Correlation between DNA content and p53 deletion in colorectal cancer.

Objective: To find out whether tumour DNA content correlates with allelic loss of p53 and other pathological features in primary colorectal carcinomas.Design: Ongoing prospective study.Setting: University hospital, Italy.Subjects: 128 patients who had undergone radical resections for colorectal carcinoma.Interventions: Flow cytometric measurement of tumour DNA content and detection of allelic loss on the short arm of chromosome 17 by Southern blot (restriction fragment length polymorphism) analysis in fresh tumour specimens.Main outcome measures: Correlation between DNA ploidy and deletion of p53, as well as between these two genetic events and clinicopathological variables.Results: Interpretable DNA histograms were obtained for 122 tumour specimens. Forty-three tumours (35%) were diploid and 79 (65%) aneuploid. The diploid tumours were significantly more common in the proximal colon (from the caecum to the splenic flexure) than in the distal colon (from the descending colon to the rectum) (p ≥ 0.002). Th...