Gastric epithelial cell proliferation and ras oncogene p21 expression in first-degree relatives of gastric cancer patients: a case-control study

Evaluation of apoptosis along with BCL-2 and Ki-67 expression in patients with intestinal metaplasia

The primary aim is to compare individuals with intestinal metaplasia (IM), chronic active gastritis (CAG), and normal gastric mucosa (NGM) in terms of apoptosis, proliferation, and Bcl-2 expression. The secondary aim is to determine whether these parameters are different between patients with and without gastric cancer in first-degree relatives. We enrolled 106 patients whose histopathological results were consistent with IM (n: 42), CAG (n: 51), or NGM (n: 13). Antral biopsies were immunohistochemically stained for Bcl-2 and Ki-67 expression. Apoptosis was detected using TUNEL assay. While no significant difference was determined between three groups with regard to apoptosis and Bcl-2 expression (p>0.05), Ki-67 expression was significantly higher in the IM group when compared with the CAG and NGM groups (29.90±22.87 vs. 18.18±16.22 vs. 18.54±20, respectively; p=0.012). Helicobacter pylori was determined to increase apoptosis (49.3% vs. 25.7%, p<0.05), nevertheless, it had no significant effect on proliferation and Bcl-2 expression. Bcl-2 and Ki-67 expression and apoptosis were not different among patients with and without a history of gastric cancer in first degree relatives. Although intestinal metaplasia cases demonstrate an increase in proliferation, no elevation is observed in apoptosis. This can be an important factor in the progression to gastric cancer.

Diverticulosis and colorectal cancer: between lights and shadows

The prevalence of diverticulosis and colorectal cancer (CRC) is markedly increased in the last century. Both diseases are highly frequent in Western countries and in aged people. Western diet--low in fiber and rich in dietary fat--has been largely regarded to play a major role in the pathogenesis of both conditions. A causal relationship between diverticulosis and CRC has been suggested in different studies. Epidemiologic series found a more frequent rectosigmoid localization of neoplastic lesions (advanced adenoma and CRC) in patients with diverticulosis as compared with controls, particularly in those with a previous diverticulitis episode or with an extensive disease. However, data are still controversial, with other studies failing to confirm this observation. Such discrepancy could be referred to the highly heterogeneous study design and setting in the different epidemiologic series. Pathologic studies showed that either macroscopic and microscopic chronic inflammation--which is regarded as risk factor for CRC development--is present in the colonic mucosa of some patients with diverticula. Moreover, alterations in the extracellular matrix, also involved in colorectal carcinogenesis, have been depicted in diverticulosis. In addition, an upward shifting of cell proliferation occurs in diverticular mucosa, and in nondiverticular patients with advanced adenomas. Finally, aberrant crypt foci--which are considered potential markers of CRC risk in ulcerative colitis--have been detected in colonic mucosa of patients with diverticulosis. Despite this substantial amount of evidence, however, the available data are not yet strong enough to suggest a more aggressive CRC prevention in diverticular as compared with nondiverticular subjects.

Risk assessment in relatives of gastric cancer patients: hyperproliferation, genetics, and Helicobacter pylori infection

Approximately 10% of cases of gastric cancer present with some kind of familial aggregation, but only 1-3% of gastric carcinomas arise as a result of clearly defined genetic syndromes that require genetic counselling and aggressive preventative measures. In the remaining families, no specific abnormalities, either genetic, biochemical or histological, responsible for the increased risk have been identified. However, several lines of evidence suggest that the increased cancer risk in first-degree relatives of gastric cancer probands is mostly dependent on Helicobacter pylori infection clustering.