Reduced expression of PTEN protein and its prognostic significance in the gastrointestinal stromal tumor.

Little is reported about the role of PTEN gene in the progression and prognosis of GISTs. This study examined the clinical implications of the tumor suppressor gene PTEN as a prognostic factor in the GISTs. Immunohistological staining and immunoblotting were employed to examine the PTEN protein expression, and its association with clinical measures. Clinicopathological features were reviewed by a retrospective examination of medical records. Reduced PTEN expression was significantly associated with tumor diameter, mitotic figure count, metastasis and pathological stage of tumor (P<0.05), and was not correlated with age, gender and tumor location (P>0.05). The 3-year survival rate of the patients with reduced PTEN expression was significantly lower than those with high PTEN expression (P<0.01). These results suggest that the expression of PTEN gene was significantly linked with the progression and metastasis of GISTs and it is an independent prognostic factor.