Prognostic Significance of p27 and Survivin in H. pylori Gastritis and Gastric Cancer

Survivin as a potential biomarker for early diagnosis of the progression of precancerous lesions to gastric cancer

BACKGROUND

Gastric cancer is a common cancer developed in a carcinogenesis process from precancerous lesions including chronic gastritis, intestinal metaplasia, and dysplasia. Survivin, an inhibitor-of-apoptosis protein, is associated with the initiation and progression of gastric cancer. The present study aimed to evaluate the immunohistochemical expression patterns of survivin and its relationship with early diagnosis of gastric cancer in Iranian patients.

METHODS

In this retrospective case-control study, immunoexpression of survivin was investigated on sections obtained from formalin-fixed paraffin-embedded tissue blocks of 38 chronic gastritis, 32 intestinal metaplasia, 20 dysplasia, 28 gastric adenocarcinoma, and 22 controls.

RESULTS

Survivin immunoexpression in chronic gastritis was higher than controls, but this difference was not statistically significant (P > 0.05). However, survivin immunoexpression had a steady significant increase from control and chronic gastritis to intestinal metaplasia to dysplasia to gastric adenocarcinoma (P < 0.05). Sensitivity, specificity, and area under the curve of survivin immunohistochemical test for the diagnosis of gastric cancer were 87.5%, 74.4%, and 0.85, respectively. Males had a significantly higher survivin expression than females (P < 0.001). Also, survivin expression was significantly higher in older patients than in younger ones (P < 0.001).

CONCLUSION

It seems that the steady increase in survivin expression from different precancerous lesions to gastric adenocarcinoma suggests that survivin can be used as a potential biomarker for the prevention and early diagnosis of gastric cancer.

A Genetic and Immunohistochemical Analysis of Helicobacter pylori Phenotypes and p27 Expression in Adenocarcinoma Patients in Jordan

Stomach (gastric) cancer is one of the most prevalent and deadly cancers worldwide and most gastric cancers are adenocarcinomas. Based on prior research, there is an association between Helicobacter pylori (H. pylori) infection together with the frequency of duodenal ulcer, distal gastric adenocarcinoma, mucosa-associated lymphoid tissue (MALT) lymphoma, and antral gastritis. Helicobacter pylori virulence and toxicity factors have been identified before that significantly influence the clinical outcomes of H. pylori infection and gastric adenocarcinoma. However, it remains unclear exactly how different strains of H. pylori affect gastric adenocarcinoma. Current research suggests this involves tumor suppressor genes, like p27 but also H. pylori toxic virulence proteins. Therefore, we quantified known H. pylori genotypes within adenocarcinoma patients to establish the prevalence of known toxins that include cytotoxin-associated gene A (cagA) as well as vacuolating cytotoxin A (vacA) within patients of variable adenocarcinoma diagnosis. This analysis used gastrectomy samples validated for DNA viability. The incidence of H. pylori in adenocarcinoma patients in Jordan was established to be 54.5% positive (ureA gene positive) with cagA genotype occurrence at 57.1%, but also in this population study vacA gene ratios found to be 24.7%:22.1%:14.3%:14.3%. (vacAs1:vacAs2:vacAm1:vacAm2). Using immunohistochemistry (IHC), we confirmed with statistical significance that p27 was dysregulated and suppressed, within nearly all H. pylori vacA genotypes. In addition, within 24.6% of H. pylori samples analyzed was a different bacterial genotype, and curiously that p27 protein expression was retained in 12% of tested adenocarcinoma H. pylori samples. This is suggestive that p27 could be used as a prognostic indicator but also that an unknown genotype could be contributing to the regulatory effects of p27 protein within this bacterial and cellular environment that may include other virulence factors and unknown immune system regulatory changes.