en Molecular Genetics & Genomics Molecular Genetics & Genomics مقاله کامل Full Length/Original Article <div style="text-align: justify;"><strong>Background:</strong> The analysis of the gene copy number alterations in tumor samples are increasingly used for diagnostic and prognostic purposes in patients with gastric cancer (GC). However, these procedures are not always applicable due to their invasive nature. In this study, we have analyzed the copy number alterations of five genes (<em>HER2</em>, <em>MDM2</em>, <em>c-MYC</em>, <em>c-MET</em>, and <em>TP53</em>) with a fixed relevance for GC in the circulating tumor cells (CTCs) of GC patients, and, accordingly, as a potential approach, evaluated their usage to complete primary tumor biopsy. <strong>Methods: </strong>We analyzed the status of the copy number alterations of the selected genes in CTCs and matched biopsy tissues from 37 GC patients using fluorescence <em>in situ </em>hybridization.<strong> Results: </strong><em>HER2</em> amplification was observed in 2 (5.41%) samples. <em>HER2</em> gene status in CTCs showed a strong agreement with its status in 36 out of 37 patients&rsquo; matched tissue samples (correlation: 97.29%; Kappa: 0.65; <em>p</em> < 0.001). <em>MDM2</em> amplification was found only in 1 (2.70%) sample; however, the amplification of this gene was not detectable in the CTCs isolated from this patient. <em>c-MYC</em> amplification was observed in 3 (8.11%) samples, and the status of its amplification in the CTCs indicated a complete agreement with its status in the matched tissue samples (correlation: 100%; Kappa: 1.0).<strong> Conclusion</strong>: Our work suggests that the amplification of <em>HER2</em> and <em>c-MYC</em> is in concordance with the CTCs and achieved biopsies, and, consequently, CTC may act as a non-invasive alternative for recording the amplification of these genes among GC patients.</div> Circulating tumor cells, Fluorescence in situ hybridization, Gene amplification 47 53 http://ibj.pasteur.ac.ir/browse.php?a_code=A-10-1-783&slc_lang=en&sid=1 Fatemeh Nevisi 0000-0003-3759-9398 No Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran Marjan Yaghmaie 0000-0001-7745-9360 Yes Hematology, Oncology and Stem cell Transplantation Research Center, Tehran University of Medical Sciences, Tehran, Iran Hossein Pashaiefar 0000-0003-0673-4841 No Hematology, Oncology and Stem cell Transplantation Research Center, Tehran University of Medical Sciences, Tehran, Iran Kamran Alimoghaddam 0000-0002-3849-6545 No Hematology, Oncology and Stem cell Transplantation Research Center, Tehran University of Medical Sciences, Tehran, Iran Masoud Iravani 0000-0003-0511-750X No Masood GI and Hepatology Clinic, Tehran, Iran Gholamreza Javadi 0000-0002-0431-9954 No Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran Ardeshir Ghavamzadeh 0000-0001-5587-0191 No Hematology, Oncology and Stem cell Transplantation Research Center, Tehran University of Medical Sciences, Tehran, Iran