Non-Hodgkin's lymphomas in Mexico. A clinicopathological and molecular analysis

Clinical Outcomes of Patients With B-Cell Non-Hodgkin Lymphoma in Real-World Settings: Findings From the Hemato-Oncology Latin America Observational Registry Study

Real-world evidence on non-Hodgkin lymphoma (NHL) management in Latin America is currently lacking. The objective of this study was to describe treatment characteristics and outcomes of NHL in Latin America.

Adult T-cell leukemia/lymphoma in South and Central America and the Caribbean: systematic search and review

Adult T-cell leukemia/lymphoma (ATL) is caused by the human T-cell lymphotropic virus type 1 (HTLV-1) which is endemic in countries of Caribbean and Central and South America. We performed a systematic search and review to identify publications on ATL in these countries to verify if this disease was getting recognition in these regions as well as the characteristics of the observed cases. The median age of 49.4 years was lower than that referred to in Japan. According to our findings in most Brazilian states and in some other countries, ATL is not being recognized and should be strongly considered in the differential diagnosis of T-cell leukemias/lymphomas. Failure to identify these cases may be due to the unsystematic realization of serology for HTLV-1 and phenotypic identification of non-Hodgkin lymphomas that may result from lack of resources. Detection of ATL cases has been more feasible with cooperation from foreign research centers. A huge effort should be made to improve the surveillance system for ATL diagnosis in most of the South- and Central-American and Caribbean countries, and this attitude should be embraced by public organs to support health professionals in this important task.

Nasal NK/T-Cell Lymphoma. A Comparative Analysis of a Mexican Population with the Other Populations of Latin-America

Nasal natural killer/T-cell lymphoma (nasal NKTCL), is a rare presentation of extranodal lymphoma in North-America and Europe, but in some countries, as China and Korea, nasal NKTCL occurred in 20 to 46 % of T-cell lymphomas. Some studies, analyzing the incidence in Latin-America, observed some differences between the various populations. However, this comparison included Argentina and Chile, Peru, and other Latin-America but not the Mexico. Thus, we performed a retrospective analysis of the patients diagnosed and treated as nasal, NKTCL, in our institution that is an academic tertiary national reference hospital of Mexico.

From 1988 to 2014, we diagnosed and treated 14,816 cases of non-Hodgkin’s lymphoma, 10,957 (73%) were of B-cell histology and 3822 (26%) were of T-cell histology. Nasal, NKTCL, was the most frequent of the T-cell histology: 40%. We compared our results with those of other countries and observed that nasal, NKTCL have a small number of cases in North-America, and in some countries of Latin-America, as Argentina, Brazil, and Chile. However, the number of NKTCL cases found in Mexico was similar to that found in Guatemala and Peru, and also in China and Korea. Our study suggests that this neoplasm could have a racial basis, but environmental factors should also be considered.

Classification of non-Hodgkin lymphoma in Central and South America: a review of 1028 cases

The distribution of non-Hodgkin lymphoma (NHL) subtypes differs around the world but a systematic study of Latin America has not been done. Therefore, we evaluated the relative frequencies of NHL subtypes in Central and South America (CSA). Five expert hematopathologists classified consecutive cases of NHL from 5 CSA countries using the WHO classification and compared them to 400 cases from North America (NA). Among the 1028 CSA cases, the proportions of B- and T-cell NHL and the sex distribution were similar to NA. However, the median age of B-cell NHL in CSA (59 years) was significantly lower than in NA (66 years; P < .0001). The distribution of high-grade (52.9%) and low-grade (47.1%) mature B-cell NHL in CSA was also significantly different from NA (37.5% and 62.5%; P < .0001). Diffuse large B-cell lymphoma was more common in CSA (40%) than in NA (29.2%; P < .0001), whereas the frequency of follicular lymphoma was similar in Argentina (34.1%) and NA (33.8%), and higher than the rest of CSA (17%; P < .001). Extranodal NK/T-cell NHL was also more common in CSA (P < .0001). Our study provides new objective evidence that the distribution of NHL subtypes varies significantly by geographic region and should prompt epidemiologic studies to explain these differences.