Analysis of 511 Lymphoma Cases in Uruguay

Reviewer: Neha Vapiwala, MD
Abramson Cancer Center of the University of Pennsylvania
Last Modified: March 21, 2007

Presenter: Gualco, G. (in Spanish)
Presenter's Affiliation: Hospital Militar, Laboratorio de Anatomía Patológica, Uruguay
Type of Session: Scientific

Background

The incidence and demographic distribution of Hodgkin's lymphoma (HL) and non-Hodgkin lymphomas (NHL) vary throughout the world. The incidences are particularly high in North America, and cases of aggressive NHLs are on the rise in Europe and North America.

This study was initiated to describe the demographic distribution of lymphomas (HL and NHL) in Uruguay.

Materials and Methods

The study describes 511 cases of newly diagnosed lymphomas with their frequency and distribution in a Uruguayan population.
All cases were classified using the WHO 2001 system, with appropriate immunophenotyping performed by the same pathologists.
204 cases were obtained from a public military hospital from 1988-2005
307 cases were obtained from a private laboratory from 2001-2005

Results

There were 82.2% (422) Non-Hodgkin’s Lymphomas (NHL) and 17.8% (89) Hodgkin’s Lymphomas (HL), and 57.9% males in the overall group.
NHL characteristics were as follows:
58.1% males
Mean age was 60 years old (range was 2 to 93)
B-cell lymphomas (BNHL) were 92.7% and T-cell lymphomas (TNHL) were 7.3%.
BNHL subtypes were distributed as follows:
Diffuse large B cell was the most frequent (37.9%)
Follicular lymphoma (28.6%)
Lymphocytic lymphoma (10%)
Mantle cell lymphoma (7.2%)
Marginal zone lymphoma was 6.2%
All the other subtypes were less than 3% each
27% of BNHL had an extra nodal presentation
The most frequent TNHL were T Non otherwise specified (29%) followed by Lymphoblast T-cell and Anaplastic large-cell lymphomas (22.6% each).
HL occurred in 57.3% (51) males.
Mean age was 37.7 years old, significantly lower for males and showed bimodal distribution (range was 6 to 80).
95.5% were classic HL (CHL): 68.2% nodular sclerosis, 21.3% mixed cellularity, 4.5% lymphocyte rich, and 3.5% lymphocyte depletion.
Male /female ratio was 1:1 for NS and 1.5 to 3:1 for the other types.
EBV was positive in 24% NS and 75% MC
4.5% of all HL were nodular lymphocyte predominance (NLP). All were males and mean age was 31.7 years old.

Author's Conclusions

The distribution and demographics of B-cell and T-cell NHL, as well as B subtypes, seen in Uruguay are described here in detail.
The characteristics of NHL seen here are similar to those observed in developed countries.
The same is also true of CHL, although there is a slightly less strong association with EBV, making it more similar to studies in the European population.

Clinical/Scientific Implications

This is the first study specifically looking at a large population of NHL and HL patients in Uruguay. The authors report a great number of demographic and pathologic details to provide a better understanding of these entities based on geographic location. It is interesting to note that the characteristics of the endemic lymphoma patient population parallel the frequency and gender/age distribution in NHL and HL of European patients. The incidence and association of CHL with EBV is also more similar to Europe than to other South American countries, suggesting a possible link to emigration patterns.

Unfortunately, the cases associated with HIV were not separately analyzed in this study. As the population of HIV positive individuals increases, the impact on lymphoma demographics will be important to monitor.