Eradication of Helicobacter pylori for primary gastric cancer and secondary gastric cancer after endoscopic mucosal resection

Differences in clinical features and morphology between differentiated and undifferentiated gastric cancer after Helicobacter pylori eradication

BACKGROUND/AIMS

Although undifferentiated gastric cancer (UGC) diagnosed after Helicobacter pylori eradication (HPE) carries a poor prognosis, characteristics of post-HPE UGC have not been evaluated in detail because of its low incidence. Therefore, we compared the clinicopathologic characteristics of UGC and differentiated gastric cancers (DGC) diagnosed after successful HPE.

METHODS

GC lesions from patients who had successfully completed HPE and who had undergone upper gastrointestinal endoscopy between January 2004 and March 2016 were analyzed. Tumors were divided into DGC and UGC groups. Clinicopathologic factors of background and tumor characteristics were compared using univariate and multiple logistic analyses.

RESULTS

A total of 129 tumors from 115 patients were evaluated; 113 tumors were in the DGC group and 16 in the UGC group. Depressed-type tumors (P = 0.024) and sub-submucosal invasion (P<0.001) were significantly higher in the UGC group. The UGC group had larger tumor diameters (25.9±7.3 mm) than the DGC group (13.2±10.2 mm) (P<0.001). Multivariate analysis showed that female sex (odds ratio [OR] 3.24, 95%CI:1.02-10.37; P = 0.047) and absent follow-up (OR 4.99, 95%CI:1.60-15.57; P = 0.006) were significant independent risk factors for UGC. The DGC group showed a gradually decreasing temporal trend by trend test (P = 0.015), while the UGC group showed a relatively constant incidence over time, although the number of cases was small.

CONCLUSION

UGC was diagnosed even after long time spans following HPE, although the number of cases was small. Female sex, and especially absent follow-up, were risks for post-HPE UGC, suggesting that diligent long-term follow-up after HPE is essential.

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.

Inflammation, Immunity, and Vaccine Development for the Gastric Pathogen Helicobacter pylori

It has been over 30 years since a link was established between H. pylori infection of the gastric mucosa and the development of chronic gastric diseases. Research in rodent models supported by data from human tissue demonstrated that the host immune response to H. pylori is limited by host regulatory T cells. Immunization has been shown to induce a potent Th1- and Th17-mediated immune response capable of eradicating or at least significantly reducing the bacterial load of H. pylori in the stomach in small animal models. These results have not translated well to humans. Clinical trials employing many of the strategies used in rodents for oral immunization including the use of a mucosal adjuvant such as Escherichia coli LT or delivery by attenuated enteric bacteria have failed to limit H. pylori infection and have highlighted the potential toxicity of exotoxin-based mucosal adjuvants. A recent study, however, utilizing a recombinant fusion protein of H. pylori urease and the subunit B of E. coli LT, was performed on over 4000 children. Efficacy of over 70% was demonstrated against naturally acquired infection compared to control volunteers one year post-immunization. Efficacy was reduced, but still above 50% at three years. This study provided new insight into the strategies for developing an improved vaccine for widespread use in countries with high infection rates and where gastric cancer (GC) remains one of the most common causes of death due to cancer.

Endoscopic and Immunohistochemical Characteristics of Gastric Cancer with versus without Helicobacter Pylori Eradication

BACKGROUND/AIMS

The rate of gastric cancer (GC) after Helicobacter pylori eradication has gradually increased; therefore, we investigate the clinicopathological features of GC following eradication in comparison with those of GC with H. pylori infection.

METHODS

This study included 50 subjects with GC after eradication (GCE) and 151 patients with GC with H. pylori infection (GCI). Clinicopathological factors were assessed. The manifestation of GC was further evaluated using immunohistochemical analysis and in situ hybridization.

RESULTS

Macroscopic analysis revealed a significantly higher ratio of depressed type /elevated type in the GCE compared with the GCI (30/19 vs. 61/77, p = 0.041). The gastric phenotype was more common in the GCE compared with the GCI, and the proportion of CDX2-positive cases was lower in the GCE (8 out of 18; 44.4%) compared with the GCI (18 out of 19; 94.7%; p = 0.00082). Ki-67 labeling index was significantly lower in the GCE (32.03 ± 22.15) compared with the GCI (79.20 ± 14.87, p < 0.0001). No patient in the GCE showed evidence of Epstein-Barr virus infection.

CONCLUSION

The clinicopathological characteristics of GC following H. pylori eradication differ from those of GC in patients with H. pylori infection in terms of morphology, mucin phenotype, and proliferation rate.

Characteristics of Synchronous and Metachronous Multiple Gastric Tumors after Endoscopic Submucosal Dissection of Early Gastric Neoplasm

Background/Aims

Endoscopic submucosal dissection (ESD) has been widely accepted as a method of treatment of early gastric tumor. This study aimed to identify the incidence and characteristics of multiple gastric tumors after ESD.

Methods

Patients with early gastric tumors who were treated by ESD from January 2004 to June 2012 and followed up with endoscopic examination periodically for at least 1 year were enrolled. All multiple gastric lesions were subsequently treated with ESD and the medical records of the patients were retrospectively reviewed.

Results

In total, 643 patients were included. The mean duration of endoscopic follow-up was 45.27±27.59 (range, 12–148) months. Overall, 144 patients (22.4%) showed multiple gastric tumors during the follow-up period (44 synchronous [6.8%] and 100 metachronous [15.5%]). The cumulative incidence rate steadily increased during the follow-up period. More than 50% of the tumors that developed at the same longitudinal location of the stomach were of the same macroscopic and histological type as the primary lesions.

Conclusions

Because synchronous and/or metachronous gastric tumors are common, considerable attention should be paid to detect multiple gastric lesions after ESD of early gastric neoplasm.

Characteristics of Primary and Metachronous Gastric Cancers Discovered after Helicobacter pylori Eradication: A Multicenter Propensity Score-Matched Study

BACKGROUND/AIMS

Gastric cancers develop even after successful Helicobacter pylori eradication. We aimed to clarify the characteristics of early gastric cancers discovered after H. pylori eradication.

METHODS

A total of 1,053 patients with early gastric cancer treated by endoscopic submucosal dissection were included. After matching the propensity score, we retrospectively investigated the clinicopathological features of 192 patients, including 96 patients who had undergone successful H. pylori eradication (Hp-eradicated group) and 96 patients who had active H. pylori infection (Hp-positive group).

RESULTS

In the Hp-eradicated group, early gastric cancers were discovered 1 to 15 years (median, 4.1 years) after H. pylori eradication. Compared with Hp-positive patients, Hp-eradicated patients showed a more frequently depressed configuration (81% vs 53%, respectively, p<0.0001) and a higher trend toward submucosal invasion (18% vs 8%, respectively, p=0.051). A multivariable analysis revealed the macroscopic depressed type to be characteristics of early gastric cancers after H. pylori eradication. Among patients in the Hp-eradicated group, metachronous cancers showed less frequent depressed lesions (68% vs 84%, respectively, p=0.049) and smaller tumor sizes (median, 11 mm vs 14 mm, respectively, p=0.014) than primary cancers.

CONCLUSIONS

Early gastric cancers after H. pylori eradication are characterized by a depressed configuration. Careful follow-up endoscopies are necessary after H. pylori eradication.

Eradication of Helicobacter pylori and Gastric Cancer: A Systematic Review and Meta-analysis of Cohort Studies

BACKGROUND

Helicobacter pylori (H. pylori) is associated with an increased risk of gastric adenocarcinoma and gastric mucosa associated lymphoid tissue (MALT) lymphoma and a decreased risk of esophageal adenocarcinoma. We aimed to assess how eradication therapy for H. pylori influences the risk of developing these cancers.

METHODS

This was a systematic review and meta-analysis. We searched PubMed, Web of Science, Embase, and the Cochrane Library and selected articles that examined the risk of gastric cancer, MALT lymphoma, or esophageal cancer following eradication therapy, compared with a noneradicated control group.

RESULTS

Among 3629 articles that were considered, nine met the inclusion criteria. Of these, eight cohort studies assessed gastric cancer while one randomized trial assessed esophageal cancer. Out of 12 899 successfully eradicated patients, 119 (0.9%) developed gastric cancer, compared with 208 (1.1%) out of 18 654 noneradicated patients. The pooled relative risk of gastric cancer in all eight studies was 0.46 (95% confidence interval [CI] = 0.32 to 0.66, I(2) = 32.3%) favoring eradication therapy. The four studies adjusting for time of follow-up and confounders showed a relative risk of 0.46 (95% CI = 0.29 to 0.72, I(2) = 44.4%).

CONCLUSIONS

This systematic review and meta-analysis indicates that eradication therapy for H. pylori prevents gastric cancer. There was insufficient literature for meta-analysis of MALT lymphoma or esophageal cancer.

Helicobacter pylori Eradication Prevents Metachronous Gastric Neoplasms after Endoscopic Resection of Gastric Dysplasia

PURPOSE

There is insufficient data about the role of eradication of H. pylori after endoscopic resection (ER) for gastric dysplasia. The aim was to investigate the benefit of H. pylori eradication after ER in patients with gastric dysplasia to prevent metachronous gastric neoplasms.

MATERIALS AND METHODS

We retrospectively reviewed 1872 patients who underwent ER of gastric dysplasia. We excluded patients with a follow-up period of <2 years or who had not undergone tests for active H. pylori infection. A total of 282 patients were enrolled. The patients were categorized into those without active H. pylori infection (H. pylori-negative group, n = 124), those who successfully underwent H. pylori eradication (eradicated group, n = 122), and those who failed or did not undergo H. pylori eradication (persistent group, n = 36).

RESULTS

Metachronous recurrence was diagnosed in 36 patients, including 19 in the H. pylori-negative group, 10 in the eradicated group, and 7 in the persistent group. The cumulative incidence of metachronous recurrence was significantly lower in the H. pylori-eradicated group in comparison with either of the H. pylori-persistent (non-eradicated or failed) groups (p = 0.039). Similarly, the incidence of metachronous recurrence was significantly lower in the H. pylori-eradicated group compared with the H. pylori-negative group (p = 0.041).

CONCLUSION

Successful H. pylori eradication may reduce the development of metachronous gastric neoplasms after ER in patients with gastric dysplasia.

Helicobacter pylori Eradication for Prevention of Metachronous Recurrence after Endoscopic Resection of Early Gastric Cancer

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.

Helicobacter pylori Eradication on the Prevention of Metachronous Lesions after Endoscopic Resection of Gastric Neoplasm: A Meta-Analysis

Background

There is controversy about the effect of Helicobacter pylori (H. pylori) eradication on the prevention of metachronous gastric cancer after endoscopic resection (ER).

Aims

The aim of this study was to systematically evaluate the effect of H. pylori eradication on the prevention of metachronous gastric lesions after ER of gastric neoplasms.

Methods

We performed a systematic search of PubMed, EMBASE, the Cochrane Library, and MEDLINE that encompassed studies through April 2014. Our meta-analysis consisted of 10 studies, which included 5881 patients who underwent ER of gastric neoplasms.

Results

When we compared the incidence of metachronous lesions between H. pylori-eradicated and non-eradicated groups, H. pylori eradication significantly lowered the risk of metachronous lesions after ER of gastric neoplasms (five studies, OR = 0.392, 95% CI 0.259 – 0.593, P < 0.001). When we compared H. pylori-eradicated and persistent groups, again, H. pylori eradication significantly lowered the incidence of metachronous lesions after ER of gastric neoplasms (six studies, OR = 0.468, 95% CI 0.326 – 0.673, P < 0.001). There was no obvious heterogeneity across the analyzed studies.

Conclusions

This meta-analysis suggests a preventive role for H. pylori eradication for metachronous gastric lesions after ER of gastric neoplasms. Thus, H. pylori eradication should be considered if H. pylori infection is confirmed during ER.

Gastric cancer: prevention, screening and early diagnosis

Gastric cancer continues to be an important healthcare problem from a global perspective. Most of the cases in the Western world are diagnosed at late stages when the treatment is largely ineffective. Helicobacter pylori (H. pylori) infection is a well-established carcinogen for gastric cancer. While lifestyle factors are important, the efficacy of interventions in their modification, as in the use of antioxidant supplements, is unconvincing. No organized screening programs can be found outside Asia (Japan and South Korea). Although several screening approaches have been proposed, including indirect atrophy detection by measuring pepsinogen in the circulation, none of them have so far been implemented, and more study data is required to justify any implementation. Mass eradication of H. pylori in high-risk areas tends to be cost-effective, but its adverse effects and resistance remain a concern. Searches for new screening biomarkers, including microRNA and cancer-autoantibody panels, as well as detection of volatile organic compounds in the breath, are in progress. Endoscopy with a proper biopsy follow-up remains the standard for early detection of cancer and related premalignant lesions. At the same time, new advanced high-resolution endoscopic technologies are showing promising results with respect to diagnosing mucosal lesions visually and targeting each biopsy. New histological risk stratifications (classifications), including OLGA and OLGIM, have recently been developed. This review addresses the current means for gastric cancer primary and secondary prevention, the available and emerging methods for screening, and new developments in endoscopic detection of early lesions of the stomach.

Efficacy of Helicobacter pylori eradication for the prevention of metachronous gastric cancer after endoscopic resection for early gastric cancer

Helicobacter pylori (H. pylori) plays an important role in gastric carcinogenesis, as the majority of gastric cancers develop from H. pylori-infected gastric mucosa. The rate of early gastric cancer diagnosis has increased in Japan and Korea, where H. pylori infection and gastric cancer are highly prevalent. Early intestinal-type gastric cancer without concomitant lymph node metastasis is usually treated by endoscopic resection. Secondary metachronous gastric cancers often develop because atrophic mucosa left untreated after endoscopic treatment confers a high risk of gastric cancer. The efficacy of H. pylori eradication for the prevention of metachronous gastric cancer remains controversial. However, in patients who undergo endoscopic resection of early gastric cancer, H. pylori eradication is recommended to suppress or delay metachronous gastric cancer. Careful and regularly scheduled endoscopy should be performed to detect minute metachronous gastric cancer after endoscopic resection.

Effect of Helicobacter pylori eradication on metachronous recurrence after endoscopic resection of gastric neoplasm

OBJECTIVES

Although many epidemiologic studies have shown that Helicobacter pylori (H. pylori) eradication has prophylactic effects on gastric cancer, their results are less clear in high-risk populations. We conducted this study to examine whether H. pylori eradication would affect the occurrence of metachronous gastric cancer after endoscopic resection in patients with early gastric cancer.

METHODS

We retrospectively analyzed 2,089 adults who underwent endoscopic resection of gastric low-grade neoplasia, high-grade neoplasia, or differentiated invasive neoplasia from 2004 to 2008 at Asan Medical Center. Of these, a total of 1,007 patients with early gastric cancer were enrolled in this study. We evaluated the demographic data, the pathology, and the incidence of metachronous recurrence by dividing them into three groups: those without active H. pylori infection (Hp negative group, n=340), those who successfully underwent H. pylori eradication (eradicated group, n=485), and those who failed or did not undergo H. pylori eradication (noneradicated group, n=182).

RESULTS

Metachronous recurrence was diagnosed in 75 patients, including 17 in the Hp, 34 in the eradicated, and 24 in the noneradicated groups. Median time to metachronous recurrence was 18 months (range, 7-75 months). The incidence of metachronous gastric cancer was 10.9 cases per 1,000 person-years in the Hp negative group, 14.7 cases per 1,000 person-years in the eradicated group, and 29.7 cases per 1,000 person-years in the noneradicated group. The hazard ratios in the noneradicated group compared with the Hp negative and eradicated groups were 2.5 (P<0.01) and 1.9 (P=0.02), respectively. H. pylori eradication reduced metachronous recurrence of gastric neoplasm, which was also shown in the secondary analysis of 1,487 patients with low-grade neoplasia and early gastric cancer.

CONCLUSIONS

Successful H. pylori eradication may reduce the occurrence of metachronous gastric cancer after endoscopic resection in patients with early gastric cancer.

Magnifying narrow-band imaging of surface maturation in early differentiated-type gastric cancers after Helicobacter pylori eradication

BACKGROUND

Even after successful Helicobacter pylori eradication, primary or metachronous gastric cancers are sometimes discovered. The endoscopic features of these cancers may be modified by controlling inflammation. Characteristic findings for such lesions in terms of narrow-band imaging with magnifying endoscopy (NBI-ME) and histopathology need to be clarified to allow accurate diagnosis.

METHODS

Distinctive NBI-ME characteristics were examined retrospectively in intramucosal or minimally submucosal and differentiated-type adenocarcinomas from a successful eradication group (42 patients, 50 lesions) and a non-eradicated control group (44 patients, 50 lesions) matched in age and sex. A "gastritis-like" appearance under NBI-ME was characterized by uniform papillae and/or tubular pits with a whitish border, regular or faint microvessels and unclear demarcation, resembling the adjacent noncancerous mucosa. Histological differentiation at the luminal surface of the cancer was evaluated according to Ki-67 immunoreactivity restricted at the middle or lower portion of the tubules. NBI-ME alteration was prospectively confirmed in 29 patients (30 lesions) after eradication therapy.

RESULTS

The frequency of a "gastritis-like" appearance was 44% (22/50) for the eradication group, which was significantly higher than the 4% (2/50) for the control group (p < 0.001). In the eradication group, the "gastritis-like" appearance was significantly correlated with histological surface differentiation (p < 0.001). In the prospective study, NBI-ME showed changes to heterogeneous papillary microstructures in 43% (10/23) of the lesions after successful eradication at short-term follow-up.

CONCLUSIONS

Identification of surface maturation under NBI-ME offers a promising approach for accurate diagnosis of early gastric cancers after successful eradication.

Identification of a high risk gastric cancer group using serum pepsinogen after successful eradication of Helicobacter pylori

BACKGROUND AND AIM

Pepsinogen (PG) method is widely used to identify high risk groups of gastric cancer. It is very useful before Helicobacter pylori eradication, but after eradication the method becomes useless because the PGI, PGII, PGI/II ratios change. Therefore, we aimed to identify a high risk group for gastric cancer using serum pepsinogen after successful eradication of H. pylori.

METHODS

A total of 261 participants were enrolled after successful eradication of H. pylori in Hokkaido University Hospital from 1995 to 2010. Participants with renal failure, taking proton pump inhibitors, and those with advanced gastric cancer were excluded. Serum levels of PGI and II were measured using chemiluminescent immunoassay method.

RESULTS

Receiver operating characteristic curves using cancerous and non-cancerous data in post-eradication determined the optimal cut-off value of PGI/II as 4.5. The sensitivity and the specificity were 65.9% and 79.3%, respectively. The usual PG method includes 48.9% of cancer cases, and the PGI/II ≤ 4.5 in post-eradication includes 65.9% of them, and it includes approximately half of the high risk group of diffuse type cancer. PGI/II ≤ 4.5 in post-eradication included many gastric cancer cases detected after eradication (12/16 = 75%).

CONCLUSION

In the identification of a high risk group for gastric cancer, we suggest that the optimal cut-off value of PGI/II after successful eradication of H. pylori is 4.5. PGI/II ≤ 4.5 in post-eradication includes more gastric cancer cases compared with the traditional PG method, and 75% of gastric cancer cases detected after eradication.

Eradication of H. pylori did not improve abnormal sonic hedgehog expression in the high risk group for gastric cancer

BACKGROUND

Sonic hedgehog (SHH) acts as a proliferation factor in both the normal mucosa and in malignant lesions. Helicobacter pylori-associated atrophic gastritis is characterized by loss of SHH.

AIM

The purpose of this study was to investigate the effects of H. pylori eradication on SHH mRNA and methylation levels in the patients at high risk for gastric cancer comparing to those in the controls.

METHODS

Gastric corpus biopsies taken from 20 patients with endoscopic resection for early gastric cancer and 14 sex- and age-matched controls before and 1 year after eradication were examined for SHH and downstream regulators mRNA expression using whole biopsy specimens and microdissected gastric glands. Methylation of SHH promoter was evaluated using quantitative methylation-specific PCR.

RESULTS

SHH mRNA levels eradication were significantly lower (2.75 × 10(-2) vs. 7.37 × 10(-2), P = 0.004) in the cancer group than in the controls. PTCH and BMP4 mRNA levels as well as MUC5AC were significantly increased only in the control group and were significantly higher in the controls than those in the cancer group after eradication. After eradication, SHH methylation levels in the non-metaplastic glands were significantly higher (86.4% vs. 22.2%, P < 0.001) in the cancer group than in the controls.

CONCLUSIONS

H. pylori eradication can enhance SHH and its downstream regulators expression diminishing SHH methylation and reverse gastric phenotype, but not in the patients with high risk for gastric cancer.

Long-term effect of Helicobacter pylori eradication on the development of metachronous gastric cancer after endoscopic resection of early gastric cancer

BACKGROUND

A prospective, randomized trial proved that Helicobacter pylori eradication significantly reduces the incidence of metachronous gastric cancer during a 3-year follow-up.

OBJECTIVE

To investigate the long-term effect of H pylori eradication on the incidence of metachronous gastric cancer after endoscopic resection of early gastric cancer.

DESIGN

Retrospective, multicenter study.

SETTING

Kyushu University Hospital and 6 other hospitals in Fukuoka Prefecture, Japan.

PATIENTS AND INTERVENTIONS

Follow-up data for 268 H pylori-positive patients who had undergone endoscopic resection of early gastric cancer were retrospectively investigated. A total of 177 patients underwent successful H pylori eradication (eradicated group), whereas 91 had persistent H pylori infection (persistent group).

MAIN OUTCOME MEASUREMENTS

The incidence of metachronous gastric cancer was compared in these 2 groups.

RESULTS

When the follow-up period was censored at 5 years, the incidence rate in the eradicated group was lower than that observed in the persistent group (P = .007). During the overall follow-up period ranging from 1.1 to 11.1 years (median 3.0 years), metachronous gastric cancer developed in 13 patients (14.3%) in the persistent group and in 15 patients (8.5%) in the eradicated group (P = .262, log-rank test). Based on a multivariate logistic regression analysis, baseline severe mucosal atrophy and a follow-up of more than 5 years were found to be independent risk factors for the development of metachronous gastric cancer.

LIMITATIONS

Retrospective study.

CONCLUSIONS

H pylori eradication does not reduce the incidence of metachronous gastric cancer. H pylori eradication should be performed before the progression of gastric mucosal atrophy.

Self-limiting risk of metachronous gastric cancers after endoscopic resection

BACKGROUND

Since endoscopic resection (ER) has been established as a treatment for early gastric cancer, metachronous multiple cancers have become a problem. It is unclear whether the risk of metachronous cancer is self-limiting or permanent. The aim of this study was to evaluate the incidence of multiple cancers after ER during a long-term follow-up study.

PATIENTS AND METHODS

A total of 234 patients who received initial ER for early gastric cancers were evaluated retrospectively. ER included endoscopic mucosal resection and endoscopic submucosal dissection. Patients were followed up with endoscopy for 3.0-19.6 years (median, 5.0 years), including 40 patients surveyed for more than 10 years. Accessory cancers detected after ER, but which could be retrospectively viewed in pre-ER pictures, were evaluated in the metachronous group.

RESULTS

Thirty patients (12.8%) developed 36 metachronous multiple cancers. The median interval between the discovery of metachronous cancer and the initial ER was 3.2 years; the longest interval was 9.7 years. Eight (22.2%) of the 36 metachronous cancers could be detected retrospectively in the picture record from pre-ER. The Kaplan-Meier curve of cumulative incidence of metachronous cancers stopped increasing after 10 years of follow up.

CONCLUSIONS

Although the residual gastric mucosa after ER is thought to be a high-risk environment, the high risk may only be the result of occult synchronous cancers. It is probable that the high risk of metachronous cancers is not continuous after 10 years.

Prevention of gastric cancer by Helicobacter pylori eradication

Attention was focused on whether the incidence of gastric cancer could be decreased by eradication of Helicobacter pylori (H. pylori) infection after H. pylori infection was found to be an important risk factor for gastric cancer,. The Japan Gast Study Group (JGSG) planned a randomized study, with the primary endpoint being the development of gastric cancer after H. pylori eradication. To design a study with a fairly small sample size and short follow-up period, the conclusion was reached that the study should be conducted in patients who had undergone endoscopic mucosal resection (EMR) for early gastric cancer because they have the highest incidence of recurrent gastric cancer. There were no differences of age, gender, tumor site, histology, tumor depth, and tumor size between the two groups. The incidence of metachronous gastric cancer in eradication group was significantly lower than in control group in the analysis ignoring observation period (Odds ratio: 0.353, 95% CI: 0.161-0.775, p=0.009). Kaplan-Meier analysis revealed that the cumulative incidence of gastric cancer was different between the two groups. The Japanese Society for Helicobacter Research has published a guideline recommending that H. pylori infection should be treated by eradication therapy following this study. New evidence obtained from our study in Japan may be helpful for the prevention and eventually elimination of gastric cancer worldwide.

[Esophageal adenoma-carcinoma and Barrett's esophagus. Gastric adenocarcinoma and Helicobacter pylori]

In the last two decades, the incidence of esophageal cancer has progressively increased, especially that of adenocarcinomas localized in the esophagogastric junction. The incidence of gastric cancer has decreased in the last few decades, although this decrease shows wide geographical variations. Thus, the prevalence of gastric cancer continues to be high in countries such as Chile, Colombia and Ireland and this disease remains the most frequent neoplasm in both sexes in China and Japan. In the meeting of the American Gastroenterological Association, notable among all the studies presented on the prevention and treatment of esophageal and gastric cancer were the following contributions: the use of clinical practice guidelines for the prevention and surveillance of Barrett's esophagus (BE) should be improved; treatment with proton pump inhibitors does not seem to reduce the risk of esophageal cancer; endoscopic therapy of intramucosal cancer through complete mucosal resection is effective; Helicobacter pylori eradication prevents the development of metachronous gastric cancer in patients treated for a first intramucosal adenocarcinoma through endoscopic resection; the risk of developing gastric cancer is 6 times higher in patients with mucosa-associated lymphoid tissue (MALT) lymphoma than in the general population; and photodynamic therapy may be an alternative for the treatment of "invisible" gastric adenocarcinoma, which should be followed-up endoscopically.

Helicobacter pylori eradication therapy may facilitate gastric ulcer healing after endoscopic mucosal resection: a prospective randomized study

BACKGROUND AND AIM

It remains unclear whether Helicobacter pylori eradication therapy affects the healing rate of iatrogenic ulcers following endoscopic mucosal resection (EMR) for gastric tumors. The aim of our study was to prospectively evaluate the effect of H. pylori eradication therapy on gastric ulcer healing after EMR.

METHODS

After EMR, patients were randomly assigned to either the H. pylori eradication group (Hp group) (lansoprazole 30 mg, amoxicillin 1000 mg, and clarithromycin 500 mg, twice a day for 7 days) or the noneradication group (proton pump inhibitor, PPI group) (lansoprazole 30 mg, twice a day for 7 days). Four weeks after EMR, the ulcer stages and size were compared between the two groups. Moreover, ulcer-related symptoms, bleeding rates, adverse effects, and drug compliance were compared.

RESULTS

A total of 64 patients were enrolled. Of these, 17 patients were excluded from the study. The two groups were comparable in terms of baseline clinicopathologic characteristics. Four weeks after EMR, the two groups did not differ with respect to ulcer stage (p = .475) or ulcer-related symptoms (p = .399). However, the ulcer reduction ratio was significantly higher in the Hp group (0.028 +/- 0.024 vs. 0.065 +/- 0.055, p < .05). No differences were observed between the two groups with regard to drug compliance, adverse drug event rates, or bleeding rates.

CONCLUSIONS

Our results suggest that H. pylori eradication therapy might improve the ulcer healing rate after EMR.

Eradication of helicobacter pylori to prevent gastroduodenal diseases: hitting more than one bird with the same stone

Helicobacter pylori (H. pylori) are gram-negative bacteria that selectively colonizes the gastric mucosa. The prevalence of H. pylori infection varies from 20 to 50% in industrialized countries to over 80% in developing countries. The infection may persist lifelong without specific treatment. Prolonged infection and inflammation due to bacterial virulence and host genetic factors will lead to chronic gastritis. A certain portion of infected patients then develop more severe pathologies such as peptic ulcer (10-15%), gastric cancer (1%), and mucosa-associated lymphoid tissue lymphoma (50.01%). Although the majority of infected patients remain asymptomatic, much of the evidence has shown that eradication of H. pylori infection can reduce the recurrence of peptic ulcer and benefit a substantial portion of patients with nonulcer dyspepsia. Though controversial in population-based clinical trials, several cost-effectiveness analyses also reveal that H. pylori eradication is cost effective in the primary prevention of gastric cancer. Therefore, the discovery of H. pylori offers the chance to prevent several gastroduodenal diseases by means of their eradication. In other words, gastroenterologists could hit more than one bird with one stone. However, there are concerns regarding application of a 'test and treat' strategy in the general population. In this review, we will focus on current evidence of H. pylori eradication in the primary and secondary prophylaxis of gastric cancer and peptic ulcer disease.

Translational research in gastric malignancy

This article discusses recent advances in gastric cancer research that have improved treatment and outcomes of gastric malignancy, or have the potential to do so. The significance of Helicobacter pylori infection and eradication, immunology, host genetics, proto-oncogenes, and epigenetic alterations in gastric cancer are discussed. Abnormal signaling through growth factor pathways (tyrosine kinases and gastrointestinal peptides) presents ample opportunities for therapeutic intervention that are currently being tested in clinical trials. Drugs targeting abnormal epigenetic changes, such as DNA hypermethylation and histone deacetylation, are also on the horizon, although most of this research is still in the preclinical phase. The potential prognostic implications of genetics and immunology in gastric cancer prognosis are also reviewed.