The controversy regarding the ideal resection margin after a curative resection of colorectal carcinoma is currently unresolved.
And a plausible mechanism for local recurrence after a curative resection has been noticed the increased proliferative capacity of the epithelium around the anastomosis. Therefore mitotic index and cell phase fraction related to DNA ploidy, which
may
reflect epithelial proliferation index, may be considered as a parameter in determining the resection margin.
To clarify this issue. 97 paraffin-embedded blocks from the surgical specimens in 20 cases who received curative resection for colorectal carcinoma and 5 paraffin-embedded blocks from the normal colonic tissues as a control group were analyzed
following
items.
1) The differences of cell phase fraction and mitotic index between the tumor and control group, 2) the correlation between cell phase fraction and mitotic index according the ploidy pattern, and finally, 3) changes of cell phase fraction and
mitotic
index according to the distance from the tumor.
12 cases(60%) of tumor were diploid and 8 cases(40%) were aneuploid in DNA pattern.
Mitotic index of the tumor(2.00±1.04) versus control group(0.89±0.26) and a group of a margin of 1 centimeter(0.58±0142) shows statistically significant(p<0.05).
But mitotic index is not well correlated with cell phase fraction in the tumor, group of a distal margin of 1 centimeter and control group, respectively.
And S phase, G2+M phase and G2+M+S phase of the tumor versus control group and group of a margin of 1 margin of 1 centimeter shows also statistically not significant.
The data suggest that the ploidy pattern of the colorectal carcinoma cannot be considered as a parameter in determining resection margin, even though a distal margin of 1 centimeter may be adequate distal clearance for most colorectal carcinomas
as
regarding mitotic index.
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