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

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

<p>Abstract</p> <p>Background</p> <p>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.</p> <p>Methods</p> <p>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.</p> <p>Results</p> <p>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%.</p> <p>Conclusion</p> <p>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.</p

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

Tendencia de la incidencia de los tumores hepáticos en la infancia

Objetivo. Evaluar la tendencia de la incidencia de los diferentes tumores hepáticos en niños residentes en el Distrito Federal. Material y métodos. Encuesta hospitalaria. Se realizó un análisis de dos bases de datos. La primera tiene registrados todos los casos de tumores hepáticos que se encontraron entre el periodo de l982 a 1991, de hospitales que atienden a niños con cáncer, residentes en la Ciudad de México. La segunda base de datos tiene registrados todos los casos de tumores hepáticos que se encontraron de 1996 a 1999 en el Hospital de Pediatría Centro Médico Nacional (CMN) "Siglo XXI" y en el Hospital General del Centro Médico Nacional "La Raza", del Instituto Mexicano del Seguro Social (IMSS). Se calcularon las tasas de incidencia anual promedio (TIAP) por cada tipo de tumor hepático. Las tasas fueron estandarizadas por el método directo, usando como población de referencia a la mundial estándar menor de l5 años. La tendencia se evaluó con las tasas de incidencia anuales y se calculó la tasa de cambio promedio que emplea la distribución de Poisson. Resultados. Durante el periodo de 1982 a 1991 la TIAP para hepatoblastoma fue el triple en hombres con 0.6 x 10(6). El grupo más afectado fue el de 1 a 4 años.()Para los hepatocarcinomas la TIAP fue de 0.14 para el sexo femenino, siendo el doble que la del sexo masculino. Para el periodo de 1996 a 1999 la TIAP para hepatoblastomas fue de 5.11 en mujeres y de 1.85 en hombres. El grupo de edad con la tasa más alta fue el de mujeres menores de un año. Para hepatocarcinomas la TIAP fue de 0.64 para hombres y de 1.23 en mujeres. El grupo de edad más afectado fue el de hombres de 10 a 14 años. No se observó tendencia significativa al incremento o decremento en la incidencia de hepatoblastomas. Para hepatocarcinomas hubo una tasa de cambio de 10%, pero tampoco fue significativa. Conclusiones. No existe en la Ciudad de México una tendencia en la incidencia de los tumores hepáticos en niños menores de 15 años, de 1982 a 1991, y de 1996 a 1999

Tendencia de la incidencia de los tumores hepáticos en la infancia Incidence trends of hepatic tumors in childhood

Objetivo. Evaluar la tendencia de la incidencia de los diferentes tumores hepáticos en niños residentes en el Distrito Federal. Material y métodos. Encuesta hospitalaria. Se realizó un análisis de dos bases de datos. La primera tiene registrados todos los casos de tumores hepáticos que se encontraron entre el periodo de l982 a 1991, de hospitales que atienden a niños con cáncer, residentes en la Ciudad de México. La segunda base de datos tiene registrados todos los casos de tumores hepáticos que se encontraron de 1996 a 1999 en el Hospital de Pediatría Centro Médico Nacional (CMN) "Siglo XXI" y en el Hospital General del Centro Médico Nacional "La Raza", del Instituto Mexicano del Seguro Social (IMSS). Se calcularon las tasas de incidencia anual promedio (TIAP) por cada tipo de tumor hepático. Las tasas fueron estandarizadas por el método directo, usando como población de referencia a la mundial estándar menor de l5 años. La tendencia se evaluó con las tasas de incidencia anuales y se calculó la tasa de cambio promedio que emplea la distribución de Poisson. Resultados. Durante el periodo de 1982 a 1991 la TIAP para hepatoblastoma fue el triple en hombres con 0.6 x 10(6). El grupo más afectado fue el de 1 a 4 años.()Para los hepatocarcinomas la TIAP fue de 0.14 para el sexo femenino, siendo el doble que la del sexo masculino. Para el periodo de 1996 a 1999 la TIAP para hepatoblastomas fue de 5.11 en mujeres y de 1.85 en hombres. El grupo de edad con la tasa más alta fue el de mujeres menores de un año. Para hepatocarcinomas la TIAP fue de 0.64 para hombres y de 1.23 en mujeres. El grupo de edad más afectado fue el de hombres de 10 a 14 años. No se observó tendencia significativa al incremento o decremento en la incidencia de hepatoblastomas. Para hepatocarcinomas hubo una tasa de cambio de 10%, pero tampoco fue significativa. Conclusiones. No existe en la Ciudad de México una tendencia en la incidencia de los tumores hepáticos en niños menores de 15 años, de 1982 a 1991, y de 1996 a 1999.<br>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 x10(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

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

<p>Abstract</p> <p>Background</p> <p>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.</p> <p>Methods</p> <p>Design: Population-based data. Hospitals: In San Salvador, El Salvador, Hospital Nacional de Niños "Benjamín 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.</p> <p>Results</p> <p>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 Salvadoran 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.</p> <p>Conclusion</p> <p>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.</p