One of the variability factors of malignant tumors, particularly breast cancer is a genetic variation due to gene polymorphism, and especially - the phenomenon of loss of heterozygosity (LOH). It has been shown that LOH in some genes could be a good prognostic marker. Thus, the aim of this work was genome-wide association study of loss of heterozygosity and Metastasis-free survival in breast cancer. The study involved 68 patients with breast cancer. To evaluate LOH status that was conducted by microarray analysis on high density DNA-chips made by firm Affymetrix CytoScanTM HD Array. 13 815 genes were evaluated in order to reveal loss of heterozygosity. The frequency of LOH varied from 0% to 63%. As a result of the associative analysis four genes EDA2R, PGK1, TAF9B and CYSLTR1 were determined, the presence of loss of heterozygosity that was associated with Metastasis-free survival. The presence of LOH in these genes is associated with low Metastasisfree survival
