Study Of Serum Tumor Markers, Tissue Protein Expression And Their Relationship With Prognosis Of Gastric Cancer

Objective: To study the level of serum tumor markers CEA, CA19-9 and CA125 and the expression of HER-2/neu, PTEN and CD44V6 protein in gastric cancer and their relationship with development, progress, invasion and prognosis of gastric cancer, thus providing reference index for predicting the prognosis of gastric cancers.Methods: The expression of HER-2/neu, PTENand CD44V6 protein in normal and gastric cancer tissues were examined with immunohistochemical staining method. The level of tumor markers CEA, CA19-9 and CA125 in serum were retrospectively analyzed from medical records of patients.Results: (1) The tissue expression of PTEN in normal samples was 90%, significantly higher than in gastric cancer (36.9%)(P<0.05).The expression of PTEN in gastric cancer was closely related to differentiation, the deepness of invasion and lymph node metastasis (P<0.05) but not related to the age, sex and pathological stages of patients(P>0.05).(2) The positive rate of CD44V6 expression in gastric cancer was 58.5%, higher than in normal gastric mucosa 10.0% (P<0.05). The expression of CD44V6 in gastric cancer was closely associated with differentiation, the deepness of invasion and lymph node metastasis (P<0.05) but not related to the age, sex and pathological stages of patients(P>0.05).(3) The expression rate of HER-2/neu in gastric cancer was 21.5%, higher than in normal gastric mucosa 10.0% (P<0.05). The difference was significant. The expression of HER-2/neu in gastric cancer was closely associated with differentiation, the deepness of invasion and lymph node metastasis (P<0.05) but not related to the age, sex and pathological stages of patients(P>0.05).(4) The expression of PTEN was negatively correlated to the expression of HER-2/neu and CD44V6 significantly(P< 0.05). However, the closely positive correlations were found between the expression of CD44V6 and HER-2/neu. (5) The three year survival rate for gastric cancer patients with positive or negative of serum tumor markers CEA, CA19-9 and CA125 were 23.1%, 44.6%, respectively. The difference was statistically significant(P<0.05). The three year survival rate for patients with positive or negative of CD44V6 and HER-2/neu expression were 25.0%, 46.2%, respectively. The difference was also statistically significant(P<0.05).Conclusion: 1. The expression of HER-2/neu, PTEN and CD44V6 protein in gastric cancer could be used as indicators for predicting the prognosis of gastric cancer. The expression of HER-2/neu protein might provide new strategy for targeted therapies of gastric cancer. 2. The level of serum tumor markers and the expression of tissue proteins in gastric cancer might correlate to the prognosis of gastric cancer.