Structural chromosome aberrations are a predictive biomarker of cancer risk. Conventional chromosome analysis widely used for these purposes detects unstable chromosome aberrations that are eliminated during cell division. Stable aberrations that may persist in the body and tend to accumulate during a lifetime can be detected by fluorescence in situ hybridization (FISH). The aim of the study was to investigate the level of chromosome damage in newly diagnosed cancer patients and control subjects by FISH. Both groups of untreated cancer patients had increased frequency of aberrant cells. However, chromosome damage affected different cytogenetic endpoints. Stable translocations and cells with complex rearrangements were elevated in breast cancer patients whereas unstable chromosome aberrations (dicentric chromosomes and acentric fragments) were elevated in gastrointestinal cancer patients. These associations observed in nonsmokers were typically not pronounced in smokers (with the exception of dicentric chromosomes in gastrointestinal patients). Exposure to tobacco smoke increased aberrations in healthy controls but not in the cancer patients. Our study suggests an association between cancer and stable chromosomal rearrangements in breast cancer patients. Unstable aberrations elevated in gastrointestinal cancer patients may be at least partly ascribed to the exposure to diagnostic X-rays.

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Air pollution is an important environmental factor influencing human health. In this study, we compared chromosome damage in city policemen from three cities in the Czech Republic: industrial Ostrava characterized by high levels of benzo[a]pyrene, Prague with heavy traffic emitting nitrogen oxides, and relatively clean Ceske Budejovice located in an area with predominantly agricultural activity. Chromosomal aberrations in lymphocytes were evaluated by fluorescence in situ hybridization with painting probes for chromosomes 1, 2, 3, and 4 in spring and autumn. An increase in the frequency of unstable chromosome aberrations, that is, dicentric chromosomes and acentric fragments, was observed in spring samples from Ostrava (p = .014 and p = .044, respectively) and Prague (p = .002 and p = .006, respectively) in comparison with Ceske Budejovice. The difference was significant only for samples taken after the winter period, when the concentration of pollutants in the air increases due to poor dispersion conditions. An increased frequency of dicentric chromosomes was observed in spring compared to autumn in both Ostrava and Prague (p = .017 and p = .023, respectively), but not in Ceske Budejovice. More breakpoints were observed on chromosome 1 than on the other chromosomes examined (p < .001). The number of breakpoints in the heterochromatin region 1p11-q12 was lower than in other parts of chromosome 1 (p < .001), suggesting a protective function of heterochromatin against damage. Our study showed, that air pollution increased the frequency of unstable chromosome aberrations, especially dicentric chromosomes. However, we did not show an effect on stable chromosome rearrangements.