Prevention of gastric cancer by Helicobacter pylori eradication

Evaluation of Prognostic Factors for Unresectable or Recurrent Gastric Cancer Treated with Nivolumab

PURPOSE

Nivolumab is useful for the treatment of unresectable/recurrent gastric cancer as third-line or later chemotherapy. However, the factors that predict the efficacy of nivolumab monotherapy remain unclear.

METHODS

We retrospectively studied the predictive factors of response in 59 consecutive patients treated with nivolumab as third-line or later chemotherapy for unresectable/recurrent gastric cancer at our hospital from October 2017 to May 2020.

RESULTS

The median follow-up was 5.9 months. The study included 45 men and 14 women (median age: 71 years). We observed that 7 patients had an Eastern Cooperative Oncology Group performance status of 0 and 52 patients had a performance status of 1-2. Forty-three patients were treated with third-line therapy, seven with fourth-line therapy, and three with fifth-line therapy. The response rate to nivolumab was 6.7% and disease control rate was 35.5%. There were 19 (32.2%) immune-related adverse events for all grades and 9 (15.2%) for grades 3 and 4. Progression-free survival was 1.90 months, and overall survival was 6.30 months. Patients with immune-related adverse events had significantly longer overall survival than those without immune-related adverse events. Multivariate analysis showed that the occurrence of immune-related adverse events and a ratio for neutrophil-to-lymphocyte ratio after 8 weeks of nivolumab treatment to the baseline neutrophil-to-lymphocyte ratio before treatment of ≤ 1.5 were independent prognostic factors for overall survival.

CONCLUSIONS

Occurrence of immune-related adverse events and changes in neutrophil-to-lymphocyte ratio during nivolumab treatment may help predict the therapeutic efficacy of nivolumab monotherapy for unresectable or recurrent gastric cancer.

Antimicrobial Effects of Lactoferrin against Helicobacter pylori Infection

Helicobacter (H.) pylori is the primary causative agent of various gastroduodenal diseases. H. pylori is an adapted microorganism that has evolved to survive in the acidic conditions of the human stomach, possessing a natural strategy for colonizing harsh environments. Despite the implementation of various eradication regimens worldwide, the eradication rate of H. pylori has decreased to less than 80% in recent years due to the emergence of antibiotic-resistant strains. This has posed a significant challenge in treating H. pylori infection, as antibiotic resistance and side effects have become increasingly problematic. Lactoferrin, a member of the transferrin family, is an iron-binding protein with antioxidant, antibacterial, antiviral, and anti-inflammatory properties that promote human health. The concentrations of lactoferrin in the gastric juice and mucosa significantly increase during H. pylori infection and are strongly correlated with the severity of gastric mucosal inflammation. Numerous researchers have studied the antimicrobial properties of lactoferrin both in vitro and in vivo. In addition, recent studies have investigated the addition of oral lactoferrin supplementation to H. pylori eradication therapy, even though monotherapy with lactoferrin does not eradicate the microorganism. In this article, we reviewed the survival strategy of H. pylori to evade the antimicrobial activity of human lactoferrin and explore the potential of lactoferrin in H. pylori eradication therapy.

Effectiveness of Helicobacter pylori eradication in preventing metachronous gastric cancer and preneoplastic lesions. A systematic review and meta-analysis

BACKGROUND

Helicobacter pylori is a significant risk factor for gastric cancer. Recent trials show eradication decreases the incidence of gastric cancer in patients with early-stage gastric cancer. However, data on gastric cancer prevention are inconsistent for patients with precancerous lesions such as atrophic gastritis and intestinal metaplasia.

AIM

The aim of the study is to assess the efficacy of H. pylori eradication in gastric cancer prevention in patients with varying risk factors for gastric cancer at baseline.

METHODS

A systematic review and meta-analysis were performed according to Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines. PubMed, Medline, and Google Scholar were searched from inception through March 2019 for randomized controlled trials (RCTs) studying H. pylori eradication on gastric cancer prevention. We estimated the odds ratio (OR) with 95% confidence interval (CI) for each outcome using a random-effects model. P values of less than 0.05 were considered significant.

RESULTS

Nine RCTs with total of 6967 patient were included in the analysis. There was significant reduction in gastric cancer incidence in the H. pylori group for patients with early gastric cancer status post endoscopic mucosal resection OR, 0.47; 95% CI, 0.33-0.67; P < 0.0001; I = 0%. There was no difference in gastric cancer incidence in patients with atrophic gastritis and intestinal metaplasia at baseline for H. pylori arm OR, 0.67; 95% CI, 0.42-1.07; P = 0.09; I = 0%). Atrophic gastritis and intestinal metaplasia improved from baseline in the H. pylori arm compared to placebo OR, 2.61; 95% CI, 1.41-4.81; P = 0.002; I = 88 and OR, 2.61; 95% CI, 1.66-4.11; P ≤ 0.0001; I = 0%, respectively.

CONCLUSIONS

H. pylori eradication is associated with reduced gastric cancer incidence in patients with early-stage gastric cancer and improvement in atrophic gastritis and intestinal metaplasia. There was no difference in gastric cancer incidence in patients with atrophic gastritis and intestinal metaplasia at baseline.

Personalizing Gastric Cancer Screening With Predictive Modeling of Disease Progression Biomarkers

Gastric cancer (GC) remains the third most common cause of cancer-related death worldwide. Infection with Helicobacter pylori is responsible for over 70% of GC incidence; colonization induces chronic inflammation, which can facilitate progression to intestinal metaplasia, dysplasia, and GC (Correa pathway). Although H. pylori eradication is a necessary first step in GC prevention, some patients continue to progress to advanced stage disease if substantial tissue damage has occurred or inflammation persists. This progression is often asymptomatic until cancer reaches stage IV, yet efficient, cost-effective screening protocols for patients who present with early stages of the Correa pathway do not exist. Given the high interpatient heterogeneity in progression time through this pathway, such screening protocols must necessarily be personalized. This requires the identification of reliable and longitudinally assessable biomarkers of patient-specific progression. Several gastric stem cell (GSC) markers including CD44, CD133, and Lgr5 are upregulated in GC. Here we show a significant stepwise increase in immunohistochemical staining for these markers in biopsies at different stages of the Correa pathway, suggesting GSC fraction to be a promising candidate biomarker for early detection of malignant transformation. We present a mathematical model capable of both simulating clinically observed increases in GSC fraction in longitudinal biopsy samples of individual patients, and forecasting patient-specific disease progression trajectories based only on characteristics identified from immunohistochemistry at initial presentation. From these forecasts, personalized screening schedules may be identified that would allow early stratification of high-risk patients, and potentially earlier detection of dysplasia or early-stage GC.

Helicobacter pylori Therapy for the Prevention of Metachronous Gastric Cancer

BACKGROUND

Patients with early gastric cancers that are limited to gastric mucosa or submucosa usually have an advanced loss of mucosal glandular tissue (glandular atrophy) and are at high risk for subsequent (metachronous) development of new gastric cancer. The long-term effects of treatment to eradicate Helicobacter pylori on histologic improvement and the prevention of metachronous gastric cancer remain unclear.

METHODS

In this prospective, double-blind, placebo-controlled, randomized trial, we assigned 470 patients who had undergone endoscopic resection of early gastric cancer or high-grade adenoma to receive either H. pylori eradication therapy with antibiotics or placebo. Two primary outcomes were the incidence of metachronous gastric cancer detected on endoscopy performed at the 1-year follow-up or later and improvement from baseline in the grade of glandular atrophy in the gastric corpus lesser curvature at the 3-year follow-up.

RESULTS

A total of 396 patients were included in the modified intention-to-treat analysis population (194 in the treatment group and 202 in placebo group). During a median follow-up of 5.9 years, metachronous gastric cancer developed in 14 patients (7.2%) in the treatment group and in 27 patients (13.4%) in the placebo group (hazard ratio in the treatment group, 0.50; 95% confidence interval, 0.26 to 0.94; P=0.03). Among the 327 patients in the subgroup that underwent histologic analysis, improvement from baseline in the atrophy grade at the gastric corpus lesser curvature was observed in 48.4% of the patients in the treatment group and in 15.0% of those in the placebo group (P<0.001). There were no serious adverse events; mild adverse events were more common in the treatment group (42.0% vs. 10.2%, P<0.001).

CONCLUSIONS

Patients with early gastric cancer who received H. pylori treatment had lower rates of metachronous gastric cancer and more improvement from baseline in the grade of gastric corpus atrophy than patients who received placebo. (Funded by the National Cancer Center, South Korea; ClinicalTrials.gov number, NCT02407119 .).

Toward early detection of Helicobacter pylori-associated gastric cancer

BACKGROUND

Gastric cancer is typically diagnosed at a late stage, leading to poor prognoses. Helicobacter pylori is responsible for 70% of gastric cancers globally, and patients with this bacterial infection often present with early stages of the carcinogenic pathway such as inflammation or gastritis. Although many patients continue to progress to advanced-stage disease after antibacterial treatment, there are no follow-up screening protocols for patients with a history of H. pylori.

METHODS

Several biomarkers (Lgr5, CD133, CD44) become upregulated during gastric carcinogenesis. A logistic regression model is developed using clinical data from 59 patients at different stages of the carcinogenic pathway to identify the likelihood of being at an advanced stage of disease for all combinations of age, sex, and marker positivity. Using these likelihood distributions and the observed rate of marker positivity increase, time to high likelihood (probability >0.8) of advanced disease for individual patients is predicted.

RESULTS

A strong correlation between marker positivity and disease stage was found for all three markers. Disease stage was accurately classified by the respective regression models for more than 86% of retrospective patients. Highly patient-specific predictions of time to onset of dysplasia were made, allowing the classification of 17 patients initially diagnosed with intestinal metaplasia into high-, intermediate-, or low-risk categories.

CONCLUSIONS

We present an approach designed to integrate pathology, mathematics, and statistics for detection of the earliest precancerous, treatable lesion. Given the simplicity and robustness of the framework, such technique has the potential to guide personalized screening schedules to minimize the risk of undetected malignant transformation.

Berberine containing quadruple therapy for initial Helicobacter pylori eradication: An open-label randomized phase IV trial

BACKGROUND

Due to increasing antimicrobial resistance, a bismuth-based quadruple regimen has been recommended as an alternative first-line therapy for Helicobacter pylori (H pylori) eradication. However, different results are varied greatly and the availability of bismuth was limited in some countries. We assessed the efficacy and safety of 14-day berberine-containing quadruple therapy as an alternative regimen for H pylori eradication.

METHODS

In a randomized, open-label, non-inferiority, phase IV trial between November 25, 2014, and October 15, 2015, 612 treatment-naive patients were randomly assigned to 14-day berberine-containing (n = 308) or 14-day bismuth-containing (n = 304) quadruple therapy. The primary outcomes were eradication rates determined by the C urea breath test (C-UBT) 28 days after the end of treatment. The secondary outcomes were adverse events and compliance.

RESULTS

The baseline demographic data including age, gender, body mass index (BMI), general condition and severity score were not statistically different in both groups. The eradication rates in bismuth and berberine groups were 86.4% (266/308) and 90.1% (274/304) in intention-to-treat (ITT) analysis (P = .149), and 89.6% (266/297) and 91.3% (273/299) in per-protocol (PP) analysis (P = .470), respectively. No statistically significant difference was found in the overall incidence of adverse events between both groups (35.7% vs 28.6%, P = .060).

CONCLUSIONS

Both regimens achieved the recommended efficacy for H pylori eradication. The berberine-containing quadruple regimen was not inferior to bismuth-containing quadruple regimen and can be recommended as an alternative regimen for H pylori eradication in the local region.

Time to local recurrence as a predictor of survival in unrecetable gastric cancer patients after radical gastrectomy

Local recurrence is common after radical surgery. However, the factors that contribute to survival after local recurrence remain unclear. In this retrospective study we analyzed the relationship between time to recurrence and survival after recurrence in 74 patients with locally recurrent gastric cancer. All patients received palliative radiotherapy with or without chemotherapy. The patients were divided into two groups according to the time between gastrectomy and local recurrence: early local recurrence (ELR, < 12 months after primary surgery), and late local recurrence (LLR, ≥12 months after primary surgery). The median overall survival (OS) time was 15 months for patients with ELR and 25 months for LLR patients. Univariate and multivariate analysis revealed that time to local recurrence was significantly associated with OS after local recurrence (P = 0.001). The hazard ratio of ELR compared with LLR patients was 0.442 (95% confidence interval: 0.264-0.741). These results indicate that early local recurrence predicted poor prognosis in gastric cancer patients with unresectable local recurrence.

Risk Factors for Metachronous Recurrence after Endoscopic Submucosal Dissection of Early Gastric Cancer

Although endoscopic submucosal dissection (ESD) is widely accepted as a curative treatment method for early gastric cancer (EGC) worldwide, metachronous recurrence often occurs after ESD for EGC. However, there are insufficient data about the role of Helicobacter pylori (H. pylori) infection and other risk factors for recurrence. We aimed to compare the metachronous lesion in the H. pylori persistent group and the eradicated group, and to identify risk factors for metachronous lesion. We retrospectively analyzed 782 patients who underwent ESD between January 2008 and December 2013. We excluded patients with dysplasia or patients who were not tested for H. pylori infection. One hundred eighty-five patients were enrolled. We studied risk factors for recurrence, and used survival analysis to test. There were 24 patients with metachronous recurrence after ESD for EGC among the group. The incidence of metachronous gastric lesions after ESD for EGC developed more in the over 70-year-old group (P = 0.025) and more in the H. pylori persistent group (P = 0.008). In conclusion, H. pylori infection and old age are independent risk factors for metachronous gastric lesions after ESD in EGC.

Pathogenesis and risk factors for gastric cancer after Helicobacter pylori eradication

Helicobacter pylori (H. pylori) infection was thought to be the main cause of gastric cancer, and its eradication showed improvement in gastric inflammation and decreased the risk of gastric cancer. Recently, a number of studies reported the occurrence of gastric cancer after successful eradication. Patients infected with H. pylori, even after eradication, have a higher risk for the occurrence of gastric cancer when compared with uninfected patients. Metachronous gastric cancer occurs frequently following the endoscopic removal of early gastric cancer. These data indicate that metachronous cancer leads to the occurrence of gastric cancer even after successful eradication of H. pylori. The pathogenesis of this metachronous cancer remains unclear. Further research is needed to identify biomarkers to predict the development of metachronous gastric cancer and methods for gastric cancer screening. In this article, we review the role of the H. pylori in carcinogenesis and the histological and endoscopic characteristics and risk factors for metachronous gastric cancer after eradication. Additionally, we discuss recent risk predictions and possible approaches for reducing the risk of metachronous gastric cancer after eradication.

Incidence of gastric cancer after endoscopic resection of gastric adenoma

BACKGROUND AND AIMS

The annual incidence of metachronous cancer after endoscopic resection (ER) of early gastric cancer (EGC) is approximately 3%. However, the incidence of gastric cancer after ER of a gastric adenoma is not known. The aim of this study was to determine whether the incidence of gastric cancer after ER of a gastric adenoma was different compared with that of metachronous cancer after ER of EGC.

METHODS

We retrospectively analyzed data from patients who underwent ER for gastric neoplasia from January 2005 to August 2013. Enrolled patients were divided into 2 groups: patients with low-grade dysplasia were included in the adenoma group and patients with high-grade dysplasia or invasive neoplasia were included in the EGC group. The main outcome was the incidence of gastric cancer after ER.

RESULTS

At a median follow-up of 28 months, gastric cancer newly developed in 13 adenoma patients (3.6%) and in 30 EGC patients (5.1%). The incidence rate of gastric cancer after ER was 14.4 cases per 1000 person-years in adenoma patients and 18.4 cases per 1000 person-years in EGC patients (P = .309 by the log-rank test). The hazard ratio of metachronous neoplasia in adenoma patients compared with EGC patients was 0.97 (95% confidence interval, 0.62-1.53). Metachronous tumors with invasion beyond the muscularis mucosa were more frequent in adenoma patients than in EGC patients (7/35 [20.0%] vs 3/63 [4.8%], P = .017).

CONCLUSION

The incidence of gastric cancer after ER for gastric adenoma was not significantly different from that of EGC. If further prospective studies confirm these findings, careful endoscopic surveillance with the same level of intensity should be considered for both gastric adenoma and EGC patients after ER.

The Japanese Viewpoint on the Histopathology of Early Gastric Cancer

Japanese histopathologists have traditionally had greater opportunity to study the histology and clinical course of early gastric cancer because of technological developments including double contrast radiography and endoscopy systems, combined with the higher incidence of gastric cancer in the general population in Japan. Endoscopic resection is now considered best practice for treatment of early gastric cancers with a negligible risk of lymph node metastasis. Histopathologic evaluation plays a critical role in assessing the likelihood of lymph node metastasis on endoscopically resected specimens. There remains disparity between Western and Japanese histopathologists in the conceptual approach to the histopathologic evaluation of neoplastic lesions in the upper gastrointestinal tract, in particular regarding lesions straddling the borderline between noninvasive and invasive disease. Although in routine practice, the clinical impact of these conceptual differences is small, this disparity does complicate international exchange of datasets and the development of globally applicable formal definitions. Here we review the current practice in histological diagnosis of early gastric cancer in Japan and discuss some of the conceptual differences between Japanese and Western histopathological assessment of lesions in the neoplastic stomach.

Chemoradiotherapy for patients with recurrent lymph-node metastasis or local recurrence of gastric cancer after curative gastrectomy

OBJECTIVES

Whether chemoradiotherapy (CRT) is clinically beneficial for the management of postoperative recurrence of advanced gastric cancer remains unclear. We retrospectively studied treatment outcomes in patients who had unresectable localized recurrence after surgery for advanced gastric cancer and evaluated the safety and efficacy of CRT.

METHODS

The study group comprised 21 patients who received concurrent CRT for unresectable localized recurrence after undergoing R0 resection for stage II/III advanced gastric cancer. Localized recurrence was defined as a few or limited recurrent lesions.

RESULTS

The recurrence pattern was anastomotic recurrence in 7 patients, abdominal lymph-node recurrence in 12, and anastomotic recurrence plus abdominal lymph-node recurrence in 2. The median total dose of radiotherapy was 48.6 Gy (range 39.6-56.0), and the CRT completion rate was 100 % (21 of 21 patients). CRT-related grade 3 or higher toxicity comprised neutropenia in 33.3 % of patients and anorexia in 9.5 %. The response rate was 61.9 % (complete response 38.1 %, partial response 23.8 %). The median overall survival was 35.0 months.

CONCLUSIONS

We conclude that CRT may become one treatment strategy for the management of unresectable localized recurrence after curative resection of advanced gastric cancer.

Does herbal medicine reduce the risk of hepatocellular carcinoma?

Many herbal medicines are effective anti-inflammatory agents and may therefore suppress the development of hepatocellular carcinoma (HCC). Recently, treatment with a single-tablet regimen containing ledipasvir and sofosbuvir resulted in high rates of sustained virologic response among patients with hepatitis C virus genotype 1 infection who did not respond to prior interferon-based treatment. Patients with chronic hepatitis C are expected to receive this treatment worldwide. However, many patients have hepatitis-like fatty liver and nonalcoholic steatohepatitis. A strategy to prevent the development of HCC in this subgroup of patients is urgently required. Whether herbal medicines can suppress the development of HCC remains to be established. However, herbal medicines are effective anti-inflammatory agents and may inhibit the development of HCC. Clinical trials exploring the effectiveness of herbal medicines in the prevention and treatment of HCC are therefore warranted. The current lack of knowledge and of educational programs is a barrier to increasing the use of potentially effective herbal medicines and performing prospective clinical trials.

Helicobacter pylori: the balance between a role as colonizer and pathogen

The isolation of Helicobacter pylori from the human stomach produced significant changes in how gastroenterologists, immunologists, epidemiologists, pathologists and microbiologists have approached gastro-duodenal diseases in the last half of the XX century. However, research of this organism has progressed greatly in the first decade of this century, evidence suggest that H. pylori is associated with disease only in humans older than 40 years, while, the lack of H. pylori colonization is associated with the emergence of new diseases, particularly in younger individuals. These differing effects of H. pylori colonization have created two contrasting concepts: the 'bad' and the 'good' Helicobacter. Following from renewed interest in the normal human microbiome, we need to reconsider our definitions and perhaps recognize that H. pylori might be a normal member of the human gastric microbiome in ancient humans that gradually, as results of the improvement in our environment, is disappearing.

Effect of Helicobacter pylori infection on gastroesophageal reflux disease

Gastroesophageal reflux disease (GERD) is a common chronic disease of the digestive system. In recent years, due to the better understanding of Helicobacter pylori (H. pylori) and the wide clinical application of proton pump inhibitors, the rate of H. pylori infection is declining, while the incidence of GERD is increasing. This phenomenon suggests a possible relationship between H. pylori infection and the incidence of GERD. The pathogenesis of GERD is related to the dysfunction of the protective esophageal barrier, esophageal motility, gastric acidity and gastric emptying, and H. pylori infection may affect these factors to exert an impact on the incidence of GERD.

[Future trends of Helicobacter pylori eradication therapy in Korea]

The prevalence of Helicobacter pylori infection in Korea shows a decreasing trend and has changed to that of developed country, especially for those below 30 years old. However, the primary antibiotic resistance rates are higher than those of developed countries. The reason for the decrease in the efficacy of standard triple therapy is mainly due to the increase in the resistance against clarithromycin. Sequential therapy seems to be more effective than the standard triple therapy, but the intention-to-treat eradication rate of sequential therapy in Korea, which is mostly under 80.0%, is still not satisfactory. Therefore, a promising regimen is needed. Recently, the Japanese health insurance system admitted 'H. pylori-infected gastritis'as an indication of eradication. Furthermore, the Kyoto Consensus Meeting on H. pylori Gastritis held from January 30th to February 1st, 2014, proposed that 'all H. pylori positive patients should be offered to receive H. pylori eradication'. This suggests that the concept of eradication has been changed from 'treatment' to 'prevention'. Various individualized tailored therapy based on the polymorphism, age and other demographic factors and antibiotic resistance has been attempted to maximize H. pylori eradication therapy. The aim of this article is to review the current epidemiology, H. pylori resistance state, treatment guideline, and to assess the possible future strategy and treatment for H. pylori infection in Korea.

Effect of Helicobacter pylori eradication on metachronous gastric cancer after endoscopic resection of gastric tumors: a meta-analysis

BACKGROUND

Although endoscopic resection is widely accepted as the curative treatment modality for early gastric cancer, secondary metachronous cancer may subsequently develop in the residual gastric mucosa. The preventive effect of Helicobacter pylori eradication on the development of metachronous gastric cancer in such cases remains controversial. The aim of this study was to determine the effect of H. pylori eradication on the development of metachronous gastric cancer after endoscopic resection of gastric neoplasm by a meta-analysis of all relevant studies.

MATERIALS AND METHODS

We performed a systematic literature search of PubMed, EMBASE, Google Scholar, and the Cochrane Library without language restrictions through March 31, 2014. We included all relevant articles, including prospective, observational, and retrospective studies. Pooled estimates (odds ratios with 95% confidence intervals) were obtained using a random effects model.

RESULTS

Thirteen studies were considered to be appropriate for this meta-analysis. Compared with the control group, the pooled odds ratio in the eradication group was 0.42 (95% confidence interval, 0.32-0.56), and there was no heterogeneity across the studies (p = .853, I(2) = 0%). Subgroup analysis of three prospective trials also showed a lower incidence of metachronous cancer in the eradication group (odds ratio, 0.39; 95% confidence interval, 0.20-0.75). There was no evidence of publication bias in this meta-analysis.

CONCLUSION

Helicobacter pylori eradication reduces the occurrence of metachronous gastric cancer in patients who have undergone endoscopic resection.

The association between Helicobacter pylori status and incidence of metachronous gastric cancer after endoscopic resection of early gastric cancer

BACKGROUND

The long-term effect of Helicobacter pylori eradication in preventing metachronous gastric cancer (GC) development after endoscopic resection (ER) of early gastric cancer (EGC) remains controversial. The aim of this study was to investigate the effect of H. pylori status on the incidence of metachronous GC after ER during long-term follow-up.

PATIENTS AND METHODS

We retrospectively reviewed the medical records of 374 patients who underwent ER for EGC. Helicobacter pylori status was assessed by histology, rapid urease test, and serology. According to the H. pylori status after ER, included patients were classified into H. pylori-negative group (n = 218), H. pylori-eradicated group (n = 49), and H. pylori-persistent group (n = 107). Metachronous GC incidence and risk factors according to H. pylori status were analyzed.

RESULTS

Median follow-up duration after ER was 4.3 years (range 1.0-11.3 years). During the follow-up period, metachronous GC had developed in 13 patients (6.0% [13/218]) in the H. pylori-negative group, 2 patients (4.1% [2/49]) in the H. pylori-eradicated group, and 16 patients (15.0% [16/107]) in the H. pylori-persistent group. Cumulative incidence of metachronous GC was significantly higher in patients with H. pylori-persistent group than in those with H. pylori-negative (p = .011, log-rank test) and H. pylori-eradicated group (p = .006, log-rank test). In a multivariate Cox proportional hazard model, age ≥65 years (hazard ratio [HR] 2.29, p = .038), family history of GC (HR 2.60, p = .014), and H. pylori-persistent status (HR 2.42, p = .019) were associated with metachronous GC development.

CONCLUSIONS

Persistent H. pylori infection after ER may increase risk of metachronous GC development.

Failure of Helicobacter pylori eradication and age are independent risk factors for recurrent neoplasia after endoscopic resection of early gastric cancer in 283 patients

BACKGROUND

Whether the incidence of metachronous gastric dysplasia and cancer could be decreased by eradication of Helicobacter pylori after endoscopic submucosal dissection (ESD) for early gastric cancer (EGC).

AIM

To compare the incidence of metachronous gastric lesion in the eradicated group and the persistent group. Second end point is to evaluate the risk factors for metachronous gastric lesions after ESD for EGC.

METHODS

In a single centre, between May 2007 and May 2010, the patients who had evidence of H. pylori infection at the time of ESD for EGC were included, and the follow-up data were analysed retrospectively.

RESULTS

We enrolled 283 patients who have shown H. pylori infection at the time of ESD for EGC. Successful eradication was achieved for 214 patients (75.6%) (Eradicated group), and 69 patients (24.4%) showed persistent H. pylori infection (Persistent group). Metachronous gastric lesions developed in 13 (18.8%) in the persistent group and 18 (8.4%) in the eradicated group (P = 0.016). In the ≥60-year-old group, the cumulative incidence of metachronous gastric cancer showed a significant increase (P = 0.012). Cumulative hazard ratio of subsequent gastric metachronous lesions differed between the eradication group and the persistent infection group (OR = 2.322, 95% CI = 1.136-4.744, P = 0.021), and ≥60 age at the time of endoscopic resection (OR = 2.803, 95% CI = 1.207-6.509, P = 0.016).

CONCLUSIONS

Both persistent H. pylori infection and old age (≥60) are independent risk factors for the increased incidence of metachronous gastric cancer.

Serum Helicobacter pylori NapA antibody as a potential biomarker for gastric cancer

Helicobacter pylori (H. pylori) infection is strongly associated with gastric cancer. However, only a minority of infected individuals ever develop gastric cancer. This risk stratification may be in part due to differences among strains. The relationship between neutrophil-activating protein (NapA) and gastric cancer is unclear. The purpose of this study is to evaluate the significance of NapA as a biomarker in gastric cancer. We used enzyme linked immunosorbent assay (ELISA) to determine the status of H. pylori infection. Indirect ELISA method was used for detection of NapA antibody titer in the serum of H. pylori infected individuals. Unconditional logistic regressions were adopted to analyze the variables and determine the association of NapA and gastric cancer. The results of study indicated serum H. pylori NapA antibody level were associated with a reduced risk for development of gastric cancer. It may be used in conjugation with other indicators for gastric cancer detection.

Serum antibody against Helicobacter pylori FlaA and risk of gastric cancer

BACKGROUND

Helicobacter pylori (H. pylori) infection is a major risk factor for gastric cancer (GC); however, only a minority of infected individuals develops GC. We aim to assess the association between serostatus of antibody against H. pylori flagellin A (FlaA) and risk of GC and to evaluate the value of serum FlaA antibody as a novel screening biomarker for GC risk.

METHODS

A hospital-based case-control study including 232 cases and 264 controls was conducted. Logistic regression was adopted to analyze the association between the serostatus of FlaA antibody and risk of GC. Serum FlaA antibody was measured by an enzyme-linked immunosorbent assay (ELISA). Receiver operating characteristic (ROC) curve was used to evaluate the screening efficacy and to identify a cutoff point of serum FlaA antibody level.

RESULTS

Helicobacter pylori infection was associated with an increased risk of GC (p = .007). A positive association between serum FlaA antibody and GC risk was observed in overall subjects and H. pylori-positive subjects (OR [95% CI]: 6.8 [4.3-10.7] and 6.9 [3.6-13.4], respectively; p < .001). The seropositivity of FlaA antibody was strongly related to GC risk in a dose-dependent manner (p for trend < .001). The optimal cutoff value (OD) was 0.1403, providing a sensitivity of 74.1% and a specificity of 64.4%. The area under the ROC curve (AUC) was 0.74 in overall subjects and 0.73 in H. pylori-positive subjects, respectively.

CONCLUSIONS

FlaA was an independent risk factor for H. pylori-related GC. Serum FlaA antibody may serve as a novel noninvasive biomarker for early detection of GC.

Current evidence of effects of Helicobacter pylori eradication on prevention of gastric cancer

Gastric cancer is the second most common cause of cancer death worldwide and is usually detected at a late stage, except in Korea and Japan where early screening is in effect. Results from animal and epidemiological studies suggest that Helicobacter pylori infection, and subsequent gastritis, promote development of gastric cancer in the infected mucosa. Relatively effective treatment regimens are available to treat H. pylori infection, and in general, mass eradication of the organism is not currently recommended as a gastric cancer prevention strategy. However, regional guidelines vary regarding the indications and recommendations for H. pylori treatment for gastric cancer prevention. In this review, we discuss the results from intervention studies, provide insight regarding current guideline recommendations, and discuss future study directions.

Case-control study of association of eosinophilic gastrointestinal disorders with Helicobacter pylori infection in Japan

Recent studies have suggested that decrease in Helicobacter pylori infection may predispose to allergic diseases. However, there are few reports of the relationships of eosinophilic gastrointestinal disorders (EGIDs), especially eosinophilic gastroenteritis (EGE), with H. pylori infection. We investigated the possible influence of H. pylori infection on EGIDs in Japanese patients. We performed a case-control study to investigate the prevalence of H. pylori infection in patients with EGIDs. Eighteen with eosinophilic esophagitis (EoE) and 22 with EGE were enrolled. For each patient, 3 age- and gender-matched normal controls (n = 120) were randomly selected from a population who received a medical check-up between April 2010 and December 2011 at the Shimane Institute of Health Science. The mean ages of the EoE and EGE patients were 50.9 ± 17 and 49.2 ± 20 years, respectively. Males were more frequently seen in the EoE group, while there was no significant gender difference in regard to EGE. Of the patients with EoE, 22.3% were infected with H. pylori, as compared to 55.5% of their age- and sex-matched normal controls. The odds ratio for EoE patients to have an H. pylori infection was 0.22 (p<0.05). In addition, 22.7% of the patients with EGE and 48.5% of their matched controls were infected with H. pylori, with odds ratio for EGE patients to have an H. pylori infection shown to be 0.31 (p<0.05). In conclusion, the prevalence of H. pylori infection was significantly lower in EGE and EoE patients in Japan as compared to normal control subjects.

[Gastric cancer risk estimate in patients with chronic gastritis associated with Helicobacter pylori infection in a clinical setting]

BACKGROUND/AIM

Severity of chronic gastritis associated with Helicobacter pylori infection (CGAHpI) could play a role in evaluating the potential risk to develop gastric cancer. Our aim was to estimate the risk for gastric cancer in a clinical setting, according to histopathologic criteria, by applying the gastric cancer risk index (GCRI) METHODS: Histopathologic study of the gastric biopsies (corpus-antrum) from consecutive adult patients that underwent gastroesophageal duodenoscopy was carried out, and the GCRI was applied in patients presenting with CGAHpI.

RESULTS

One hundred eleven patients (77% female) with a mean age of 38.6±13.1 years were included. Active Helicobacter pylori infection (aHpi) was diagnosed in 77 cases (69.40%). In 45% of the cases with aHpi, pangastritis (23%) or corpus-predominant gastritis (22%) was diagnosed. Nine cases were diagnosed with intestinal metaplasia (8%), 7 of which (77.70%) were in the aHpi group. Twenty one percent of the patients with aHpi had a GCRI of 2 (18.10%) or 3 (2.50%) points (high risk index), while 79.10% accumulated a GCRI of 0 or 1 points (low risk index). Of the patients with no aHpi, none of them had 3 points (p=0.001). Of the 18 patients that accumulated 2 or 3 points, 6 (33.30%) presented with intestinal metaplasia (all with pangastritis and corpus-predominant gastritis), of which 4 cases (66.60%) had aHpi.

CONCLUSIONS

The estimated gastric cancer risk in patients with CGAHpI in the clinical setting studied was relatively low and 5% of the patients had a histopathologic phenotype associated with an elevated risk for developing gastric cancer.

D1 versus D2 lymphadenectomy for gastric cancer

Significant variability exists throughout the world in the extent of lymphadenectomy that is performed for gastric adenocarcinoma. D2 lymphadenectomy is the standard lymphadenectomy performed in high incidence countries such as Japan and South Korea, and less extensive lymphadenectomies are often performed in lower incidence countries such as the Unites States. This article reviews the evidence on the extent of lymphadenectomy that should be performed for gastric adenocarcinoma.

Hepatitis C virus-related hepatocellular carcinoma: An insight into molecular mechanisms and therapeutic strategies

Hepatitis C virus (HCV) infects more than 170 million people worldwide, and thereby becomes a series global health challenge. Chronic infection with HCV is considered one of the major causes of end-stage liver disease including cirrhosis and hepatocellular carcinoma. Although the multiple functions of the HCV proteins and their impacts on the modulation of the intracellular signaling transduction processes, the drive of carcinogenesis during the infection with HCV, is thought to result from the interactions of viral proteins with host cell proteins. Thus, the induction of mutator phenotype, in liver, by the expression of HCV proteins provides a key mechanism for the development of HCV-associated hepatocellular carcinoma (HCC). HCC is considered one of the most common malignancies worldwide with increasing incidence during the past decades. In many countries, the trend of HCC is attributed to several liver diseases including HCV infection. However, the development of HCC is very complicated and results mainly from the imbalance between tumor suppressor genes and oncogenes, as well as from the alteration of cellular factors leading to a genomic instability. Besides the poor prognosis of HCC patients, this type of tumor is quite resistance to the available therapies. Thus, understanding the molecular mechanisms, which are implicated in the development of HCC during the course of HCV infection, may help to design a general therapeutic protocol for the treatment and/or the prevention of this malignancy. This review summarizes the current knowledge of the molecular mechanisms, which are involved in the development of HCV-associated HCC and the possible therapeutic strategies.

Role of urokinase plasminogen activator receptor in gastric cancer: a potential therapeutic target

Recent advancements in cancer research have led to major breakthroughs; however, the impact on overall cancer-related death rate remains unacceptable. Thus, further insights into tumor markers and subsequent development of targeted therapies are urgently needed. For decades the urokinase plasminogen activator (uPA) system has been thought to drive tumor progression by mediating directed extracellular proteolysis on the surface of migrating or invading cells. Intervention with this proteolysis by targeting of uPA receptor (uPAR) has been proposed to represent a novel approach for inhibiting tumor progression. Recent data have provided new insights into the role of uPAR in gastric cancer progression. In addition to mediating proteolysis, this receptor also appears to mediate cell signaling, proliferation, and survival, and these observations have revealed novel ways to target uPAR. In this review, we discuss uPAR expression in gastric cancer, the relationship between uPAR and Helicobacter pylori, and recent insights into uPAR-signaling mechanisms. The role of uPAR as a cancer target in gastric cancer is also summarized.

Observation of gastric mucosa in Bangladesh, the country with the lowest incidence of gastric cancer, and Japan, the country with the highest incidence

BACKGROUND

The prevalence of Helicobacter pylori (H. pylori) infection is high, but the incidence of gastric cancer is low in natives of Bangladesh. The gastric mucosa was observed in Bangladeshi patients to investigate the differences between Bangladeshis and Japanese.

MATERIALS AND METHODS

The study involved 418 Bangladeshi and 2356 Japanese patients with abdominal complaints who underwent endoscopy examinations and had no history of H. pylori eradication. The prevalence of H. pylori infection and the gastric mucosa in H. pylori-positive patients were compared between age-, gender-, and endoscopic diagnosis-matched Bangladeshi and Japanese subjects.

RESULTS

The prevalence of H. pylori infection was higher in Bangladeshi than in Japanese subjects (60.2 and 45.1%, respectively). All the scores for chronic inflammation, neutrophil activity, glandular atrophy, and intestinal metaplasia were significantly lower in H. pylori-positive Bangladeshis than in H. pylori-positive Japanese. The ratio of the corpus gastritis score (C) to the antrum gastritis score (A) (C/A ratio) was <1 (antrum-predominant gastritis) in all age groups of Bangladeshi subjects, whereas the C/A ratio changed from <1 to more than 1 (corpus-predominant gastritis) with aging in Japanese subjects.

CONCLUSIONS

The scores for glandular atrophy and intestinal metaplasia in H. pylori-positive Bangladeshis were significantly lower than those in Japanese. All age groups of Bangladeshis had antrum-predominant gastritis, whereas corpus-predominant gastritis was more common than antrum-predominant gastritis in older Japanese age groups. These results may explain the low incidence of gastric cancer in Bangladeshis and the high incidence in Japanese.

Recent development of gastric cancer prevention

A mass screening program using photofluorography has been used as a secondary prophylaxis of gastric cancer in Japan. However, we are at a turning point for reconsidering the strategy of gastric cancer prevention because of various problems with photofluorography. The shift from current secondary prophylaxis to primary prophylaxis is now required. After a Japanese multicenter randomized controlled trial showed that Helicobacter pylori eradication reduced the incidence of metachronous gastric cancer after endoscopic resection of early gastric cancer, primary prophylaxis of gastric cancer has gained greater attention. The combination of H. pylori eradication as a primary prophylaxis and screening as a secondary prophylaxis is necessary for the elimination of gastric cancer in Japan. The strategy of test, treat and screening for H. pylori infection is effective in reducing the incidence and mortality of gastric cancer in communities with a high incidence of gastric cancer. We have proposed a program of risk stratification based on the presence of H. pylori infection with or without atrophic gastritis followed by targeted interventions.

The Role of CD44 in the Pathogenesis, Diagnosis, and Therapy of Gastric Cancer

CD44 is a transmembrane glycoprotein and surface receptor for hyaluronan that is involved in the response of cells to their microenvironment. CD44 splice variants play roles in carcinogenesis, differentiation, and lymph node metastasis and are predictive of the prognosis for various carcinomas, including gastric cancer. Current data suggest that gastric tissue stem cells and gastric cancer stem cells both express the splice variant, CD44v9. Overall, the data regarding the alterations that occur in CD44 and its splice variants in response to acute and chronic infection with Helicobacter pylori are scant and poorly elucidated in terms of possible changes in expression that occur in gastric cancer precursor lesions, such as chronic atrophic gastritis, pyloric metaplasia and intestinal metaplasia. In this study, we discuss the available data and suggest which new data would likely be useful in clinical practice. We also discuss the potential for CD44-targeted therapeutic strategies in gastric cancer. CD44 and its splice variants are positively associated with the initiation and progression of gastric cancer and may also play important roles in diagnosis, therapy and prognosis. CD44 research has been active but fragmented, and it may offer new therapeutic approaches to gastric cancer.

The Role of CD44 in the Pathogenesis, Diagnosis, and Therapy of Gastric Cancer

CD44 is a transmembrane glycoprotein and surface receptor for hyaluronan that is involved in the response of cells to their microenvironment. CD44 splice variants play roles in carcinogenesis, differentiation, and lymph node metastasis and are predictive of the prognosis for various carcinomas, including gastric cancer. Current data suggest that gastric tissue stem cells and gastric cancer stem cells both express the splice variant, CD44v9. Overall, the data regarding the alterations that occur in CD44 and its splice variants in response to acute and chronic infection with Helicobacter pylori are scant and poorly elucidated in terms of possible changes in expression that occur in gastric cancer precursor lesions, such as chronic atrophic gastritis, pyloric metaplasia and intestinal metaplasia. In this study, we discuss the available data and suggest which new data would likely be useful in clinical practice. We also discuss the potential for CD44-targeted therapeutic strategies in gastric cancer. CD44 and its splice variants are positively associated with the initiation and progression of gastric cancer and may also play important roles in diagnosis, therapy and prognosis. CD44 research has been active but fragmented, and it may offer new therapeutic approaches to gastric cancer.

Epidemiology of Helicobacter pylori infection and public health implications

This review summarizes studies on the epidemiology and public health implications of Helicobacter pylori published in peer-reviewed journals from April 2010 through March 2011. Prevalence rates vary widely between different geographical regions and ethnic groups. An interesting study from the USA identified the degree of African ancestry as an independent predictor of H. pylori infection. Two studies have demonstrated early childhood as the period of transmission of infection and identified an infected sibling as an important risk factor. An oral-oral route of spread has been substantiated with several studies showing the presence of H. pylori in the oral cavity. Studies have shown the presence of H. pylori in drinking water and the role of poor living conditions and sanitation in H. pylori infection, supporting an oral-fecal route of spread. Screening for H. pylori as a gastric cancer pre-screening strategy has been described in Japan, and the importance of H. pylori eradication as a gastric cancer-prevention strategy has now been further emphasized in Japanese guidelines. Two studies have shown a decrease in the burden of dyspepsia and peptic ulcer disease with H. pylori eradication.

Epidemiology of Helicobacter pylori infection and public health implications

This review summarizes studies on the epidemiology and public health implications of Helicobacter pylori published in peer-reviewed journals from April 2010 through March 2011. Prevalence rates vary widely between different geographical regions and ethnic groups. An interesting study from the USA identified the degree of African ancestry as an independent predictor of H. pylori infection. Two studies have demonstrated early childhood as the period of transmission of infection and identified an infected sibling as an important risk factor. An oral-oral route of spread has been substantiated with several studies showing the presence of H. pylori in the oral cavity. Studies have shown the presence of H. pylori in drinking water and the role of poor living conditions and sanitation in H. pylori infection, supporting an oral-fecal route of spread. Screening for H. pylori as a gastric cancer pre-screening strategy has been described in Japan, and the importance of H. pylori eradication as a gastric cancer-prevention strategy has now been further emphasized in Japanese guidelines. Two studies have shown a decrease in the burden of dyspepsia and peptic ulcer disease with H. pylori eradication.

The human microbiome and surgical disease

OBJECTIVE

The purpose of this review article is to summarize what is currently known about microbes associated with the human body and to provide examples of how this knowledge impacts the care of surgical patients.

BACKGROUND

Pioneering research over the past decade has demonstrated that human beings live in close, constant contact with dynamic communities of microbial organisms. This new reality has wide-ranging implications for the care of surgical patients.

METHODS AND RESULTS

Recent advances in the culture-independent study of the human microbiome are reviewed. To illustrate the translational relevance of these studies to surgical disease, we discuss in detail what is known about the role of microbes in the pathogenesis of obesity, gastrointestinal malignancies, Crohn disease, and perioperative complications including surgical site infections and sepsis. The topics of mechanical bowel preparation and perioperative antibiotics are also discussed.

CONCLUSIONS

Heightened understanding of the microbiome in coming years will likely offer opportunities to refine the prevention and treatment of a wide variety of surgical conditions.

Applicability of a rapid stool antigen test, using monoclonal antibody to catalase, for the management of Helicobacter pylori infection

BACKGROUND

Most monoclonal antibody-based stool antigen tests are of the "send-out" format. Rapid Testmate pylori antigen (Rapid TPAg) uses monoclonal antibody and is an "in-the-office" test. The aim of this study was to examine the usefulness of Rapid TPAg for the management of H. pylori infection.

METHODS

One-hundred and two consecutive patients who received H. pylori eradication therapy underwent both urea breath test (UBT) and Rapid TPAg at 5-6 weeks after finishing the eradication therapy. Stool samples were maintained at -20, 5, 25, and 40°C and subjected to Rapid TPAg after 1-7 days. Stool samples were also tested by enzyme immunoassay (EIA) to quantify antigenicity.

RESULTS

The agreement between Rapid TPAg and UBT in the evaluation of the results of H. pylori eradication treatment was 94.1%. The overall accuracy of Rapid TPAg and UBT to determine H. pylori eradication was 98.0 and 96.0%, respectively. The results of Rapid TPAg were not altered after storage of samples at -20 to 40°C for 7 days. Antigenicity quantified by EIA did not decrease significantly after 7 days.

CONCLUSIONS

Rapid TPAg is a useful diagnostic test for immediate and accurate determination of the results of H. pylori eradication therapy. The antigenicity of stool sample suspensions was preserved for 7 days in the collection devices.

The inhibitory effect of celecoxib on mouse hepatoma H22 cell line on the arachidonic acid metabolic pathway

Nowadays, patients with chronic hepatitis C in all countries are generally treated with interferon (IFN), and more than 50% of patients become HCV-RNA negative following PEG-IFN plus ribavirin therapy, but unfortunately, the IFN therapy is not effective in about 70% of patients with HCV-associated LC. In Japan, HCC actually develops in about 7% of those patients every year. A strategy for preventing HCC development other than IFN therapy is, therefore, urgently needed for those patients. We reported that the recurrence rate and the development of HCC was more rapid in the high serum ALT level (>80 IU) patients with HCV-associated LC. Sho-saiko-to, Juzen-taiho-to, and stronger-neo minophagen C are herbal medicines used in Japan to treat chronic viral liver diseases, and they work by reducing inflammatory processes and controlling ALT levels. Aggressive reduction therapy for ALT levels in HCV-LC patients could significantly prevent HCC development.

Strategy for eliminating gastric cancer in Japan

A study conducted by the Japan Gast Study Group showed that eradication of Helicobacter pylori reduced the risk of gastric cancer by about one-third. However, it did not completely prevent the onset of latent gastric cancer among those at high risk (i.e., with atrophic gastritis). To prevent deaths from gastric cancer, it is necessary to eradicate H. pylori infection. We propose a program of risk stratification based on the presence of H. pylori infection with or without atrophic gastritis followed by targeted interventions. Those at no risk for gastric cancer (no H. pylori, no atrophic gastritis) need no therapy or follow-up. Those at low risk (H. pylori infected, nonatrophic gastritis) need only H. pylori eradication therapy. The smaller groups at high or very high risk need eradication and cancer surveillance. We estimated the costs and the benefits of this strategy. Gastric cancer screening by simultaneous measurement of serum pepsinogen and H. pylori antibody combined with eradication of H. pylori in all individuals at risk would initially increase national healthcare expenditure, but this would be offset by markedly reducing the cost of treating gastric cancer. The proposed strategy should prevent about 150,000 deaths from gastric cancer during the 5 years after its adoption. If the loss caused by these deaths is also taken into account, the economic effect of this strategy becomes enormous. It would probably reduce the incidence of gastric cancer by more than 80-90% within 10 years. The Japanese government should take the initiative to implement this strategy as soon as possible.

Recent knowledge of the relationship between Helicobacter pylori and gastric cancer and recent progress of gastroendoscopic diagnosis and treatment for gastric cancer

Gastric cancer is a multi-step process and multi-factorial disease. However, Helicobacter pylori plays the most important role in gastric carcinogenesis because most gastric cancers including both intestinal type and diffuse type arise from mucosa infected by H. pylori. The relationship between H. pylori infection and gastric cancer has been proved in epidemiological studies, animal experiments with Mongolian gerbils, and clinical prospective studies. Significant preventive effect of H. pylori eradication was reported in Japanese randomized study for secondary gastric cancer after endoscopic resection of primary gastric cancer and meta-analysis of randomized studies. The Japanese Society for Helicobacter Research has published a guideline recommending that H. pylori infection should be treated by eradication therapy to suppress the incidence of gastric cancer. The development of endoscopic technology has advanced the diagnosis and treatment of gastric cancer. In the diagnosis of gastric cancer, image enhancement endoscopy including magnifying observation with narrow-band imaging system and microscopic magnifying observation opens the possibility of optical biopsy. Endoscopic resection for early stage of gastric cancer has been established as proper treatment of early gastric cancer. Recently endoscopic submucosal dissection had made en bloc resection possible for mucosal cancers >2 cm in diameter. Because of endoscopic submucosal dissection, endoscopic resection is indicated in a greater number of cases. Although the use of endoscopic treatment for gastric cancer has been increasing steadily, long-term outcome data is necessary.