Expression of PI3K/p-AKT/p-mTOR in gastric carcinoma and its correlation with clinicopathologic characteristics.

73 Background: The objective of this study was to explore the expression patterns of PI3K/p-AKT/p-mTOR in gastric cancer (GC) and its relationship with clinicopathological characteristics and thereby to understand the role of activated PI3K/AKT/mTOR pathway in the initiation and development of gastric cancer. Methods: Envision immunohistochemistry assay was used to examine the expression patterns of PI3K, p-AKT and p-mTOR in primary GC sites, metastatic lymph nodes and peritumoral mucosa among 50 patients who underwent radical gastrectomy for stage I-IV (M0) gastric cancer. Results: The PI3K, p-AKT and p-mTOR showed significantly higher expressions in primary tumor sites and metastatic lymph nodes as compared to that of the peritumoral mucosa. The study of the pathway components and clinicopathological characteristics revealed that p-AKT and p-mTOR expressions were selectively higher in primary tumors with less than 5 cm diameter. The PI3K, p-AKT and p-mTOR positive patients had shorter median survival time as compared to the patients negative for them (42.8 m vs. 57.0 m, 46.8 m vs. 55.9 m, 47.2 m vs. 53.0 m). However, the differences were not statistically significant. Conclusions: Activation of PI3K/AKT/mTOR pathway was associated with the development and prognosis of gastric cancer. The expression of PI3K/p-AKT/p-mTOR was correlated well with tumor specificity in gastric cancer and they might have some potential as promising targets for clinical therapy.