DNA aneuploidy and cell proliferation in familial adenomatous polyposis.

Two hundred and thirteen samples from 20 patients with familial adenomatous polyposis (FAP) were investigated by flow cytometry and the results compared with 100 sporadic adenomas. Eleven of the 20 (55%) yielded one or more DNA aneuploid samples with an overall incidence within FAP adenomas of 12%. Despite a similar level of DNA aneuploidy in sporadic adenomas, it was commonly detected at a smaller polyp size. The degree of cell proliferation was found to be similar in the two groups (median %S+G2 15.8% v 16.4%) but larger FAP adenomas demonstrated a higher level of cell proliferation than smaller adenomas. DNA aneuploidy had no value as a predictor of a synchronous carcinoma and appeared to be an early change in the development of carcinoma in these patients.