Expert Recommendations for the Diagnosis, Treatment, and Management of Adult B-Cell Acute Lymphoblastic Leukemia in Latin America.

PURPOSE: Despite strong induction chemotherapy response rates, only 30%-40% of patients with adult B-cell acute lymphoblastic leukemia (ALL) attain long-term remission. This study analyzes ALL in Latin America (LA) and recommends diagnosis, treatment, and management protocols. METHODS: The Americas Health Foundation organized a panel of hematologists from Argentina, Brazil, Chile, Colombia, and Mexico to examine ALL diagnosis and therapy and produce recommendations. RESULTS: Lack of regional data, unequal access to diagnosis and therapy, inadequate treatment response, and uneven health care distribution complicate adult ALL management. The panel recommended diagnosis, first-line and refractory treatment, and post-transplantation maintenance. Targeted treatments, including rituximab, blinatumomab, and inotuzumab ozogamicin, are becoming available in LA and must be equitably accessed. CONCLUSION: This review adapts global information on treating ALL to LA. Governments, the medical community, society, academia, industry, and patient advocates must work together to improve policies.

Treatment of Acute Myeloid Leukemia with the FLT3 Gene Mutation.

In acute myeloid leukemia (AML), mutations of the Fms-like tyrosine kinase 3 receptor (FLT3) and its overexpression are related with hyperleukocytosis, higher risk of relapse, and decrease of both disease-free survival and overall survival. It has been suggested that this phenomenon confers proliferative and survival advantages to the malignant blast cells. As a consequence, it is an attractive therapeutic target. As the best treatment strategy for mutated FLT3 AML remains to be defined, the addition of FLT3 inhibitor drugs to chemotherapy or to the bone marrow transplant approach has become a growing strategy. With encouraging results, this combination seems to be an attractive option. Relevant data regarding the current treatment trends on mutated FLT3 AML is reviewed here.

Acute Leukemia Characteristics are Different Around the World: the Mexican Perspective.

BACKGROUND: The incidence of acute leukemia (AL) has increased. Its prognosis is variable and depends on several baseline characteristics with a highly heterogeneous presentation. In Mexico, large-scale descriptive studies have not yet been published; the objective of this study was to analyze the initial basic characteristics of patients diagnosed with AL in our population. PATIENTS AND METHODS: In this multicenter, retrospective study, 1018 patients ≥ 16 years of age and diagnosed with AL between 2009 and 2014, were included. We described age, gender, complete blood count, and AL subtype according to flow cytometry analysis. RESULTS: Acute lymphoblastic leukemia (ALL) was as common as acute myeloid leukemia (AML) (51% vs. 49%). The median age was 31 years. Only 9.6% of patients with ALL were positive for the Philadelphia chromosome. No gender differences were observed. The median age at presentation of AML was 43 years. Acute promyelocytic leukemia was the most frequent AML subtype (38.3%), with a median age of 37 years. CONCLUSION: ALL is equally as frequent as AML in patients ≥16 years of age. Philadelphia-positive prevalence is less frequent than that reported in literature. AML cases occur in a younger age in comparison with other countries. There is a higher rate of acute promyelocytic leukemia among our patients compared with other non-Latin American populations. This study is the largest ever performed in Mexico regarding descriptive AL data.

Placing ion channels into a signaling network of T cells: from maturing thymocytes to healthy T lymphocytes or leukemic T lymphoblasts.

T leukemogenesis is a multistep process, where the genetic errors during T cell maturation cause the healthy progenitor to convert into the leukemic precursor that lost its ability to differentiate but possesses high potential for proliferation, self-renewal, and migration. A new misdirecting "leukemogenic" signaling network appears, composed by three types of participants which are encoded by (1) genes implicated in determined stages of T cell development but deregulated by translocations or mutations, (2) genes which normally do not participate in T cell development but are upregulated, and (3) nondifferentially expressed genes which become highly interconnected with genes expressed differentially. It appears that each of three groups may contain genes coding ion channels. In T cells, ion channels are implicated in regulation of cell cycle progression, differentiation, activation, migration, and cell death. In the present review we are going to reveal a relationship between different genetic defects, which drive the T cell neoplasias, with calcium signaling and ion channels. We suggest that changes in regulation of various ion channels in different types of the T leukemias may provide the intracellular ion microenvironment favorable to maintain self-renewal capacity, arrest differentiation, induce proliferation, and enhance motility.

Current patient management of chronic myeloid leukemia in Latin America: a study by the Latin American Leukemia Net (LALNET).

BACKGROUND: Treatment recommendations have been developed for management of patients with chronic myeloid leukemia (CML). METHODS: A 30-item multiple-choice questionnaire was administered to 435 hematologists and oncohematologists in 16 Latin American countries. Physicians self-reported their diagnostic, therapeutic, and disease management strategies. RESULTS: Imatinib is available as initial therapy to 92% of physicians, and 42% of physicians have access to both second-generation tyrosine kinase inhibitors. Standard-dose imatinib is the preferred initial therapy for most patients, but 20% would manage a young patient initially with an allogeneic stem cell transplant from a sibling donor, and 10% would only offer hydroxyurea to an elderly patient. Seventy-two percent of responders perform routine cytogenetic analysis for monitoring patients on therapy, and 59% routinely use quantitative polymerase chain reaction. For patients who fail imatinib therapy, 61% would increase the dose of imatinib before considering change to a second-generation tyrosine kinase inhibitor, except for patients aged 60 years, for whom a switch to a second-generation tyrosine kinase inhibitor was the preferred choice. CONCLUSIONS: The answers to this survey provide insight into the management of patients with CML in Latin America. Some deviations from current recommendations were identified. Understanding the treatment patterns of patients with CML in broad population studies is important to identify needs and improve patient care.

Genotype and allele frequency of PAI-1 promoter polymorphism in healthy subjects from the west of Mexico. Association with biochemical and hematological parameters.

We investigated the genotype and allelic frequency of the -675 bp insertion/deletion polymorphism at the PAI-1 gene promoter, in healthy Mexican subjects. It was compared to the lipid profile and hematological parameters, and to other healthy worldwide populations. A Mexican population sample of 110 individuals was studied. Demographic data and clinical characteristics of the subjects were registered. Fasting lipid profile, serum glucose, fibrinogen, hematological parameters and leukocyte genomic DNA isolation from peripheral blood were performed in all the participants. Screening of the PAI-1 genotype was done by PCR and restriction analysis. Genotype 4G/4G, 4G/5G, 5G/5G frequency in Mexican healthy subjects was: 14.55%, 39.09%, 46.36%, respectively, whereas the allelic frequency for 5G allele was 65.9%. A significant lesser frequency for 4G allele and related genotypes (4G/4G and 4G/5G) was established in healthy subjects from Mexico, respect to all the compared populations. A particular genotype and allelic frequency of this PAI-1 polymorphism was established in Mexico. The clinical parameters were not associated according to each genotype of PAI-1.