The Role And Significance Of Mismatch Repair Protein In The Diagnosis Of Hereditary Non-polyposis Colorectal Cancer

[objective]1.To assessment of the feasibility of microarray technology combined immunohistochemical techniques in the large-scale retrospective trials.2.To screen for HNPCC by the family history of malignant tumor3.To explore the role and significance of the mismatch repair protein in the diagnosis of hereditary nonpolyposis colorectal cancer.[methods]1.407cases of surgical specimens of colorectal cancer tissue were selected, the expression of mismatch repair proteins (MLH1,MSH2,MSH6and PMS2) by using tissue microarray technology and immuohistochemistry.2. Compared the results of all the negative specimens and10cases randomly selected in the positive specimens by using TMA and IHC.3. Screening for HNPCC according to the clinical criteria of s-HNPCC,HNPCC diagnostic criteria formulated by the cooperative group of hereditary colorectal cancer,Amsterdam Ⅱ and Bethesda guidancestandard4. Evaluation in the distribution of mismatch repair proteins missing in the HNPCC tumor tissue specimens.[Results]1. Assessment the feasibility of the tissue microarray technique used in large-scale retrospective experimentsTissue microarray:1628(407X4) slice of tumor tissue, positive rate of94.59%, negative rate of5.41%; conventional immunohistochemistry:98(88+10)slices of tumor tissue sections, positive rate of12.24%,87.76%of the negative ratetissue microarray and the accuracy of the results of routine immunization group of slices does not have significant difference (P>0.05).2. The role and significance of Mismatch repair protein in the diagnosis of Hereditary non-polyposis colorectal cancer11of407cases of patients with cancer family history. It was diagnosed as hereditary nonpolyposis colorectal cancer according to the clinical diagnostic criteria for hereditary nonpolyposis colorectal cancer; except for off-chip and uncertain outcome of the57exceptions,48cases performance to lack of MMR protein expression:MLH1/PMS230cases; MSH2/MSH68; MSH67cases; of PMS22, MLH1MSH6PMS21case. MMR protein expression rate:MLH1,rate of negative8.86%(31/350); the MSH2,rate of negative2.29%(8/350); MSH6, rate of negative4.57%(16/350); PMS2rate of negative0.86%(3/350). Immunohistochemical methods in the diagnosis of hereditary nonpolyposis colorectal cancer sensitivity was91%(10/11).[Conclusion]1.The tissue microarray/tissue chip technique provides a reliable method to investigate marker expression by offering a rapid, economic and accurate screening of tissue specimens on a large scale.2. Screening for HNPCC is feasible by the expression of MMR protein by Immunohistochemical.