PS-01-018 PAK 6 immunohistochemistry marker in non-small cell lung cancer (NSCLC) A. Kucukosmanoglu * , O. D. İlara Colakkadıoglu, K. Bakir * University of Gaziantep, Pathology, Turkey Objective: PAK 6 is a member of P21-activated kinase family. Many human tumor express and activate this family. Because of their role in cell transformation, they become therapeutic targets. They have important roles in cell survival, cell proliferation and cell migration. They affect cell growth and tumor invasion. Method: 175 cases with NSCLC reported in Gaziantep University Pathology Department between 2000 and 2010, reviewed retrospectively. Immunohistochemically nuclear and cytoplasmic PAK 6 stainings were considered positive and scored according to degree of staining. Results: Our cases included 110 squamous cell carcinoma, 49 adenocarcinoma, 9 adeno squamous carcinoma and 7 large cell carcinoma. There was no significantly associated between tumor types and PAK6 staining. 38 of 175 patients showed recurrence and of 23 cases showed nuclear staining but there were no statistically significance (p:0,267). 31 cases died from the disease and in 21 of these cases nuclear stainig was very intresting, inspite of statistical results. Conclusion: In this study PAK 6 staining patern and score were compared with tumor type, size, recurrence, mortality and lymph node involvement in NSCLC. And we found no statistically significance. 150 of 175 case with NSCLC stained with PAK 6. These results suggest that PAK 6 was expressed in lung like prostat, plasenta and breast.