[Flow cytometric analysis of colorectal cancer and polyps]

Thirty-four cases of colorectal cancer, 24 cases of polyps of various types and 30 cases of control colorectal mucosa were analysed by flow cytometry for DNA content in order to study their relation to histopathology and prognosis. The result showed that the DNA content of 6 out of 24 polyps (25%) were aneuploid, and all of these 6 cases with aneuploid DNA content were adenomas accompanied with mild to severe dysplasia, and six cases of juvenile polyps were diploid. There was a correlation between DNA aneuploid and severe dysplasia (P less than 0.05), but not with the histopathologic type. Twenty-three out of 34 cancers were aneuploid (68%), and correlation was noticed between the DNA Index (DI) and Dukes' classification (F = 17.37), but not with the differentiation of tumors. Patients with DNA aneuploid tumours had a worse prognosis than those with only DNA diploid tumours. Therefore, DNA ploidy of colorectal cancers detected by flow cytometry is of prognostic value for colorectal cancer.