Immunohistochemical Expression of p53 and Ki67 in Colorectal Adenomas and Prediction of Malignancy and Development of New Polyps

The aim of this study was to investigate the immunohistochemical expression of p53 and Ki67 in colorectal adenomas in order to clarify their significance as indicators of malignancy and development of new polyps. Seventy-eight polyps were removed from 51 patients and examined. Twenty-nine patients (56.9%) had adenomas with low-grade atypia (13 of them developed new polyps at 3-year follow-up) and 22 (43.1%) had adenomas with high-grade atypia (6 of them developed new polyps at 3-year follow-up). We tested the association between p53 and Ki67 expression and various clinicopathological variables, and regression analysis was performed to identify the risk factors for malignancy and development of new adenomas. A significant correlation between the grade of atypia and p53 immunoreactivity was observed. Ki67 expression was not related to atypia and no correlation was found between p53 and Ki67 immunoreactivity. Regression analysis showed that size (p=0.0002) and p53 staining (p=0.0111) were the selected factors related to malignant transformation, whereas the number of synchronous primary polyps emerged as the only predictive factor of development of new adenomas, although without statistical significance. The expression of biological markers may be in future added to the currently examined features of polyps; however, further studies are needed to better define their predictive value.

Adult colonic intussusception caused by malignant tumor of the transverse colon

Adult colonic intussusception is rare and often originates from neoplasms. In emergency situations it can be difficult to diagnose. Our aim was to show how the integration of readily available diagnostic means in emergency situations can help in making a correct diagnosis of this disease. A 68-year old male patient presented with vomiting and abdominal pain. The abdomen was distended, with pain to palpation in the left quadrants without a mass. Plain radiographs of the abdomen showed a large amount of gas in the small bowel and in the right and transverse colon. A barium enema demonstrated an endoluminal filling defect in the descending colon. Abdominal ultrasonography revealed the presence of intraperitoneal fluid and thickened left colonic wall at the site of the lesion, with an aspect of a "double ring" consistent with intussusception. A solid formation was also revealed at a point distal to the thickened colonic wall. At emergency laparotomy an approximately 8-cm-long mass was palpable through the left colon. A colostomy was fashioned, and subsequently colonoscopy revealed the presence of a left colon tumor. At the subsequent operation an invagination of the left transverse colon into the descending colon was confirmed. The left transverse and descending colon were resected with high ligation of the left colic artery. Macroscopic examination of the invaginating head showed a vegetating transverse colon neoplasm. We conclude that in emergency settings the association of readily available diagnostic means such as plain abdominal radiography, water soluble contrast enema and ultrasonography may yield reliable information for diagnosing colonic intussusception.

cagA positive and negative Helicobacter pylori strains are simultaneously present in the stomach of most patients with non-ulcer dyspepsia: relevance to histological damage

BACKGROUND/AIMS

Infection with Helicobacter pylori strains harbouring the cagA gene (cagA+) is associated with an increased risk of developing peptic ulcer and gastric cancer. The aim of this study was to assess whether H pylori isolates with different cagA status were present in patients with non-ulcer dyspepsia, and whether a variable cagA status is relevant to histological gastric mucosal damage and glandular cell proliferation.

METHODS

Well separated H pylori colonies (between 2 and 25) from primary plates, per gastric area, for each of 19 patients with non-ulcer dyspepsia were examined for cagA by hybridisation. Western blotting was used to examine both representative colonies for CagA expression and the patients' sera for antibody response to CagA. Glandular gastric cell proliferation was assessed immunohistochemically.

RESULTS

Of the 747 colonies examined, 45.3% were cagA+. All colonies from four patients were cagA+, and all colonies from two patients were cagA-. In 13 patients (68%) both cagA+ and cagA- colonies were found. CagA expression of isolates corresponded to their cagA status. H pylori strains with different CagA molecular masses were present in three patients. Results based on all 19 patients studied showed that the prevalence of cagA+ colonies in areas with mucosal atrophy associated or not with intestinal metaplasia (67.9%) was significantly higher than in normal mucosa (44.7%) and mucosa from patients with chronic gastritis (44.0%) (p < 0.001). High levels of cell proliferation were associated with histological atrophy with or without intestinal metaplasia, but not with the possession of cagA by organisms colonising the same mucosal sites.

CONCLUSIONS

Most patients with nonulcer dyspepsia are infected by both cagA+ and cagA- H pylori colonies. The cagA status of infecting organisms may play a role in the development of atrophy and intestinal metaplasia.