Tehran University of Medical Sciences International Journal of Hematology-Oncology and Stem Cell Research 2008-2207 7 3 2013 09 15 15 20 Zohreh Sanaat Tabriz University of Medical Science, Tabriz, Iran. Monireh Halimi Tabriz University of Medical Science, Tabriz, Iran. Morteza Ghojezadeh Tabriz University of Medical Science, Tabriz, Iran. Amir Hossein Pirovi Tabriz University of Medical Science, Tabriz, Iran. Jalil Vaez Gharamaleki Tabriz University of Medical Science, Tabriz, Iran. Ali Esfahani Tabriz University of Medical Science, Tabriz, Iran. Iraj Aswadi Kermani Tabriz University of Medical Science, Tabriz, Iran. Jamal Eivazi Ziae Tabriz University of Medical Science, Tabriz, Iran 2015 10 14 Introduction: Gastric cancer remains the second most common cause of cancer-related deaths worldwide. In many malignancies like, lung and breast, multiple prognostic factors are known, such as mutations in Ki-67, HER-2/neu, p53. In this study, we evaluated immunohistochemical protein expression patterns of cell-cycle-regulators p53, proliferation marker Ki-67, surface expression of CD44, HER-2/neu oncogene proposed as useful prognostic factors. Methods: In this descriptive-analytic study, we evaluate 100 patients with gastric cancer who were referred to Shahid Ghazi Hospital or other oncology clinics of Tabriz University of Medical Sciences in 2005-2010. Patients with pathologic confirmation of gastric cancer were selected. Expression of p53, ki-67, CD-44, HER-2/neu were detected by immunohistochemical staining. Results: In this study, 100 patients with gastric cancer participated. 76(76%) were men and 24(24%) were women with mean age of 64.02(8.05) years. Seventy two samples were intestinal type and 28 were diffuse type. CD44 was positive in 27(27%) patients. P53 was positive in 35(35%) patients. Ki-67 was positive in 53(53%) patients. HER-2/neu was positive in 51(51%) patients. Conclusion: The frequency of positive p53, Ki-67, CD44 and HER-2/neu varied in different studies. Positive Ki-67 and HER-2/neu were not associated with changes in survival but positive p53 and CD44 were significantly associated with improved survival. https://ijhoscr.tums.ac.ir/index.php/ijhoscr/article/view/449 https://ijhoscr.tums.ac.ir/index.php/ijhoscr/article/download/449/348