-Lymphocytes of Breast and Esophageal Cancer Patients as Determined by Micronucleus Assay

Radiosensitivity/Human lymphocytes/Breast cancer/Esophageal cancer/Micronuclei. Enhanced chromosomal radiosensitivity is a feature of many cancer predisposition conditions, indic-ative of the important role of chromosomal alterations in carcinogenesis. In this study the cytokinesis-blocked micronucleous assay was used to compare the radiosensitivity of blood lymphocytes obtained from Iranian breast or esophageal cancer patients (n = 50, n = 16; respectively) with that of control indi-viduals (n = 40). For each sample, one thousand binucleate lymphocytes were analyzed before and after in vitro exposure to 3 Gy of g rays. The radiation-induced frequency of micronucleus was significantly higher in the breast cancer group (261/1,000 binucleated cells) than in esophageal cancer group (241/1,000 binucleated cells, P < 0.01) or in the control group (240/1,000 binucleated cells, P < 0.01). The results indicate that breast cancer patients are more radiosensitive compared to normal healthy individuals or esophageal cancer patients. Increased radiosensitivity could be due to defects in DNA repair genes involved in breast cancer formation. Since patients with esophageal cancer did not show elevated radiosen-sitivity, it is assumed that the contribution of radiosensitivity-related genes to the development of esoph-ageal cancer may be smaller than the contribution of those genes to breast cancer