title: Increased prevalence of malignant diseases in the close neighborhood of children with cancer.
abstract: Clustering of cancer in families may be due to chance, inherited genetic mutations, common exposure to environmental agents, or a combination of these factors. The authors, to address a clinical impression that cancer occurs more often in the environment of a child with cancer, investigated whether the prevalence of cancer among children and adults in the neighborhood of children with cancer was higher than the prevalence in the neighborhood of healthy children. One hundred thirty-seven children diagnosed with a malignant disease between 1981 and 1992 at the Department of Pediatrics, University Hospital of Linköping, Sweden, were investigated and compared with 232 healthy control children. The control children were traced from the official Swedish population registry. It was found that 13 percent of the children with cancer and six percent of the control children were close neighbors of other children diagnosed with cancer (p < .05). Cancer also was more common in the circles of acquaintances around the children with cancer than in circles of acquaintances around control children (p < .03). The frequency of cancer in the neighborhood or in the circle of acquaintances was significantly greater in older children than in younger children. These results support the hypothesis that environmental factors can initiate or precipitate cancer in children as well as in adults.
authors.affiliation: Division of Pediatrics, Department of Health and Environment, Linköping University, S-581 85 Linköping, Sweden. Ulf.Samuelsson@lio.se
authors.forename: Ulf
authors.initials: U
authors.lastname: Samuelsson
authors.forename: Britt
authors.initials: B
authors.lastname: Gustafsson
authors.forename: Johnny
authors.initials: J
authors.lastname: Ludvigsson
mesh_terms: D000293:Adolescent; D000328:Adult; D016022:Case-Control Studies; D002648:Child; D002669:Child Welfare; D002675:Child, Preschool; D004777:Environment; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D009369:Neoplasms / Q000453:epidemiology*; D010379:Peer Group; D015995:Prevalence; D012307:Risk Factors