Effectiveness of Gastric Cancer Screening on Gastric Cancer Incidence and Mortality in a Community-Based Prospective Cohort

Bio-assay of the non-amidated progastrin-derived peptide (G17-Gly) using the tailor-made recombinant antibody fragment and phage display method: a biomedical analysis

In this research, four novel and sensitive immunosensors for electrochemical determination of G17-Gly were designed based on signal amplification and tailor-made recombinant antibody technology. Anti-G17-Gly antibody fragments (i.e. scFv and VL specific to the N- and C-terminal of G17-Gly) were immobilized onto a polymeric nanocomposite comprising poly cetyl trimethyl ammonium bromide (P(CTAB)) as the conductive matrix, chitosan (CS) as a biocompatible agent and gold nanoparticles (AuNPs) as the signal amplification element. The high surface area provided by AuNPs and the small size of scFv/VL establish the basis for immobilizing a high amount of the anti-G17-Gly on the surface of the electrode for detecting G17-Gly in human plasma samples. Under optimal conditions, the designed immunosensors provide an excellent analytical capability for detecting and determining G17-Gly in human plasma samples with a linear range from 0.5 mM to 0.05 pM and a LLOQ of 0.05 pM. The sensitivity order of the immunosensors was Ag/2-mercaptoethanol/phage displaying scFv/P(CTAB-CS)-AuNP/GE, Ag/2-mercaptoethanol/phage displaying VL/P(CTAB-CS)-AuNP/GE, Ag/BSA/scFv/P(CTAB-CS)-AuNP/GE, and Ag/BSA/VL/P(CTAB-CS)-AuNP/GE. The aforementioned characteristics demonstrate that the proposed immune-devices can be used in biological and clinical diagnosis as reliable tools for identifying different oncobiomarkers.

CD40 DNA hypermethylation in primary gastric tumors; as a novel diagnostic biomarker

AIMS

Gastric cancer (GC) remains one of the deadliest malignancies worldwide due to its poor prognosis. DNA methylation changes, as an early event during tumor progression, constitute attractive markers for cancer diagnostics. In the current study, CD40 DNA methylation was investigated in GC as a novel epigenetic biomarker.

MAIN METHODS

We first analyzed DNA methylation microarrays from the Gene Expression Omnibus database on GC samples to evaluate the potential diagnostic value of CD40 methylation. Moreover, using q-MSP, in a set of internal samples including GC primary tumors and adjacent normal specimens, CD40 DNA methylation levels were determined. The Cancer Genome Atlas (TCGA) data on GC was also analyzed for further validation.

KEY FINDINGS

Our results illustrated significant CD40 hypermethylation in GC samples compared to normal specimens which was significantly correlated with the clinical stage of malignancy. Besides, the high accuracy of CD40 methylation as a diagnostic biomarker in GC was confirmed using the ROC curve analysis with an AUC value of 0.9089. Also, gene set enrichment analysis showed that CD40 is mainly involved in biological processes regulating immune response activation in GC. Further analysis of other prevalent cancer entities in TCGA showed that CD40 hypermethylation is a common event during tumor progression and could be considered as a potential biomarker for the detection of breast, colorectal, and prostate cancers as well.

SIGNIFICANCE

The finding of this study suggests that CD40 methylation as a potential pan biomarker could be a valuable target for liquid biopsy application of human cancers.

Laparoscopic management of gastric remnant ischemia after laparoscopic distal gastrectomy with Billroth-I anastomosis-A case report

INTRODUCTION

Gastric remnant ischemia after laparoscopic distal gastrectomy (LDG) in gastric cancer patients is a very rare but life-threatening condition, especially when accompanied by a splenic infarction or unplanned splenectomy.

PRESENTATION OF CASE

A 72-year-old male with no comorbid diseases was diagnosed with a well-differentiated adenocarcinoma of the lower stomach and underwent LDG with D2 lymph node dissection. However, a splenic artery injury necessitated a splenectomy intra-operatively, and delta anastomosis was performed based on a clinically viable remnant stomach. During the late post-operative period, the patient developed abdominal pain and showed increased levels of inflammatory biomarkers with hemodynamic stability. Esophagogastroduodenoscopy (EGD) showed necrotic patches over the distal part of the remnant stomach with normal anastomosis and duodenal mucosa. Progression of the necrosis was noted on follow up EGD performed 15 days post-surgery. Total laparoscopic subtotal gastrectomy with Roux-en-Y reconstruction was performed and the patient recovered uneventfully.

DISCUSSION

Careful dissection of the lymph nodes over the major vessels is essential to avoid complications in gastric cancer patients requiring LDG. Moreover, major complications occurring intra-operatively may necessitate changes in the surgical plan, including re-excision of the remnant stomach or conversion to Roux-en-Y reconstruction.

CONCLUSION

Careful evaluation of the clinical findings and close observation with EGD can help detect mucosal demarcation lines and ascertain the perfect timing for intervention in cases with suspected ischemia. Although gastric remnant ischemia requires emergency treatment, laparoscopic management is a feasible option when performed by an expert surgeon.

The long-term population impact of endoscopic screening programmes on disease burdens of gastric cancer in China: A mathematical modelling study

BACKGROUND

Gastric cancer (GC) incidence and mortality in China remained high due to delayed diagnosis and accounted for about half of the world's GC cases and deaths. Early detection with endoscopic screening and consequent timely treatment can significantly improve survival. This study aimed to explore the long-term population impact of endoscopic screening on national GC disease burdens in China.

METHODS

Most of previous studies investigated the disease burdens of cancer using Markov model or age-period-cohort (APC) model, which are difficult to estimate the population size of undiagnosed cases. In this paper, we proposed a new dynamic compartmental model based on GC natural history and calibrated model outputs to diagnosed GC cases and GC-related death counts using Markov Chain Monte Carlo methods. We investigated the impact of screening strategies with various coverage (10%, 40%, 70%) and frequency (every 1, 3, 5 years) on disease burdens.

RESULTS

We estimated that 2.22 (95%CI: 1.97-2.47) million Chinese are living with GC in 2019, among which, 42.7% (40.3-45.0%) remained undiagnosed. Without systematic screening, we projected 10.46 (9.07-11.86) million incident cases and 7.35 (6.59-8.11) million GC-related deaths over the next 30 years (2019-2049). Screening with coverage rate at 10%, 40%, 70% every 3 years could prevent 0.85 (0.63-1.06), 2.32 (1.79-2.86), and 3.04 (2.38-3.70) million incident cases, and prevent 1.17 (1.01-1.32), 3.08 (2.70-3.46), and 3.93 (3.46-4.40) million deaths respectively, compared with 'no screening' scenario. Screening would substantially increase the number of diagnosed GC cases within the first three years of program initiation, but this number would quickly reduce below 'no screening' scenario. Three-yearly screening at the above coverage rates would reduce the proportion of undiagnosed GC cases to 38.8% (36.9-40.7%), 25.5% (23.4-27.6%), and 17.8% (16.0-19.6%) by 2049, respectively. Delaying implementation of the screening program would substantially reduce its effectiveness.

CONCLUSIONS

Initiating national endoscopic screening programmes would likely have a major effect on reducing GC incidence and mortality in China. Health resources should be substantially increased and directed to treatment of GC to cope with the initial rise in diagnosed GC cases.

Review and Comparison of Cancer Biomarker Trends in Urine as a Basis for New Diagnostic Pathways

Cancer is one of the major causes of mortality worldwide and its already large burden is projected to increase significantly in the near future with a predicted 22 million new cancer cases and 13 million cancer-related deaths occurring annually by 2030. Unfortunately, current procedures for diagnosis are characterized by low diagnostic accuracies. Given the proved correlation between cancer presence and alterations of biological fluid composition, many researchers suggested their characterization to improve cancer detection at early stages. This paper reviews the information that can be found in the scientific literature, regarding the correlation of different cancer forms with the presence of specific metabolites in human urine, in a schematic and easily interpretable form, because of the huge amount of relevant literature. The originality of this paper relies on the attempt to point out the odor properties of such metabolites, and thus to highlight the correlation between urine odor alterations and cancer presence, which is proven by recent literature suggesting the analysis of urine odor for diagnostic purposes. This investigation aims to evaluate the possibility to compare the results of studies based on different approaches to be able in the future to identify those compounds responsible for urine odor alteration.

Awareness of risk factors and warning symptoms and attitude towards gastric cancer screening among the general public in China: a cross-sectional study

OBJECTIVES

This study aimed to assess the knowledge of risk factors and warning symptoms and attitude towards gastric cancer screening among the general population in China.

SETTING

Hunan province, China PARTICIPANTS: Individuals aged older than 18 years were recruited using a cluster sampling method.

DESIGN

A cross-sectional study, and a pretested structured questionnaire was used to assess participants' awareness of gastric cancer.

PRIMARY AND SECONDARY OUTCOME MEASURES

Knowledge level of risk factors and warning symptoms of gastric cancer, gastric cancer screening attitude, sociodemographic factors associated with gastric cancer knowledge and screening behaviour.

RESULTS

This study comprised 1200 participants with a mean age of 40.31 (SD 16.73) years, of whom 622 (51.8%) were women. The mean score for gastric cancer knowledge was 8.85/22 (SD 6.48). There were 47.0% of the participants who had a low knowledge level about the risk factors and warning symptoms of gastric cancer. In total, 83.8% believed screening is helpful for early detection of gastric cancer, and 15.2% had undergone gastric cancer screening. The most common reason for not undergoing screening was having 'no symptoms' (63.0%), followed by 'fear of undergoing gastroscopy' (38.1%). Independent factors related to lower knowledge levels included male sex, living in rural areas, lower educational level, working as a farmer and without a family history of gastric cancer (p<0.05). Factors independently associated with screening behaviour included white-collar employment, higher income and having upper gastrointestinal tract diseases (p<0.05).

CONCLUSIONS

In China, people have poor knowledge about risk factors and warning symptoms of gastric cancer, but a majority have a positive attitude towards the benefits of gastric cancer screening. Being asymptomatic and having a fear of gastroscopy were the main self-reported reasons for not undergoing screening. These results highlight the urgent need for educational campaigns to improve gastric cancer awareness.

Gastric Cancer - From Aetiology to Management: Differences Between the East and the West

Gastric cancers are highly prevalent in both the East and the West, although they differ in aetiology and prognostic outcome. Management of gastric cancer from screening to definitive treatment varies substantially between Eastern and Western countries and regions, owing to numerous factors, including government incentives to carry out population-wide screening programmes to detect early disease, differences in clinical and biological tumour behaviours and responsiveness to treatment, patient accessibility to effective treatment, etc. This review highlights and contrasts the differences in tumour aetiology and histology, as well as the management approaches between the East and the West, which gives important insights and inspirations on future international multicentre research collaboration to combat this dreadful malignancy.

Modeling the Surface Field From an Ingested Radio Transmitter With an Approximate Attenuation Model for Gastroenterology Investigations

OBJECTIVE

The precise location of an ingested radio transmitter/sensor is of importance in gastroenterology studies. Given the complex geometry of the gut and the very large variations in human size and electromagnetic characteristics, inverse modeling from surface-based measurements is very complex, and a unique location solution is not possible. This paper proposes a simple method based on far-field approximation of the attenuated field from the ingested transmitter.

METHODS

The validation experiments for an ellipsoid cylinder using averaged electromagnetic properties of the human gastrointestinal tract (conductivity 0.87 S/m, relative permittivity 62) and a Hertzian dipole radiator inside the body with a frequency of 433 MHz were conducted assuming a receiver dynamic range of less than 100 dB.

RESULTS

The surface field intensity distribution patterns and the amplitude ranges were established for different positions and orientation of the dipole in every segment of the tract. The reliability of the method was verified by comparison with finite-difference time-domain modeling.

CONCLUSION

The method provides an analytical solution to estimate the surface field intensity depending on the dipole location and orientation with a negligible computational cost.

SIGNIFICANCE

This efficient algorithm can be incorporated into an inversion algorithm for localization of wireless endoscopy sensors to allow precise targeted treatment.

Extended Gastrectomy for T4b Gastric Adenocarcinoma: Single-Surgeon Experience

PURPOSE

This study reports single-surgeon experience with extended gastrectomy including en-bloc resection of adjacent organs/structures for T4b stage gastric adenocarcinoma. Time-related changes in patient selection criteria and outcomes were also analyzed.

METHODS

All consecutive gastrectomies for adenocarcinoma performed between May 2004 and December 2017 were extracted from prospectively collected database to study surgical and oncologic results. Time-related changes in outcomes were examined according to three time periods.

RESULTS

Five hundred eighty-seven gastrectomies were performed throughout the study period including 87 (14.8%) extended resections. The latter most often included pancreatosplenectomy, colon, and liver resections (21, 16, and 11 patients, respectively) resulting in similar postoperative outcomes and survival. Extended gastrectomy was associated with larger tumor size (8.4 vs 5.6 cm), performing total gastrectomy (55.2 vs 35.2%, p < 0.01) and increased blood loss (375 vs 150 ml, p < 0.01) compared with standard gastrectomy. Larger experience in extended gastrectomy allowed for expanding patient selection criteria, considering complex resections and extensive lymphadenectomy. Median and 3-year survival following extended gastrectomy for T4b adenocarcinoma were 14 months and 18%, respectively, which was comparable to standard gastrectomy for T4a adenocarcinoma (p = 0.48). Obesity, nodal stage and type of gastrectomy were associated with survival in T4b adenocarcinoma in the univariable analysis. Obesity and N3a and N3b stages were independent predictors in the multivariable model.

CONCLUSIONS

Extended gastrectomy for T4b gastric adenocarcinoma provides satisfactory surgical outcomes even with expanded patient selection criteria and regardless of the organ involved. Given its poor prognosis, neoadjuvant therapy should be considered to improve the long-term oncologic results.

Screening for gastric cancer with magnetically controlled capsule gastroscopy in asymptomatic individuals

BACKGROUND AND AIMS

Gastric cancer (GC) is the fourth most common cancer and the fourth leading cause of cancer death worldwide. In some Asian countries, screening EGD has greatly improved the survival rate. However, patients' discomfort and the need for sedation may limit adherence to screening programs. Previous studies have shown good tolerance and good agreement of magnetically controlled capsule gastroscopy (MCCG) with EGD. This study was designed to assess the application of MCCG in GC detection in an asymptomatic population.

METHODS

In this observational cohort study, 3182 asymptomatic individuals undergoing MCCG in 99 participating medical examination centers from April to December 2016 were enrolled. Patients with ulcers and suspected malignancies were referred for gastroscopy and biopsy. The detection rate of GC and focal lesions were used to explore the application of MCCG in asymptomatic individuals.

RESULTS

Seven patients (0.22%) were diagnosed with GC among the enrolled 3182 individuals, accounting for 0.74% (7/948) in patients over 50 years. No gender disparity was observed. EGD and biopsy confirmed adenocarcinoma in all cases of suspected malignancy. Benign polyps, gastric ulcers, and submucosal tumors were found in 10.4%, 4.9%, and 3.6% of patients, respectively. There was a trend for the prevalence of focal lesions to increase with age. MCCG examination proved to be safe.

CONCLUSIONS

MCCG can detect cancer and benign lesions and is safe and clinically feasible in a large population. Studies of its role in a screening program should be considered.

Endoscopic Screening in Asian Countries Is Associated With Reduced Gastric Cancer Mortality: A Meta-analysis and Systematic Review

BACKGROUND & AIMS

It is not clear how endoscopic screening for gastric cancer affects incidence or mortality. We performed a systematic review and meta-analysis to evaluate the relationship between endoscopic screening for gastric cancer and mortality and incidence.

METHODS

We conducted a systematic search of PubMed and EMBASE for published cohort and case-control studies of adults without gastric cancer who underwent endoscopic screening at least once that included a comparator and reported outcomes of mortality or incidence through March 8, 2018. Two investigators independently reviewed the included studies and extracted relevant data. The effect estimate of interest was the relative risk (RR). We used a random effects model to combine RRs and 95% confidence intervals (Cis).

RESULTS

Our final analysis included 6 cohort studies and 4 nested case-control studies comprising 342,013 individuals, all from Asia. The combined result (RR, 0.60; 95% CI, 0.49-0.73) indicated that endoscopic screening was associated with a 40% RR reduction in gastric cancer mortality. We did not observe an association between endoscopic screening and incidence (RR, 1.14; 95% CI, 0.93-1.40). Subgroup analysis showed significant reductions in gastric cancer mortality after endoscopic screening compared with no screening (RR, 0.58; 95% CI, 0.48-0.70) or radiographic screening (RR, 0.33; 95% CI, 0.12-0.91). However, endoscopic screening did not significantly reduce mortality compared with expected deaths (RR, 0.67; 95% CI, 0.38-1.16).

CONCLUSIONS

In a systematic review and meta-analysis, we found that endoscopic screening may reduce the risk of death from gastric cancer and not affect incidence in Asian countries. Population-based prospective cohort studies are warranted to confirm our findings.

Gastric Mucosal Atrophy Impedes Housekeeping Gene Methylation in Gastric Cancer Patients

PURPOSE

Helicobacter pylori infection induces phenotype-stabilizing methylation and promotes gastric mucosal atrophy that can inhibit CpG-island methylation. Relationship between the progression of gastric mucosal atrophy and the initiation of CpG-island methylation was analyzed to delineate epigenetic period for neoplastic transformation.

Materials and Methods

Normal-appearing gastric mucosa was biopsied from 110 H. pylori-positive controls, 95 H. pylori-negative controls, 99 gastric cancer patients, and 118 gastric dysplasia patients. Gastric atrophy was assessed using endoscopic-atrophic-border score. Methylation-variable sites of eight CpG-island genes adjacent to Alu (CDH1, ARRDC4, PPARG, and TRAPPC2L) or LTR (MMP2, CDKN2A, RUNX2, and RUNX3) retroelements and stomach-specific TFF3 gene were analyzed using radioisotope-labeled methylation-specific polymerase chain reaction.

RESULTS

Mean ages of H. pylori-positive controls with mild, moderate, and severe atrophy were 51, 54, and 65 years and those of H. pylori-associated TFF3 overmethylation at the three atrophic levels (51, 58, and 63 years) tended to be periodic. Alu-adjacent overmethylation (50 years) was earlier than TFF3 overmethylation (58 years) in H. pylori-positive controls with moderate atrophy. Cancer patients with moderate atrophy showed late Alu-adjacent (58 years) overmethylation and frequent LTR-adjacent overmethylation. LTR-adjacent overmethylation was frequent in cancer (66 years) and dysplasia (68 years) patients with severe atrophy.

CONCLUSION

Atrophic progression is associated with gastric cancer at moderate level by impeding the initiation of Alu-adjacent methylation. LTR-adjacent methylation is increased in cancer patients and subsequently in dysplasia patients.

Preoperative gastric lavage in gastric cancer patients undergoing surgical, endoscopic or minimally invasive treatment: An oncological measure preventing peritoneal spillage of intragastric cancer cells and development of related metastases

In addition to classical metastatic pathways, recently gastric cancer was described having an alternative route called "endoluminal exfoliation". Provisional analyses demonstrated, in fact, this kind of shedding is associated with several clinico-pathological features indicative of aggressive behavior and resulted to be an independent prognostic factor entailing poor prognosis. Compared with non-sowing counterparts, in fact, patients affected with exfoliating early and advanced gastric carcinomas met with shorter overall survival, disease free survival, progression free survival and time to tumor progression. In spite of these interesting results, however, the clinico-pathological and oncological significance of this unconventional metastatic route is still to be clarified. Such an investigation is further urged by the increasing widespread employment of minimally invasive treatments for gastric cancer which include a wide spectrum of intragastric interventions and maneuvers. Indeed, endoscopic mucosal resection, endoscopic submucosal dissection, endoscopic full-thickness resection, intragastric laparoscopic surgery and hybrid procedures all take place inside of the stomach. However, iatrogenic perforations can occur during execution of these treatments leading to spillage of malignant cells from gastric to the peritoneal cavity or trocar insertion sites. Furthermore, many other gastric conditions and interventions can collide with endogastric presence of floating cancer cells: spontaneous ulceration or perforation, laparotomy surgery, gastrointestinal occlusion, diverticula. Viability, migration and intraluminal transportability of the intragastric floating cancer cells represents another original and intriguing topic. All these considerations led us to entertain the hypothesis that removing the exfoliated cancer cells from the gastric lumen could save patients from the dreaded potential risk of spillage. Performing gastric lavage before starting any kind of tumor intervention could be the most appropriate procedure to adopt with prophylactic intent. Should our speculation prove to be clinically significant, preoperative gastric lavage should be pointed out as a simple but cogent method useful for preventing oncological mishaps such as spillage of gastric cancer cells and development of related recurrences or metastases.