RÉSUMÉ
Background and purpose:Hereditary nonpolyposis colorectal cancer(HNPCC) which related to inheritance is an autosomal dominant inheritance.There are many screening standards differing presently from country to country.The Amsterdam standard is internationally recognized.These screening standards are just based on family history and clinical manifestations which can not reflect the essence of the disease.At present,the golden standard for screening HNPCC is mismatch repair genes detection that is in the experimental stage.The purpose of this study was to investigate the expression of mismatch repair genes hMSH2 and hMLH1 in HNPCC and their clinicopathological signif icance,and to fi nd a simple,fast and economic method for screening HNPCC.Methods:Immunohistochemical staining was used to detect the expression of hMSH2 and hMLH1 in 20 cases with HNPCC(Group A),20 cases with ordinary hereditary colorectal cancer(Group B),20 cases with sporadic colorectal cancer(Group C),and 20 cases with colorectal polyps(Group D).Results:The expression rates of hMSH2 and hMLH1 in Group A,B,C and D were 35%(7/20),70%(14/20),95%(19/20) and 100%(20/20) respectively,which illustrated that the probability of HNPCC and the negative expression of hMSH2 and hMLH1 was reduced from Group A to Group D.There were signifi cant differences among these groups(P0.05).Conclusion:The negative expression of hMSH2 and hMLH1 was signifi cantly correlated with HNPCC and location and differentiation of colon carcinoma.Immunohistochemical staining may be useful for screening HNPCC.