Study on ras gene mutations in mucosas ad jacent to colorectal cancer

Mucoaa adjacent to colorectal cancer often differs from normal mueoaa in both morphology and histochemiatry. Some reports showed that mucoaas adjacent to cancer were in the state of precancer-oua. We examined Ifi-ras gene mutations in 13 colorectal cancers and their adjacent mucasas by PCR-RFLP. There are 2 cases with ki-raa mutations in both tissues，2 casea with ki-raa muca-lions only in cancer tissue，and 1 case with lei-ras mutation only in mucosa adjacent to cancer. The results show that ki-ras mutations occured in some mucoaaa adjacent to cancer. Which confirm that ki-ras mutation may occur at the early stages of carcinogenesis and development of colorectal can-cars. No distinct relations o! gene alteration exists between cancer and adjacent mucoaa tissues.