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

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

Higher risk for acute childhood lymphoblastic leukaemia in Swedish population centres 1973-94

A population-based sample of acute childhood leukaemia cases in Sweden 1973–94 was analysed by a geographical information system (GIS) for spatial leukaemia distribution in relation to population density. The annual incidence rate for acute lymphoblastic leukaemia (ALL) was 3.6, and for acute non-lymphoblastic leukaemia (ANLL) 0.7, cases per 100 000 children. Incidence rates in population centres, constituting 1.3% of Sweden's land area and approximately 80% of the population, compared with the rest of Sweden showed a statistically significant excess of ALL [odds ratio (OR) 1.68; 95% confidence interval (CI) 1.44–1.95], but not ANLL (OR 1.13; 95% CI 0.98–1.32). An increasing trend, however not statistically significant, was found for ALL incidence with both increasing population density in parishes and increasing degree of urbanity in municipalities. These findings support the theories that some environmental factors associated with high population density, such as infectious agents, may be of aetiological importance for childhood acute lymphoblastic leukaemia. © 1999 Cancer Research Campaig

Cancer in the offspring of radiation workers: an investigation of employment timing and a reanalysis using updated dose information

An earlier case-control study found no evidence of paternal preconceptional irradiation (PPI) as a cause of childhood leukaemia and non-Hodgkin's lymphoma (LNHL). Although fathers of children with LNHL were more likely to have been radiation workers, the risk was most marked in those with doses below the level of detection. The timing of paternal employment as a radiation worker has now been examined. The previously reported elevated risk of LNHL in the children of male radiation workers was limited to those whose fathers were still radiation workers at conception or whose employment also continued until diagnosis. Children whose fathers stopped radiation work prior to their conception were found to have no excess risk of LNHL. It was not possible to distinguish between the risks associated with paternal radiation work at conception and at the time of diagnosis. A reanalysis of the original study hypothesis incorporating updated dosimetric information gave similar results to those obtained previously. In particular, the risks of LNHL did not show an association with radiation doses received by the father before conception. It seems likely that the increased risk of LNHL among the children of male radiation workers is associated with an increased exposure to some infective agent consequent on high levels of population mixing

Cancer in the offspring of female radiation workers: a record linkage study

This study uses record linkage between the National Registry of Childhood Tumours (NRCT) and the National Registry for Radiation Workers to re-assess our earlier finding that the offspring of women radiation workers exposed to ionising radiation before the child's conception may be at an increased risk of childhood cancer. An additional 16 964 childhood cancer patients taken from the NRCT, together with the same number of matched controls, are included. Pooled analyses, based on the new and original datasets, include 52 612 cases and their matched controls. Relative risks (RRs) for maternal employment as a radiation worker, maternal exposure or not during the relevant pregnancy and pattern of employment relative to conception and diagnosis dates were calculated

Incidence of Sarcoma Histotypes and Molecular Subtypes in a Prospective Epidemiological Study with Central Pathology Review and Molecular Testing

International audienceBACKGROUND: The exact overall incidence of sarcoma and sarcoma subtypes is not known. The objective of the present population-based study was to determine this incidence in a European region (Rhone-Alpes) of six million inhabitants, based on a central pathological review of the cases. METHODOLOGY/PRINCIPAL FINDINGS: From March 2005 to February 2007, pathology reports and tumor blocks were prospectively collected from the 158 pathologists of the Rhone-Alpes region. All diagnosed or suspected cases of sarcoma were collected, reviewed centrally, examined for molecular alterations and classified according to the 2002 World Health Organization classification. Of the 1287 patients screened during the study period, 748 met the criteria for inclusion in the study. The overall crude and world age-standardized incidence rates were respectively 6.2 and 4.8 per 100,000/year. Incidence rates for soft tissue, visceral and bone sarcomas were respectively 3.6, 2.0 and 0.6 per 100,000. The most frequent histological subtypes were gastrointestinal stromal tumor (18%; 1.1/100,000), unclassified sarcoma (16%; 1/100,000), liposarcoma (15%; 0.9/100,000) and leiomyosarcoma (11%; 0.7/100,000). CONCLUSIONS/SIGNIFICANCE: The observed incidence of sarcomas was higher than expected. This study is the first detailed investigation of the crude incidence of histological and molecular subtypes of sarcomas

Residential mobility and risk of childhood acute lymphoblastic leukaemia: an ecological study

We conducted an ecological analysis of childhood acute lymphoblastic leukaemia-incidence data from children ⩽5 years old during 1992–1998 from the Surveillance, Epidemiology, and End Results Program in 200 counties and Hawaii. The response variable was the count of cases in each county race–sex stratum, examined in relation to data from the United States Census and the United States Department of Agriculture. The final models for both sexes included race, proportion moved during 1985–1990, and proportion of households with income ⩾$5000 as potential predictors. Incidence was lower among black boys (rate ratio (RR)=0.5) and black girls (RR=0.4) than among other children of the same sex; no other significant racial differences were detected. Incidence was elevated among males (but not females) residing in counties where ⩾50$5000 (RR=1.5). These sex differences in risk factors were unexpected

Demographic History of Indigenous Populations in Mesoamerica Based on mtDNA Sequence Data

The genetic characterization of Native American groups provides insights into their history and demographic events. We sequenced the mitochondrial D-loop region (control region) of 520 samples from eight Mexican indigenous groups. In addition to an analysis of the genetic diversity, structure and genetic relationship between 28 Native American populations, we applied Bayesian skyline methodology for a deeper insight into the history of Mesoamerica. AMOVA tests applying cultural, linguistic and geographic criteria were performed. MDS plots showed a central cluster of Oaxaca and Maya populations, whereas those from the North and West were located on the periphery. Demographic reconstruction indicates higher values of the effective number of breeding females (Nef) in Central Mesoamerica during the Preclassic period, whereas this pattern moves toward the Classic period for groups in the North and West. Conversely, Nef minimum values are distributed either in the Lithic period (i.e. founder effects) or in recent periods (i.e. population declines). The Mesomerican regions showed differences in population fluctuation as indicated by the maximum Inter-Generational Rate (IGRmax): i) Center-South from the lithic period until the Preclassic; ii) West from the beginning of the Preclassic period until early Classic; iii) North characterized by a wide range of temporal variation from the Lithic to the Preclassic. Our findings are consistent with the genetic variations observed between central, South and Southeast Mesoamerica and the North-West region that are related to differences in genetic drift, structure, and temporal survival strategies (agriculture versus hunter-gathering, respectively). Interestingly, although the European contact had a major negative demographic impact, we detect a previous decline in Mesoamerica that had begun a few hundred years before