[The expression of MG7 corresponding antigen in gastrointestinal polyps and its relation with cancer].

We studied 112 patients with polyps of the stomach, gallbladder and colorectum by immunohistochemical staining with monoclonal antibody (MG7) against gastric cancer and avidin-biotin complex (ABC) technique. The positive expression of the MG7-corresponding antigen (MG7-Ag) was 100%, 100%, and 60.0% respectively in villous, mixed and tubular polyps. A close correlation was shown between dysplasia of grade II and the positive expression of MG7-Ag (p < 0.05). The positive expression was significantly related to canceration (P < 0.025). No malignancy was found in 45 patients with negative expression. But 12 of 67 patients with positive expression developed cancers in 3 to 38 months. The patients with positive expression of MG7-Ag were high risk group developing cancer.