[Cancer in children from State of Mexico]. / Cáncer en niños residentes del Estado de Mexico.

The greatest number (n = 1462) of new cases of childhood cancer was registered in the state of Mexico. Approximately 70 % were leukemias (50.8%), lymphomas (9.6%), and central nervous system tumors (CNST, 9.5%). The overall incidence was 111.2 (all rates per 1000 000 children/year), with the lowest incidences being those for lymphomas and CNST (9.9 and 10.3, respectively). The incidence of germ cell tumors was the highest (9.1) of the five jurisdictions studied. The male/female ratio was 1.1 and the greatest incidence was found for children less than five years of age. The incidence showed a trends to decrease, with the greatest reduction in the period 1996-2001 (average annual percent change: -7.4; CI 95% = -13.8, -0.4). Of the children with solid tumors, 56.4% were diagnosed as being in either stage III or IV.

[Incidence and trends of neuroblastoma in Mexican children attending at Instituto Mexicano del Seguro Social]. / Incidencia y tendencia del neuroblastoma en niños derechohabientes del IMSS.

BACKGROUND: Neuroblastoma (NB) is the principal tumor of the sympathetic nervous system in children. OBJECTIVE: to describe the epidemiological and clinical characteristics of Mexican children with NB. METHODS: A population-based, prolective study, with data obtained from the Childhood Cancer Registry of the Instituto Mexicano del Seguro Social. The frequencies and incidence of the variables of the study were obtained by age and sex. The trend was calculated with the annual percentage of change. RESULTS: Of a total of 2758 children with cancer, 72 (2.6%) were identified in the Group IV, according to the International Classification of Childhood Cancer. The average incidence for NB was 3.8, the highest incidence was found in Guerrero. NB was highest in the group under one year of age (18.5). The male/female ratio was 1.1 and there was no trend toward an increase. Stages III and IV were presented in 88% of the cases. There was no association between the stages, the age at the TD, or the histological pattern. CONCLUSIONS: It is possible that the low incidence of NB in Mexican children is due to the difficulty in early diagnosis due the majority of the cases was diagnosed in the advanced stages.

Epidemiological and some clinical characteristics of neuroblastoma in Mexican children (1996-2005).

BACKGROUND: Neuroblastoma (NB) is the principal tumor of the sympathetic nervous system in children under one year of age. The incidence in developed countries is greater than that in developing countries. The aim of this article is to present the epidemiological and some clinical characteristics of Mexican children with NB. METHODS: A population-based, prolective study, with data obtained from the Childhood Cancer Registry of the Instituto Mexicano de Seguro Social. STATISTICAL ANALYSIS: The simple frequencies of the variables of the study and the annual average incidence (per 1,000,000 children/years) by age and sex were obtained. The trend was evaluated by calculating the annual percentage of change. The curves of Kaplan-Meyer were employed for the survival rate and the log-rank test was used to compare the curves. RESULTS: Of a total of 2,758 children with cancer registered during the period from 1996-2005, 72 (2.6%) were identified as having Group IV, defined according to the International Classification of Childhood Cancer. The incidence for NB was 3.8 per 1,000,000 children/year; NB was highest in the group of children under one year of age, followed by the group of children between the ages 1-4 years (18.5 and 5.4 per 1,000,000 children/years, respectively). The male/female ratio was 1.1 and there was no trend toward an increase. The time of diagnosis was 26 days (median), but varied according to the stage at diagnosis. Stages III and IV were presented in 88% of the cases. There was no association between the stage, the age at time of diagnosis, or the histological pattern. The overall five-year survival rate was 64%; the patients with stage I, II, III, or IVs did not die; and the five-year survival rate of cases in Stage IV was 40%. CONCLUSION: It is possible that the low incidence of neuroblastoma in Mexican children is due to the difficulty in diagnosing the cases with the best prognosis, some of which could have had spontaneous regression. There was no trend to an increase; the majority of the cases were diagnosed in the advanced stages; and the overall five-years survival rate was similar to that for developed countries.

The age incidence of childhood B-cell precursor acute lymphoblastic leukemia in Mexico City.

The objective of this population-based survey was to assess the peak age of incidence of B-cell precursor acute lymphoblastic leukemia (ALL) in children in Mexico City (MC). All patients were classified according to their immunophenotype, and only B-cell precursor and T-lineage were analyzed. Rates of incidence were calculated x10 children. Of the 364 children from MC who were included in this study, immunophenotyping had been performed for 81.6%. The frequency of B-cell precursor ALL was 76.1%, whereas T lineage ALL showed a frequency of 23.6%. Peak age for ALL was 2 to 3 years of age. B-cell precursor ALL was the major contributor to peak age; T lineage ALL showed a peak among 1 and 3 years of age. We conclude that the age peak for children with ALL in MC is within the ranges reported for developed countries and that B-cell precursor ALL is the main contributor to these peak.

[Cancer epidemiology in adolescents of 15 and 16-year-old]. / Epidemiología del cáncer en adolescentes de 15 y 16 años.

OBJECTIVE: to present the frequency of different types of cancer in adolescents with 15 and 16-year-old treated at the Instituto Mexicano del Seguro Social (IMSS) in Mexico City (MC) hospitals. METHODS: it was an observational and prolective study. During January 1 of 1996 to December 31 of 2005, were analyzed new cases of adolescents of 15 and 16-year-old with malignant neoplasms in adolescents at IMSS. The neo-plasms were grouped according with the International Classification of Childhood Cancer; they were stratified by age, sex, and place of residence, and the frequency of these variables were obtained. RESULTS: a total of 207 cases were registered. Leukemias were more frequent with 55 cases (26.6%); the second place was for bone tumors with 36 cases (17.4%) and the third place were lymphomas with 32 cases (15.5%). There were not cases of retinoblastoma and renal tumors; only 8 cases of carcinomas (3.9%) were registered. The greatest frequency was observed in males with 116 cases (56.0%), with male/female ratio of 1.3:1. Mexico City and State of Mexico were more frequent places of residence with 70.5% of cases. Near of forty nine percent of cases (48.8%) with solid tumors were diagnosed in III or IV stages. CONCLUSIONS: the pattern of cancer was different from older adolescents (15 to 19-year-old), it is necessary to conduct studies of survey in order to determine epidemiology of cancer in the Mexican adolescents.

Incidence of cancer in children residing in ten jurisdictions of the Mexican Republic: importance of the Cancer registry (a population-based study).

BACKGROUND: In 1996, Mexico started to register cases of childhood cancer. Here, we describe the incidence of cancer in children, residing in ten Mexican jurisdictions, who were treated by the Instituto Mexicano del Seguro Social (IMSS). METHODS: New cases of childhood cancer, which were registered prospectively in nine principal Medical Centers of IMSS during the periods 1998-2000 (five jurisdictions) and 1996-2002 (five jurisdictions), were analyzed. Personnel were specifically trained to register, capture, and encode information. For each of these jurisdictions, the frequency, average annual age-standardized incidence (AAS) and average annual incidence per period by sex and, age, were calculated (rates per 1,000,000 children/years). RESULTS: In total 2,615 new cases of cancer were registered, with the male/female ratio generally >1, but in some tumors there were more cases in females (retinoblastoma, germ cells tumors). The principal groups of neoplasms in seven jurisdictions were leukemias, central nervous system tumors (CNS tumors), and lymphomas, and the combined frequency for these three groups was 62.6 to 77.2%. Most frequently found (five jurisdictions) was the North American-European pattern (leukemias-CNS tumors-lymphomas). Eight jurisdictions had AAS within the range reported in the world literature. The highest incidence was found for children underless than five year of age. In eight jurisdictions, leukemia had high incidence (>50). The AAS of lymphomas was between 1.9 to 28.6. Chiapas and Guerrero had the highest AAS of CNS tumors (31.9 and 30.3, respectively). The frequency and incidence of neuroblastoma was low. Chiapas had the highest incidence of retinoblastoma (21.8). Germ-cell tumors had high incidence. CONCLUSION: The North American-European pattern of cancers was the principal one found; the overall incidence was within the range reported worldwide. In general but particularly in two jurisdictions (Yucatán and Chiapas), it will be necessary to carry out studies concerning the causes of cancer in children. Due to the little that is known about the incidence of cancer in Mexican children, it will be necessary to develop a national program to establish a cancer registry for the whole of the country.

[General and specific incidence of cancer among children affiliated to the Mexican Institute of Social Security]. / Incidencia general y específica de cáncer en niños derechohabientes del IMSS.

OBJECTIVE: To determine the epidemiology of cancer among children from eleven Mexican states affiliated to Mexican Social Security Institute (Instituto Mexicano del Seguro Social, IMSS). METHODS: 2663 Cases of children with cancer were prospectively registered between 1996 and 2002 in the main IMSS medical centers. The cases were classified according to the International Classification for Childhood Cancer. The general and specific cancer incidences (rate per million children/year, age standardized) were obtained. RESULTS: The principal groups of cancer in nine states were leukemias, lymphomas and central nervous system tumors (CNST). In eight states, the incidence was similar than reported worldwide (100 to 180); Chiapas had the highest incidence (203.5). Leukemias had higher incidence in seven States (>50). The highest incidences of CNST were observed in Chiapas and Guerrero (31.9 and 30.3); The incidence of neuroblastoma was low. Chiapas showed the highest incidence of retinoblastoma, bone tumors and carcinomas (21.8, 12.2 and 5.9 respectively); Puebla had the highest incidence of liver tumors (11.3) in which stages III and IV were the most frequent (67.8 %). CONCLUSIONS: The main groups of cancer in Mexican children were leukemias, CNST, and lymphomas. Some states had high incidence; more than 50 % of children with solid tumors were diagnosed in advanced stages.

Incidence of leukemias in children from El Salvador and Mexico City between 1996 and 2000: population-based data.

BACKGROUND: There are very few studies that report the incidence of acute leukemias in children in Latin America. This work assesses the incidence of acute leukemias, between 1996 and 2000, in children from 0-14 years old who were attended at the Mexican Social Security Institute in Mexico City and in children from 0-11 years old in El Salvador. DESIGN: Population-based data. Hospitals: In San Salvador, El Salvador, Hospital Nacional de Niños "Benjamin Bloom", the only center in El Salvador which attends all children, younger than 12 years, with oncologic disease. The Pediatric Hospital and the General Hospital of the Mexican Social Security Institute in Mexico City, the only centers in Mexico City which attend all those children with acute leukemia who have a right to this service. DIAGNOSIS: All patients were diagnosed by bone marrow smear and were divided into acute lymphoid leukemia (ALL), acute myeloid leukemia (AML), chronic myeloid leukemia (CML), and unspecified leukemias (UL). The annual incidence rate (AIR) and average annual incidence rate (AAIR) were calculated per million children. Cases were stratified by age and assigned to one of four age strata: 1) <1 year; 2) 1-4 years; 3) 5-9 years, or 4) 10-14 or 10-11 years, for Mexico City and El Salvador, respectively. RESULTS: The number of cases was 375 and 238 in El Salvador and Mexico City, respectively. AAIRs in Mexico City were 44.9, 10.6, 2.5, 0.5, and 58.4 per million children for ALL, AML, CML, UL, and total leukemias, respectively. The AAIRs in El Salvador could not be calculated because the fourth age stratum in El Salvador included children only from 0-11 years old. The incidence rates for the Salvadorian group of 0-11 year olds were 34.2, 7.1, 0.6, 0.2, and 43.2 per million children for ALL, AML, CML, UL, and total leukemias, respectively. CONCLUSION: Reported AIRs for each age group in El Salvador were similar to those from other American countries. The AAIR of ALL in Mexico City is one of the highest reported for North America.

Frequency of cancer in children residing in Mexico City and treated in the hospitals of the Instituto Mexicano del Seguro Social (1996-2001).

BACKGROUND: The objective of this article is to present the frequency of cancer in Mexican children who were treated in the hospitals of the Instituto Mexicano del Seguro Social in Mexico City (IMSS-MC) in the period 1996-2001. METHODS: The Registry of Cancer in Children, started in 1996 in the IMSS-MC, is an on-going, prospective register. The data from 1996 through 2001 were analyzed and the different types of cancer were grouped according to the International Classification for Cancer in Children (ICCC). From this analysis, the general and specific frequencies by age and by sex were obtained for the different groups of neoplasms. Also, the frequency of the stage of the disease that had been diagnosed in cases of children with solid tumors was obtained. RESULTS: A total of 1,702 new cases of children with cancer were registered, with the male/female ratio at 1.1/1. Leukemias had the highest frequency with 784 cases (46.1%) and, of these, acute lymphoblastic leukemias were the most prevalent with 614 cases (78.3%). Thereafter, in descending order of frequency, were tumors of the central nervous system (CNST) with 197 cases (11.6%), lymphomas with 194 cases (11.4%), germinal cell tumors with 110 cases (6.5%), and bone tumors with 97 cases (5.7%). The highest frequency of cancer was found in the group of one to four year-olds that had 627 cases (36.8%). In all the age groups, leukemias were the most frequent. In the present work, the frequency of Hodgkin's disease (~4%) was found to be lower than that (~10%) in previous studies and the frequency of tumors of the sympathetic nervous system was low (2.3%). Of those cases of solid tumors for which the stage of the disease had been determined, 66.9% were diagnosed as being Stage III or IV. CONCLUSIONS: The principal cancers in the children treated in the IMSS-MC were leukemias, CNST, and lymphomas, consistent with those reported by developed countries. A 2.5-fold reduction in the frequency of Hodgkin's disease was found. Of the children, the stage of whose disease had been determined, two thirds were diagnosed as having advanced stages of the disease.

[Trends of 6 primary causes of mortality in Mexican children in 1971-2000. Epidemiologic transition in children]. / Tendencia de seis principales causas de mortalidad en niños mexicanos durante el periodo 1971-2000. La transición epidemiológica en los niños.

OBJECTIVE: To determine trends of six main causes of mortality in Mexican children < 15 years of age. TYPE OF STUDY: Observational, descriptive and retrospective. STUDY PERIOD: January 1, 1971 to December 31, 2000. Studied Population: Children < 15 years of age, Statistic Analysis: mortality rates were obtained due to perinatal causes, respiratory infections, intestinal infections, accidents, congenital malformations (CM), and cancer (CA). They were stratified according to age groups in < 1 year, 1 to 4 years, 5 to 14 years, and 1 to 14 years of age. Percentage differences were calculated between 1971 and 2000, as were respective trends. RESULTS: Global decrease in mortality was according to age group, 83.5% in 0 to 14-year-old, 71.3% in under one year old, 90.5 in 1 to 4-years-old, 79.2% in 5 to 14-year-old. The largest decrease in all groups was observed for infectious causes (> 90%), and increased CM between 120.1 to 160.5%, and CA between 28.0 to 56.4%. CONCLUSIONS: Mortality in Mexican children has decreased significantly. Infectious causes show the most important reduction, the CM and CA showing largest increase. Accidents, although they reveal some tendency to decrease, are first cause of death in the group 1 to 14 years of age. Present data indicate the need to continue programs to provide care for infections diseases, and to establish new programs that include care for accidents, CM, and CA in children.

Epidemiological characteristics of retinoblastoma in children attending the Mexican Social Security Institute in Mexico City, 1990-94.

The object of this study is to present descriptive epidemiological characteristics of retinoblastoma (Rb) in children aged 0-14 years, seen at the Mexican Social Security Institute hospitals in Mexico City (MC) from 1990 to 1994. This is a retrospective, observational hospital survey. Clinical records of 52 Rb cases were reviewed; 39 were patients who did not reside in MC (non-residents), and 13 were MC residents. The study period was 1990-94. The male/female ratio (M/F) was 1.6. Average annual incidence (AAI) was estimated by age and sex (rates per 1000000). Annual average percentage change (AAPC) in incidence rates was estimated in children from 0 to 14 years. The AAI for MC residents was 3.2; the highest rate being for those <1 year olds (rate of 20.8); AAPC was 6.9% [95% CI -27.5, 57.4]; the highest incidence was for the south-eastern region of MC residents (rate of 5.9); 13 cases (25%) were diagnosed at stage III or IV, and 11 cases (21.2%) were bilateral. Incidence of Rb is similar to that in developed countries and shows no increasing trend. Patients from communities outside MC are more frequently diagnosed at stages III and IV.

[Trends in the incidence of hepatic tumors in childhood]. / Tendencia de la incidencia de los tumores hepáticos en la infancia.

OBJECTIVE: To evaluate the incidence trends of hepatic tumors among children living in Mexico City. MATERIAL AND METHODS: A cross-sectional hospital survey was conducted to yield two databases. The first database contains the registry of all the cases of hepatic tumors occurring during the period 1982-1991, in public hospitals of Mexico City. The second database contains all hepatic tumor cases found between 1996 and 1999 in Hospital de Pediatría del Centro Médico Nacional "Siglo XXI" and in Hospital General del Centro Médico La Raza, both hospitals pertaining to Instituto Mexicano del Seguro Social (Mexican Institute of Social Security). The average annual incidence rates (AAIR) were calculated for each type of hepatic tumor. The rates were standardized with the direct method, using as standard the world population under 15 years of age. The trends were evaluated with the annual incidence rates and the average rate of change assuming a Poisson distribution. RESULTS: The AAIR for hepatoblastoma during the period 1982-1991 was three times higher for men than for women, with a value of 0.6 x 10(6). The group of 1-4 years of age was the most affected. For hepatocarcinomas the AAIR was two-fold for women (0.14) as compared to men. Between 1996-1999 the AAIR for hepatoblastoma was 5.11 in women and 1.85 in men. The age group with the highest rate was women under one year of age. The AAIR for hepatocarcinoma was 0.64 for males and 1.23 for females. The most affected age group was males aged 10 to 14 years. No significant upward or downward trend was found in the incidence of hepatoblastomas. A non-significant change rate of 10% was found for hepatocarcinoma. CONCLUSIONS: No significant trends were observed in the incidence of hepatic tumors in children of Mexico City aged under 15 years, during the periods 1982-1991 and 1996-1999. The English version of this paper is available at: http://www.insp.mx/salud/index.html.

Tendencia de la incidencia de los tumores hepáticos en la infancia / Trends in the incidence of hepatic tumors in childhood

OBJECTIVE: To evaluate the incidence trends of hepatic tumors among children living in Mexico City. MATERIAL AND METHODS: A cross-sectional hospital survey was conducted to yield two databases. The first database contains the registry of all the cases of hepatic tumors occurring during the period 1982-1991, in public hospitals of Mexico City. The second database contains all hepatic tumor cases found between 1996 and 1999 in Hospital de PediatrÝa del Centro MÚdico Nacional "Siglo XXI" and in Hospital General del Centro MÚdico La Raza, both hospitals pertaining to Instituto Mexicano del Seguro Social (Mexican Institute of Social Security). The average annual incidence rates (AAIR) were calculated for each type of hepatic tumor. The rates were standardized with the direct method, using as standard the world population under 15 years of age. The trends were evaluated with the annual incidence rates and the average rate of change assuming a Poisson distribution. RESULTS: The AAIR for hepatoblastoma during the period 1982-1991 was three times higher for men than for women, with a value of 0.6 x 10(6). The group of 1-4 years of age was the most affected. For hepatocarcinomas the AAIR was two-fold for women (0.14) as compared to men. Between 1996-1999 the AAIR for hepatoblastoma was 5.11 in women and 1.85 in men. The age group with the highest rate was women under one year of age. The AAIR for hepatocarcinoma was 0.64 for males and 1.23 for females. The most affected age group was males aged 10 to 14 years. No significant upward or downward trend was found in the incidence of hepatoblastomas. A non-significant change rate of 10 was found for hepatocarcinoma. CONCLUSIONS: No significant trends were observed in the incidence of hepatic tumors in children of Mexico City aged under 15 years, during the periods 1982-1991 and 1996-1999. The English version of this paper is available at: http://www.insp.mx/salud/index.html.

El cáncer, un problema de salud que incrementa en el niño: un reto para conocer su epidemiología en los niños mexicanos / Childhoo cancer: an increasing health problem and a challenge to disclose its epidemiology in Mexico

Objetivo: revisar en el ámbito mundial y nacional los datos epidemiológicos más relevantes de la incidencia de cáncer en los niños. Establecer una perspectiva del impacto que han causado en la patología del niño y principalmente en los niños mexicanos. Metodología: se seleccionaron los artículos más relevantes sobre la incidencia de cáncer en los niños publicados en los últimos 15 años, de donde pudiera obtenerse las características de tiempo, lugar y persona. Para la incidencia de cáncer en los niños mexicanos, además, se incluyeron datos de un estudio multicéntrico que se está realizando. Resultados: la incidencia mundial de cáncer en el niño se encuentra entre 100 y 182 x 106. Existen diferentes patrones de presentación, la incidencia es más frecuente en los hombres, en los menores de 5 años, en la raza blanca y al parecer en el medio urbano. Parece que hay una tendencia de la incidencia al incremento. En países desarrollados la mortalidad por cáncer ha disminuido significativamente. En los niños residentes del Distrito Federal derechohabientes del Instituto Mexicano del Seguro Social, al parecer hay tendencia al incremento y comparten características similares con los niños de otros países. La mortalidad por cáncer no tiende a disminuir. Los datos epidemiológicos de cáncer para niños de otros estados son muy escasos. Conclusiones: al parecer existe tendencia al incremento de la incidencia de cáncer en el niño. En México, es necesario diseñar estrategias institucionales o nacionales integrales, tanto para conocer mejor la epidemiología del cáncer en el niño, como para dar un mejor tratamiento a los niños que desarrollan una neoplasia.

Factores que incluyen en la no-donación de sangre en los familiares de pacientes de un hospital pediátrico / Factors that influence non-donation of blood in families of pediatric hospital patients

Objetivo. Identificar los factores que intervienen en la no-donación de sangre.Material y métodos. Estudio prospectivo de casos y controles. Se entrevistó a familiares de pacientes hospitalizados y se aplicó un cuestionario para evaluar sus conocimientos sobre la sangre y las actitudes hacia la donación sanguínea. Se consideró como caso a todos los familiares que no donaron sangre y como control a los que donaron.Resultados: Se estudiaron 121 individuos, 30 casos y 91 controles. La edad promedio de los casos fue 32.3ñ8.1 años y de los controles 28.8ñ7.9 años (p= 0.04). Como factores de riesgo se encontraron: sexo femenino (OR=6.3; IC95 por ciento 2.4 a 17.1); estar casado (OR=3.7; IC95 por ciento 1.3 a 10. 5). Entre los grupos no hubo diferencias en relación con su nivel de conocimientos acerca de la sangre. Los familiares que donaron tuvieron más actitudes positivas hacia la donación sanguínea (casos 5.9ñ1.6; controles 6.4ñ1.2; P: 0.049). Dentro de las actitudes que más influyeron para la no-donación fueron: marearse al ver sangre (OR= 5.2- IC95 por ciento 1.3-21.4), tener miedo a donar sangre (OR= 2.2; IC95 por ciento 0.8-6.0) y ponerse nervioso cuando ven sangre (OR= 4. 1 IC95 por ciento 1.5-10.9). Conclusiones: Entre los familiares de los pacientes hospitalizados que donan sangre influyen más las actitudes personales positivas hacia la donación que los conocimientos que se tengan acerca de la misma.