Epidemiology of the non-Hodgkin's lymphomas: Distributions of the major subtypes differ by geographic locations

Background: There has been no previous systematic study of the distribution of the major subtypes of non-Hodgkin's lymphoma (NHL) across geographic regions, although there have been isolated reports of such differences.Design: As part of a clinical evaluation of the International Lymphoma Study Group (ILSG) classification of NHL, we classified 1378 NHLs from eight different geographic sites (Omaha, NE, USA; Vancouver, BC, Canada; Capetown, South Africa; London, England; Würzburg/Göttingen, Germany; Lyon, France; Locarno/Bellinzona, Switzerland; and Hong Kong) using the ILSG classification.Results: Substantial differences were found in the distribution of the major subtypes of NHL across geographic regions (P < 0.0001). A greater percentage of follicular lymphoma was seen in North America, London and Capetown (31% versus 14% at other sites). Peripheral T-cell lymphoma was more common in London, Capetown and Hong Kong (9%) than elsewhere (3%). In Locarno/Bellinzona, higher percentages of mediastinal large B-cell lymphoma (9% versus 2% elsewhere) and mantle cell lymphoma (14% versus 6% elsewhere) were seen. Angiocentric nasal T-/NK-cell lymphoma was only seen in Hong Kong (8%) and Lyon (2%).Conclusions: Our study provides evidence that the distribution of NHL subtypes differs by geographic region. These findings suggest that geographical differences in etiologic or host factors may be responsible for the observed differences in the distribution of cases across NHL subtypes.     

Prognostic factors influencing survival in patients with B-cell small lymphocytic lymphoma

The term "B-cell small lymphocytic lymphoma" (B-SLL) is generally reserved for patients with lymph node masses that show the histology and immunophenotype of B-cell chronic lymphocytic leukemia (B-CLL) but who are not leukemic. The aim of our study was to define clinical factors that predict for survival in B-SLL. Thirty-nine patients with B-SLL and with less than 5,000 mature-appearing lymphocytes/microL in the peripheral blood were studied. The median follow-up of survivors was 6.6 years (range, 1.6-12.3 years). The estimated 5-year overall survival (OS) and failure-free survival (FFS) were 66% and 23%, respectively. In the univariate analysis, significant adverse predictors for OS were age > or =60 years, B symptoms, elevated serum LDH, low hemoglobin (<11 g/dL), and high International Prognostic Index (IPI) score (3-5). In multivariate analysis, the IPI score was the only significant predictor of OS. Anemia and B symptoms were additionally predictive of poor OS in patients with low IPI scores.     

Hair Dyes and Risk of Glioma Among Nebraska Women

The etiology of brain cancer is not well understood. We conducted a population-based case–control study among 112 white women in Nebraska who were newly diagnosed with glioma between July 1988 and June 1993, and 215 controls, to identify risk factors for this disease. A 1.7-fold increased risk of glioma was observed for women who ever used hair coloring products (95% confidence interval (CI) = 1.0–2.9, 62 cases), and a 2.4-fold risk for those who used permanent hair coloring products (odds ratio (OR) = 2.4, 95% CI = 1.3–4.5, 39 cases). For women with the most aggressive form of glioma, glioblastoma multiforme, risk increased with duration of exposure to 4.9 (95% CI = 1.6–15.7, 10 cases) after 21 or more years of permanent hair coloring use. Higher risks were observed with earlier age at first use, but we did not see an exposure-response pattern with frequency of use of permanent dyes. No association was observed with use of non-permanent (sometimes called temporary or semi-permanent) hair coloring products. These suggestive findings need confirmation in future studies with larger sample sizes, fewer proxy respondents, and the ability to evaluate the effect of changes in formulations over time.     

An update of the epidemiology of non-Hodgkin's lymphoma

The incidence of non-Hodgkin's lymphoma (NHL) has increased approximately 80% since the 1970s, and is now the fifth most common cancer in the United States. The incidence of NHL is approximately 50% higher among men than women and 35% higher among white people than black people. The incidence rates of all subtypes of NHL have increased, especially diffuse large-cell and immunoblastic subtypes. Extranodal NHL has increased more rapidly than nodal NHL. The overall NHL incidence rates stabilized in the early 1990s and then began to decrease between 1996 and 2000, resulting in part from a decrease in the incidence of AIDS. The incidence of NHL types not associated with AIDS and NHL in groups at low risk of AIDS has continued to increase throughout the 1990s. The increasing incidence of NHL is poorly understood. Improved diagnostic techniques, the effects of the human immunodeficiency virus epidemic, and immunosuppressive therapies accounted for only one third of the increase. Increase in NHL may be attributed to immunodeficiency, various infections, familial aggregation, blood transfusion, genetic susceptibility to NHL, diet, and chemical exposures to pesticides and solvents. Some studies also suggest that associations between risk factors and specific NHL subtypes may be stronger than associations between the same risk factors and NHL in aggregate. Future epidemiologic studies should incorporate the new World Health Organization classification of NHL and new techniques such as cytogenetic molecular analyses to identify subtype-specific etiologic factors. Evaluation of polymorphisms in genes involved in immune function, inflammation, and the activation or detoxification of environmental and occupational chemicals is also warranted.     

Diffuse large B-cell lymphoma: a clinicopathologic analysis of 444 cases classified according to the updated Kiel classification

The purpose of this study was: to compare the survival of diffuse large B-cell lymphomas (DLBCL) stratified according to the up-dated Kiel classification. A retrospective study of a cohort of 1378 cases was organized in 1996 by the Non-Hodgkin's Lymphoma Classification Project, and the DLBCL were classified according to the updated Kiel classification. The distribution of the different types and subtypes was as follows: centroblastic (CB, 85.4%), composed of the polymorphic (CB-PM, 58.6%), monomorphic (CB-MM, 17.1%) and multilobated (CB-ML, 9.7%) subtypes; immunoblastic (IB, 11.2%), with (8.3%) or without (2.9%) plasmacytoid differentiation; and anaplastic large cell lymphoma (ALCL) of B-cell type (3.4%). The rate of diagnostic agreement between pathologists was 78% for CB and 65% for IB lymphoma. The 5-year overall survival (OAS) for the entire group was 47% and the 5-year failure-free survival (FFS) was 42%. No significant differences in survival were found between the three major groups (CB, IB, ALCL). However, the 5-year OAS and FFS of patients with DLBCL not containing immunoblasts (CB-MM+CB-ML) was 51 and 52%, respectively, and was significantly better than the survival of those containing immunoblasts (CB-PM+IB+ALCL), which was 44 and 38% (p = 0.06 and p = 0.037), respectively. These results did not appear to be due to differences in the clinical features of the two groups, and was most significant for patients with low stage or low risk disease. However, histologic subtyping was not an independent risk factor for the entire group by multivariate analysis. In conclusion, patients with CB-MM and CB-ML (without immunoblasts) had a significantly better OAS and FFS than those with CB-PM, IB and ALCL (with immunoblasts). Therefore, we conclude that additional studies are still needed to further evaluate the importance of immunoblastic differentiation in DLBCL.     

Agricultural use of organophosphate pesticides and the risk of non-Hodgkin's lymphoma among male farmers (United States)

Objective: Data from three population-based case–control studies conducted in Kansas, Nebraska, Iowa, and Minnesota were pooled to evaluate the relationship between the use of organophosphate pesticides and non-Hodgkin's lymphoma (NHL) among white male farmers. Methods: The data set included 748 cases of non-Hodgkin's lymphoma and 2236 population-based controls. Telephone or in-person interviews were utilized to obtain information on the use of pesticides. Odds ratios (OR) adjusted for age, state of residence, and respondent status, as well as other pesticide use where appropriate, were estimated by logistic regression. Results: Use of organophosphate pesticides was associated with a statistically significant 50% increased risk of NHL, but direct interviews showed a significantly lower risk (OR = 1.2) than proxy interviews (OR = 3.0). Among direct interviews the risk of small lymphocytic lymphoma increased with diazinon use (OR = 2.8), after adjustment for other pesticide exposures. Conclusions: Although we found associations between the risk of NHL and several groupings and specific organophosphate pesticides, larger risks from proxy respondents complicate interpretation. Associations, however, between reported use of diazinon and NHL, particularly diffuse and small lymphocytic lymphoma, among subjects providing direct interviews are not easily discounted.     

Richter's syndrome with different immunoglobulin light chain types. Molecular and cytogenetic features indicate a common clonal origin.

To investigate the issue of clonality in Richter's syndrome, phenotypic, molecular genetic, and cytogenetic studies were performed on tumor tissue from a patient with concurrent chronic lymphocytic leukemia and diffuse large cell lymphoma in a single lymph node specimen. The tumor was biphenotypic for immunoglobulin (Ig) expression with surface Ig lambda-positive chronic lymphocytic leukemia and surface and cytoplasmic Ig kappa-positive diffuse large cell lymphoma. DNA samples prepared from areas of the lymph node rich in chronic lymphocytic leukemia cells and diffuse large cell lymphoma cells were examined in parallel. Identical Ig heavy chain gene rearrangements were detected in the BamHI and EcoRI digests of the two samples, but the patterns of rearrangement were different in the HindIII and PstI digests. Because it is very unlikely that multiple rearranged Ig heavy chain gene fragments of identical size would be found in more than one enzyme digest from two independently derived B-cell clones, it is probable that the two processes originated from a single clone. Modifications after rearrangement probably accounted for the differing band sizes seen in the HindIII and PstI digests. These conclusions are supported by cytogenetic analysis, which revealed two clones with a common primary abnormality (trisomy 12), one of which also exhibited secondary abnormalities. Therefore, Richter's syndrome may represent a composite tumor of common clonal origin, even when differences in light chain expression are identified.