Is there association between handedness and radiosensitivity in breast cancer women?

Radiosensitivity is a biological response to radiation. This response depends on many factors such as radiation factors as well as biological system factors. It is shown that identical doses of radiation for the treatment of Cancer patients produce different biological responses that are assumed to be depend on different specifications of the biological systems. However, by elimination of these factors, people may still show different biological responses such as acute and low responses to radiotherapy in similar doses of radiation. Some reports indicate that breast cancer, immune diseases including autoimmune diseases such as lupus, Myasthenia Gravies and even the rate of allergy are more frequent in left-handed compared to right-handed individuals. The main goal of the present study is determination of radiosensitivity in left-handed compared to right-handed in breast cancer women by cytogenetic assay. Peripheral venous blood samples (10 ml) of 30 breast cancer women (10 left- and 20 right-handed) were divided into two identical parts. One part is exposed to 2 Gy Co-60 gamma rays, and the second part is considered as non-exposed controls. Lymphocytes were cultured in standard media, and cytokinesis blocked to score micronuclei in bi-nucleated cells. The frequency of micronuclei in 1,000 cells in each sample is considered as the rate of radiosensitivity and was compared in left- and right-handed breast cancer women by appropriate statistical analysis. Results showed that radiosensitivity index in left-handers is higher than right-handers also mean frequency of MN in exposed group of left-handers compare to right-handers is elevated. It seems that left-handed breast cancer women are more radiosensitive than right-handed. More investigations on right- and left-handed healthy people are ongoing in our laboratory.