Assessment of micronuclei frequency in the peripheral blood lymphocytes in patients with gastric cancer before and after chemotherapy treatment

Cancer is one of the leading causes of illness and mortality in the world. There are different ways to treat cancer, the most common being chemotherapy and radiotherapy. On a positive note, these treatments produce some fatal chromosomal damages in tumour cells, but they also produce some chromosomal damages in healthy cells with long-term side effects. Some of these mutations can lead to a double-strand break in the to rejoin the daughter nuclei and turning into micronuclei (MN).Previous researches, using cytogenetical studies, have proven that there is a specific relationship between the frequency of MN formation in the peripheral blood of healthy subjects and the possibility of cancer incidence. Therefore, it can be concluded that cytogenetical studies such as Cytokinesis Block Micronucleus assay (CBMN) can help cancer prediction and study of treatment caused complications.In this study, blood samples of 25 gastric cancer patients undergoing chemotherapy treatment, were extracted before and after treatment and cultured in a complete culture medium (FBS 10%), with 200 microliters of PHA, for 44-45 hours in a 37˚C incubator. Then, 50 microliters of cytochalasin-B were added and the samples were left for a further 27 hours. At the 72nd hour, the cells were taken to the harvesting stage of the test. Finally, 1000 bi-nucleated cells were counted under microscope in order to find the amounts of micronuclei.The average numbers of micronuclei, before and after treatment, was 310.76 with a standard deviation of 76.44 in 1000 lymphocytes. Also, the average survival rate was 13.56 months with a standard deviation of 2.21 months. It is also understood that patient s gender and age did not have a significant effect on MN frequency and life expectancy. (P<0.05)This research shows that MN frequency has increased significantly after treatment. Also, it is noticeable from the results that the survival rate in different age and gender groups are under the influence of MN frequency; as the MN amount increases, the patient s life expectancy decreases.