Endoscopic Screening and Surveillance for Gastric Cancer

Exploring the effect of NK-cell related molecules on the prognosis and tumor microenvironment of gastric cancer patients: Evidence from large sample populations

Background

Natural killer (NK) cells play a significant role in anti-tumor immunity, and their involvement has been documented in various cancers. However, a deeper understanding of the mechanisms by which NK cells influence gastric cancer progression remains necessary.

Methods

We utilized the Cancer Genome Atlas (TCGA) database to acquire transcriptional profiles, clinical information, and mutation data for gastric cancer patients. R software and associated packages were employed for all analyses of this publicly available data.

Results

We used multiple algorithms to evaluate the tumor microenvironment in gastric cancer samples. We performed differential expression analysis to pinpoint genes related to NK cells. Utilizing this data, we developed a prognostic model featuring three crucial NK cell-related genes: MAB21L2, ARPP21, and MUCL1. This model showed strong predictive performance in the training and validation groups. Consistently, patients identified as high-risk according to our model had worse overall survival rates. To further elucidate the biological differences between high-risk and low-risk patients, we performed enrichment analyses focusing on biological pathways and immune-related factors. Additionally, we observed a correlation between higher risk scores and non-responsiveness to treatment. Interestingly, high-risk patients were found to be potentially more sensitive to axitinib. We selected MUCL1 for further investigation due to its potential role in the model. While MUCL1 mRNA levels were elevated in both gastric cancer and paired normal tissues, protein expression analysis using the Human Protein Atlas database revealed a decrease in MUCL1 protein levels within tumor tissues.

Conclusions

Our findings contribute to a more comprehensive understanding of the role of NK cells in gastric cancer and highlight MUCL1 as a promising therapeutic target.

Development of esophagogastroduodenoscopy in China: results from the national census in 2013 and 2020

Background

Given the significant burden of upper digestive diseases, there has been a substantial increase in the utilization of esophagogastroduodenoscopy (EGD) in China from 2012 to 2019. The objective of this study is to investigate the development, practice, and factors influencing the widespread use of EGD during this period.

Methods

Two national censuses were conducted among all hospitals in mainland China that perform gastrointestinal endoscopy. These censuses aimed to extract information on the infrastructure, volume, and quality of EGD. The analysis of potential factors influencing EGD practice was based on real-world data from open access sources.

Results

From 2012 to 2019, the number of hospitals performing EGD in mainland China increased from 1,518 to 2,265 (1.49-fold) in tertiary hospitals and from 3,633 to 4,097 (1.12-fold) in secondary hospitals, respectively. The national utilization rate of EGD also increased from 1,643.53 to 2,018.06 per 100,000 inhabitants, indicating a 1.23-fold increase. Regions with more endoscopists per 100,000 inhabitants (OR 9.61, P<0.001), more tertiary hospitals performing EGD per million inhabitants (OR 2.43, P<0.001), higher incidence of esophageal and gastric cancer (OR 2.09, P=0 016), and higher number of hospitals performing EGD per million inhabitants (OR 1.77, P=0.01) tended to provided more numerous and qualitied EGD. And hospital grading, regional GDP, incidence of esophageal and gastric cancer and the volume of EGD were observed as the significantly relevant factors of malignant dictation rate (MDR) (P<0.05), but not the number and educational background of endoscopists.

Conclusion

Over the past seven years, China has made significant progress in EGD. However, challenges persist in terms of quality and inequality.

Endoscopic advances in the management of gastric cancer and premalignant gastric conditions

Gastric cancer is the fifth most common cancer and in 2018, it was the third most common cause of cancer-related deaths worldwide. Endoscopic advances continue to be made for the diagnosis and management of both early gastric cancer and premalignant gastric conditions. In this review, we discuss the epidemiology and risk factors of gastric cancer and emphasize the differences in early vs late-stage gastric cancer outcomes. We then discuss endoscopic advances in the diagnosis of early gastric cancer and premalignant gastric lesions. This includes the implementation of different imaging modalities such as narrow-band imaging, chromoendoscopy, confocal laser endomicroscopy, and other experimental techniques. We also discuss the use of endoscopic ultrasound in the diagnosis and staging of early gastric cancer. We then discuss the endoscopic advances made in the treatment of these conditions, including endoscopic mucosal resection, endoscopic submucosal dissection, and hybrid techniques such as laparoscopic endoscopic cooperative surgery. Finally, we comment on the current suggested recommendations for surveillance of both gastric cancer and its premalignant conditions.

Role of Adjuvant Radiotherapy in Gastric Cancer

Although continuous improvement in the treatment outcome of localized gastric cancer has been achieved through early screening, diagnosis, and treatment and the active application of surgery and adjuvant chemotherapy, the necessity of adjuvant radiotherapy (RT) remains controversial. In this review, based on the results of two recently published randomized phase III studies (Adjuvant Chemoradiation Therapy In Stomach Cancer 2 and ChemoRadiotherapy after Induction chemoTherapy of Cancer in the Stomach) and a meta-analysis of six randomized trials including these two studies, the role of adjuvant RT in gastric cancer was evaluated and discussed, especially in patients who underwent curative gastrectomy with D2 lymphadenectomy. This article also reported the possible indications for adjuvant RT in the current clinical situation and in future research to enable patient-specific treatments according to the risk of recurrence.

Outcomes of upper endoscopy screening in Lynch syndrome: a meta-analysis

BACKGROUND AND AIMS

Lynch syndrome (LS) predisposes affected individuals to a high lifetime risk of malignancies, including colorectal, endometrial, gastric, and duodenal cancers. The role of upper GI (UGI) cancer screening in LS has been uncertain, but recent studies have evaluated its utility.

METHODS

Databases were queried through December 2021 to identify studies that examined upper endoscopy screening in LS using EGD. Mantel-Haenszel pooled odds ratios and 95% confidence intervals (CIs) for outcomes were constructed using a random-effects model to identify pooled odds of endoscopic findings in persons with LS. Event rates for detection of gastric and duodenal cancers, high-risk lesions, and clinically actionable findings were calculated. Statistical heterogeneity was assessed using the I² statistic.

RESULTS

Nine studies were identified with 2356 LS patients undergoing approximately 7838 EGDs. In total, 47 LS-associated UGI cancers (18 gastric and 29 duodenal cancers), 237 high-risk lesions, and 335 clinically actionable findings were identified. The pooled event rate for detection of any UGI cancer, high-risk lesions, and clinically actionable findings during screening were .9% (95% CI, .3-2.1; I² = 89%), 4.2% (95% CI, 1.6-10.9; I² = 98%), and 6.2% (95% CI, 2.2-16.5; I² = 99%), respectively. There was no difference between LS-associated gene and gastric or duodenal cancer detection.

CONCLUSIONS

In LS, there is evidence that endoscopic screening detects UGI cancers, precancerous lesions, and other clinically actionable findings that favor its use as a part of cancer risk management in LS.

In vivo and autopsy validation of alpha-synuclein seeding activity using RT-QuIC assay in the gastrointestinal tract of patients with Parkinson's disease

OBJECTIVE

In the present study, real-time quaking-induced conversion (RT-QuIC) assay was used to evaluate pathologic alpha-synuclein (AS) seeding activity in formalin-fixed paraffin-embedded (FFPE) tissue from the gastrointestinal (GI) tract of Parkinson's disease (PD) patients.

METHODS

This study was conducted in two parts: Part I. a preliminary autopsy study that included four autopsy-confirmed patients with synucleinopathy (2 PD, 1 dementia with Lewy bodies [DLB], and 1 multiple system atrophy [MSA]) and two normal autopsy controls. Frozen and FFPE tissues of the brain were obtained. Part II. a clinical case-control study that included 20 clinically diagnosed PD patients and matched controls. Surgically resected FFPE tissues from the upper and lower GI tracts were used. The RT-QuIC assay was performed to evaluate pathologic seed amplification using frozen or FFPE tissues. The presence or absence of AS aggregation was confirmed by conventional phosphorylated AS (pAS) immunohistochemistry (IHC).

RESULTS

In Part I, RT-QuIC assay showed pathologic AS amplification in frozen and FFPE brain tissues of PD and DLB patients, and FFPE stomach tissue of PD patients but not in the MSA patient and controls. In Part II, pathologic seeding activity was found in 10% (2/20) of the stomach tissues of clinical PD patients but in none of the matched controls. IHC showed pAS-positive staining in 55% of patients (11/20) and 15% of controls (3/20).

CONCLUSION

The present study results showed that the RT-QuIC assay using FFPE tissue of the GI tract was inadequate as a biomarker in PD.

Automated Disease Detection in Gastroscopy Videos Using Convolutional Neural Networks

A large percentage of the world's population is affected by gastric diseases ranging from erosion and ulcer to serious ailments such as gastric cancer, which is mainly caused by Helicobacter pylori(H.pylori) infection. While most erosions and ulcers are benign, severe cases of gastric diseases can still develop into cancer. Thus, early screening and treatment of all gastric diseases are of great importance. Upper gastroscopy is one such common screening procedure that visualizes the patient's upper digestive system by inserting a camera attached to a rubber tube down the patient's digestive tracts, but since the procedure requires manual inspection of the video feed, it is prone to human errors. To improve the sensitivity and specificity of gastroscopies, we applied deep learning methods to develop an automated gastric disease detection system that detects frames of the video feed showing signs of gastric diseases. To this end, we collected data from images in anonymous patient case reports and gastroscopy videos to train and evaluate a convolutional neural network (CNN), and we used sliding window to improve the stability of our model's video performance. Our CNN model achieved 84.92% sensitivity, 88.26% specificity, and 85.2% F1-score on the test set, as well as 97% true positive rate and 16.2% false positive rate on a separate video test set.