Helicobacter pylori-associated Chronic Atrophic Gastritis and Progression of Gastric Carcinogenesis

Roles of the tumor microenvironment in the resistance to programmed cell death protein 1 inhibitors in patients with gastric cancer

Despite the continuous developments and advancements in the treatment of gastric cancer (GC), which is one of the most prevalent types of cancer in China, the overall survival is still poor for most patients with advanced GC. In recent years, with the progress in tumor immunology research, attention has shifted toward immunotherapy as a therapeutic approach for GC. Programmed cell death protein 1 (PD-1) inhibitors, as novel immunosuppressive medications, have been widely utilized in the treatment of GC. However, many patients are still resistant to PD-1 inhibitors and experience recurrence in the advanced stages of PD-1 immunotherapy. To reduce the occurrence of drug resistance and recurrence in GC patients receiving PD-1 immunotherapy, to maximize the clinical activity of immunosuppressive drugs, and to elicit a lasting immune response, it is essential to research the tumor microenvironment mechanisms leading to PD-1 inhibitor resistance in GC patients. This article reviews the progress in studying the factors influencing the resistance to PD-1 inhibitors in the GC tumor microenvironment, aiming to provide insights and a basis for reducing resistance to PD-1 inhibitors for GC patients in the future.

Streptococcus anginosus in the development and treatment of precancerous lesions of gastric cancer

The microbiota is strongly association with cancer. Studies have shown significant differences in the gastric microbiota between patients with gastric cancer (GC) patients and noncancer patients, suggesting that the microbiota may play a role in the development of GC. Although Helicobacter pylori (H. pylori) infection is widely recognized as a primary risk factor for GC, recent studies based on microbiota sequencing technology have revealed that non-H. pylori microbes also have a significant impact on GC. A recent study discovered that Streptococcus anginosus (S. anginosus) is more prevalent in the gastric mucosa of patients with GC than in that of those without GC. S. anginosus infection can spontaneously induce chronic gastritis, mural cell atrophy, mucoid chemotaxis, and heterotrophic hyperplasia, which promote the development of precancerous lesions of GC (PLGC). S. anginosus also disrupts the gastric barrier function, promotes the proliferation of GC cells, and inhibits apoptosis. However, S. anginosus is underrepresented in the literature. Recent reports suggest that it may cause precancerous lesions, indicating its emerging pathogenicity. Modern novel molecular diagnostic techniques, such as polymerase chain reaction, genetic testing, and Ultrasensitive Chromosomal Aneuploidy Detection, can be used to gastric precancerous lesions via microbial markers. Therefore, we present a concise summary of the relationship between S. anginosus and PLGC. Our aim was to further investigate new methods of preventing and treating PLGC by exploring the pathogenicity of S. anginosus on PLGC.

Differential diagnosis of gastric low- and high grade dysplasia using C6orf15 protein

OBJECTIVE

To investigate the expression of C6orf15 protein in gastric endoscopic biopsy specimens and its usage as an ancillary diagnostic biomarker in determining the grade of gastric dysplasia.

METHODS

We selected 102 patients with gastric endoscopic biopsy specimens from Jinling Hospital. These were divided into four groups: 22 cases of gastric mucosal benign lesions, 28 with low-grade dysplasia (LGD, intestinal-type: 21 cases，foveolar-type: 7cases), 28 with high-grade dysplasia (HGD, intestinal-type: 20 cases，foveolar-type: 8 cases), and 24 cases of gastric adenocarcinoma. We examined the expressions of C6orf15, P53, and Ki67 in 102 gastric endoscopic biopsy specimens, including 47 cases with accompanying endoscopic submucosal dissection (ESD) specimens, using immunohistochemistry.

RESULTS

In gastric HGD and gastric adenocarcinoma, the c6orf15 protein exhibits diffuse and strong cytoplasmic expression in tumor cells. Conversely, in gastric LGD and benign gastric mucosal lesions, the c6orf15 protein shows negative or faint yellow cytoplasmic staining. The expression rate of C6orf15 in high-grade gastric dysplasia (HGD, 93 %) and gastric adenocarcinoma (100 %) was significantly higher than in the gastric mucosal benign lesion group (0 %) and the low-grade dysplasia (LGD, 7 %) group (P < 0.001).

CONCLUSION

The detection of C6orf15 protein expression could serve as a valuable adjunctive diagnostic tool for distinguishing between gastric HGD, LGD, and benign lesions. The combined assessment of C6orf15, P53, and Ki67 expressions may be beneficial in determining the grade of gastric dysplasia and evaluating the risk of progression in gastric mucosal lesions in clinical practice.

Histopathological staging of atrophic lesions of gastric mucosa

Objective

To study the histopathological staging of atrophic lesions of the gastric mucosa.

Methods

Histology and immunohistochemistry were used to closely examine 2144 specimens of atrophic gastric mucosa that were taken from endoscopic biopsies.

Results

When the gastric mucosa epithelium is affected by infection, chemical stimulation, immune factors, genetic factors, and other factors, it may cause an atrophy of gastric mucosa epithelium and a decrease in the number of glands, intestinal metaplasia, hyperplasia of smooth muscle fibers, and atrophy of stem cells in the proliferative zone. In this study, we characterized the above lesions as atrophic lesions of the gastric mucosa. Based on the morphological and histological characteristics of the lesion, as well as the law of cell proliferation and transformation during its occurrence and development, we propose five stages. We also noted the onset age, gender correlation, and histopathological characteristics of each stage of gastric mucosal atrophies.

Conclusion

Understanding the pathological staging of gastric mucosal atrophy is essential for treating patients correctly and keeping track of changes in malignant cells. It is also very important in preventing the initiation of gastric cancer or from getting worse.