01-07-2009, 01:58 AM
Non-Hodgkin lymphoma (NHL) describes a group of cancers which arise from lymphocytes, a type of white blood cell. NHL is distinct from Hodgkin lymphoma in its pathologic features, epidemiology, common sites of involvement, clinical behavior, and treatment. The non-Hodgkin lymphomas are a diverse group of diseases with varying courses, treatments, and prognoses.Non-Hodgkin lymphoma may develop in any organ associated with the lymphatic system (e.g. spleen, lymph nodes, or tonsils). Most cases start with infiltration of lymph nodes, but some subtypes may be restricted to other lymphatic organs. The diagnosis of non-Hodgkin lymphoma requires a biopsy of involved tissue. The numerous subtypes of non-Hodgkin lymphoma are typically grouped into three distinct categories based on their aggressiveness. These categories are indolent (or low-grade), aggressive (or intermediate-grade), and highly aggressive (or high-grade). The treatment of indolent or low-grade lymphoma may initially involve a period of observation, while aggressive or highly aggressive non-Hodgkin lymphoma is typically treated with chemotherapy and/or radiation therapy."Stage III"indicates that the cancer has spread to both sides of the diaphragm, including one organ or area near the lymph nodes or the spleen.The most significant factor in overall prognosis is the grade, or aggressiveness, of the lymphoma. Indolent (low-grade) non-Hodgkin's lymphoma is generally not curable, but is typically slowly progressive and responds temporarily to therapy. Aggressive and highly aggressive (intermediate- and high-grade) NHL's are potentially curable with combination chemotherapy. Long-term survival or cure rates for these diseases vary with a number of prognostic factors.The International Prognostic Index, or IPI, is the most widely used prognostic system for non-Hodgkin's lymphoma. This system uses 5 factors:AgeLactate dehydrogenase level (a blood test)Performance statusClinical stageSites of extranodal diseaseHowever, it should be noted that the IPI was developed prior to the introduction of rituximab. As rituximab has become a standard part of therapy for B-cell NHL's, the impact on the prognostic value of the IPI is unclear.The International Prognostic Index (IPI) is a clinical tool developed by oncologists to aid in predicting the prognosis of patients with aggressive non-Hodgkin's lymphoma. Prior to 1993, when the IPI was developed, the primary consideration in assessing prognosis was the Ann Arbor stage alone, but this was increasingly found to be an inadequate means of predicting survival outcomes, and so other factors were studied.A retrospective analysis was performed on 2031 patients with aggressive non-Hodgkin's lymphoma, of all ages, treated with a doxorubicin-based chemotherapy regimen such as CHOP between 1982 and 1987.[1] Several patient characteristics were analyzed to determine whether they were associated with differences in survival, and the factors that emerged as significant were, in addition to the Ann Arbor stage: age, elevated serum lactate dehydrogenase (LDH), performance status, and number of extranodal sites of disease.
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