops slowest. Diffuse large B-cell lymphoma (DLBCL) and Burkitt’s lymphoma are both aggressive B-cell lymphomas, but treatment for these two types of NHL differs. Burkitt’s lymphoma requires more intensive treatment than DLBCL.
Gene expression profiling explores the patterns of genes that are active in tumor cells. Studies suggest that gene expression may provide information about prognosis or likely response to treatment in several types of cancer. This technique may allow for more accurate classification of cancer type than currently available methods.
Two studies published in the same issue of the New England Journal of Medicine explored the use of gene-expression profiling in the diagnosis of Burkitt’s lymphoma. Both studies identified gene expression profiles that were linked with Burkitt’s lymphoma, and both studies found that some lymphomas that had been classified as DLBCL using standard methods were reclassified as Burkitt’s lymphoma using gene-expression profiling. Similarly, a small number of lymphomas that had originally been classified as Burkitt’s were reclassified as DLBCL.
Although the techniques used in these studies require further exploration and are not available for standard clinical use, both studies suggest that gene expression profiling may eventually allow for more accurate identification and improved treatment of patients with Burkitt’s lymphoma.
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