[Factors associated with high grade dysplasia and cancer in colorectal adenoma]

The aim of this study was to assess the risk factors associated with high grade dysplasia (HGD) and cancer (CA) in colorectal polyps. We studied prospectively all colorectal polyps endoscopically resected from 6/91 to 12/93. Analyzed variables were age, sex and initial symptoms of patients, and number, localization, size and histologic characteristics of polyps. Adenomas were classified, according to the proportion of villous component, into tubular, villous A (1%-25% of villous component), villous B (26%-75%), villous C (76%-99%) and villous D 100%). One hundred polyps were resected from 67 patients (polyp/patient ratio:1.49). Mean age of patients was 63.9 +/- 10.3 year and 47 (70%) were men. Hematochezia was the main symptom (46%) and all of these patients had rectosigmoid polyps. Ninety three (93%) polyps were adenomas: Tubular 40 (43%), villous A 17 (18%), villous B 16 (17%), villous C 12 (13%) and villous D 8 (9%); 5 (5%) hyperplastic, 1 (1%) hammartoma and 1 (1%) inflammatory. Ten (11%) adenomas had foci of adenocarcinoma, 28 (30%) mild dysplasia, 42 (45%) moderate dysplasia and 20 (14%) high grade dysplasia. The percentage of villous C and D adenomas with cancer was 20% vs 3.6% of villous A adenomas (p: < 0.05) and 0% of villous B adenomas (p: < 0.-01). The percentage of villous C and D adenomas with HGD was 40% vs 10.7% of villous A adenomas (p: < 0.01%) and 6% of villous B adenomas (p: < 0.02). Mean size was 1.78 +/- 0.6 cm in adenomas with HGD and 1.28 +/- 0.7 cm in adenomas without HGD (NS). We didn't observe complications of the polipectomy. We conclude that colorectal polyps prevail in men with a 2:1 relationship. Patients who referred hematochezia as presenting symptom, had rectosigmoid polyps. High grade dysplasia and cancer were associated with the proportion of villous component but not with polyp's size or patient's age or sex.