Comparison Of HER-2 Detection Methods For Gastric Cancer By Using Single And Double Paraffin Blocks And Analysis Of Prognostic Factors In Gastric Cancer

Purpose:1.The aim is to investigate the practicability of immunohistochemical double paraffin blocks method for detecting HER-2 protein in gastric cancer and to analyze the correlation between overexpression of HER-2 and clinicopathological parameters.2.To investigate the expression of Ki-67 protein in gastric cancer and its relation with clinicopathological parameters and overexpression of HER-2.3.To analyze the predictor for prognosis of gastric cancer.Methods:1.By using immunohistochemical method(IHC)to detect the expression of HER-2 in gastric cancer,2500 gastric cancer specimens were divided into two groups:one group using 1 histological paraffin block(single-block group,n=956)and anther group using 2 histological paraffin blocks(double-block group,n=1544).In the double-block group,the higher HER-2 score was used as the final interpretation result,and the corresponding clinical pathological parameters of the two sets of data were analyzed comprehensively.2.By using immunohistochemical method(IHC)to detect the expression of Ki-67 in gastric cancer with the selected specimens(n = 1034)and analysis its relation with clinicopathological parameters and overexpression of HER-2.3.To visit 194 gastric cancer cases with 5-years follow-up time and with completed follow-up data for prognostic analysis.Results:1.In the single-block group,the number of cases with HER-2 score of 0,1+,2+and 3+ were 582(60.9%),158(16.5%),122(12.8%)and 94(9.8%)respectively.In the double-block group,the number of cases with HER-2 score of 0,1+,2+ and 3+ were 815(52.8%),377(24.4%),160(10.4%)and 192(12.4%),of which 412 cases(26.7%)showed inconsistent results in double paraffin blocks.The positive rate of HER-2 in the double-block group was higher than that in the single-block group(3+).2.The expression of HER-2 in gastric cancer is related to the location of the tumor histological type and differentiation degree(P<0.05),and the gender,age,tumor size,depth of invasion,lymph node metastasis and distant metastasis has no significant correlation(P>0.05).3.The expression of Ki-67 in gastric cancer is related to the size of the tumor,depth of invasion,lymph node metastasis,TNM classification and HER-2 overexpression(P<0.05),and the gender,age,the location of the tumor,histological type,differentiation degree and distant metastasis has no significant correlation(P>0.05).4.Kaplan-Meier survival analysis and Log-rank test showed that the prognosis of gastric cancer is related to the tumor size,differentiation degree,depth of invasion lymph node metastasis,distant metastasis,TNM classification and Her-2 overexpression(P<0.05).Cox proportional hazards analysis showed that TNM staging(HR = 3.073,P<0.001),the degree of tumor differentiation(HR = 1.500,P = 1.500)and HER-2 overexpression(HR = 1.930,P = 1.930)are the independent risk factors of gastric cancer prognosis.Conclusion:1.The positive rate of HER-2 in the double-block group was higher than that in the single-block group.lmmunohistochemical double-block method is a more efficient,economical and practical method for the detection of HER-2 in gastric cancer.2.Over-expression of HER-2 is closely related to tumor location,histological type and differentiation degree.3.Over-expression of Ki-67 is closely related to the size of the tumor,depth of invasion,lymph node metastasis,TNM classification and HER-2 overexpression.4.TNM classification,tumor differentiation degree and Her-2 overexpression can be served as independent predictor for prognosis of gastric cancer.