The alkaline comet assay, or single cell gel electrophoresis, is one of the most popular methods for assessing DNA damage in human population. One of the open issues concerning this assay is the identification of those factors that can explain the large inter-individual and inter-laboratory variation. International collaborative initiatives such as the hCOMET project - a COST Action launched in 2016 - represent a valuable tool to meet this challenge. The aims of hCOMET were to establish reference values for the level of DNA damage in humans, to investigate the effect of host factors, lifestyle and exposure to genotoxic agents, and to compare different sources of assay variability. A database of 19,320 subjects was generated, pooling data from 105 studies run by 44 laboratories in 26 countries between 1999 and 2019. A mixed random effect log-linear model, in parallel with a classic meta-analysis, was applied to take into account the extensive heterogeneity of data, due to descriptor, specimen and protocol variability. As a result of this analysis interquartile intervals of DNA strand breaks (which includes alkali-labile sites) were reported for tail intensity, tail length, and tail moment (comet assay descriptors). A small variation by age was reported in some datasets, suggesting higher DNA damage in oldest age-classes, while no effect could be shown for sex or smoking habit, although the lack of data on heavy smokers has still to be considered. Finally, highly significant differences in DNA damage were found for most exposures investigated in specific studies. In conclusion, these data, which confirm that DNA damage measured by the comet assay is an excellent biomarker of exposure in several conditions, may contribute to improving the quality of study design and to the standardization of results of the comet assay in human populations.

• Klíčová slova
• Biomarkers, Comet assay, DNA damage, Human biomonitoring, Pooled analysis,
• MeSH
• biologické markery krev   MeSH
• kometový test metody   MeSH
• lidé MeSH
• poškození DNA genetika   fyziologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• biologické markery MeSH

OBJECTIVES: The high incidence of head and neck cancer (HNC), significantly associated with living environment and behaviour, can be prevented more efficiently. The aim of this study was to evaluate the environmental and behavioural risk factors for HNC. METHODS: Using a detailed questionnaire on social status, education, living and occupational environment exposures, family cancer and lifestyle, HNC patients (103 cases, 76.7% of men) were compared with control subjects (244 subjects, 73% of men) balanced by age: mean (standard deviation) 63.8 (9.3) and 63.8 (9.0) for cases and controls, respectively. RESULTS: The results of this study showed that smoking and low education were significant risk factors for HNC regardless of sex. Family HNC and breast cancer were significant predictors of HNC risk. CONCLUSION: The study confirmed previous results that smoking and low education are significantly associated with HNC. Additionally, results pointed to significant HNC and breast cancer risk in HNC patient's families that may have originated from passive smoking or a smoking habit stemming from social environments that support it. Better dissemination programmes regarding smoking risks for children and adults are needed, targeting not only individuals but also families.

• Klíčová slova
• aetiology, education, family cancer, head and neck cancer, smoking,
• MeSH
• dítě MeSH
• dospělí MeSH
• genetická predispozice k nemoci * MeSH
• incidence MeSH
• kouření epidemiologie   MeSH
• lidé MeSH
• nádory hlavy a krku epidemiologie   etiologie   genetika   MeSH
• pití alkoholu epidemiologie   MeSH
• průzkumy a dotazníky MeSH
• rizikové faktory MeSH
• sexuální faktory MeSH
• sociální determinanty zdraví MeSH
• studie případů a kontrol MeSH
• věkové faktory MeSH
• zdravé chování * MeSH
• znečištění tabákovým kouřem * MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• znečištění tabákovým kouřem * MeSH