The quantitation of DNA and growth fraction in the different step from dysplastic to neoplastic process in large bowel is the aim of this study. 70 colonic polyps were studied. The fresh specimens were processed and DNA analysis was carried out using a Partec CA II flow cytometer and the growth fraction was tested with KI-67 monoclonal antibody. The percentage of S-phase cells has been calculated with the Multicycle program. Our results demonstrated that 7 adenomas were tubulo-villous with mild dysplasia, 39 with mild-moderate dysplasia, 1 with severe dysplasia, 5 were polypoid carcinomas, 2 juvenile polyps, 1 polypoid leiomyoma, 1 inflammatory fibroid polyps. DNA analysis showed a diploid DNA content in non adenomatous polyps, in all adenomas with mild dysplasia, in 37 with mild-moderate dysplasia, in 8 cases with moderate-severe dysplasia and 1 cancer. Aneuploidy was discovered in 2 cases with mild-moderate dysplasia, in 6 cases with moderate-severe dysplasia, in the case of severe dysplasia and in 4 cases of carcinomas. Best indexes of linear correlation (Pearson's r) has been found between S-phase and DNA index (r = .75) and between S-phase and KI-67 (r = .82).
In conclusion: 1) No relationship was found between DNA content and age, sex, size and location of polyps. 2) Aneuploidy is strictly related to moderate-severe grade of dysplasia therefore it is an important element in the development of adenomacarcinoma sequence. 3) DNA-index, S-phase and KI-67 are strictly related.