Helicobacter pylori (Hp) is one of most common pathogens causing gastrointestinal disorder including gastric ulcer, duodenal ulcer and gastric cancer, etc. It has been verified as class I carcinogen by WHO. Nowadays, combination antibiotics and proton pump inhibitor are mainly used to erase Hp in clinical application. However, with the increased resistance of Hp, the vaccine against Hp might become the best strategy to eradicate Hp. Elements including urease, virulence factor, outer membrane protein, flagella, play an important role in Hp infection, colonization and reproduction. They have become potential candidate antigens in the development of Hp vaccine, as reported in previous studies. Presently, these antigens-centric vaccines have been tested in animal models. Therefore, this article reviews the studies on Hp vaccine with urease, virulence genes, outer membrane protein and flagella as their candidate antigens, in an attempt to provide insights for research in this regard.
Animals ; Helicobacter pylori ; Urease/genetics* ; Helicobacter Infections/prevention & control* ; Vaccines ; Membrane Proteins

Although the age-adjusted incidence of gastric cancer is declining, the absolute number of new cases of gastric cancer is increasing due to population growth and aging. An effective strategy is needed to prevent this deadly cancer. Among the available strategies, screen-and-treat for Helicobacter pylori infection appears to be the best approach to decrease cancer risk; however, implementation of this strategy on the population level requires a systematic approach. The program also must be integrated into national healthcare priorities to allow the limited resources to be most effectively allocated. Implementation will require adoption of an appropriate screening strategy, an efficient delivery system with a timely referral for a positive test, and standardized treatment regimens based on clinical efficacy, side effects, simplicity, duration, and cost. Within the population, there are subpopulations that vary in risk such that a "one size fits all" approach is unlikely to be ideal. Sensitivity analyses will be required to identify whether the programs can be utilized by heterogeneous populations and will likely require adjustments to accommodate the needs of subpopulations.
Health Priorities ; Helicobacter Infections/complications/diagnosis/microbiology/*therapy ; Helicobacter pylori ; Humans ; Mass Screening ; Stomach Neoplasms/microbiology/*prevention & control

Gastric cancer is associated with high morbidity and mortality worldwide. To reduce the socioeconomic burden related to gastric cancer, it is very important to identify and manage high risk group for gastric cancer. In this review, we describe the general risk factors for gastric cancer and define high risk group for gastric cancer. We discuss strategies for the effective management of patients for the prevention and early detection of gastric cancer. Atrophic gastritis (AG) and intestinal metaplasia (IM) are the most significant risk factors for gastric cancer. Therefore, the accurate selection of individuals with AG and IM may be a key strategy for the prevention and/or early detection of gastric cancer. Although endoscopic evaluation using enhanced technologies such as narrow band imaging-magnification, the serum pepsinogen test, Helicobacter pylori serology, and trefoil factor 3 have been evaluated, a gold standard method to accurately select individuals with AG and IM has not emerged. In terms of managing patients at high risk of gastric cancer, it remains uncertain whether H. pylori eradication reverses and/or prevents the progression of AG and IM. Although endoscopic surveillance in high risk patients is expected to be beneficial, further prospective studies in large populations are needed to determine the optimal surveillance interval.
Gastroscopy ; Helicobacter Infections/complications/diagnosis ; Humans ; Risk Factors ; Socioeconomic Factors ; Stomach Neoplasms/*diagnosis/etiology/prevention & control/therapy

Most gastric cancers are caused by infection with the common human bacterial pathogen, Helicobacter pylori. It is now accepted that gastric cancer can be prevented and virtually eliminated by H. pylori eradication and this knowledge was responsible for country-wide H. pylori eradication combined with secondary cancer prevention for those with residual risk that was introduced in Japan in 2013. Korea is a high H. pylori prevalence and high gastric cancer incidence country and a good candidate for a gastric cancer elimination program. The presence of an H. pylori infection is now considered as an indication for treatment of the infection. However, antimicrobial drug resistance is common among H. pylori in Korea making effective therapy problematic. Country-wide studies of the local and regional antimicrobial resistance patterns are needed to choose the most appropriate therapies. H. pylori and gastric cancer eradication can be both efficient and cost effective making it possible and practical to make Korea H. pylori and gastric cancer free. There is no reason to delay.
Anti-Bacterial Agents/*therapeutic use ; Disease Eradication ; Drug Resistance, Bacterial ; Helicobacter Infections/*drug therapy/epidemiology/microbiology ; Helicobacter pylori/*drug effects/growth & development ; Humans ; Prevalence ; Primary Prevention/*methods ; Republic of Korea/epidemiology ; Risk Assessment ; Risk Factors ; Stomach Neoplasms/epidemiology/microbiology/*prevention & control ; Treatment Outcome

OBJECTIVEAlthough Helicobacter pylori (H. pylori) is considered as the main etiological factor for gastric cancer, the strategy of screening and treating the oncogenic bacterium is still controversial. The objective was to evaluate the status and progress of the cognition about the relationship between H. pylori infection and gastric cancer from a clinical aspect.

DATA SOURCESThe data used in this review were mainly from the PubMed articles published in English from 1984 to 2015.

STUDY SELECTIONClinical research articles were selected mainly according to their level of relevance to this topic.

RESULTSGastric cancer is the fifth most common malignancy and the third leading cause of cancer deaths worldwide. The main etiological factor for gastric cancer is H. pylori infection. About 74.7-89.0% gastric cancer was related to H. pylori infection. Up to date, some regional gastric cancer prevention programs including the detection and treatment of H. pylori infection are under way. Current data obtained from the randomized controlled trials suggest that population-based H. pylori screening and treatment is feasible and cost-effective in preventing gastric cancer; however, a population-based H. pylori eradication campaign would potentially lead to bacterial resistance to the corresponding antibiotics, as well as a negative impact on the normal flora.

CONCLUSIONSThe important questions of feasibility, program costs, appropriate target groups for intervention, and the potential harm of mass therapy with antibiotics must first be answered before implementing any large-scale program.

Anti-Bacterial Agents ; therapeutic use ; Cost-Benefit Analysis ; Helicobacter Infections ; economics ; prevention & control ; Helicobacter pylori ; drug effects ; pathogenicity ; Humans ; Mass Screening ; economics ; Stomach Neoplasms ; microbiology ; prevention & control

Controversies persist regarding the effect of Helicobacter pylori eradication on the development of metachronous gastric cancer after endoscopic resection of early gastric cancer (EGC). The aim of this study was to assess the efficacy of Helicobacter pylori eradication after endoscopic resection of EGC for the prevention of metachronous gastric cancer. A systematic literature review and meta-analysis were conducted using the core databases PubMed, EMBASE, and the Cochrane Library. The rates of development of metachronous gastric cancer between the Helicobacter pylori eradication group vs. the non-eradication group were extracted and analyzed using risk ratios (RRs). A random effect model was applied. The methodological quality of the enrolled studies was assessed by the Risk of Bias table and by the Newcastle-Ottawa Scale. Publication bias was evaluated through the funnel plot with trim and fill method, Egger's test, and by the rank correlation test. Ten studies (2 randomized and 8 non-randomized/5,914 patients with EGC or dysplasia) were identified and analyzed. Overall, the Helicobacter pylori eradication group showed a RR of 0.467 (95% CI: 0.362-0.602, P < 0.001) for the development of metachronous gastric cancer after endoscopic resection of EGC. Subgroup analyses showed consistent results. Publication bias was not detected. Helicobacter pylori eradication after endoscopic resection of EGC reduces the occurrence of metachronous gastric cancer.
Adult ; Aged ; Aged, 80 and over ; Combined Modality Therapy/statistics & numerical data ; Comorbidity ; Female ; Gastroscopy/*statistics & numerical data ; Helicobacter Infections/epidemiology/*prevention & control ; Humans ; Incidence ; Male ; Middle Aged ; Neoplasms, Second Primary/*epidemiology/pathology/*prevention & control ; Risk Factors ; Stomach Neoplasms/*epidemiology/pathology/*surgery ; Treatment Outcome

As a commensal or a pathogen, Helicobacter pylori can change the balance of a complex interaction that exists among gastric epithelial cells, microbes, and their environment. Therefore, unraveling this complex relationship of these mixtures can be expected to help prevent cancer as well as troublesome unmet medical needs of H. pylori infection. Though gastric carcinogenesis is a multi-step process, precancerous lesion can be reversible in the early phase of mucosal damage before reaching the stage of no return. However, biomarkers to predict rejuvenation of precancerous atrophic gastritis have not been identified yet and gastric cancer prevention is still regarded as an impregnable fortress. However, when we take the journey from H. pylori-associated gastritis to gastric cancer, it provides us with the clue for prevention since there are two main preventive strategies: eradication and anti-inflammation. The evidence supporting the former strategy is now ongoing in Japan through a nation-wide effort to eradicate H. pylori in patients with chronic gastritis, but suboptimal apprehension to increasing H. pylori resistance to antibiotics and patient non-compliance still exists. The latter strategy has been continued in the author's research center under siTRP (short-term intervention to revert premalignant lesion) strategy. By focusing on the role of inflammation in the development of H. pylori-associated gastric carcinogenesis, this review is intended to explain the connection between inflammation and gastric cancer. Strategies on H. pylori eradication, removal of inflammation, and reverting preneoplastic lesion will also be introduced. In the end, we expect to be able to prevent gastric cancer by take a detour from the unpleasant journey, i.e. from H. pylori-associated gastritis to gastric cancer.
Animals ; Anti-Bacterial Agents/pharmacology/therapeutic use ; Biomarkers/metabolism ; Disease Models, Animal ; Gastritis/*etiology ; Helicobacter Infections/*complications/drug therapy ; Helicobacter pylori/drug effects/metabolism/physiology ; Humans ; Stomach Neoplasms/etiology/*prevention & control ; Virulence Factors/metabolism

No abstract available.
Anti-Bacterial Agents/*therapeutic use ; Antioxidants/*therapeutic use ; Helicobacter Infections/*drug therapy ; Helicobacter pylori ; Humans ; Randomized Controlled Trials as Topic ; Risk Reduction Behavior ; Stomach Neoplasms/*prevention & control ; Treatment Outcome ; Vitamins/*therapeutic use

BACKGROUNDHelicobacter pylori (Hp) is a common and potentially curable cause of gastric mucosa lesion. This study investigated the relationship of Hp infection with histological changes in gastric mucosa and gastric cancer in Hp-positive patients compared with Hp-eradication patients followed up for ten years.

METHODSFrom an initial group of 1 006 adults, 552 Hp-positive subjects were randomly assigned to a treatment group (T; n = 276) or a placebo group (P; n = 276). In the randomized, double-blind, placebo-controlled, parallel trial, T group subjects received oral doses of omeprazole, amoxicillin and clarithromycin for 1 week; those in the P group received a placebo. One month after treatment ended, a 13C urea breath test was performed, and Hp was undetectable in 88.89% of the T group. All subjects were followed at 1, 5, 8, and 10 years after treatment, with endoscopy and biopsies for histological examination.

RESULTSGastric mucosa inflammation was significantly milder in the T group than that in the P group one year after Hp eradication and this persisted for 10 years. Glandular atrophy and intestinal metaplasia (IM) had deteriorated in both groups during ten years. However, the increased score of glandular atrophy at both the gastric antrum and corpus, and IM only at the gastric antrum, in the P group was more obvious than that in the T group. During the 10 years, 9 patients were diagnosed with gastric cancer (2 in the T group; 7 in the P group; P = 0.176). When mucosal atrophy was absent at the gastric antrum and corpus when entering the study, the incidence of gastric cancer in the P group (n = 6) was much higher than that in the T group (n = 0, P = 0.013).

CONCLUSIONSHp eradication may significantly diminish and help halt progression of gastric mucosal inflammation and delay the development of IM and atrophy gastritis. Hp eradication is helpful for reducing the risk for gastric cancer, especially in the early stage of Hp infection.

Adult ; Aged ; Amoxicillin ; therapeutic use ; Anti-Bacterial Agents ; therapeutic use ; Clarithromycin ; therapeutic use ; Double-Blind Method ; Female ; Follow-Up Studies ; Gastric Mucosa ; drug effects ; pathology ; Gastritis, Atrophic ; diagnosis ; drug therapy ; Helicobacter Infections ; drug therapy ; Helicobacter pylori ; pathogenicity ; Humans ; Male ; Middle Aged ; Omeprazole ; therapeutic use ; Stomach Neoplasms ; diagnosis ; prevention & control

Gastric cancer is the second leading cause of cancer-related mortality and the fourth most common cancer globally. There are, however, distinct differences in incidence rates in different geographic regions. While the incidence rate of gastric cancer has been falling, that of gastric cardia cancers is reportedly on the rise in some regions. Helicobacter pylori (H. pylori) infection is a major risk factor of non-cardia gastric cancer, and data has emerged concerning the role of H. pylori eradication for primary prevention of gastric cancer. Dietary, lifestyle and metabolic factors have also been implicated. Although addressing these other factors may contribute to health, the actual impact in terms of cancer prevention is unclear. Once irreversible histological changes have occurred, endoscopic surveillance would be necessary. A molecular classification system offers hope for molecularly tailored, personalised therapies for gastric cancer, which may improve the prognosis for patients.
Female ; Global Health ; Helicobacter Infections ; complications ; prevention & control ; Helicobacter pylori ; Humans ; Incidence ; Male ; Obesity ; complications ; Risk Factors ; Stomach Neoplasms ; epidemiology ; genetics ; microbiology ; prevention & control