Use of Genotoxicity Methods for Human Biomonitoring: Prevention – Diagnosis and Therapy of Cancer

A variety of different methods have been used to investigate the radiosensitivity of cancer patients treated with radiotherapy in order to predict the risk for developing adverse effects, improve the therapeutic success, and patient’s quality-of-life.The most investigations were realised with peripheral blood cells from head and neck cancer, breast cancer, and prostate cancer patients. The irradiation response of patient-derived lymphocytes has been associated with acute and late normal tissue reactions to radiotherapy. The approaches which were used include measurements of cytotoxic effects (including apoptosis and cell cycle delay), identification and analyses of specific genes and use of methods which reflect genotoxicity and DNA repair. The most frequently employed approaches that detect damage of the genotoxic material which is induced by ionizing radiation (double strand breaks and oxidative damage) are chromosomal aberration (CA) analyses of metaphase cells, micronucleus (MN) experiments detecting structural and numerical CA, γH2AX assays which can be used to measure double strand breaks, and single cell gel electrophoresis (SCGE) assays reflecting single and double DNA strand breaks . Individual differences in the repair capacity were mainly studied in SCGE experiments in which the time kinetics of the disappearance of “comets” was measured. Overall the results of these studies are highly controversial, possibly due to inconsistent experimental designs and methodological shortcomings (including small study groups)...