I. THE ROLE OF RESEARCH ETHICS COMMITTEES IN OBSERVATIONAL STUDIES: EPIDEMIOLOGICAL REGISTRIES, CASE REPORTS, INTERVIEWS, AND RETROSPECTIVE STUDIES.

It is often unclear to the clinical investigator whether observational studies should be submitted to a research ethics committee (REC), mostly because, in general, no active or additional interventions are performed. Moreover, obtaining an informed consent under these circumstances may be challenging, either because these are very large epidemiological registries, or the subject may no longer be alive, is too ill to consent, or is impossible to contact after being discharged. Although observational studies do not involve interventions, they entail ethical concerns, including threats such as breaches in confidentiality and autonomy, and respect for basic rights of the research subjects according to the good clinical practices. In this context, in addition to their main function as evaluators from an ethical, methodological, and regulatory point of view, the RECs serve as mediators between the research subjects, looking after their basic rights, and the investigator or institution, safeguarding them from both legal and unethical perils that the investigation could engage, by ensuring that all procedures are performed following the international standards of care for research. The aim of this manuscript is to provide information on each type of study and its risks, along with actions to prevent such risks, and the function of RECs in each type of study.

Effect of imatinib on plasma glucose concentration in subjects with chronic myeloid leukemia and gastrointestinal stromal tumor.

BACKGROUND: Type 2 diabetes mellitus has become one of the most important public health concerns worldwide. Due to its high prevalence and morbidity, there is an avid necessity to find new therapies that slow the progression and promote the regression of the disease. Imatinib mesylate is a tyrosine kinase inhibitor that binds to the Abelson tyrosine kinase and related proteins. It enhances ß-cell survival in response to toxins and pro-inflammatory cytokine. The aim of this study is to evaluate the effect of imatinib on fasting plasma glucose in subjects with normal fasting glucose, subjects with impaired fasting glucose and in subjects with type 2 diabetes mellitus. METHODS: We identified 284 subjects diagnosed with chronic myeloid leukemia or gastrointestinal stromal tumors from the Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran database. 106/284 subjects were treated with imatinib. We compared the effect of imatinib on fasting plasma glucose after 1 and 6 months of treatment. We used ANOVA test of repeated samples to determine statistical significance in fasting plasma glucose before imatinib treatment and the follow-up. Statistical analysis was performed with Statistical Package for the Social Sciences v22. RESULTS: We included a total of 106 subjects: 76 with fasting plasma glucose concentrations < 100 mg/dL (normal FG), 19 subjects with fasting plasma glucose concentrations ≥100 mg/dL (impaired fasting glucose), and 11 subjects with ≥126 mg/dL (type 2 diabetes mellitus). We found a significant increase in fasting plasma glucose concentration in the normal fasting glucose group (p = 0.048), and a significant decrease in fasting plasma glucose concentration in the type 2 diabetes mellitus group (p = 0.042). In the impaired fasting glucose group, we also found a tendency towards a decrease in fasting plasma glucose (p = 0.076). We identified 11 subjects with type 2 diabetes mellitus, of whom, 7 (64%) had a reduction in their fasting plasma glucose concentrations after 6 months. A significant glycosylated hemoglobin reduction (p = 0.04) was observed. CONCLUSION: Subjects with chronic myeloid leukemia or gastrointestinal stromal tumor with type 2 diabetes mellitus had a significant reduction in fasting plasma glucose and glycosylated hemoglobin at 1 and 6 months while using imatinib.

Expression of HER2/Neu in B-Cell Acute Lymphoblastic Leukemia.

BACKGROUND: The expression of HER2/neu in B-cell acute lymphoblastic leukemia has been reported in previous studies. OBJECTIVE: The objective of this research was to study the expression of HER2/neu on the blasts of patients with acute leukemia from the Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran. METHODS: From June 2015 to February 2016, a HER2/neu monoclonal antibody was added to the panel of antibodies that we routinely use in patients with acute leukemia. An expression of ≥ 30% was considered positive. RESULTS: We studied 33 patients: 19 had de novo leukemia (57.6%), three (9.1%) were in relapse, and in 11 (33.3%) their status could not be specified. Seventeen patients (51.5%) were classified as B-cell acute lymphoblastic leukemia with a median expression of HER2/neu of 0.3% (range 0-90.2). Three patients with B-cell acute lymphoblastic leukemia were positive for HER2/neu: 89.4%, 90.9%, and 62.4%. The first and third patient had de novo B-cell acute lymphoblastic leukemia. The second patient was in second relapse after allogeneic stem cell transplant. All three patients were categorized as high-risk at the time of diagnosis. CONCLUSIONS: In the studied Mexican population, we found a positive expression of HER2/neu in 17% of the B-cell acute lymphoblastic leukemia patients, similar to previous studies in which the expression was found in 15-50%.

Diagnosing and treating mixed phenotype acute leukemia: a multicenter 10-year experience in México.

Mixed phenotype acute leukemia (MPAL) in adults represents nearly 2 to 5 % of all acute leukemia cases. There are two large studies throughout the world and only case reports and small series have been reported in Latin America. This study retrospectively analyses the clinical characteristics and survival of 27 patients with MPAL evaluated in three medical institutions of Mexico. All cases meet World Health Organization 2008 criteria; 70.3 % of patients had B lymphoid/myeloid lineage MPAL. Induction chemotherapy protocols included 7 + 3 hyper-CVAD, high-density schedules, and pediatric-like regimens such as New York II and total XI. Complete remission was achieved in 23/27 patients (85.2 %). Only one patient died due to chemotherapy-induced aplasia during remission induction (5.2 %). In 68 % of cases, we were able to administer maintenance therapy as a regimen in lymphoblastic leukemia. At the time of analysis, 70.4 % of the patients in the entire cohort had died mainly as result of disease progression (73.6 %). Disease-free survival was 13 months (95 % CI, 9.6-16.3 months) and overall survival was 14.8 months (95 % CI 13.4-16.27). Survival rates are low and standardized therapy for the management of this type of leukemia is still lacking. This is the largest series reported in Mexico and to the best of our knowledge in Latin America.

Small MAF genes variants and chronic myeloid leukemia.

Chronic myeloid leukemia (CML) is one of the most frequent hematological neoplasia worldwide. The abnormal accumulation of reactive oxygen species may be an important factor in CML development. The transcription factor NRF2 can regulate the transcription of a battery of antioxidant and detoxificant genes after heterodimerizing with small-Maf proteins. Although the participation of NRF2 in the development of chronic degenerative diseases has been thoroughly studied, the role of small-Maf genes has not been documented. We have identified polymorphisms in the three MAF genes (F, G and K) and assessed their association with CML. Over 266 subjects with CML and 399 unrelated healthy donors have been studied. After sequencing each MAF gene by Sanger technology, we found 17 variants in MAFF gene, eight in MAFG and seven in MAFK. In the case-control study, the homozygote genotype CC for the rs9610915 SNP of MAFF was significantly associated with CML. The frequency of the ACC haplotype from MAFK was significantly lower than controls. After stratification by gender, the ACC and GTG haplotypes were associated only with males with CML. These novel data suggest an association between MAFF and MAFG and the development of CML.

[National guidelines of diagnosis and treatment of the non-Hodgkin lymphoma]. / Guías nacionales de diagnóstico y tratamiento de linfoma no Hodgkin.

Non-Hodgkin lymphoma comprises a heterogeneous group of haematological malignancies, classified according to their clinic, anatomic-pathological features and, lately, to their molecular biomarkers. Despite the therapeutic advances, nearly half of the patients will die because of this disease. The new diagnostic tools have been the cornerstone to design recent therapy targets, which must be included in the current treatment guidelines of this sort of neoplasms by means of clinical trials and evidence-based medicine. In the face of poor diagnoses devices in most of the Mexican hospitals, we recommend the present diagnose stratification, and treatment guidelines for non-Hodgkin lymphoma, based on evidence. They include the latest and most innovative therapeutic approaches, as well as specific recommendations for hospitals with limited framework and therapy resources.

[Current therapeutic advances in the treatment of non-Hodgkin lymphoma]. / Actualidades terapéuticas en el tratamiento de linfoma no Hodgkin.

Lymphoma is a lymphoid cell cancer that originates in lymphoid tissues. Non Hodgkin (NHL) type represents 90% of cases. In Mexico, NHL constitutes the third most common cancer in males and the sixth among females. NHL treatment has achieved significant advances in the last decade and NHL is currently becoming a disease with a high probability of cure. Rituximab has become an alternative for the treatment of NHL. Rituximab is a monoclonal antibody that targets the CD20 antigen expressed in the mature malignant B cells. It induces NHL B cells destruction by complement-mediated citotoxicity, apoptosis and sensitization to the toxic effect of chemotherapy. Rituximab has revolutionized treatment results by offering patients with aggressive NHL a higher possibility of cure and in the case of the intractable forms of NHL it increases the disease free period. The standard treatment for a patient with NHL is rituximab-CHOP (immunotherapy). In addition, rituximab has pharmacoeconomic advantages as shown in various cost-utility and cost-effectiveness studies.

[Molecular basis of cancer]. / Bases moleculares del cáncer.

Cancer is a group of diseases characterized by an autonomous proliferation of neoplastic cells which have a number of alterations, including mutations and genetic instability. Cellular functions are controlled by proteins, and because these proteins are encoded by DNA organized into genes, molecular studies have shown that cancer is a paradigm of acquired genetic disease. The process of protein production involves a cascade of several different steps, each with its attendant enzymes, which are also encoded by DNA and regulated by other proteins. Most steps in the process can be affected, eventually leading to an alteration in the amount or structure of proteins, which in turn affects cellular function. However, whereas cellular function may be altered by disturbance of one gene, malignant transformation is thought to require two or more abnormalities occurring in the same cell. Although there are mechanisms responsible for DNA maintenance and repair, the basic structure of DNA and the order of the nucleotide bases can be mutated. These mutations can be inherited or can occur sporadically, and can be present in all cells or only in the tumor cells. At the nucleotide level, these mutations can be substitutions, additions or deletions. Several of the oncogenes discussed below, including the p53, c-fms, and Ras genes, can be activated by point mutations that lead to aminoacid substitution in critical portions of the protein. This article examines the current concepts relating to cellular mechanism that underlie the molecular alterations that characterize the development of cancer.

[Thalidomide-associated bradycardia in patients with hematologic diseases: a single institution experience]. / Bradicardia asociada al uso de talidomida en pacientes con enfermedades hematológicas: experiencia en una sola institución.

Thalidomide, an immunomodulatory and antiangiogenic agent, is useful in the treatment of some hematologic and oncologic diseases. Up to 6.8% of thalidomide-treated patients present bradycardia. Herein the incidence of thalidomide-associated bradycardia in patients with hematologic diseases treated in a single institution is reported. In a 34-month period, 33 patients with different hematologic diseases (multiple myeloma [MM], 20; myelodysplastic syndrome, eight; Waldenström macroglobulinemia, two; non-Hodgkin's lymphoma, two; malignant histiocytosis, one) were treated with thalidomide. Of them, five (15.1%) had bradycardia, all with MM. Bradycardia was detected with a daily thalidomide dose ranging from 100 to 300 mg and the time patients received thalidomide before cardiac event went from one to 18 months. In all affected cases the electrocardiogram showed sinus bradycardia with cardiac frequency between 32 to 48 beats per minute. Time to normal cardiac beat recovery ranged from 12 to 21 days after thalidomide discontinuation. There were no fatalities due to thalidomide-associated bradycardia. It is concluded that: a) thalidomide-associated bradycardia was detected only in patients with MM, b) herein the incidence of bradycardia was higher as compared with other series, and c) in patients with MM thalidomide therapy must be prescribed with caution particularly in those with cardiovascular diseases of any etiology.

Mixed-phenotype acute leukemia: suboptimal treatment when the 2008/2016 WHO classification is used.

BACKGROUND: Different criteria have been used to diagnose mixed-phenotype acute leukemia (MPAL), which has impacted the number of individuals diagnosed with this pathology. Better outcomes have been reported when using acute lymphoblastic leukemia (ALL)-type chemotherapy in the treatment of MPAL. METHODS: We compared the outcome of 4 groups of patients with MPAL. Group 1 included patients diagnosed using the 2008/2016 World Health Organization (WHO) classification; group 2 included patients diagnosed using the European Group for the Immunological Characterization of Leukemias (EGIL) criteria; group 3 included patients diagnosed using either the EGIL or the 2008/2016 WHO criteria; and group 4 was comprised of patients diagnosed with MPAL using the EGIL classification only. RESULTS: We found a significantly worse disease-free survival (groups 1-4) and overall survival (OS) (groups 2 and 3) when comparing MPAL patients to other acute leukemia (AL) patients. A significantly better OS was obtained in patients (groups 2-4) treated with ALL-type chemotherapy compared to acute myeloid leukemia (AML)-type regimens. CONCLUSION: In light of these results, and because a trend (P=0.06) was found with regard to a better OS in group 4 when compared to other AL patients, an argument can be made that the 2008/2016 WHO classification is underpowered to diagnose all MPAL cases, potentially resulting in the suboptimal treatment of some individuals with AL.

I. The role of research ethics committees in observational studies: epidemiological registries, case reports, interviews, and retrospective studies

Abstract It is often unclear to the clinical investigator whether observational studies should be submitted to a research ethics committee (REC), mostly because, in general, no active or additional interventions are performed. Moreover, obtaining an informed consent under these circumstances may be challenging, either because these are very large epidemiological registries, or the subject may no longer be alive, is too ill to consent, or is impossible to contact after being discharged. Although observational studies do not involve interventions, they entail ethical concerns, including threats such as breaches in confidentiality and autonomy, and respect for basic rights of the research subjects according to the good clinical practices. In this context, in addition to their main function as evaluators from an ethical, methodological, and regulatory point of view, the RECs serve as mediators between the research subjects, looking after their basic rights, and the investigator or institution, safeguarding them from both legal and unethical perils that the investigation could engage, by ensuring that all procedures are performed following the international standards of care for research. The aim of this manuscript is to provide information on each type of study and its risks, along with actions to prevent such risks, and the function of RECs in each type of study.

Actualidades terapéuticas en el tratamiento de linfoma no Hodgkin / Current therapeutic advances in the treatment of non-Hodgkin lymphoma

El linfoma es un cáncer de las células linfoides originado en los tejidos linfoides. El tipo no Hodgkin (LNH) representa 90% de los casos. En México, el linfoma no Hodgkin constituye el tercer cáncer más común en el sexo masculino y el sexto en el femenino. El tratamiento del linfoma ha tenido un avance muy significativo en la última década, pasando a ser una neoplasia con alta probabilidad de curación. Actualmente se dispone de rituximab, un anticuerpo monoclonal dirigido contra el antígeno CD20 expresado en las células malignas B maduras, que induce la destrucción de las células del linfoma no Hodgkin tipo B a través de citotoxicidad mediada por complemento, apoptosis y sensibilización al efecto tóxico de la quimioterapia. Rituximab ha revolucionado los resultados del tratamiento al poder ofrecer a los pacientes con linfomas agresivos una mayor posibilidad de curación, y en los linfomas indolentes aumenta el periodo sin enfermedad. El tratamiento estándar actual en pacientes con linfoma no Hodgkin agresivo es rituximab-CHOP (inmunoquimioterapia). La adición de rituximab al tratamiento del linfoma no Hodgkin tiene ventajas fármaco-económicas, demostradas en estudios de costo-utilidad y costo-efectividad.

Lymphoma is a lymphoid cell cancer that originates in lymphoid tissues. Non Hodgkin (NHL) type represents 90% of cases. In Mexico, NHL constitutes the third most common cancer in males and the sixth among females. NHL treatment has achieved significant advances in the last decade and NHL is currently becoming a disease with a high probability of cure. Rituximab has become an alternative for the treatment of NHL. Rituximab is a monoclonal antibody that targets the CD20 antigen expressed in the mature malignant B cells. It induces NHL B cells destruction by complement-mediated citotoxicity, apoptosis and sensitization to the toxic effect of chemotherapy. Rituximab has revolutionized treatment results by offering patients with aggressive NHL a higher possibility of cure and in the case of the intractable forms of NHL it increases the disease free period. The standard treatment for a patient with NHL is rituximab-CHOP (immunotherapy). In addition, rituximab has pharmacoeconomic advantages as shown in various cost-utility and cost-effectiveness studies.

Bradicardia asociada al uso de talidomida en pacientes con enfermedades hematológicas: experiencia en una sola institución / Thalidomide-associated bradycardia in patients with hematologic diseases: A single institution experience

Thalidomide, an immunomodulatory and antiangio genie agent, is useful in the treatment of some hematologic and oncologic diseases. Up to 6.8% of thalidomide-treated patients present bradycardia. Herein the incidence of thalidomide-associated bradycardia in patients with hematologic diseases treated in a single institution is reported. In a 34-month period, 33 patients with different hematologic diseases (multiple myeloma [MM], 20; myelodysplastic syndrome, eight; Waldenstróm macroglobulinemia, two; non-Hodgkin's lymphoma, two; malignant histiocytosis, one) were treated with thalidomide. Of them, five (15.1%) had bradycardia, all with MM. Bradycardia was detected with a daily thalidomide dose ranging from 100 to 300 mg and the time patients received thalidomide before cardiac event went from one to 18 months. In all affected cases the electrocardiogram showed sinus bradycardia with cardiac frequency between 32 to 48 beats per minute. Time to normal cardiac beat recovery ranged from 12 to 21 days after thalidomide discontinuation. There were no fatalities due to thalidomide-associated bradycardia. It is concluded that: a) thalidomide-associated bradycardia was detected only in patients with MM, b) herein the incidence of bradycardia was higher as compared with other series, and c) in patients with MM thalidomide therapy must be prescribed with caution particularly in those with cardiovascular diseases of any etiology.

La talidomida, agente inmunomodulador y antiangiogénico, es útil en el tratamiento de enfermedades hematologicas y oncológicas. Los efectos adversos asociados al uso de talidomida son múltiples e incluyen bradicardia sinusal que se presenta hasta en 6.8% de los casos. En el presente estudio se informa la frecuencia de bradicardia asociada al uso de talidomida en pacientes con enfermedades hematologicas atendidos en una sola institución. En un lapso de 34 meses se encontró que 33 pacientes con diversos padecimientos hematológicos (mieloma múltiple [MM], 20; síndrome mielodisplásico, ocho; macroglobulinemia de Waldenstróm, dos; linfoma no Hodgkin, dos; histiocitosis maligna, uno) recibieron tratamiento con talidomida. De ellos, cinco (15.1%) presentaron bradicardia, todos con MM. La dosis de talidomida al momento de la bradicardia fue de entre 100 a 300 mg por día y el tiempo que recibieron el fármaco antes del evento osciló entre uno y 18 meses. El electrocardiograma mostró bradicardia sinusal en todos los casos con frecuencia cardiaca (FC) de entre 32 a 48 latidos por minuto. Suspendida la talidomida la FC se normalizó en todos los enfermos en un tiempo que osciló entre 12 a 21 días. Ninguno de los pacientes falleció por esta complicación. Se concluye que: a) la bradicardia asociada a talidomida se identificó sólo en pacientes con MM, b) la frecuencia de bradicardia en nuestra serie fue superior a la informada en otras y c) en MM el tratamiento con talidomida debe prescribirse con precaución en aquellos pacientes con algún padecimiento cardiovascular de cualquier etiología.