['Biomonitoring is currently applied in the estimation of health risks after overexposure to ionizing radiation (IR). The aim of this study was to compare the association of dicentric chromosomes and acentric fragments (AF) with cancer risk in subjects exposed to IR, as well as in control subjects.', 'The study was performed on 3,574 subjects (2,030 subjects exposed to IR and 1,544 control subjects). The mean follow-up period was 8 years.', 'In subjects reporting exposure to IR, the presence of AFs and dicentric chromosomes was associated with a significant increase in cancer risk, hazard ratio (HR)=1.78 (95% confidence interval (CI)=1.01-3.13) and HR=1.73 (95% CI=1.03-2.90), respectively.'] Do frequency of Acentric Fragments Are Associated with Cancer Risk in Subjects Exposed to Ionizing Radiation?