[1263] Comparison of Non-Hodgkin Lymphoma Subtypes in Guatemala and North America/Western Europe

A Morovic, H Molina-Kirsch, J Diebold, K Maclennan, K Muller-Hermelink, B Nathwani, J Armitage, D Weisenburger, for the International Non-Hodgkin Lymphoma Classification Project. University of Nebraska Medical Center, Omaha, NE

Background: Comparisons of the relative frequencies of subtypes of non-Hodgkin lymphoma (NHL) between different geographic regions are rarely documented in the literature. In this study, we contrast the frequencies of NHL subtypes between developed countries and a developing country, Guatemala. We used a new immunostain algorithm for the classification of diffuse large B-cell lymphoma (DLBCL) into germinal center B-cell-like (GCB) and non-GCB subtypes, and compared the frequencies of these subtypes between Guatemala and the developed countries.
Design: We reviewed 194 consecutive cases of NHL from Guatemala and contrasted the frequency of the different subtypes to those in North America and Western Europe (Ann Oncol. 9:717,1998). Also, we subclassified 83 cases of DLBCL from Guatemala to GCB and non-GCB subtypes using a new algorithm (Mod Pathol. 21:250A, #1144, 2008) and the following antibodies: GCET1, CD10, BCL6, MUM1 and FOXP1. We compared the frequencies of the GCB and non-GCB subtypes in the Guatemalan series with two series from developed countries, one representing North America and Western Europe (PNAS.100:9991, 2003) and the another representing North America alone (Mod Pathol. 21:250A, #1144, 2008).
Results: DLBCL is the most common NHL in Guatemala (45%) and its frequency is higher when compared to North America or Europe (28-31%). The frequency of follicular lymphoma is markedly decreased in Guatemala (10.3%) compared to North America (31-32%) and Europe (17-28%). Nasal NK/T cell lymphoma is rare in North America and Europe (0-2%), but it made up 7.7% of all NHL in Guatemala. When the new algorithm was applied to 83 DLBCL cases from Guatemala, 44 were classified as GCB and 39 as non-GCB subtype. This group was compared to the DLBCL series from North America and Europe which included 217 cases (134 GCB, 83 non-GCB), and the series from North America which included 147 cases (84 GCB, 63 non-GCB), but there were no significant differences between these groups, with p values of 0.17 and 0.57, respectively.
Conclusions: DLBCL is the most common NHL in Guatemala and its relative frequency is increased compared to North America and Western Europe, whereas the relative frequency of follicular lymphoma is decreased in Guatemala. There were no significant differences in the frequency of DLBCL subtypes in Guatemala compared to North America and Europe.
Category: Hematopathology

Tuesday, March 10, 2009 9:30 AM

Poster Session III # 130, Tuesday Morning