Comparative study of chemo-sensitivity expressed as micronuclei in lymphocytes of breast cancer patients, their unaffected first degree relatives and normal controls as a possible prognostic marker

Background: genomic instability is one of primary causes for malignant celltransformation. in this study induced genomic instability expressed as micronucleiin breast cancer (bc) patients with different stages of the disease compared withtheir unaffected first degree relatives (fdr) and normal unrelated controls wasinvestigated. materials and methods: the background and net micronucleusfrequency as well as other cellular damages induced after in vitro treatment with 25μg/ml of bleomycin were evaluated using cytokinesis block micronucleus-cytomeassay in peripheral blood lymphocytes of 120 iranian individuals comprised of 40 bcpatients, 40 fdrs and 40 normal control groups. considering the protocol for eachperson total of 1,000 binucleated cells with well-preserved cytoplasm were blindscored on coded slides. results: the net frequency of micronuclei wasdramatically higher in breast cancer patients compared with controls. alsothe net micronucleus (mn) frequency was significantly higher in fdrscompared with normal unrelated control. considering cancer stages andclinical parameters, our results showed that the higher net frequency of mnwas observed in higher stages and distant metastasis. conclusion: this highermn frequency both background and bleomycin induced in fdr compared withcontrol group, clearly demonstrates that mn frequencies are determined by genecfactors to a major part and mn frequencies represent an intermediate phenotypebetween molecular dna repair mechanisms and the cancer phenotype and affirmsthe approaches that are made to utilize them as predictors’ cancer risk . also theassociation between mn frequency and metastasis proposes it as a possibleprognostic marker.