en Cancer Biology Cancer Biology مقاله کوتاه Short Communication <strong>Background:</strong> Aberrant activation of phosphatidylinositol-3 kinases (PI3K)/AKT/mTOR (mammalian target of rapamycin) pathway is a critical event during gastric cancer progression. Selective function of AKT inhibitor AZD5363 in <em>PI3KCA</em> mutant gastric cancer necessitates the assessment of <em>PI3KCA</em> mutations in these patients. <strong>Methods: </strong>The study included 100 patients with gastric cancer who underwent surgical resection at Imam Reza Hospital, Tehran, Iran, between January 2009 and December 2016. Mutations in codon 1047 of <em>PIK3CA</em> were evaluated by tetra-primer ARMS-PCR and direct sequencing methods. <strong>Results: </strong>We detected p.H1047R and p.H1047L in eight and three samples, respectively. Also, a significant association was found between <em>PIK3CA</em> mutations and lymphatic invasion. Kaplan-Meier analysis demonstrated no significant differences in overall survival between patients with and without mutations. <strong>Conclusion: </strong>Our study detected gain-of-function mutations in exon 20 of <em>PI3KCA</em> gene in 11% of gastric cancer patients. Future studies are needed to assess the mutation rate in other regions of this gene to find eligible patients for targeted therapies. Mutation, Phosphatidylinositol-3 kinases, Somach neoplasms 87 91 http://ibj.pasteur.ac.ir/browse.php?a_code=A-10-1-724&slc_lang=en&sid=1 Mostafa Iranpour No AJA Cancer Epidemiology Research and Treatment Center (AJA-CERTC), AJA University of Medical Sciences, Tehran, Iran Mahyar Nourian No AJA Cancer Epidemiology Research and Treatment Center (AJA-CERTC), AJA University of Medical Sciences, Tehran, Iran Sana Saffari No Department of Biology, Tehran North Branch, Islamic Azad University, Tehran, Iran Esmaeil Samizadeh No Department of Pathology, AJA University of Medical Sciences, Tehran, Iran Mahdieh Mirghafori No Department of Biology and Anatomical Sciences, Shahid Beheshti University of Medical Sciences, Tehran, Iran Shahrokh Iravani No AJA Cancer Epidemiology Research and Treatment Center (AJA-CERTC), AJA University of Medical Sciences, Tehran, Iran Soudeh Ghafouri-Fard 0000-0002-0223-499X Yes Department of Medical Genetics, Shahid Beheshti University of Medical Sciences, Tehran, Iran