Correlation Between Antioxidant Enzyme-Activities and the Chromosome-Damage Induced by Radiotherapy and Chemotherapy in Breast-Cancer Patients

ALEJANDRO DANIEL BOLZAN; MARTHA S. BIANCHI; NÉSTOR O. BIANCHI

CANCER JOURNAL

Association Pour le Developpement de la Communication Cancerologique

Lugar: Villejuif; Año: 1993 vol. 6 p. 142 - 146

0765-7846

Background - There is evidence indicating that SOD activity may influence the chromosomal sensitivity of lympho­cytes to radiation and radiomimetic agents. Methods - The physiological activities of antioxidant enzymes (AOE) catalase (CAT), peroxidases (POD) and super­oxide dismutase (SOD) in whole blood and the yield of radio-and/or chemotherapy-induced chromosome damage were studied in 8 breast cancer patients. Enzymatic dosages were performed before therapy. Results - Blood AOE activities were higher in the cancer patient group than in the normal control group. In patients treated with radiotherapy we found a negative correlation between SOD levels and chromosomal radiosensitivity. Patients treated with radiation plus chemostatic compounds showed lower frequencies of chromosome aberrations than patients treated with radiation only. This effect was probably due to the mortality of lymphocytes with high levels of chromosomal aberrations. Correlation between AOE levels in blood and in normal and cancer mammary tissues showed a significant negative correlation between SOD activity in blood and cancer cells and a significant positive correlation between POD in blood and cancer tissues. Conclusions -Our results suggest that SOD activity in whole blood may be useful to estimate the radiation dose to employ in the therapy of breast cancer. Key words: Antioxidant enzymes, Superoxide dismutase, Catalase, Peroxidases, Chromosome damage, Radiotherapy, Chemotherapy, Breast cancer.