Differences in Prognostic Factors between Diffuse Non-Hodgkin's Lymphoma and Lymphoma Type of Adult T-Cell Leukemia

Sixty-four Japanese patients with diffuse non-Hodgkin's lymphoma (NHL) were classified into human T-cell leukemia virus type I (HTLV-I) non-related diffuse NHL (41 cases) and HTLV-I related diffuse NHL, i.e. lymphoma type of adult T-cell leukemia (ATL-lymphoma, 23 cases) on the bases of serological detection of HTLV-I antibody and the detection of HTLV-I proviral DNA in malignant cells. The survival curves between diffuse NHL and ATL-lymphoma were quite different. Therefore, it is important to know the differences in prognostic factors, if any, affecting the survival in two groups: diffuse NHL and ATL-lymphoma cases. In diffuse NHL patients, factors found to be important were age, performance status, stage, organ involvement, hemoglobin concentrations and platelet count in the peripheral blood, serum lactic dehydrogenase (LDH) and calcium levels. However, none of these factors were useful for ATL-lymphoma patients, except for the serum calcium level. Thus, prognostic factors should be considered separately for diffuse NHL and ATL-lymphoma.