Cancer clusters brain

Children are at greater risk than adults for many cancers. Leukemia and brain cancer account for half of all childhood cancers. The causes of these cancers are often obscure, but research has shown that in utero exposures can start the carcinogenic process that becomes fully manifest after birth. Mixtures of chemicals, most notably tobacco smoke and pesticides, are known causative childhood cancer agents. Other chemical mixtures identified as carcinogenic to children are examined in the next chapter on cancer clusters. 

Cluster 7 Brain Cancer Cluster—Electronics Workers... 

A brain cancer cluster was found at an electronics components manufacturing plant. I10l The chemicals used in the plant included... 

Cluster 8 Brain Cancer Cluster—Petrochemical Workers... 

A brain cancer cluster was documented among petrochemical workers 11 The raw materials and chemicals manufactured in the plant included a broad range of lipophilic and hydrophilic compounds, among them... 

The three cancer clusters just discussed are interesting to analyze. Two different sets of chemical mixtures (in electronics workers and petrochemical workers) induced brain cancers in those exposed, whereas in one instance (the second electronics worker group) only the children of those exposed developed brain cancer. These studies show that different mixtures of chemicals can induce the same cancer types and that different mechanisms are at work in the development of the same cancer type. In all three clusters, none of the individual chemicals that the workers were exposed to is known to be causative for brain cancer. 

Cluster 1 Childhood Leukemia 468 Cluster 2 Prostate Cancer 468 Clusters 3-6 Testicular Cancer 469 Cluster 7 Brain Cancer Cluster—Electronic Workers 469 Cluster 8 Brain Cancer Cluster—Petrochemical Workers 470 Cluster 9 Brain Cancers in Offspring of Electronic Workers 470 Cluster 10 Kidney Cancer Cluster 471 Cluster 11 Colorectal Cancer Cluster 471 Cluster 12 Multiple Cancer Cluster 471 Cluster 13 Lung Cancer Cluster 472 Cluster 14 Childhood Leukemia 472 Cluster 15 Multiple Cancer Clusters 473 Cluster 16 Toxic Waste Disposal Site-Related Clusters 474... 

The three cancer clusters just discussed are interesting to analyze. Two different sets of chemical mixtures (in electronics workers and petrochemical workers) induced brain cancers in those exposed, while in one instance (the second electronics... 

Clusters of childhood cancer have been identified in several locations and suspected in others. Leukemia and brain cancer are the two most prevalent of these cancer clusters in children. The following are examples of these two types of children s cancer clusters. 

Extrahypothalamic OX-B-like immunoreactivity, reminiscent to that of CRF, has been described in clustered GABAergic neuronal populations, in the lateral division of central nucleus ofthe amygdala, the bednucleus of the stria terminalis, and in the hippocampus. Moreover, ectopic expression of preproorexin mRNA in the gut, ependymal cells, neuroblastomas, and of orexin receptors in adrenal gland, cancer and hematopietic stem cells suggests yet unexplored roles of orexins as paracrine factors controlling blood-brain barrier, and tumor or stem cell function. 

Austin and Schnatter (1983a) conducted a cohort study of 6588 white male workers employed at a petrochemical plant in the United States between 1941 and 1977. The study was conducted to investigate a cluster of brain tumours that was reported earlier in the same population (Alexander et al., 1980). There were 765 deaths (SMR, 0.8) and 150 cancer deaths (SMR, 0.9) observed. A greater than expected number (based on national rates) of brain cancers (SMR, 1.6 95% confidence interval (CI), 0.8-2.8, based on 12 cases) was observ ed. Austin and Schnatter (1983b) also conducted a nested case-control study to examine the relationship between the risk of primary brain tumours and exposures at the facility. No significant association with 1,2-dichloroethane exposure was observed. 

Cluster 9 Brain Cancers in Offspring of Electronics Workers... 

Approximately half of the families with the Li-Fraumeni cancer syndrome carry one mutant p53 allele in somatic cells (Malkin et al., 1990 Srivastava et al., 1990 see review in Kleihues et al., 1997). This disease is characterized by familial clustering of various cancers, particularly early-onset breast cancer, sarcomas, leukemias, and brain and adrenocortical tumors. Mice with targeted nonfunctional p53 alleles provide an experimental model for this disorder. Early spontaneous tumors, primarily lymphomas and sarcomas, arise frequently in p53 / and p53+/ mice, reflecting the Li-Fraumeni syndrome in these respects. Curiously, mammary and brain tumors are uncommon in p53 knockout mice (Donehower, 1996b Eng et al., 1997). 

World War I gas warfare research included working with over 70 arsenical compounds. Research testing and disposal at one facility has resulted in elevated arsenic being found on 160 residential properties. Soil removals began in 2002. Diseases include aplastic anemia, brain and bone cancers, pernicious anemia (often misdiagnosed arsenic toxicity), cancers of the larynx, and learning disabilities. Where the range or CWM complex is transferred, small disease clusters may serve to identify potential burial sites. 

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