Helicobacter pylori in gastric cancer: Features of infection and their correlations with long-term results of treatment

Abstract

Background: Helicobacter pylori (H. pylori) is a spiral-shaped bacterium responsible for the development of chronic gastritis, gastric ulcer, gastric cancer (GC), and MALT-lymphoma of the stomach. H. pylori can be present in the gastric mucosa (GM) in both spiral and coccoid forms. However, it is not known whether the severity of GM contamination by various vegetative forms of H. pylori is associated with clinical and morphological characteristics and long-term results of GC treatment.

Aim: To establish the features of H. pylori infection in patients with GC and their correlations with clinical and morphological characteristics of diseases and long-term results of treatment.

Methods: Of 109 patients with GC were included in a prospective cohort study. H. pylori in the GM and tumor was determined by rapid urease test and by immunohistochemically using the antibody to H. pylori. The results obtained were compared with the clinical and morphological characteristics and prognosis of GC. Statistical analysis was performed using the Statistica 10.0 software.

Results: H. pylori was detected in the adjacent to the tumor GM in 84.5% of cases, of which a high degree of contamination was noted in 50.4% of the samples. Coccoid forms of H. pylori were detected in 93.4% of infected patients, and only coccoid-in 68.9%. It was found that a high degree of GM contamination by the coccoid forms of H. pylori was observed significantly more often in diffuse type of GC (P = 0.024), in poorly differentiated GC (P = 0.011), in stage T3-4 (P = 0.04) and in N1 (P = 0.011). In cases of moderate and marked concentrations of H. pylori in GM, a decrease in 10-year relapse free and overall survival from 55.6% to 26.3% was observed (P = 0.02 and P = 0.07, respectively). The relationship between the severity of the GM contamination by the spiral-shaped forms of H. pylori and the clinical and morphological characteristics and prognosis of GC was not revealed.

Conclusion: The data obtained indicates that H. pylori may be associated not only with induction but also with the progression of GC.

Keywords: Coccoid and spiral forms of bacteria; Gastric cancer; Helicobacter pylori; Overall survival; Rapid urease test; Relapse free survival.

Figure 1

The features of Helicobacter pylori localization in gastric mucosa in patients with gastric cancer. A: Coccoid forms of Helicobacter pylori (H. pylori) in the gastric pit. The some bacteria within the cytoplasm of epithelium cells (arrows); B: The spiral (black arrows) and coccoid (orange arrows) forms of H. pylori on the surface of superficial-foveolar gastric epithelium; C: The bacteria in the surface mucous gel layer of stomach (arrows); D: The point inclusions giving a positive reaction with antibodies to H. pylori within the cytoplasm of epithelial cells of deep gastric glands (arrows); E: The point inclusions giving a positive reaction with antibodies to H. pylori within the cytoplasm of the immune cells of the lamina propria of gastric mucosa (arrows); F: The point inclusions giving a positive reaction with antibodies to H. pylori within the cytoplasm of intraepithelial lymphocytes (arrows). Immunoperoxidase staining with anti-H. pylori antibody, immersion. Bars: A: 20 μm; B: 10 μm; C: 20 μm; D-F: 10 μm.

Figure 2

The features of Helicobacter pylori localization in omentum and lymph node in patients with gastric cancer. A: The small group of cocci located in the central part of the omentum adipocyte; B: The congestions of bacteria around the nucleus of lymphocytes in the paracortical area of lymph node. Immunoperoxidase staining with anti-Helicobacter pylori antibody, immersion, Bars: 10 μm.

Figure 3

10-year overall surviving and relapse-free surviving of patients with gastric cancer depending on the presence of antibiotic therapy 1-1.5 mo before surgery (P = 0.02). A: 10-year overall surviving; B: Relapse-free surviving.

Figure 4

10-year overall surviving and relapse-free surviving of patients with T3-4N1-2M0 stages of gastric cancer depending on the presence of antibiotic therapy 1-1.5 mo before surgery (P = 0.78). A: 10-year overall surviving; B: Relapse-free surviving.

Figure 5

10-year overall surviving and relapse-free surviving of patients with gastric cancer depending on the concentration of Helicobacter pylori coccoid forms in the gastric mucosa (P = 0.02). A: 10-year overall surviving; B: Relapse-free surviving.