Expression And Clinical Significance Of PIK3CA In Gastric Stromal Tumors

Objective: To investigate the expression of PIK3CA gene in different degree ofmalignancy of gastrointestinal stromal tumors, as well as the its correlation withclinicopathological parameters. We also quantitatively analysis the protein expression ofPIK3CA in gastrointestinal stromal tumor, and explore its significance in the clinicalprognosis and therapeutic applications.Methods: Specimens including71cases of gastric stromal tumor (low risk:10cases;moderate risk:21cases; high risk:40cases), tumor adjacent tissues and normal gastrictissue were selected from January2006to December2010in Taizhou People’s Hospital.Immunohistochemistry was used to detect the PIK3CA protein expression in different riskof gastric stromal tumor, and the relevance between PIK3CA protein expression andclinicopathological parameters were analyzed. Spearman rank correlation was performedto analysis the correlation between PIK3CA expression and clinicopathological features ofgastric stromal tumors. Kaplan-Meier survival curves was used to analysis the relationshipbetween PIK3CA expression and prognosis of patients. PIK3CA protein content wasdetected in secimens by Western Blot.Results:1、Positive rates of PIK3CA protein were20.0%,38.1%and75.0%in low risk,moderate risk and high inter-risk gastric stromal tumor tissue respectively. PIK3CAexpression in gastric stromal tumor tissue was positively correlated with local invasion ormetastasis.2、Univariate analysis showed that: PIK3CA expression levels were significantlyassociated with survival, the difference was statistically significant. Expression of PIK3CAin adjacent tissues was significantly lower than in gastric stromal tumor (p=0.02), andsignificantly higher than in normal gastric tissue (p=0.04). Conclusion：1、。There were positive rate and upward trend of PIK3CA protein expressing amonglow risk, medium risk and high risk of gastric stromal tumors, and PIK3CA gene has acertain significance to determine prognosis of gastric stromal tumors.2、PIK3CA protein expression significantly increased in gastric stromal tumor,indicating that PIK3CA plays a role in the occurrence and development of gastric stromaltumor.3、PIK3CA play a synergistic role in progress and the transfer process of gastricstromal tumor. PIK3CA can become target of gastric stromal tumor detection, suggestingthat in the course of the treatment of cancer, targeted therapy for PIK3CA may affect tumorinvasion and metastasis, reducing recurrence and distant metastasis.