Altered expression of hMSH2 in sporadic colorectal cancer, surrounding mucosa and at distant colonic mucosa

Background: Mismatch repair gene hMSH2 is involved in correction of mispairing during replication and its mutation is associated both with microsatellite instability and with hereditary colorectal cancer. We evaluated its involvement in sporadic colorectal cancer tumorigenesis too. Materials and Methods: The protein expression pattern of hMSH2 was evaluated on 29 cases of resected sporadic adenocarcinoma using an immunohistochemical approach. Results: In 14 cases, lack of hMSH2 protein expression was observed in adenocarcinoma and in peritumoral mucosa. In 12 patients, hMSH2 resulted in strong expression in the tumour as well as in the surrounding mucosa and at distant mucosa. In three cases, hMSH2 protein expression in tumoral, adjacent and at distance normal mucosa resulted negative. Conclusion: Repair genes could play an important role in tumour progression and in sporadic colorectal cancer. Detection of protein expression by immunohistochemistry may be a method to select tumours for successive genetic investigations.