Flow cytometric analysis of the DNA content in colorectal adenomas with focal cancers.
OBJECTIVE
Variable results have been reported on the nuclear DNA content of colorectal polyps. The significance of DNA aneuploidy in the malignant transformation of colorectal polyps was evaluated.


METHODS
We analyzed by flow cytometry the nuclear DNA content of freshly frozen samples of 50 colorectal adenomas with or without focal cancers, analyzing separately the adenomatous and cancerous regions of the polyps.


RESULTS
In the adenomatous regions of the 50 polyps, the DNA was diploid in 43 and aneuploid in 7; the adenomas with DNA aneuploidy in the adenomatous regions were more frequently accompanied by focal cancers than were the DNA-diploid adenomas (P < 0.01). In 60% of the polyps with DNA aneuploidy in the cancerous regions, the DNA was also aneuploid in the adenomatous region and had similar DNA indices; this result suggests that the DNA aneuploidy had already occurred during the adenomatous stage, which lends support to the concept of the adenoma-carcinoma sequence. DNA aneuploidy in the adenomatous region was significantly correlated with the size of colorectal polyps (P < 0.05).


CONCLUSIONS
DNA aneuploidy may be an important indicator for the early diagnosis of malignant transformation of colorectal polyps.
Suzuki
S
S
First Department of Internal Medicine, Okayama University Medical School, Japan.
Mizuno
M
M
Tomoda
J
J
Ohmori
M
M
Tsuji
T
T
D000236:Adenoma / Q000737:chemistry*; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000782:Aneuploidy; D002471:Cell Transformation, Neoplastic; D015179:Colorectal Neoplasms / Q000737:chemistry*; D004273:DNA, Neoplasm / Q000032:analysis*; D004171:Diploidy; D005434:Flow Cytometry; D006651:Histocytochemistry; D006801:Humans; D007417:Intestinal Polyps / Q000737:chemistry; D008875:Middle Aged
D004273:DNA, Neoplasm