The Asia-Pacific Consensus Conference was convened to review and synthesize the most current information on Helicobacter pylori management so as to update the previously published regional guidelines. The group recognized that in addition to long-established indications, such as peptic ulcer disease, early mucosa-associated lymphoid tissue (MALT) type lymphoma and family history of gastric cancer, H. pylori eradication was also indicated for H. pylori infected patients with functional dyspepsia, in those receiving long-term maintenance proton pump inhibitor (PPI) for gastroesophageal reflux disease, and in cases of unexplained iron deficiency anemia or idiopathic thrombocytopenic purpura. In addition, a population 'test and treat'strategy for H. pylori infection in communities with high incidence of gastric cancer was considered to be an effective strategy for gastric cancer prevention. It was recommended that H. pylori infection should be tested for and eradicated prior to long-term aspirin or non-steroidal anti-inflammatory drug therapy in patients at high risk for ulcers and ulcer-related complications. In Asia, the currently recommended first-line therapy for H. pylori infection is PPI-based triple therapy with amoxicillin/metronidazole and clarithromycin for 7 days, while bismuth-based quadruple therapy is an effective alternative. There appears to be an increasing rate of resistance to clarithromycin and metronidazole in parts of Asia, leading to reduced efficacy of PPI-based triple therapy. There are insufficient data to recommend sequential therapy as an alternative first-line therapy in Asia. Salvage therapies that can be used include: (i) standard triple therapy that has not been previously used; (ii) bismuth-based quadruple therapy; (iii) levofloxacin-based triple therapy; and (iv) rifabutin-based triple therapy. Both CYP2C19 genetic polymorphisms and cigarette smoking can influence future H. pylori eradication rates. Key wordshelicobacter pylori:diagnosis, helicobacter pylori:treatment and antimicrobial resistance, H. pylori and gastric cancer.

Background and Aim: Gastric cancer is a major health burden in the Asia-Pacific region but consensus on prevention strategies has been lacking. We aimed to critically evaluate strategies for preventing gastric cancer. Methods: A multidisciplinary group developed consensus statements using a Delphi approach. Relevant data were presented, and the quality of evidence, strength of recommendation, and level of consensus were graded. Results:Helicobacter pylori infection is a necessary but not sufficient causal factor for non-cardia gastric adenocarcinoma. A high intake of salt is strongly associated with gastric cancer. Fresh fruits and vegetables are protective but the use of vitamins and other dietary supplements does not prevent gastric cancer. Host-bacterial interaction in H. pylori infection results in different patterns of gastritis and differences in gastric acid secretion which determine disease outcome. A positive family history of gastric cancer is an important risk factor. Low serum pepsinogens reflect gastric atrophy and may be useful as a marker to identify populations at high risk for gastric cancer. H. pylori screening and treatment is a recommended gastric cancer risk reduction strategy in high-risk populations. H. pylori screening and treatment is most effective before atrophic gastritis has developed. It does not exclude the existing practice of gastric cancer surveillance in high-risk populations. In populations at low risk for gastric cancer, H. pylori screening is not recommended. Firstline treatment of H. pylori infection should be in accordance with national treatment guidelines. Conclusion: A strategy of H. pylori screening and eradication in high-risk populations will probably reduce gastric cancer incidence, and based on current evidence is recommended by consensus.

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.

Intestinal metaplasia (IM) is a pre-malignant condition of the gastric mucosa associated with increased gastric cancer (GC) risk. We performed (epi)genomic profiling of 138 IMs from 148 cancer-free patients, recruited through a 10-year prospective study. Compared with GCs, IMs exhibit low mutational burdens, recurrent mutations in certain tumor suppressors (FBXW7) but not others (TP53, ARID1A), chromosome 8q amplification, and shortened telomeres. Sequencing identified more IM patients with active Helicobacter pylori infection compared with histopathology (11%-27%). Several IMs exhibited hypermethylation at DNA methylation valleys; however, IMs generally lack intragenic hypomethylation signatures of advanced malignancy. IM patients with shortened telomeres and chromosomal alterations were associated with subsequent dysplasia or GC; conversely patients exhibiting normal-like epigenomic patterns were associated with regression.

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