Chromosomal aberrations and SCEs as biomarkers of cancer risk.

Previous studies have suggested that the frequency of chromosomal aberrations (CAs), but not of sister chromatid exchanges (SCEs), predicts cancer risk. We have further examined this relationship in European cohorts comprising altogether almost 22,000 subjects, in the framework of a European collaborative project (CancerRiskBiomarkers). The present paper gives an overview of some of the results of the project, especially as regards CAs and SCEs. The results confirm that a high level of CAs is associated with an increased risk of cancer and indicate that this association does not depend on the time between CA analysis and cancer detection, i.e., is obviously not explained by undetected cancer. The present evidence indicates that both chromatid-type and chromosome-type CAs predict cancer, even though some data suggest that chromosome-type CAs may have a more pronounced predictive value than chromatid-type CAs. CA frequency appears to predict cancers at various sites, although there seems to be a particular association with gastrointestinal cancers. SCE frequency does not appear to have cancer predictive value, at least partly due to uncontrollable technical variation. A number of genetic polymorphisms of xenobiotic metabolism, DNA repair, and folate metabolism affect the level of CAs and might collectively contribute to the cancer predictivity of CAs. Other factors that may influence the association between CAs and cancer include, e.g., exposure to genotoxic carcinogens and internal generation of genotoxic species. Although the association between CA level and cancer is seen at the group level, an association probably also exists for the individual, although it is not known if an individual approach could be feasible. However, group level evidence should be enough to support the use of CA analysis as a tool in screening programs and prevention policies in occupational and environmental health.

Spontaneous Abortions of Known Karyotype Related to Occupational and Environmental Factors: A Case-Referent Study.

The aim of the study was to examine the roles of occupational and environmental factors in relation to spontaneous abortions with known karyotypes. A case-referent study was performed among 793 women hospitalized for spontaneous abortion and 808 referents attending ultrasound screening at 17-18 weeks of pregnancy. Chromosomal analysis were obtained for 371 abortuses and 679 referent newborns. Significantly elevated odds ratios (ORs) for abortions with abnormal chromosomes were found for maternal psychological strain at work (OR:1.8), exposure to anesthetic gases (OR:6.9), video display unit work >/= 1/2 working day (OR:1.9), and sales work (OR:2.0). An association with paternal security work (OR:3.0) was possibly confounded by maternal exposure to psychological strain. Abortuses with normal chromosomes were associated with maternal sales work (OR:1.9) and psychological (OR:2.3) and physical (OR:1.6) strain at home, and with paternal construction work (OR:2.1) and physical strain at home (OR:1.9). No relationship between air pollution and spontaneous abortion was observed regardless of karyotype.