Single-parameter DNA flow cytometric analysis of normal-appearing colonic mucosa does not predict the presence of colonic neoplasia.

We wished to determine whether DNA flow cytometric analysis could detect DNA abnormalities in normal-appearing mucosa of patients with colonic neoplasia. Eighty-five patients were studied either at colonoscopy or at surgical resection. Forty-five had macroscopically normal colonoscopy; 13 had adenomatous polyps, and 27 had colorectal carcinoma. Biopsies were obtained from the cancer and from normal-appearing mucosa 5 cm from the lesion. The patients who had normal colonoscopy had rectal biopsies. The samples were prepared for analysis on a Coulter EPICS C flow cytometer. Cells were analyzed for presence of aneuploidy (%AN), percent in DNA synthetic phase (%S), and percent growth fraction (%GF = %S + %G2M). Aneuploidy was present in 12 of 27 carcinomas (44%), but in none of the samples from polyps or normal-appearing colorectal mucosa adjacent to cancers. The %S from cancers was greater than those from polyps (9.6 +/- 6.3 vs. 5.1 +/- 1.8, p less than 0.005). However, %S from specimens arising from normal-appearing mucosa 5 cm distant from cancer could not be differentiated from the rectal mucosa of macroscopically normal colons (5.9 +/- 2.5 vs. 5.2 +/- 2.7). The %GF of cancer specimens was greater than those from adenomas (26.0 +/- 11.0 vs. 10.8 +/- 3.7, p less than 0.005). However, the %GF of normal-appearing mucosa 5 cm distant from the cancer was similar to the findings from mucosa arising from macroscopically normal colons (10.5 +/- 3.3 vs. 11.0 +/- 3.4). In conclusion, DNA flow cytometric analysis of normal-appearing colonic mucosa from patients with colonic carcinoma does not demonstrate abnormalities of DNA content or cell cycle kinetics, and therefore, cannot predict the presence of colonic neoplasia.