[1465] Classification of Non-Hodgkin Lymphoma in South America: A Review of 1028 Cases

Javier A Laurini, Anamarija M Perry, Eugene Boilesen, Martin A Bast, Bharat N Nathwani, Jacques Diebold, Kenneth A MacLennan, H Konrad Mueller-Hermelink, James O Armitage, Dennis D Weisenburger. University of Nebraska Medical Center, Omaha, NE

Background: The relative frequencies of non-Hodgkin lymphoma (NHL) subtypes vary in different parts of the world. Although extensive studies have been conducted in North America (NA) and western Europe, no studies have assessed the distribution of NHL subtypes in South America (SA). The aim of this study was to evaluate the clinical features and distribution of NHL subtypes in SA as compared to NA.
Design: A panel of five expert hematopathologists reviewed consecutive cases of NHL from five SA countries and classified them according to the World Health Organization classification. A consensus diagnosis was reached in each case (Blood 89:3909,1997). For comparison, we used a cohort of 400 similarly-accrued consecutive cases of NHL from NA.
Results: Among the 1028 SA NHL cases, 198 were from Argentina, 227 from Brazil, 207 from Chile, 224 from Guatemala, and 172 from Peru. The distribution of B-cell and T-cell NHL was similar in SA and NA (p=0.14), and no significant differences were observed in the sex distribution between SA and NA (p=0.60). However, the mean age of patients with B-cell NHL in SA (56 years) was significantly lower than in NA (62 years; p<0.0001). Among mature B-cell NHL, the distribution of high grade (52.9%) and low grade (47.1%) cases in SA was significantly different from NA (37.5% and 62.5%, respectively; p<0.0001). Diffuse large B cell lymphoma was more common in SA (44.4%) than in NA (32.3%; p=0.0011), whereas the reverse was true for follicular lymphoma (22.6% vs 37.3%, respectively; p<0.0001). However, the frequency of follicular lymphoma was similar in Argentina (39%) and NA (37%), and higher than the rest of SA (19%; p<0.0001). Extranodal NK/T-cell NHL, nasal type, was more prevalent in SA (p=0.0034) with most of the cases seen in Guatemala (p<0.0001), and adult T-cell leukemia /lymphoma was largely restricted to Peru where it represented 5.4% of NHL (p=0.0002).
Conclusions: Our study provides new evidence that the distribution of NHL subtypes varies by geographic region, and suggests that both etiologic and host risk factors play a role in the epidemiology of NHL subtypes in SA.
Category: Hematopathology

Monday, March 19, 2012 9:30 AM

Poster Session I Stowell-Orbison/Surgical Pathology/Autopsy Awards Poster Session # 206, Monday Morning


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