Expression of PTEN Protein in Human Gastric Carcinoma and Its Prognosis

Objective To study the role of PTEN mutation in the development of gastric carcinoma and its relationship with prognosis.Methods A panel of human primary gastric tissue with respect to the presence of PTEN mutation was examined by immunohistochemistry,and PTEN expression was analyzed with clinical pathologic characteristics of tumor and the patients' survival rate observed after one year,three years or five years.Results Immunohistochemistry staining showed that clearly brown staining was restricted to cytoplasm.The positive rate of PTEN protein in neighboring non-tumor mucosa was higher than those in gastric carcinoma(100% vs 66%,P0.005).The expression level marked as(-),(+),(++),(+++) in neighboring non-tumor mucosa group was 0%,18.9%,34.0%,47.2% and that in the gastric carcinoma group was 34%,26.4%,24.5%,and 15.1%,respectively(P0.005).Decreased expression level of PTEN protein was significantly associated with tumor depth,lymph node metastasis,histologic grade and pTNM stage(P0.05).However no significant relationship was found with gender,age,tumor location,tumor size,distant metastasis and presence of tumor thrombus(P0.05).Conclusion Mutation of PTEN may be involved in tumorigenesis and progression of gastric carcinoma.For patients with positive mutation of PTEN protein,the survival rates for one year,three years or five years are significantly higher than those with negative mutation of PTEN protein.It is suggested that PTEN can be an objective marker for its pathological and biological behaviors of gastric carcinoma.