Epidemiology of childhood acute leukemias in marginalized populations of the central-south region of Mexico: results from a population-based registry.

Introduction: Acute leukemias (AL) are the main types of cancer in children worldwide. In Mexico, they represent one of the main causes of death in children under 20 years of age. Most of the studies on the incidence of AL in Mexico have been developed in the urban context of Greater Mexico City and no previous studies have been conducted in the central-south of the country through a population-based study. The aim of the present work was to identify the general and specific incidence rates of pediatric AL in three states of the south-central region of Mexico considered as some of the marginalized populations of Mexico (Puebla, Tlaxcala, and Oaxaca). Methods: A population-based study was conducted. Children aged less than 20 years, resident in these states, and newly diagnosed with AL in public/private hospitals during the period 2021-2022 were identified. Crude incidence rates (cIR), standardized incidence rates (ASIRw), and incidence rates by state subregions (ASIRsr) were calculated. Rates were calculated using the direct and indirect method and reported per million children under 20 years of age. In addition, specific rates were calculated by age group, sex, leukemia subtype, and immunophenotype. Results: A total of 388 cases with AL were registered. In the three states, the ASIRw for AL was 51.5 cases per million (0-14 years); in Puebla, it was 53.2, Tlaxcala 54.7, and Oaxaca de 47.7. In the age group between 0-19 years, the ASIRw were 44.3, 46.4, 48.2, and 49.6, in Puebla, Tlaxcala, and Oaxaca, respectively. B-cell acute lymphoblastic leukemia was the most common subtype across the three states. Conclusion: The incidence of childhood AL in the central-south region of Mexico is within the range of rates reported in other populations of Latin American origin. Two incidence peaks were identified for lymphoblastic and myeloid leukemias. In addition, differences in the incidence of the disease were observed among state subregions which could be attributed to social factors linked to the ethnic origin of the inhabitants. Nonetheless, this hypothesis requires further investigation.

Persistently high incidence rates of childhood acute leukemias from 2010 to 2017 in Mexico City: A population study from the MIGICCL.

Introduction: Over the years, the Hispanic population living in the United States has consistently shown high incidence rates of childhood acute leukemias (AL). Similarly, high AL incidence was previously observed in Mexico City (MC). Here, we estimated the AL incidence rates among children under 15 years of age in MC during the period 2010-2017. Methods: The Mexican Interinstitutional Group for the Identification of the Causes of Childhood Leukemia conducted a study gathering clinical and epidemiological information regarding children newly diagnosed with AL at public health institutions of MC. Crude age incidence rates (cAIR) were obtained. Age-standardized incidence rates worldwide (ASIRw) and by municipalities (ASIRm) were calculated by the direct and indirect methods, respectively. These were reported per million population <15 years of age; stratified by age group, sex, AL subtypes, immunophenotype and gene rearrangements. Results: A total of 903 AL cases were registered. The ASIRw was 63.3 (cases per million) for AL, 53.1 for acute lymphoblastic leukemia (ALL), and 9.4 for acute myeloblastic leukemia. The highest cAIR for AL was observed in the age group between 1 and 4 years (male: 102.34 and female: 82.73). By immunophenotype, the ASIRw was 47.3 for B-cell and 3.7 for T-cell. The incidence did not show any significant trends during the study period. The ASIRm for ALL were 68.6, 66.6 and 62.8 at Iztacalco, Venustiano Carranza and Benito Juárez, respectively, whereas, other municipalities exhibited null values mainly for AML. Conclusion: The ASIRw for childhood AL in MC is among the highest reported worldwide. We observed spatial heterogeneity of rates by municipalities. The elevated AL incidence observed in Mexican children may be explained by a combination of genetic background and exposure to environmental risk factors.

Cancer incidence and mortality in children in the Mexican Social Security Institute (1996-2013).

OBJECTIVE: To identify the cancer incidence and mortality in Mexican Social Security Institute beneficiary (MSSI-B) children during 1996-2013. MATERIALS AND METHODS: Both cancer cases (n=4 728) and deaths (n=2 378) were analyzed in MSSI-B children who were registered in five states of the Mexican Republic. The incidence and mortality trends and the incidences (rate x 1 000 000 children / year) of the type of cancer, age, sex, and place of residence were obtained. RESULTS: For both indicators (incidence and mortality), there was a downward trend for the period of 1996-2001 and a stable trend for 2002-2013. This occurred in the overall mortality and incidence trends of the Estado de México and Chiapas and in the leukemia and the acute lymphoid subgroups. The annual overall incidence was 128 cases per 1 000 000 children. Leukemia, lymphomas, and central nervous system tumors were the principal cancer groups. CONCLUSIONS: Cancer mortality for the period of 2002-2013 did not diminish. Interinstitutional and/or international research should be designed to improve the care of these children.

Cancer incidence and mortality in children in the Mexican Social Security Institute (1996-2013) / Incidencia y mortalidad por cáncer en niños atendidos en el Instituto Mexicano del Seguro Social (1996-2013)

Abstract Objective: To identify the cancer incidence and mortality in Mexican Social Security Institute beneficiary (MSSI-B) children during 1996-2013. Materials and methods: Both cancer cases (n=4 728) and deaths (n=2 378) were analyzed in MSSI-B children who were registered in five states of the Mexican Republic. The incidence and mortality trends and the incidences (rate x 1 000 000 children / year) of the type of cancer, age, sex, and place of residence were obtained. Results: For both indicators (incidence and mortality), there was a downward trend for the period of 1996-2001 and a stable trend for 2002-2013. This occurred in the overall mortality and incidence trends of the Estado de México and Chiapas and in the leukemia and the acute lymphoid subgroups. The annual overall incidence was 128 cases per 1 000 000 children. Leukemia, lymphomas, and central nervous system tumors were the principal cancer groups. Conclusions: Cancer mortality for the period of 2002-2013 did not diminish. Interinstitutional and/or international research should be designed to improve the care of these children.

Resumen Objetivo: Mostrar la incidencia y mortalidad por cáncer en niños derechohabientes del Instituto Mexicano del Seguro Social (DH-IMSS) (periodo 1996-2013). Material y métodos: Se analizaron los casos (n=4 728) y las muertes (n=2 378) por cáncer en niños DH-IMSS registrados en cinco estados de la República mexicana. Se obtuvo la tendencia de la incidencia y mortalidad y la incidencia por tipo de cáncer, edad, sexo y lugar de residencia. Resultados: Para ambos indicadores (incidencia y mortalidad) hubo tendencia a la disminución para el periodo 1996-2001 y estabilidad para 2002-2013; esto sucedió para la tendencia global, para el Estado de México y Chiapas, para las leucemias y para el subgrupo de las linfoide agudas. La incidencia global fue de 128 x 1 000 000 niños/año; las leucemias, tumores del sistema nervioso central y linfomas fueron los principales grupos de cáncer. Conclusiones: La mortalidad por cáncer para el periodo 2002-2013 no ha disminuido; deben diseñarse investigaciones interinstitucionales e internacionales para mejorar la atención médica de estos niños.

[History of the cancer registry in Mexico]. / Historia del registro de cáncer en México.

A cancer registry is to record the data which let us to know the epidemiology of neoplasm, but led us take a decision in medical policy about this health problem that benefit patients. In this paper we did a brief historical review about models and attempts for having a cancer registry in Mexico. However, since 1940 "the fight against cancer" was declared, we have not had a confident cancer registry today validated and built with data from whole the country. In 1982, the Registro Nacional del Cancer was created. The design and validation of a registration card in four hospitals were the main results. In 1988, the Registro Nacional del Cancer was reinforced with a computerized system for facilitation the data capture. In 1994, it was signed the first interinstitutional agreement that led to Registro Histopatol6gico de Neoplasias Malignas. In 1996, the Instituto Mexicano del Seguro Social established a cancer registry in children in Mexico with the intention to have data from this population.