e14502 Background: Currently known markers of lung adenocarcinoma are insufficient to predict the development of this disease, which makes the search for new molecular markers a relevant problem. Our purpose was to analyze changes in genes copy number variation (CNV) in tumor and non-tumor cells of the lung in patients with (T1-3N1-2M0-1) and without (T1-3N0M0) metastasis to identify potential molecular markers for the prediction of the disease development. Methods: The study was performed on tissue sections from FFPE blocks of 90 patients diagnosed with lung adenocarcinoma. Tumor and non- tumor cells were isolated using laser microdissection (Palm MicroBeam, Carl Zeiss). Copy numbers of 32 genes (BAX, BCL2, C-FLAR, P53, MDM2, BFAR, SEMA3B, RASSF1A, CASP9, CASP3, CASP8, SOX2, OCT4, NANOG, PIK3, MKI67, HV2, HIF1A1, XRCC1, MMP1, TERT, CTNNB1, VEGFA, KRAS, EGFR, GRB2, SOS1, MAPK1, STAT1, BRAF, FTO, mir3678) were determined by Real-Time qPCR (ACTB, B2M, GAPDH - reference genes). Statistical analysis was performed using the Mann-Whitney test. Results: A pooled sample (n = 90) showed significant (p < 0.005) increase in the copy numbers of MAPK1 and SOX2 and decreased copy numbers of the mir3678, HV2, BAX and CASP3 genes in tumor cells compared to non-tumor. Patients with metastatic and non-metastatic lung adenocarcinoma had significant (p < 0.05) differences in genes copy number in tumor cells compared to non-tumor ones: patients with T1-3N1-2M0-1 (n = 50) – decreased copy numbers of the mir3678, HV2, MDM2, P53, XRCC1, CASP3 and OCT4 genes and increased SOX2 copy number; patients with T1-3N0M0 (n = 40) – increased copy numbers of the MAPK1 and mir3678 genes and decreased HV2 copy number. Conclusions: The detected changes in copy numbers of genes responsible for the regulation of apoptosis, proliferation, oxidative phosphorylation and the function of the EGFR signaling pathway in lung tumor cells revealed new molecular markers to predict the risk of metastasis ( mir3678, MDM2, Р53, SOX2, XRCC1, CASP3, OCT4, MAPK1).