Thyroid carcinoma in children, adolescents, and young adults in Brazil: A report from 11 population-based cancer registries.

BACKGROUND: The increasing incidence of thyroid cancer has been described worldwide. Overdiagnosis, improved imaging, and increased environmental risk factors have contributed to the rising incidence. The objective of this study was to analyze the population incidence rate and trends during the period of 2000-2013 in children, adolescents and young adults (AYAs) in Brazil. METHODS: Data were extracted from 11 population-based cancer registries (PBCRs) encompassing the five geographic regions of Brazil. Incidence rates per million in children (0-14) and AYAs (15-39) according to world population were analyzed according to sex, age, and type of carcinoma. Incidence trends were evaluated using joinpoint regression. RESULTS: During 2000 to 2013, we identified 11,081 children and AYAs (0-39 years) with thyroid carcinoma in 11 PBCRs, with an age-adjusted incidence rate (AAIR) of 42 cases per million. Females had a higher AAIR of 66 cases per million versus 14 cases per million in males. Age-specific incidence rate (ASR) increased with age. Geographic variation was also observed; the Midwest and Southeast regions had the highest ASR in all age groups. The lowest ASR in all age groups was seen in the North region. Papillary subtype was the most common. Overall, the incidence rates in children and AYAs significantly increased from 0.2 in 2000 to 2.8 in 2013 and from 47.1 to 115.3, respectively, with an annual average percent change of 18.8 [8.1; 30.6] for children and 7.9 [CI 5.6; 10.3] for AYAs. CONCLUSIONS: Rates of thyroid cancer, particularly the papillary subtype, are steadily increasing in children and AYAs, especially among females. There are variations among geographic areas. This increased incidence is unlikely to be explained by screening, as children less than 14 years of age do not typically undergo medical surveillance. Environmental risk factors must be investigated.

Rare cancers in childhood and adolescence in Brazil: First report of data from 19 population-based cancer registries.

BACKGROUND: Rare childhood cancer is challenging to define. The Italian Pediatric Rare Tumor (TREP) Study considers rare tumors to include solid malignancies characterized by an annual incidence rate of <2 cases per 1 million and not enrolled in clinical trials. The objective of the current study was to analyze the population incidence rate of rare tumors among children and adolescents (those aged birth-19 years) in Brazil. METHODS: Incidence data were obtained from 19 population-based cancer registries covering the 5 geographic regions in Brazil. Newly diagnosed cases were selected according to the TREP definition, using the International Classification of Diseases for Oncology. To calculate the crude incidence rate, the numbers of incident children and adolescents with a specific rare cancer were divided by the corresponding person-years lived for the population aged <20 years during the same period. RESULTS: Two tumors had an incidence rate that was >2 cases per 1 million (thyroid and skin cancers) in adolescents only. Several tumors demonstrated variations in incidence across the Brazilian regions. Adrenocortical carcinoma had a high incidence rate (4 cases per 1 million) in the south region among children aged <10 years. Thyroid and skin carcinoma had higher incidence rates in the midwest, southeast, and south regions. CONCLUSIONS: Due to the extraordinary rarity of these events, networking is important for improving basic research, clinical studies, and trials. Centralization of diagnosis is the only way to improve the diagnosis and treatment of children affected by these rare diseases. The registration and surveillance of rare pediatric cancers are crucial from a public health point of view, and therefore the quality of registration has to be improved.

Incidence Trends of Cervical Cancer in Adolescents and Young Adults: Brazilian Population Based Data.

PURPOSE: High incidence rates for cervical cancer in adolescents and young adults (AYAs: 15-29 years) make this the most common carcinoma in Brazil. Our aim was to analyze the incidence trends for cervical cancer (CC) and in situ neoplasia (IsN) among this age group. METHODS: Incidence data were extracted from 21 Brazilian population-based cancer registries (PBCRs). Tumors with behavior code/3 (malignant) were classified as CC. Tumors with behavior code/2 were classified as IsN. Age-adjusted and age-specific incidence rates were calculated for individuals aged 15-19 years, 20-24 years, and 25-29 years. Incidence trends were evaluated by joinpoint regression analyses. RESULTS: The median incidence rate of CC for AYA in Brazil was 3.63 per 100,000, with the highest rate observed in Recife (27.50 per 100,000). Significant increase in incidence for CC was identified in two PBCRs, with decreased rates for three PBCRs. The median incidence rate of IsN was 16.78 per 100,000 and was highest in Roraima (93.37 per 100,000). Increased incidence rates for IsN were identified in six PBCRs, with significant decreases in two PBCRs. CONCLUSION: The incidence rate for CC among AYA in Brazil is high and warrants intervention in terms of both prevention and control.

Birth weight and risk of childhood solid tumors in Brazil: a record linkage between population-based data sets.

OBJECTIVE: To analyze the relationship between the development of childhood solid tumors and 1) birth weight and 2) fetal growth, using two Brazilian population-based data sets. METHODS: A case-cohort study was performed using two population-based data sets, and linkage between the Live Birth Information System (Sistema de Informação sobre Nascidos Vivos, SINASC) and 14 population-based cancer registries (PBCRs) was established. Four controls per case were chosen randomly from the SINASC data set. Tumors were classified as central nervous system (CNS), non-CNS embryonal, and other tumors ("miscellaneous"). Adjustments were made for potential confounders (maternal age, mode of delivery, maternal education, birth order, gestational age, sex, and geographic region). Odds ratios (ORs) with 95% confidence intervals (CIs) were computed using unconditional logistic regression analysis. RESULTS: In a trend analysis, for every 500 g of additional birth weight, the crude OR was 1.12 (CI: 1.00-1.24) and the adjusted OR was 1.02 (CI: 0.90-1.16) for all tumors. For every 1 000 g of additional birth weight, the crude OR was 1.25 (CI: 1.00-1.55) and the adjusted OR was 1.04 (CI: 0.82-1.34) for all tumors. Among children diagnosed after reaching the age of 3 years, in the miscellaneous tumor category, the OR was significantly increased for every additional 500 g and 1 000 g of birth weight. CONCLUSIONS: The study data suggested that increased birth weight was associated with childhood solid tumor development, especially among children more than 3 years old with "miscellaneous" tumors.

Trends in Cancer Mortality Among Adolescents and Young Adults in Brazil.

PURPOSE: Adolescents and young adults (AYA) with cancer comprise an intermediate age group between pediatric and adult oncology, and have a spectrum of different types of cancers. Survival among this group has not improved as much as in younger children with cancer. The aim of this study was evaluate the trends in cancer mortality of AYA aged 15-29 years in Brazil. METHODS: Data were extracted from the Atlas of Cancer Mortality databases from 1979 to 2013. Age-specific mortality rates were calculated based on the deaths from each type of cancer and the period via a direct method using the proposed world population age groups. To identify significant changes in the trends, we performed joinpoint regression analysis. RESULTS: The mortality rates per million were 54 deaths in those aged 15-19 years, 61 deaths in those aged 20-24 years, and 88 deaths in those aged 25-29 years. Leukemias, lymphomas, and central nervous system (CNS) tumors occurred at high rates in all age groups. Rates of cervical cancer were highest in those aged 25-29 years. There were significant increases in mortality trends in the North and Northeast regions for all tumor groups, especially CNS tumors. A small decrease in the mortality rate from lymphomas was observed in the South and Southeast regions. CONCLUSION: Mortality in Brazilian AYA was slightly higher than in other studies conducted throughout the world. When separated by tumor type, Brazil presents a specific pattern, with high mortality from cervical cancer.

Birth weight and risk of childhood solid tumors in Brazil: a record linkage between population-based data sets / El peso al nacer y el riesgo de formación de tumores sólidos en la niñez en el Brasil: vinculación de registros entre conjuntos de datos poblacionales

ABSTRACT Objective To analyze the relationship between the development of childhood solid tumors and 1) birth weight and 2) fetal growth, using two Brazilian population-based data sets. Methods A case–cohort study was performed using two population-based data sets, and linkage between the Live Birth Information System (Sistema de Informação sobre Nascidos Vivos, SINASC) and 14 population-based cancer registries (PBCRs) was established. Four controls per case were chosen randomly from the SINASC data set. Tumors were classified as central nervous system (CNS), non-CNS embryonal, and other tumors (“miscellaneous”). Adjustments were made for potential confounders (maternal age, mode of delivery, maternal education, birth order, gestational age, sex, and geographic region). Odds ratios (ORs) with 95% confidence intervals (CIs) were computed using unconditional logistic regression analysis. Results In a trend analysis, for every 500 g of additional birth weight, the crude OR was 1.12 (CI: 1.00–1.24) and the adjusted OR was 1.02 (CI: 0.90–1.16) for all tumors. For every 1 000 g of additional birth weight, the crude OR was 1.25 (CI: 1.00–1.55) and the adjusted OR was 1.04 (CI: 0.82–1.34) for all tumors. Among children diagnosed after reaching the age of 3 years, in the miscellaneous tumor category, the OR was significantly increased for every additional 500 g and 1 000 g of birth weight. Conclusions The study data suggested that increased birth weight was associated with childhood solid tumor development, especially among children more than 3 years old with “miscellaneous” tumors.

RESUMEN Objetivo Analizar la relación entre la aparición de tumores sólidos en la niñez y 1) el peso al nacer y 2) el crecimiento fetal, a partir de dos conjuntos de datos poblacionales del Brasil. Métodos Se efectuó un estudio de casos en una cohorte a partir de dos conjuntos de datos poblacionales y se vinculó el sistema de información de nacidos vivos (Sistema de Informação sobre Nascidos Vivos, SINASC) con 14 registros oncológicos poblacionales. Se eligieron al azar cuatro controles por caso del conjunto de datos del SINASC. Los tumores se clasificaron en tres tipos: del sistema nervioso central (SNC), embrionarios ajenos al SNC y otros (“misceláneos”). Se hicieron ajustes en función de los posibles factores de confusión (edad materna, modalidad de parto, educación materna, orden de nacimiento, edad gestacional, sexo y región geográfica) y se calcularon las razones de posibilidad (OR) con un intervalo de confianza (IC) del 95 % mediante análisis de la regresión logística incondicional. Resultados En el análisis de las tendencias, se observó que, en todos los tumores, cada 500 g adicionales de peso al nacer la OR bruta fue de 1,12 (IC: 1,00-1,24) y la OR ajustada, de 1,02 (IC: 0,90-1,16), mientras que, cada 1 000 g adicionales, la OR bruta fue de 1,25 (IC: 1,00-1,55) y la OR ajustada, de 1,04 (IC: 0,82-1,34). En cuanto a los niños diagnosticados después de los 3 años de edad, en la categoría de tumores misceláneos, la OR fue significativamente más alta con cada 500 g y 1 000 g adicionales de peso al nacer. Conclusiones Los datos del estudio indican que el peso alto al nacer está asociado a la aparición de tumores sólidos en la niñez, especialmente de la categoría “misceláneos” y en los niños mayores de 3 años de edad.

Maternal and Birth Characteristics and Childhood Embryonal Solid Tumors: A Population-Based Report from Brazil.

BACKGROUND: Several maternal and birth characteristics have been reported to be associated with an increased risk of many childhood cancers. Our goal was to evaluate the risk of childhood embryonal solid tumors in relation to pre- and perinatal characteristics. METHODS: A case-cohort study was performed using two population-based datasets, which were linked through R software. Tumors were classified as central nervous system (CNS) or non-CNS-embryonal (retinoblastoma, neuroblastoma, renal tumors, germ cell tumors, hepatoblastoma and soft tissue sarcoma). Children aged <6 years were selected. Adjustments were made for potential confounders. Odds ratios (OR) with 95% confidence intervals (CI) were computed by unconditional logistic regression analysis using SPSS. RESULTS: Males, high maternal education level, and birth anomalies were independent risk factors. Among children diagnosed older than 24 months of age, cesarean section (CS) was a significant risk factor. Five-minute Apgar ≤8 was an independent risk factor for renal tumors. A decreasing risk with increasing birth order was observed for all tumor types except for retinoblastoma. Among children with neuroblastoma, the risk decreased with increasing birth order (OR = 0.82 (95% CI 0.67-1.01)). Children delivered by CS had a marginally significantly increased OR for all tumors except retinoblastoma. High maternal education level showed a significant increase in the odds for all tumors together, CNS tumors, and neuroblastoma. CONCLUSION: This evidence suggests that male gender, high maternal education level, and birth anomalies are risk factors for childhood tumors irrespective of the age at diagnosis. Cesarean section, birth order, and 5-minute Apgar score were risk factors for some tumor subtypes.

Cancer Incidence Among Adolescents and Young Adults (15 to 29 Years) in Brazil.

The spectrum of cancers commonly found in adolescents and young adults (AYAs) differs from those in children and adults; therefore, the childhood classification is not appropriate for this population. Here we used a newly proposed classification system to reclassify cases of AYAs from Brazilian population-based cancer registries (PBCRs) in 5 geographic regions of Brazil. We aimed to describe the cancer incidence rates within this age group according to PBCR. Using the world population, incidence rates per million were analyzed in each diagnostic subgroup according to sex and age at diagnosis (15 to 19 y, 20 to 24 y, and 25 to 29 y). The median incidence rate was 232.31 per million for females and 218.07 per million for males. Incidence increased with age, with the highest rate observed for 25- to 29-year-olds in both sexes. Carcinomas, lymphomas, and skin tumors were most frequent among AYAs. High incidence rates of cervix-uterus carcinoma were observed in most PBCRs. AYAs present epidemiological characteristics that differ from those of children, reinforcing the need for a new classification. This study describes, for the first time, the cancer incidence rate in AYAs in Brazil, and we believe that our findings represent the Brazilian profile.

Lymphoma subtype incidence rates in children and adolescents: first report from Brazil.

BACKGROUND: Lymphoma is the third most common pediatric malignancy. The purpose of this study was to analyze the incidence rates of lymphoma in children and adolescents in Brazil. METHODS: All cases of Hodgkin lymphoma (HL), non-Hodgkin lymphoma (NHL), and Burkitt lymphoma (BL) were extracted from 14 population-based cancer registries (PBCRs) from 2000 to 2005, and included children and adolescents 0-19 years old. Analyses included age-adjusted incidence rates (AAIRs) and age-specific incidence rates (ASIRs) by each PBCR. A social exclusion index (SEI) was built and used as proxy for socioeconomic status (SES) levels. Correlations between SES and incidence rates were investigated using Spearman's test. RESULTS: The median incidence of lymphoma was 22.7/million. AAIRs of lymphomas varied from 12.9 (Salvador) to 34.5 per million (São Paulo). Median AAIR was 8.8/million, 9.8/million, and 2.9/million for NHL, HL, and BL, respectively. In all PBCRs except that of Recife, AAIR was slightly higher in males than females. The median ASIR was highest for HL (18.5/million) at 15-19 years for both genders. For NHL there were two peaks for ASIR: 11.1/million (1-4 years of age) and 13.2/million (15-19 years of age). The median ASIR for BL was highest among children aged 1-4 years (4.7/million) and in males. Higher SEI correlated with higher incidence of HL (P = 0.06), whereas rates of NHL and BL did not correlate with SEI. Borderline different incidence rates were observed in HL correlated with cities with higher SEIs. CONCLUSION: Incidence rates of lymphomas in Brazil do not differ compared to rates reported worldwide, although SES differences deserve further investigation.

Socioeconomic status and the incidence of non-central nervous system childhood embryonic tumours in Brazil.

BACKGROUND: Childhood cancer differs from most common adult cancers, suggesting a distinct aetiology for some types of childhood cancer. Our objective in this study was to test the difference in incidence rates of 4 non-CNS embryonic tumours and their correlation with socioeconomic status (SES) in Brazil. METHODS: Data was obtained from 13 Brazilian population-based cancer registries (PBCRs) of neuroblastoma (NB), Wilms'tumour (WT), retinoblastoma (RB), and hepatoblastoma (HB). Incidence rates by tumour type, age, and gender were calculated per one million children. Correlations between social exclusion index (SEI) as an indicator of socioeconomic status (SES) and incidence rates was investigated using the Spearman's test. RESULTS: WT, RB, and HB presented with the highest age-adjusted incidence rates (AAIRs) in 1 to 4 year old of both genders, whereas NB presented the highest AAIR in ≤11 month-olds. However, differences in the incidence rates among PBCRs were observed. Higher incidence rates were found for WT and RB, whereas lower incidence rates were observed for NB. Higher SEI was correlated with higher incidences of NB (0.731; p = 0.0117), whereas no SEI correlation was observed between incidence rates for WT, RB, and HB. In two Brazilian cities, the incidence rates of NB and RB were directly correlated with SEI; NB had the highest incidence rates (14.2, 95% CI, 8.6-19.7), and RB the lowest (3.5, 95% CI, 0.7-6.3) in Curitiba (SEI, 0.730). In Natal (SEI, 0.595), we observed just the opposite; the highest incidence rate was for RB and the lowest was for NB (4.6, 95% CI, 0.1-9.1). CONCLUSION: Regional variations of SES and the incidence of embryonal tumours were observed, particularly incidence rates for NB and RB. Further studies are necessary to investigate risk factors for embryonic tumours in Brazil.

Childhood leukemia incidence in Brazil according to different geographical regions.

BACKGROUND: Resource-rich countries tend to have a higher incidence of childhood acute lymphoblastic leukemia (ALL), whereas lower rates are seen in more deprived countries. This study describes the incidence of childhood acute leukemia in Brazil, an upper middle-income country, based on data from 16 population-based cancer registries (PBCRs). PROCEDURE: Data were examined from 16 PBCRs in Brazilian cities located in five geographical regions during the period from 1997 to 2004. Incidence rates were analyzed according to gender, age, and type of leukemia. The Wilcoxon test was performed to evaluate for gender-age based difference between by leukemia type. RESULTS: The median age-adjusted incidence rate (AAIR) of leukemia in children aged 0-14 years old was 53.3 per million. A different AAIR was found regarding ALL and myeloproliferative disorders (MPD) that ranged from 24.8 to 76.84 per 1,000,000 children. Manaus, although located in a poor area of Brazil, exhibited the highest AAIR (56.6 per million) of ALL. Goiania had the highest AAIR (24.5 per million) of MPD. The median age-specific incidence rate (ASIR) for the 16 Brazilian PBCRs demonstrated a marked peak in incidence of ALL at age 3 years old, in both genders. CONCLUSIONS: This population-based study of childhood leukemia demonstrates that substantial regional differences exist regarding the incidence of acute leukemia in Brazil, which warrants further ecological study.

Cancer incidence among children and adolescents in Brazil: first report of 14 population-based cancer registries.

The Brazilian Population-Based Cancer Registry (PBCR) was started in 1967; today there are 20 PBCRs in Brazil. We report the first descriptive analysis of the incidence of childhood cancer based on data from 14 PBCRs, corresponding to 15% of the child and adolescent population in Brazil. Data were obtained from registry databases, including information on population coverage and data quality indicators. The International Classification of Childhood Cancer was used. Age-adjusted rates were calculated by world population. Incidence by cancer registry, age, sex, and cancer type were calculated per 1,000,000 children. Age-adjusted rates per 1,000,000 children/adolescents ranged from 92 to 220 among the 14 PBCRs. The principal groups of cancers were leukemia, lymphoma and central nervous tumors. The median incidence rate of childhood cancer in the 14 PBCRs was 154.3 per million; children 1-4 years of age had the highest incidence rates. The Brazilian PBCRs provide important information about pediatric cancer incidence in an emerging country. The observed incidence rates of childhood leukemia were similar to previous reported rates, and the age-specific incidence rates of retinoblastoma (0-4 years of age) were higher than those for developed countries. These data can be used as baseline incidence rates of childhood and adolescent cancer in Brazil in future epidemiological studies.