Non-Hodgkin Lymphoma Epidemiology in Children From 2 Socioeconomic Regions in Mexico: 20-Year Registry (1996-2015).

PURPOSE: We analyzed the epidemiologic characteristics of different types of non-Hodgkin Lymphoma (NHL), excluding Burkitt Lymphoma, in 2 Mexican regions with different socioeconomic status. MATERIALS AND METHODS: In this surveillance study, we analyzed the incidence rates (cases per million children/year) of different types of NHL according to the ICCC3, registered in 1996-2015, from 2 different socioeconomic regions in Mexico: central and southern, with higher and lower status, respectively. RESULTS: The principal NHL subgroups were precursor (IIb1), mature B cell (IIb2), mature T/NK cell, and no other specification (NOS; 42.3%, 15.8%, 14.1%, and 27.8%, respectively). In both regions, the overall incidence rates were similar (central=5.3, 95% confidence interval [CI], 4.6-6.1 vs. southern=6.3, 95% CI, 4.6-8.4); also, there were no differences by types (precursor cell LNH, 2.3 vs. 2.5; mature B cell, 0.9 vs. 0.8; mature T/NK cells, 0.8 vs. 0.8; and NOS, 1.4 vs. 2.3). In both regions, a decreasing trend was found (central= -0.17%, 95% CI, -0.03 to -0.3, P=0.04; southern= -0.32%, 95% CI, -0.07 to -0.57, P=0.02), with major reduction of NHL NOS from 1996 to 2000. In both regions, men predominated (2.1:1). CONCLUSIONS: Socioeconomic status did not influence the incidence rates of NHL. In this study, we found a reduction of NHL NOS, possibly due to better typing.

Overweight and obesity as predictors of early mortality in Mexican children with acute lymphoblastic leukemia: a multicenter cohort study.

BACKGROUND: Mexico City has one of the highest incidences and mortality rates of acute lymphoblastic leukemia (ALL) in the world and a high frequency of early relapses (17%) and early mortality (15%). Otherwise, childhood overweight and obesity are reaching epidemic proportions. They have been associated with poor outcomes in children with ALL. The aim of present study was to identify if overweight and obesity are predictors of early mortality and relapse in Mexican children with ALL. METHODS: A multicenter cohort study was conducted. ALL children younger than 15 years old were included and followed-up during the first 24 months after diagnosis. Overweight and obesity were classified according World Health Organization (WHO) and Centers for Disease Control and Prevention (CDC) criteria. Early mortality and early relapses were the main outcomes. RESULTS: A total of 1070 children were analyzed. Overweight/obesity at diagnosis were predictors of early mortality (WHO: HR = 1.4, 95%CI:1.0-2.0; CDC: HR = 1.6, 95%CI:1.1-2.3). However, no associations between overweight (WHO: HR = 1.5, 95%CI:0.9-2.5; CDC: HR = 1.0; 95% CI:0.6-1.6) and obesity (WHO: HR = 1.5, 95%CI:0.7-3.2; CDC: HR = 1.4; 95%CI:0.9-2.3) with early relapse were observed. CONCLUSIONS: Overweight and obese patients embody a subgroup with high risk of dying during leukemia treatment.

Socioeconomic inequalities in survival of children with acute lymphoblastic leukemia insured by social security in Mexico: a study of the 2007-2009 cohorts.

BACKGROUND: Although acute lymphoblastic leukemia (ALL) 5 years survival in minors has reached 90%, socioeconomic differences have been reported among and within countries. Within countries, the difference has been related to the socioeconomic status of the parents, even in the context of public health services with universal coverage. In Mexico, differences in the mortality of children with cancer have been reported among sociodemographic zones. The Instituto Mexicano del Seguro Social (IMSS), the country's main social security institution, has reported socioeconomic differences in life expectancy within its affiliated population. Here, the socioeconomic inequalities in the survival of children (< 15 years old) enrolled in the IMSS were analyzed. METHODS: Five-year survival data were analyzed in cohorts of patients diagnosed with ALL during the period 2007-2009 in the two IMSS networks of medical services that serve 7 states of the central region of Mexico. A Cox proportional risk model was developed and adjusted for the socioeconomic characteristics of family, community of residence and for the clinical characteristics of the children. The slope of socioeconomic inequality of the probability of dying within five years after the diagnosis of ALL was estimated. RESULTS: For the 294 patients studied, the 5 years survival rate was 53.7%; the median survival was 4.06 years (4.9 years for standard-risk diagnosis; 2.5 years for high-risk diagnosis). The attrition rate was 12%. The Cox model showed that children who had been IMSS-insured for less than half their lives had more than double the risk of dying than those who had been insured for their entire lives. CONCLUSIONS: We did not find evidence of socioeconomic inequalities in the survival of children with ALL associated with family income, educational and occupational level of parents. However, we found a relevant gradient related social security protection: the longer children's life insured by social security, the higher their probability of surviving ALL was. These results add evidence of the effectiveness of social security, as a mechanism of wealth redistribution and a promoter of social mobility. Extending these social security benefits to the entire Mexican population could promote better health outcomes.

Correction to: socioeconomic inequalities in survival of children with acute lymphoblastic leukemia insured by social security in Mexico: a study of the 2007-2009 cohorts.

Following publication of the original article [1], the author reported her name has been erroneously spelled as Blanca E. Pelcastre. The full name is Blanca E. Pelcastre-Villafuerte.

Identification and Characterization of Novel Fusion Genes with Potential Clinical Applications in Mexican Children with Acute Lymphoblastic Leukemia.

Acute lymphoblastic leukemia is the most common type of childhood cancer worldwide. Mexico City has one of the highest incidences and mortality rates of this cancer. It has previously been recognized that chromosomal translocations are important in cancer etiology. Specific fusion genes have been considered as important treatment targets in childhood acute lymphoblastic leukemia (ALL). The present research aimed at the identification and characterization of novel fusion genes with potential clinical implications in Mexican children with acute lymphoblastic leukemia. The RNA-sequencing approach was used. Four fusion genes not previously reported were identified: CREBBP-SRGAP2B, DNAH14-IKZF1, ETV6-SNUPN, ETV6-NUFIP1. Although a fusion gene is not sufficient to cause leukemia, it could be involved in the pathogenesis of the disease. Notably, these new translocations were found in genes encoding for hematopoietic transcription factors which are known to play an important role in leukemogenesis and disease prognosis such as IKZF1, CREBBP, and ETV6. In addition, they may have an impact on the prognosis of Mexican pediatric patients with ALL, with the potential to be included in the current risk stratification schemes or used as therapeutic targets.

Importancia del "diagnóstico temprano" en los niños con cáncer para mejorar el pronóstico: concepto con poco sustento científico.

La mortalidad por cáncer en niños mexicanos no ha disminuido a los niveles informados en países desarrollados. Una explicación frecuentemente declarada es el alto porcentaje (57.3 %) de pacientes diagnosticados en estadios avanzados (III/IV), atribuible a errores en la sospecha o en la metodología empleada, consideración dudosa si se toma en cuenta que el tiempo de diagnóstico y la proporción de estadios avanzados en México son semejantes a los de países desarrollados. En la mayoría de los niños con cáncer, los días transcurridos desde el primer síntoma a momento del diagnóstico oncológico no correlacionan con el estadio clínico y tampoco con la probabilidad de supervivencia. El éxito en la supervivencia depende en gran medida del tratamiento integral (específico y de la atención a las complicaciones). Esta visión obliga a estrategias dirigidas principalmente a invertir más recursos en opciones terapéuticas eficaces y eficientes, capacitación oncológica integral del equipo de salud (médicos, enfermeras, técnicos), tecnologías diagnósticas, fomento a la colaboración interinstitucional e internacional y apoyo socioeconómico a las familias durante el proceso terapéutico.Cancer mortality in Mexican children has not decreased to the levels reported in developed countries. A commonly proposed explanation is the high percentage (53.7%) of patients diagnosed at advanced stages (III/IV), which is attributed to erroneous assumptions or mistakes in the diagnostic approach ­a questionable consideration taking into account that both time to diagnosis and the proportion of advanced stage cases in Mexico are similar to those in developed countries. In most cancer cases in children, the number of days elapsed from the moment of the first symptom to the cancer diagnosis is not correlated with clinical stage, and neither with the probability of survival. Survival success largely depends on comprehensive treatment (specific and for the care of complications). This view calls for strategies mainly aimed at spending more resources on efficacious and efficient therapeutic strategies, comprehensive oncology training of healthcare personnel (physicians, nurses and technicians), diagnostic technologies, promotion of interinstitutional and international collaboration and socioeconomic support to families during the therapeutic process.

Clinical and Epidemiological Characteristics of Burkitt Lymphomas in Pediatric Patients from Two Defined Socioeconomic Regions in Mexico.

We analyzed clinical and epidemiological characteristics of Burkitt lymphoma (BL) in two defined socioeconomic regions in Mexico: high socioeconomic region (HSER; with two political jurisdictions) and low socioeconomic region (LSER; with three jurisdictions). Of the 63 cases registered in the Childhood Cancer Registry (1996-2013), 45 (71.4%) were from HSER and 18 (28.6%) from LSER. The incidence was higher in the LSER (3.1 vs. 1.4 cases per million children/year). The sporadic form and Stages III/IV predominated in both regions. Only one post-renal transplant (HSER) was found. The male/female ratio was higher in the LSER (5.0 vs. 1.4). The peak incidence was in the 1-4 age group for LSER, and in the 5-9 age group for HSER. This difference in the sporadic BL by socioeconomic regions may be related to different exposure factors.

Incidence of Childhood Hodgkin Lymphoma in Mexico by Histologic Subtypes and Socioeconomic Regions.

BACKGROUND: Incidence rates of the histologic subtypes of Hodgkin lymphoma (HL) differed with socioeconomic conditions. MATERIALS AND METHODS: HL cases from the Register of Childhood Cancer (below 15 y of age) for 2 socioeconomic regions were analyzed. Central region has a high socioeconomic index; and the southern region a low index. The incidence rates (cases per million children/year) were estimated according to histologic subtypes, age groups, sex, clinical stages, time to diagnosis, and overall survival by regions. RESULTS: The overall incidence was greater in the south (6.8 vs. 4.6), principally due to higher incidence of mixed cellularity subtype (3.8 vs. 1.0). In the south, the highest incidence was found in the 5- to 9-year-old group (9.2), whereas in the central region it was found in the 10- to 14-year-old group (7.4). There was a delay of ∼3 weeks in the time to diagnosis (P=0.36) in the south, but no difference in the percentage of advanced stages, adjusted by histologic subtype (61%, III and IV). The overall survival was 71%, differences were identified only for mixed cellularity cases (center=89.2 vs. south=61.5%, P=0.03). CONCLUSIONS: Incidences of HL subtypes differed in relation to socioeconomic conditions in Mexico. In the south, the incidence of mixed cellularity was higher and there was an earlier peak of presentation.

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.

[Descriptive epidemiology of children with acute myeloid leukemia residing in Mexico City: a report from the Mexican Inter-Institutional Group for Identifying Childhood Leukemia Causes]. / Epidemiología descriptiva de la leucemia mieloide aguda (LMA) en niños residentes de la Ciudad de México: reporte del Grupo Mexicano Interinstitucional para la Identificación de las Causas de la Leucemia en Niños.

INTRODUCTION: Acute myeloid leukemias represent the second most common childhood leukemia subtype. In Mexico, there are few studies on descriptive epidemiology for this disease. AIMS: To report acute myeloid leukemia incidence for children less than 15 years of age in the Metropolitan Area of the Valley of Mexico for a period of five years (2010-2014) and to analyze whether there are differences in the incidence of acute myeloid leukemia by regions. MATERIAL AND METHODS: A descriptive study was conducted in nine public hospitals in Mexico City. The crude annual average incidence rate and adjusted average annual incidence rate were calculated. RESULTS: A total of 190 patients with diagnosis of de novo acute myeloid leukemia were analyzed. Male sex (57.2%) and acute myeloid leukemia-M3 subtype (25.3%) were more frequent. The adjusted average annual incidence rates for Mexico City and for the Metropolitan Area of the Valley of Mexico were 8.18 and 7.74 per million children under 15 years old, respectively. CONCLUSIONS: It seems that childhood acute myeloid leukemia incidence is increasing in Mexico City, which makes the identification of associated risk factors imperative.

Childhood lymphoma incidence patterns by ICCC-3 subtype in Mexico City metropolitan area population insured by Instituto Mexicano del Seguro Social, 1996-2010.

PURPOSE: We reviewed the childhood lymphomas epidemiological data for the Mexico City metropolitan area (MCMA). METHODS: Data analysis from children (0-14 years old) diagnosed with lymphoma during the period 1996-2010 was performed at the Mexican Childhood Cancer Registry. Histological subtype was determined according to the International Classification of Childhood Cancer 3 (ICCC-3). Age-adjusted incidence rates were calculated per 1,000,000 children/year by age, gender, and ICCC-3 subtype; trends, by average annual percent change (AAPC). RESULTS: A total of 328 lymphoma cases included in the study had an incidence rate of 11.8, showing a decreasing trend [AAPC: -3.5; CI 95% (-5.9, -1.0)], primarily due to non-Hodgkin lymphomas (NHL) and Hodgkin lymphoma (HL) mixed cellularity subtype. NHL had the major incidence (5.8), with the precursor cell subtype being the most frequent (38.3%). Nodular sclerosis was the most frequent HL subtype. The incidence of Burkitt lymphoma was low (1.3). During the study period, there was an important reduction in the not-otherwise-specified subtype of NHL, which translated into a relative increase in the IIb3 subtype [AAPC: 7.3 (1.2, 13.8)]. Low incidences of NHL and of HL and NHL were found for < 1-year-olds and for 10- to 14-year-olds, respectively. Incidence rates for children in the MCMA, particularly the < 1 and 10-14 age groups, were lower than those for developed countries. The overall male/female ratio was 2.3. CONCLUSIONS: There was a trend toward a reduced incidence, for some lymphoma subtypes, in particular for NOS lymphomas, which may be the result of improvement in diagnostic techniques.

Maternal diet in pregnancy and acute leukemia in infants: a case-control study in Mexico City.

Introduction: Epidemiological studies around the world on acute leukemia (AL) and risk factors in infants are scarce. Infant AL has been proposed to originate in utero, which facilitates its study by establishing a short exposure time in pregnant women to environmental and dietary factors that could contribute to the risk of or protection against leukemia. We hypothesized that maternal diet during pregnancy may be an important factor involved in AL in offspring. Methods: We conducted a hospital-based case-control study from 2010 to 2019 on maternal diet during pregnancy in nine high-specialty public hospitals of different health institutions that diagnose and offer treatment to children with AL in Mexico City. Cases (n=109) were children ≤24 months of age with de novo diagnosis of AL, and controls (n=252) were children obtained in hospitals from second-level medical care matched for age, sex, and health institution. Maternal diet during pregnancy was obtained by a semiquantitative food frequency questionnaire. Unconditional logistic regression models were used to assess the association between food groups and infant AL. Potential confounders were assessed by constructing directed acyclic graphs (DAGs) with Dagitty software in which adjusted options were identified for the construction of unconditional logistic regression models. Results: Cases were slightly predominantly female (52.3%). The years of education of the mother in cases and controls was 0-9 on average, and those who reported smoking cigarettes and consuming alcohol during pregnancy did so at a low frequency. Regarding the mother's diet, the main findings were that the consumption of allium vegetables during pregnancy was inversely associated with AL for medium and high consumption (OR=0.26, 95% CI 0.14-0.46; P-trend< 0.001). In contrast, the high consumption of high-fat dairy products had a positive association with AL (OR=2.37, 95% CI 1.30-4.34; P-trend<0.001). No association was found between consumption of topoisomerase II inhibitor foods during pregnancy and AL. Conclusion: The results suggest that maternal intake during pregnancy of allium vegetables, specifically garlic, is inversely associated with the development of AL in children ≤24 months old. On the other hand, consumption of high-fat dairy products is positively associated with AL in children ≤24 months old.

[Trends of cancer mortality rates in children and adolescents by level of marginalization in Mexico (1990-2009)]. / Tendencia de la mortalidad por cáncer en niños y adolescentes según grado de marginación en México (1990-2009).

OBJECTIVE: To determine childhood and adolescent cancer mortality by the level of marginalization in Mexico. MATERIALS AND METHODS: We used 1990-2009 death certificates estimating age-standardized rates. We calculated the Average Annual Percent Change (AAPC) using the Joinpoint Regression program available at the National Cancer Institute to assess tendency. RESULTS: Cancer mortality rates increased. AAPC were 0.87% male and 0.96% female children, and for adolescents were: males 1.22% and females 0.63%. The neoplasm pattern in infants was leukemia -central nervous system- lymphomas; and in adolescents it was leukemia -bone and articulation- lymphomas. The increase in cancer mortality corresponded to the high and highest marginated areas of each state. CONCLUSION: The increase in highly marginated areas may be partly explained by well-documented local registration of deaths. Further studies focusing on survival are required in order to better assess the effectiveness of cancer detection and medical treatment in our country.

Childhood acute leukemias are frequent in Mexico City: descriptive epidemiology.

BACKGROUND: Worldwide, acute leukemia is the most common type of childhood cancer. It is particularly common in the Hispanic populations residing in the United States, Costa Rica, and Mexico City. The objective of this study was to determine the incidence of acute leukemia in children who were diagnosed and treated in public hospitals in Mexico City. METHODS: Included in this study were those children, under 15 years of age and residents of Mexico City, who were diagnosed in 2006 and 2007 with leukemia, as determined by using the International Classification of Childhood Cancer. The average annual incidence rates (AAIR), and the standardized average annual incidence rates (SAAIR) per million children were calculated. We calculated crude, age- and sex-specific incidence rates and adjusted for age by the direct method with the world population as standard. We determined if there were a correlation between the incidence of acute leukemias in the various boroughs of Mexico City and either the number of agricultural hectares, the average number of persons per household, or the municipal human development index for Mexico (used as a reference of socio-economic level). RESULTS: Although a total of 610 new cases of leukemia were registered during 2006-2007, only 228 fit the criteria for inclusion in this study. The overall SAAIR was 57.6 per million children (95% CI, 46.9-68.3); acute lymphoblastic leukemia (ALL) was the most frequent type of leukemia, constituting 85.1% of the cases (SAAIR: 49.5 per million), followed by acute myeloblastic leukemia at 12.3% (SAAIR: 6.9 per million), and chronic myeloid leukemia at 1.7% (SAAIR: 0.9 per million). The 1-4 years age group had the highest SAAIR for ALL (77.7 per million). For cases of ALL, 73.2% had precursor B-cell immunophenotype (SAAIR: 35.8 per million) and 12.4% had T-cell immunophenotype (SAAIR 6.3 per million). The peak ages for ALL were 2-6 years and 8-10 years. More than half the children (58.8%) were classified as high risk. There was a positive correlation between the average number of persons per household and the incidence of the pre-B immunophenotype (Pearson's r, 0.789; P = 0.02). CONCLUSIONS: The frequency of ALL in Mexico City is among the highest in the world, similar to those found for Hispanics in the United States and in Costa Rica.

[Cancer registry in children, why and how was there carried out the registry?]. / Por qué y cómo se llevó a cabo el registro de cáncer en niños.

Because there is no national program for the registration of cancer in Mexico, the epidemiology of cancer in the population throughout the country is unknown. Thus, the aim was to measure the incidence and the trends that cancer in children at the Instituto Mexicano del Seguro Social (IMSS). A cancer registry (CR) was established in the hospitals located in Mexico City, which are maintained by IMSS. These hospitals provide medical care also to those children who live in the states of Mexico, Morelos, Guerrero, and Chiapas. This population-based registry was started in 1996 and is on-going. Medical personnel (cancer registrars) were specifically trained to collect these data. The data collected during the period 1996-2007 was analyzed. The objective of this registry was to ensure that the collected data completed the quality criteria (completeness, validity, timeliness) in order to estimate the incidence and trends of cancer in the children residing in the five aforementioned jurisdictions of Mexico. Such epidemiological data may lead to a better understanding not only for planning medical treatment, but also to a possible prevention measures of the disease.

[Evaluation of quality in a cancer registry]. / Evaluación de la calidad del registro de cáncer.

The results of the cancer data registered during 1996-2007 demonstrates how fundamental is the work the registrar in the integrity of a Registry of Childhood Cancer. The work consisted: collecting the complete information available (the number of cases and information of the variables), encoding the information according to international standards, and classifying the data by capturing, analyzing, and producing the respective reports. The objective of having quality data (complete, valid and timely) is to estimate the incidence and trends of cancer in the population. The professional for the registration does not exist in the current Mexican work force. Given that a national program of cancer registries is of vital importance for improved planning medical care, allotment of medical resources, in cancer research. It will be necessary to create such a profession by establishing national standards and training programs.

[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.

[The cancer registry is fundamental for the treatment, prevention and control of childhood cancer]. / El registro del cáncer en niños, fundamental para prevenir, atender y controlar la enfermedad.

During the last 10 years cancer in the Mexican pediatric population is growing. It is the second leading cause of death (children 1 to 14 years of age). The first step in controlling these diseases by registering the cases. Cancer Registry (CR) is fundamental for gaining knowledge that can be used for planning medical treatment and future research into causal factors and for the prevention. A CR is an information system designed to collect and encode data concerning individuals with cancer, and then to disseminate the compiled epidemiological results to various groups of stakeholders. Data are obtained from a hospital or group of hospitals, with special emphasis being placed on the quality of the data (completeness, validity and timeliness data). It is necessary a group of highly trained individuals called registrars, who are experts in the collection, encoding, and dissemination of internal reports to researchers and medical personnel. There are two main types of registries: those that are hospital based and those that are population based. The categories of data that should be collected are demographic data of the patient; descriptors of the cancer; details of the treatment administered; and details of the outcome of the treatment. It must be emphasized that all data conceming patients with cancer should be held in the strictest confidence.

[The quality of cancer registry. From a methodology approach]. / Calidad del registro de cáncer. Aspectos metodológicos.

Since 1996 at the unit of epidemiological research of the "Hospital de Pediatría en Centro Medico Nacional Siglo XXI" a cancer registry in children has been done. This registry has been a pioneer with special features like be only in child population attended in Mexico City. The following paper describes the main characteristics of the registry, the strategy used to obtain the data, the quality criterion applied for selecting data like timeliness, validated and complete. A longitudinal and prolective data was obtained. There was a training period for obtaining and register the data. The data was obtained from children with neoplasm attended at the mentioned hospital above. The diagnosis of a solid neoplasm was established by histology and marrow aspirated studies. The population studied was children (0-14 years). It was calculated the incidence (per 1000 000 children/year) by age, sex, diagnosis and place of residence. The trend was evaluated by estimating the average annual percent of change.

[Cancer in children from Mexico City]. / Cáncer en niños residentes del Distrito Federal.

In the Federal District (FD) of Mexico, a total of 1175 new cases of childhood cancer were registered between 1996 and 2007. These cases demonstrated the North American/European pattern for neoplasias, with the order of incidence being leukemias (44.1%), tumors of the central nervous system (13.5%), and lymphomas (12.0%). The overall incidence was 131.6 (all rates per 1000 000 children/year). The male/female ratio was 1.2 and the incidence was greater for those less than five years of age. The southwestern and southeastern zones of the FD had the highest incidences (170.0 and 145.2, respectively). The FD was unique among the jurisdictions under study in that non-Hodgkin lymphomas were recorded for children under one year of age (incidence: 4.1). Of the five jurisdictions studied, the highest frequency (2.5%) and incidence (3.7) of liver tumors in children were found in the FD. The incidence showed a tendency to decrease over the years. The solid tumors (55.4 %) were diagnosed in Ill or IV stage.