1.   In addition, the labelling index of benign tumours with low grade dysplasia was significantly lower than that in those with high grade dysplasia.

2.   Therefore it seems that the EGF concentration in the cells does not explain the greater carcinogenic potential of mucosa with high grade dysplasia.

3.   Surgery was performed in cases of persistent high grade dysplasia, or carcinoma.

4.   Forty patients were found to have low grade dysplasia in at least one biopsy.

5.   Nineteen continued to exhibit low grade dysplasia in at least one subsequent biopsy.

6.   Four of the patients who had low grade dysplasia previously were negative for dysplasia at colectomy.