Management of precancerous conditions and lesions in the stomach (MAPS): guideline from the European Society of Gastrointestinal Endoscopy (ESGE), European Helicobacter Study Group (EHSG), European Society of Pathology (ESP), and the Sociedade Portuguesa de Endoscopia Digestiva (SPED)

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.

Screening for and surveillance of gastric cancer

Although the prevalence of gastric cancer (GC) progressively decreased during the last decades, due to improved dietary habit, introduction of food refrigeration and recovered socio-economic level, it still accounts for 10% of the total cancer-related deaths. The best strategy to reduce the mortality for GC is to schedule appropriate screening and surveillance programs, that rises many relevant concerns taking into account its worldwide variability, natural history, diagnostic tools, therapeutic strategies, and cost-effectiveness. Intestinal-type, the most frequent GC histotype, develops through a multistep process triggered by Helicobacter pylori (H. pylori) and progressing from gastritis to atrophy, intestinal metaplasia (IM), and dysplasia. However, the majority of patients infected with H. pylori and carrying premalignant lesions do not develop GC. Therefore, it remains unclear who should be screened, when the screening should be started and how the screening should be performed. It seems reasonable that screening programs should target the general population in eastern countries, at high prevalence of GC and the high-risk subjects in western countries, at low prevalence of GC. As far as concern surveillance, currently, we are lacking of standardized international recommendations and many features have to be defined regarding the optimal diagnostic approach, the patients at higher risk, the best timing and the cost-effectiveness. Anyway, patients with corpus atrophic gastritis, extensive incomplete IM and dysplasia should enter a surveillance program. At present, screening and surveillance programs need further studies to draw worldwide reliable recommendations and evaluate the impact on mortality for GC.

Gastric ulcer patients are more susceptible to developing gastric cancer compared with concomitant gastric and duodenal ulcer patients

Intestinal metaplasia (IM) and dysplasia are precancerous lesions of gastric cancer (GC); however, the prevalence of IM and dysplasia in patients exhibiting single gastric ulcer (GU) and concomitant gastric and duodenal ulcer (CGDU) varies. In the present study consecutive patients who had undergone esophagogastroduodenal endoscopy were retrospectively screened, and those presenting with GU or CGDU were further evaluated for IM and dysplasia. Patients diagnosed with GC or lymphoma and patients with a history of anti-Helicobacter pylori, non-steroidal anti-inflammatory medicine (NSAIM), H₂-receptor antagonist or proton pump inhibitor therapy, were excluded from the present study. Of the 204,073 consecutively screened cases, 8,855 (4.3%) and 2,397 (1.2%) were diagnosed with GU and CGDU, respectively. A total of 1,722 GU and 233 CGDU patients were excluded; thus, 7,133 and 2,164 cases of GU and CGDU, respectively (n=9,297), were included in the present study. IM and dysplasia were observed in 1,348 (14.5%) and 210 (2.3%) patients, respectively. IM was more frequently identified in GU patients compared with CGDU patients (16.4 vs. 8.3%; odds ratio [OR], 2.158; 95% confidence interval [CI], 1.830–2.545; χ²=86.932; P<0.001); furthermore, GU patients exhibited significantly more frequent IM compared with CGDU patients at the gastric antrum (14.2 vs. 5.5%; OR, 2.818; 95% CI, 2.199–3.610; χ²=72.299; P<0.001), gastric incisura (24.0 vs. 14.1%; OR, 1.922; 95% CI, 1.502–2.432; χ²=30.402; P<0.001) and gastric corpus (12.6 vs. 3.3%; OR, 4.259; 95% CI, 1.030–17.609; χ²=4.736; P=0.026). Dysplasia was significantly more frequently identified in GU patients compared with CGDU patients (2.7 vs. 0.7%; OR, 4.027; 95% CI, 2.376–6.823; χ²=31.315; P<0.001), with GU patients exhibiting significantly more severe dysplasia at the gastric antrum (2.4 vs. 0.7%; OR, 3.339; 95% CI, 1.735–6.425; χ²=14.652; P<0.001) and the gastric incisura (2.9 vs. 0.7%; OR, 4.255; 95% CI, 1.694–10.689; χ²=11.229; P<0.001). Additionally, mild IM was more frequently identified in GU patients compared with CGDU patients (15.2 vs. 7.1%; OR, 2.353; 95% CI, 1.972–2.807; χ²=94.798; P<0.001) and dysplasia of a mild (1.7 vs. 0.6%; OR, 2.807; 95% CI, 1.580–4.987; χ²=13.519; P<0.001) or moderate/severe grade (1.1 vs. 0.09%; OR, 11.642; 95% CI, 2.857–47.439; χ²=18.896; P<0.001) was more frequent in GU patients compared with CGDU patients. IM and dysplasia were more frequently observed in GU compared with CGDU patients in the present study, which may be associated with an increased probability of developing GC.

Endoscopic surveillance of gastrointestinal premalignant lesions: current knowledge and future directions

PURPOSE OF REVIEW

Provide an evidence-based resource for the surveillance of gastrointestinal premalignant lesions, focusing on the scientific articles reported recently.

RECENT FINDINGS

No randomized controlled clinical trials exist to definitively support the efficacy of surveillance programs for Barrett's esophagus and gastric intestinal metaplasia. However, surveillance of these premalignant lesions is recommended by some of the leading organizations. To optimize the usefulness of surveillance programs, targeting high-risk patients might maximize its benefits. A Barrett's esophagus segment of at least 3 cm and evidence of intestinal metaplasia can help stratify those patients at highest risk for progression to esophageal adenocarcinoma. The location, extent, and severity of intestinal metaplasia are indicators of risk of developing gastric cancer. Patients with extensive intestinal metaplasia should be offered endoscopic surveillance. Quality in the baseline colonoscopy is crucial to decrease the risk of interval colorectal cancers. The importance of serrated polyps, as well as their surveillance intervals, is emphasized.

SUMMARY

To optimize the usefulness of surveillance programs, targeting high-risk patients might maximize its benefits. Future research is needed to design more effective surveillance strategies. Recently, emerging imaging techniques hold promise for improving sensitivity of endoscopic surveillance of premalignant conditions in the gastrointestinal tract.

Management of Helicobacter pylori infection in Latin America: a Delphi technique-based consensus

AIM

To optimize diagnosis and treatment guidelines for this geographic region, a panel of gastroenterologists, epidemiologists, and basic scientists carried out a structured evaluation of available literature.

METHODS

Relevant questions were distributed among the experts, who generated draft statements for consideration by the entire panel. A modified three-round Delphi technique method was used to reach consensus. Critical input was also obtained from representatives of the concerned medical community. The quality of the evidence and level of recommendation supporting each statement was graded according to United States Preventive Services Task Force criteria.

RESULTS

A group of ten experts was established. The survey included 15 open-ended questions that were distributed among the experts, who assessed the articles associated with each question. The levels of agreement achieved by the panel were 50% in the first round, 73.3% in the second round and 100% in the third round. Main consensus recommendations included: (1) when available, urea breath and stool antigen test (HpSA) should be used for non-invasive diagnosis; (2) detect and eradicate Helicobacter pylori (H. pylori) in all gastroscopy patients to decrease risk of peptic ulcer disease, prevent o retard progression in patients with preneoplastic lesions, and to prevent recurrence in patients treated for gastric cancer; (3) further investigate implementation issues and health outcomes of H. pylori eradication for primary prevention of gastric cancer in high-risk populations; (4) prescribe standard 14-d triple therapy or sequential therapy for first-line treatment; (5) routinely assess eradication success post-treatment in clinical settings; and (6) select second- and third-line therapies according to antibiotic susceptibility testing.

CONCLUSION

These achievable steps toward better region-specific management can be expected to improve clinical health outcomes.

Review article: the epidemiology and prevention of gastric cancer

BACKGROUND

Gastric cancer can be divided into cardia and noncardia gastric adenocarcinoma (NCGA). Non cardia gastric cancer is a disease that has declined in global incidence but has remained as an extremely lethal cancer.

AIM

To review recent advances in epidemiology and strategies in prevention of non cardia gastric cancer.

METHODS

A rapid literature search strategy was developed for all English language literature published before March 2013. The search was conducted using the electronic databases PubMed and EMBASE. The search strategy included the keywords 'stomach neoplasms', 'gastric cancer', 'epidemiology', 'risk factor', 'early detection of cancer', 'mass screening', 'cancer burden', 'prevention' and 'cost-effectiveness'. The search strategy was adjusted according to different requirements for each database. The specific search was also performed in cancer-related websites for country-specific information. The search was limited to past 10 years.

RESULTS

Gastric cancer is the fifth most common cancer but the third leading cause of cancer death. The case fatality rate is 75%. Screening by radiological or endoscopic methods has limited success in prevention of gastric cancer. Helicobacter pylori has been identified as a carcinogen, accounting for 60-70% of gastric cancer globally and eradication is a potential preventive measure. A meta-analysis in 2009 demonstrated that individuals treated with H. pylori eradication therapy can reduce gastric cancer risk. The extended Shandong Intervention trial that lasted 14.3 years showed that H. pylori eradication therapy significantly reduced gastric cancer incidence by 39%. Consensus groups from Asia, Europe and Japan have recommended H. pylori eradication as primary prevention in high-risk areas. Following eradication therapy, endoscopic surveillance of pre-malignant lesions using enhanced imaging appears to be another promising preventive strategy.

CONCLUSIONS

Gastric cancer remains a major diagnostic and therapeutic challenge. There is emerging evidence that H. pylori eradication in high gastric cancer regions can lead to a decline in the incidence of this highly lethal disease.

At the bedside: Helicobacter pylori, dysregulated host responses, DNA damage, and gastric cancer

Clinical trials performed in populations at high GC risk have demonstrated that eradication of Helicobacter pylori from the stomach with a course of combination antimicrobials helps prevent gastric carcinogenesis when they are administered before precancerous lesions have yet developed. In this review, we consider the insights into H. pylori-associated gastric carcinogenesis that have been gained from these and many other clinical studies in the field to highlight priority areas for basic research and clinical investigation. Among these are defining the magnitude of the risk reduction that may be achieved in clinical practice and at a population level by H. pylori eradication and investigating when, during the slow multistep progression to GC, intervention will be of the most benefit. Additional strategies to prevent GC induced by H. pylori, including chemoprevention, dietary modification, and close endoscopic surveillance, may also have value in augmenting the risk reduction. Why only a small subpopulation of those infected by H. pylori go on to develop GC may be partially explained by genetic susceptibility related to SNPs in several genes regulating the intensity of the gastric inflammatory response to H. pylori. Investigation of the basic mechanisms underlying the promotion of GC by H. pylori and the associated inflammatory response will likely continue to improve clinical strategies for the prevention of one of the most common causes of cancer death globally. See related review, At the Bench: H. pylori, dysregulated host responses, DNA damage, and gastric cancer.

Effect of Helicobacter pylori eradication on subsequent dysplasia development after endoscopic resection of gastric dysplasia

BACKGROUND/AIMS

Eradication of Helicobacter pylori reduces the incidence of gastric cancer, and may inhibit gastric dysplasia progression into gastric cancer. The aim of this study was to investigate the effect of eradication of Helicobacter on the incidence of subsequent gastric dysplasia development after endoscopic resection.

METHODS

Medical records of patients who underwent endoscopic resection for gastric dysplasia were retrospectively reviewed. Presence of H. pylori was assessed by the Campylobacter-like organism test and histology. The rate of subsequent dysplasia development after endoscopic resection between the eradication group and non-eradication group was compared.

RESULTS

Total of 129 patients positive for H. pylori infection were included for analysis. Of these, 85 patients received successful eradication therapy and 44 patients did not receive eradication therapy or failed to achieve successful eradication. Sex, mean age and pathologic grade of dysplasia did not differ between the two groups. In univariate analysis, the grade of intestinal metaplasia (p=0.013) significantly differed between metachronous dysplasia group and non-metachrounous dysplasia group. In multivariate analysis, eradication of H. pylori (p=0.014) was related to reduced incidence of subsequent gastric dysplasia development after endoscopic resection.

CONCLUSIONS

Eradication of H. pylori likely has a beneficial effect in preventing the development of subsequent gastric dysplasia, a premalignant lesion of gastric cancer, after endoscopic resection.

Temporal changes in serum biomarkers and risk for progression of gastric precancerous lesions: a longitudinal study

Effectively managing precancerous lesions is crucial to reducing the gastric cancer (GC) burden. We evaluated associations of temporal changes in multiple serological markers (pepsinogen I [PGI], PGII, PGI/II ratio, gastrin-17 and anti-Helicobacter pylori IgG) with risk for progression of gastric precancerous lesions. From 1997 to 2011, repeated esophagogastroduodenoscopies with gastric mucosal biopsies and blood sample collections were conducted on 2,039 participants (5,070 person-visits) in the Zhuanghe Gastric Diseases Screening Program, Liaoning, China. Serum biomarkers were measured using ELISA, and gastric biopsies were evaluated using standardized histologic criteria. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using generalized estimating equations for correlated binary outcomes. The ORs for progression of gastric conditions comparing those whose serum PGI, PGII, and anti-H. pylori IgG levels increased ≥ 50% relative to those whose decreased ≥ 50% were, respectively 1.67 (CI, 1.22-2.28), 1.80 (CI, 1.40-2.33) and 1.93 (CI, 1.48-2.52). The OR for those whose PGI/II ratio decreased ≥ 50% relative to those whose increased ≥ 50% was 1.40 (CI, 1.08-1.81), and for those whose PGII and anti-H. pylori IgG levels both increased ≥ 50% relative to those whose levels both decreased ≥ 50% the OR was 3.18 (CI, 2.05-4.93). Changes in gastrin-17 were not statistically significantly associated with progression. These findings suggest that temporal changes in serum PGI, PGII, PGI/II ratio, and anti-H. pylori IgG levels (especially PGII and anti-H. pylori IgG combined) may be useful for assessing and managing risk for progression of gastric precancerous lesions.

The learning curve for narrow-band imaging in the diagnosis of precancerous gastric lesions by using Web-based video

BACKGROUND

A simplified narrow-band imaging (NBI) endoscopy classification of gastric precancerous and cancerous lesions was derived and validated in a multicenter study. This classification comes with the need for dissemination through adequate training.

OBJECTIVE

To address the learning curve of this classification by endoscopists with differing expertise and to assess the feasibility of a YouTube-based learning program to disseminate it.

DESIGN

Prospective study.

SETTING

Five centers.

PARTICIPANTS

Six gastroenterologists (3 trainees, 3 fully trained endoscopists [FTs]).

INTERVENTIONS

Twenty tests provided through a Web-based program containing 10 randomly ordered NBI videos of gastric mucosa were taken. Feedback was sent 7 days after every test submission.

MAIN OUTCOME MEASUREMENTS

Measures of accuracy of the NBI classification throughout the time.

RESULTS

From the first to the last 50 videos, a learning curve was observed with a 10% increase in global accuracy, for both trainees (from 64% to 74%) and FTs (from 56% to 65%). After 200 videos, sensitivity and specificity of 80% and higher for intestinal metaplasia were observed in half the participants, and a specificity for dysplasia greater than 95%, along with a relevant likelihood ratio for a positive result of 7 to 28 and likelihood ratio for a negative result of 0.21 to 0.82, were achieved by all of the participants. No constant learning curve was observed for the identification of Helicobacter pylori gastritis and sensitivity to dysplasia. The trainees had better results in all of the parameters, except specificity for dysplasia, compared with the FTs. Globally, participants agreed that the program's structure was adequate, except on the feedback, which should have consisted of a more detailed explanation of each answer.

LIMITATIONS

No formal sample size estimate.

CONCLUSION

A Web-based learning program could be used to teach and disseminate classifications in the endoscopy field. In this study, an NBI classification for gastric mucosal features seems to be easily learned for the identification of gastric preneoplastic lesions.

Gastric biopsies: the gap between evidence-based medicine and daily practice in the management of gastric Helicobacter pylori infection

BACKGROUND

Many consider histology to be the gold standard for Helicobacter pylori detection. Because the number and distribution of H pylori organisms vary, particularly in patients taking proton pump inhibitors (PPIs), the American Gastroenterological Association recommends discontinuing PPIs two weeks before endoscopy, and taking biopsies from both the body and antrum.

OBJECTIVE

To assess the influence of clinical practice on the histopathological detection of H pylori infection.

METHODS

Electronic patient records were evaluated for the sites of gastric sampling and PPI use at endoscopy. One hundred fifty cases with biopsies taken from both antrum and body were randomly selected for pathological re-review with special stains. The gastric regions sampled, H pylori distribution and influence of clinical factors on pathological interpretation were assessed.

RESULTS

Between 2005 and 2010, 10,268 biopsies were taken to detect H pylori. Only one region was sampled in 60% of patients (antrum 47%, body 13%). Re-review of biopsies taken from both antrum and body indicated that the correct regions were sampled in only 85 (57%) patients. Of these, 54 were H pylori positive and 96 were H pylori negative. H pylori was present in the antrum in only 15% of the patients and body only in 21%. Of 96 H pylori-negative patients, two were reinterpreted as positive. Forty-seven per cent of patients were taking PPIs at endoscopy, contributing to both false-negative and false-positive diagnoses.

CONCLUSION

Despite national and international guidelines for managing H pylori infection, the American Gastroenterological Association guidelines are infrequently adhered to, with PPIs frequently contributing to false diagnosis; sampling one region only increases the likelihood of missing active infection by at least 15%.

Gastric cancer: descriptive epidemiology, risk factors, screening, and prevention

Less than a century ago, gastric cancer was the most common cancer in the United States and perhaps throughout the world. Despite its worldwide decline in incidence over the past century, gastric cancer remains a major killer across the globe. This article reviews the epidemiology, screening, and prevention of gastric cancer. We first discuss the descriptive epidemiology of gastric cancer, including its incidence, survival, mortality, and trends over time. Next, we characterize the risk factors for gastric cancer, both environmental and genetic. Serologic markers and histological precursor lesions of gastric cancer and early detection of gastric cancer using these markers are reviewed. Finally, we discuss prevention strategies and provide suggestions for further research.

Gastric cancer: descriptive epidemiology, risk factors, screening, and prevention

Less than a century ago, gastric cancer was the most common cancer in the United States and perhaps throughout the world. Despite its worldwide decline in incidence over the past century, gastric cancer remains a major killer across the globe. This article reviews the epidemiology, screening, and prevention of gastric cancer. We first discuss the descriptive epidemiology of gastric cancer, including its incidence, survival, mortality, and trends over time. Next, we characterize the risk factors for gastric cancer, both environmental and genetic. Serologic markers and histological precursor lesions of gastric cancer and early detection of gastric cancer using these markers are reviewed. Finally, we discuss prevention strategies and provide suggestions for further research.

Changing prevalence patterns in endoscopic and histological diagnosis of gastritis? Data from a cross-sectional Central European multicentre study

BACKGROUND AND AIMS

Traditionally, Helicobacter infection is considered to be the most common cause of gastritis. In the cross-sectional Central European histoGERD trial, we assessed the prevalence of different types of gastritis, correlating histological and endoscopic diagnoses.

METHODS

A total of 1123 individuals participated in an observational multicentre study. Endoscopists classified individuals as positive or negative for gastritis and rendered the putative cause. Pathologists evaluated biopsy specimens based upon the Updated Sydney System.

RESULTS

Histological diagnosis of gastritis was made in 639 (56.9%) participants. In all, 210 (18.7%) individuals were diagnosed with Helicobacter gastritis, 215 (19.1%) with post Helicobacter gastritis, 234 (20.8%) with reactive gastropathy, 26 (2.3%) with autoimmune gastritis, and 6 (0.5%) with focally enhanced gastritis related to Crohn's disease. In 46 out of 639 (7.2%) individuals diagnosed with gastritis, combinations of different histological subtypes were noted the most common being reactive gastropathy and post Helicobacter gastritis. Endoscopic diagnosis of gastritis was made in 534 (47.6%) individuals.

CONCLUSIONS

Reactive gastropathy was more common than active Helicobacter gastritis, and the majority of cases attributable to Helicobacter infection were no longer ongoing, i.e. post Helicobacter gastritis. Agreement between histological and endoscopic diagnoses was better in reactive gastropathy than in Helicobacter gastritis.

Management of Helicobacter pylori-related diseases in the Baltic States

Helicobacter pylori infection has been recognized as the main trigger of stomach-related diseases. The huge variation in H. pylori infection patterns across the globe requires targeted research and close monitoring of this infection in different regions. The Baltic countries have witnessed enormous changes in socioeconomic conditions in the last years. Evolution of H. pylori infection and related diseases has been a key interest of gastroenterology centers in the Baltic States over the last two decades, translating into up-to-date scientific data that are valuable locally and on the European level. The East-West gradient in the prevalence of H. pylori infection is still evident in the Baltic countries, but the gap is becoming smaller, and similar trends are expected for the coming years. Clarithromycin-based triple therapy remains the first-line treatment of H. pylori in the region; however, careful monitoring of resistance rates in the future remains highly relevant, though routine resistance testing is not available in all the countries. A high prevalence of gastric cancer is still notable in the Baltic States; nevertheless, a steady decline in gastric cancer incidence in Lithuania, Latvia and Estonia is present and expected to be continuing during the coming decades. Currently, H. pylori-related diseases still constitute a substantial part of gastroenterologists' workload in the region. This paper reviews epidemiological, diagnostic, treatment as well as basic research trends on H. pylori infection and related diseases in the Baltic States during the last two decades.

Helicobacter pylori and gastric cancer

Infection with Helicobacter pylori is established as the major risk factor for gastric cancer development. Damage of the mucosal barrier due to H. pylori-induced inflammation enhances the carcinogenic effect of other risk factors such as salt intake or tobacco smoking. The genetic disposition of both the bacterial strain and the host can increase the potential towards gastric cancer formation. Genetic variance of the bacterial proteins CagA and VacA is associated with a higher gastric cancer risk, as are polymorphisms and epigenetic changes in host gene coding for interleukins (IL1β, IL8), transcription factors (CDX2, RUNX3) and DNA repair enzymes. Application of high-throughput assays for genome-wide assessment of either genetic structural variance or gene expression patterns may lead to a better understanding of the pathobiological background of these processes, including the underlying signaling pathways. Understanding of the stepwise alterations that take place in the transition from chronic atrophic gastritis, via metaplastic changes, to invasive neoplasia is vital to define the 'point of no return' before which eradication of H. pylori has the potential to prevent gastric cancer. Currently, eradication as preventive strategy is only recommended for high-incidence regions in Asia; large population studies with an adequate follow-up are required to demonstrate the effectiveness of such an approach in Western populations.

Helicobacter pylori infection--management from a European perspective

Since the first European Consensus Report on Helicobacter pylori management in 1996 and the strong indication for therapy of peptic ulcer disease and other benign gastroduodenal pathologies, the list of indications for therapeutic interventions has been extended to selected extradigestive diseases. Test-and-treat and search-and-treat strategies have been implemented for patients with dyspeptic symptoms and prevention of H. pylori-related complications (gastric cancer included), respectively. Screen and treat strategies are in discussion but are still lacking any structured implementation. For diagnosis of H. pylori, accurate noninvasive and endoscopy-based tests are widely available across Europe, and individual tests are selected according to patient needs and clinical settings. Standard proton pump inhibitor-based triple therapy faces increasing failure rates mainly because of clarithromycin resistance, but alternative first-line options bismuth quadruple, or non-bismuth quadruples in various combinations have emerged as effective first-line alternatives. After treatment failure, defined rescue therapies including individual antibiotic-sensitive testing are recommended.

Progress in diagnosis and treatment of precancerous lesions and early gastric cancer

Gastric cancer is the fourth most prevalent cancer worldwide and the second cause of cancer-related death. The 5-year survival rate for early gastric cancer after treatment is 84%-99%. Early detection and treatment of precancerous lesions are pivotal to improved patient survival. The development of various endoscopic (e.g., endoscopic ultrasound, narrowband imaging, magnifying endoscopy and chromoendoscopy), imaging and laboratory technologies has significantly improved the rate of diagnosis of early cancer and precancerous lesions. In addition, endoscopic techniques (e.g., endoscopic submucosal dissection) and minimally invasive surgery (e.g., laparoscopy) make the therapy of early cancer and precancerous lesions better and less invasive, reduce the incidence of postoperative complications, and improve the quality of life of patients after surgery.

Guidance on the effective use of upper gastrointestinal histopathology

Given the ever-increasing demand for upper gastrointestinal endoscopy, for diagnosis and surveillance, there is a need to consider when it is appropriate, and when it is not appropriate, to take an endoscopic biopsy for histological evaluation. In this article, we consider this in relation to each of the anatomical compartments encountered during oesophagogastroduodenoscopy, and in relation to the common clinical scenarios and endoscopic abnormalities encountered. There are clear indications to biopsy suspicious ulceration or mass lesions and for investigation of some inflammatory conditions, such as eosinophilic oesophagitis and coeliac disease. Increasing guidance is available on optimal biopsy sites and biopsy numbers to maximise yield from histology. Outside these areas, the endoscopist should consider whether biopsy of normal or abnormal appearing mucosa is likely to contribute to patient management, to ensure effective use of limited healthcare resources.

OLGA and OLGIM stage distribution according to age and Helicobacter pylori status in the Korean population

BACKGROUND

The Operative Link for Gastritis Assessment (OLGA) and the Operative Link on Gastric Intestinal Metaplasia Assessment (OLGIM) staging systems have been suggested to provide risk assessment for gastric cancer. This study aimed to evaluate the distribution of OLGA and OLGIM staging by age and Helicobacter pylori status.

MATERIALS AND METHODS

We studied 632 subjects who underwent esophagogastroduodenoscopy for gastric cancer screening. Helicobacter pylori status and histologic changes were assessed using the updated Sydney system. Stage III and IV OLGA or OLGIM stages were considered as high-risk stages.

RESULTS

The rate of H. pylori infection was 59.0% (373/632). Overall, the proportion of high OLGA and OLGIM stages was significantly increased with older age (p < .001 for both). Old age (OR = 5.17, 6.97, and 12.23 for ages in the 40's, 50's, and 60's, respectively), smoking (OR = 2.54), and H. pylori infection (OR = 8.46) were independent risk factors for high-risk OLGA stages. These risk factors were the same for high-risk OLGIM stages. In the H. pylori-positive subgroup, the proportion of high-risk OLGA stages was low (6.9%) before the age of 40, but increased to 23.0%, 29.1%, and 41.1% for those in their 40s, 50s, and 60s, respectively (p < .001). High-risk OLGIM stages showed a similar trend of 2.8% before the age of 40 and up to 30.1% for those in their 60s. High-risk OLGA and OLGIM stages were uncommon in the H. pylori-negative group, with a respective prevalence of 10.3% and 3.4% even among those in their 60s.

CONCLUSIONS

Because high-risk OLGA and OLGIM stages are uncommon under the age of 40, H. pylori treatment before that age may reduce the need for endoscopic surveillance for gastric cancer.

Risk factors for intestinal metaplasia in concomitant gastric and duodenal ulcer disease

The aim of this study was to estimate the prevalence and risk factors of intestinal metaplasia (IM) in concomitant gastric and duodenal ulcer (CGDU) disease by retrospectively reviewing consecutive patients who had undergone esophagogastroduodenal endoscopy. Patients who received the endoscopic diagnosis of CGDU disease were selected for analysis and the recorded demographic, endoscopic, clinical and outcome data, including data on the development of IM, were extracted. Associations of the various parameters with IM were estimated by logistic regression analysis and described by the odds ratio (OR) with a 95% confidence interval (CI). Among the total 204,073 consecutive patients screened, 2,397 (1.2%) were diagnosed with CGDU disease. Following application of the exclusion criteria, a total of 2,149 cases were included in the study. The IM prevalence was 8.4%, represented by 153 mild cases, 26 moderate cases and one severe case. Multivariate analysis identified age ≥50 years (OR=2.606, 95% CI=1.889-3.597, χ²=34.000, P<0.001), ulcer at the gastric incisura (OR=2.644, 95% CI=1.926-3.630, χ²=36.142, P<0.001) and Helicobacter pylori (H. pylori) infection (OR=2.338, 95% CI=1.573-3.474, χ²=17.648, P<0.001) as independent risk factors for the development of IM. In addition, the moderate and severe IM grades were more frequently detected in males than in females (18.8% vs. 5.8%; OR=3.769, 95% CI=1.083-13.121, χ²=4.887, P=0.036). IM in patients with CGDU disease is not uncommon. CGDU patients with ongoing H. pylori infection, gastric incisura involvement, older age and/or male gender may be at a higher risk of IM.

Short term micronutrient-antioxidant supplementation has no impact on a serological marker of gastric atrophy in Zambian adults: retrospective analysis of a randomised controlled trial

BACKGROUND

Gastric cancer is a major contributor to cancer deaths in Zambia but, as elsewhere, no preventive strategies have been identified. We set out to investigate the possibility of reducing gastric atrophy, a premalignant lesion, using micronutrient-antioxidant supplementation.

METHODS

We analysed 215 archival samples from a randomised controlled trial of micronutrient-antioxidant supplementation carried out from 2003 to 2006. Participants were randomised to receive either the supplement or placebo and had been taking the allocated intervention for a mean of 18 (range 14-27) months when the samples used in this study were taken. We used low pepsinogen 1 to 2 (PEP1:2) ratio as a surrogate marker of gastric atrophy. A PEP 1:2 ratio of less than three was considered low. HIV serology, age, nutritional status, smoking, alcohol intake and gastric pH were also analysed. Ethical approval was obtained from the University of Zambia Biomedical Research Ethics Committee (011-04-12). The randomized trial was registered (ISRCTN31173864).

RESULTS

The overall prevalence of low PEP 1:2 ratio was 15/215 (7%) and it did not differ between the placebo (8/103, 7.8%) and micronutrient groups (7/112, 6.3%; HR 1.24; 95% CI 0.47-3.3; P = 0.79). The presence of low PEP 1:2 ratio was not influenced by HIV infection (HR 1.07; 95% CI 0.37-3.2; P =0.89) or nutritional status but it inversely correlated with gastric pH (Spearman's rho = -0.34; P = 0.0001). Age above 40 years was associated with atrophy, but neither alcohol nor smoking had any influence.

CONCLUSION

Short term micronutrient supplementation does not have any impact on PEP 1:2 ratio, a serological marker of gastric atrophy. PEP 1:2 ratio inversely correlates with gastric pH.

Diagnostic yield of the light blue crest sign in gastric intestinal metaplasia: a meta-analysis

BACKGROUND

The diagnostic yield of light blue crest(LBC) sign, which was observed by narrow band imaging with magnification endoscopy(NBI-ME), in detecting gastric intestinal metaplasia(IM) has shown variable results.

OBJECTIVE

We aimed to assess the diagnostic value of LBC under NBI-ME for detecting gastric IM.

METHODS

We performed a literature search of the Medline/PubMed, Embase, Web of Science, Science Direct and the Cochrane Library Databases; and a meta-analysis of pooled sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and SROC area under the curve, using fixed- and random-effects models, for the accuracy of LBC-based IM diagnosis.

RESULTS

We initially included 4 articles, but excluded 1 article to counter significant heterogeneity. When pooled, the remaining 3 articles, which included 247 patients with 721 lesions, showed the following patterns in IM diagnosis: sensitivity: 0.90 (95% confidence interval [CI] 0.86-0.92); specificity: 0.90 (95% CI 0.86-0.93), positive likelihood ratio: 8.98 (95% CI 6.42-12.58), negative likelihood ratio: 0.12 (95% CI 0.09-0.16), and SROC area under the curve: 0.9560.

LIMITATIONS

As the studies varied by their definitions for positive LBC, endoscopy types, biopsy protocols, race of patient cohort, and physicians' proficiency, some sample sizes were limited so that subgroup analyses could not be performed.

CONCLUSION

We concluded that observing LBC under NBI-ME is an accurate and precise means of diagnosing gastric IM.

Gastric cancer: descriptive epidemiology, risk factors, screening, and prevention

Less than a century ago, gastric cancer was the most common cancer in the United States and perhaps throughout the world. Despite its worldwide decline in incidence over the past century, gastric cancer remains a major killer across the globe. This article reviews the epidemiology, screening, and prevention of gastric cancer. We first discuss the descriptive epidemiology of gastric cancer, including its incidence, survival, mortality, and trends over time. Next, we characterize the risk factors for gastric cancer, both environmental and genetic. Serologic markers and histological precursor lesions of gastric cancer and early detection of gastric cancer using these markers are reviewed. Finally, we discuss prevention strategies and provide suggestions for further research.

Is lesion size an independent indication for endoscopic resection of biopsy-proven low-grade gastric dysplasia?

BACKGROUND/AIM

The standard treatment for patients with gastric low-grade dysplasia (LGD) remains controversial, even though diagnosis of LGD is increasingly common as esophagogastrodeuodenoscopy becomes more available. The aim of this study was to identify a lesion size cut-off as an indication for endoscopic resection (ER) for patients with LGD.

RESULTS

We retrospectively reviewed 285 lesions initially diagnosed as LGD by endoscopic forceps biopsies (EFB) from 2007 to 2010 in Kyung Hee University Hospital, Seoul, Korea. All patients underwent ER. A total of 285 lesions from 257 patients were assessed. After ER, 239 LGD (83.9 %) showed histological concordance and the remaining 46 (16.1 %) cases revealed an upgraded histology [22 high-grade dysplasia (7.7 %), and 24 differentiated adenocarcinoma (8.4 %)]. Univariate analyses demonstrated that lesion size, erythema, depression, and erosion were significant predictors of upgraded LGD (P < 0.001). Multivariate analysis showed that a lesion size ≥2 cm, erythema, and a depressed-type lesion were independent predictors of upgraded histology (P = 0.014, odds ratio 3.27, 95 % confidence interval 1.28-8.39).

CONCLUSIONS

Our data suggest that a substantial number of LGD diagnoses based on EFB were not representative of the entire lesion. We recommend ER if gastric LGD has at least one of the following risk factors: surface erythema and a depressed type regardless of size, or ≥2 cm size regardless of abnormal surface configuration.

Gastritis staging: interobserver agreement by applying OLGA and OLGIM systems

Atrophic gastritis remains a difficult histopathological diagnosis with low interobserver agreement. The aim of our study was to compare gastritis staging and interobserver agreement between general and expert gastrointestinal (GI) pathologists using Operative Link for Gastritis Assessment (OLGA) and Operative Link on Gastric Intestinal Metaplasia (OLGIM). We enrolled 835 patients undergoing upper endoscopy in the study. Two general and two expert gastrointestinal pathologists graded biopsy specimens according to the Sydney classification, and the stage of gastritis was assessed by OLGA and OLGIM system. Using OLGA, 280 (33.4 %) patients had gastritis (stage I-IV), whereas with OLGIM this was 167 (19.9 %). OLGA stage III- IV gastritis was observed in 25 patients, whereas by OLGIM stage III-IV was found in 23 patients. Interobserver agreement between expert GI pathologists for atrophy in the antrum, incisura angularis, and corpus was moderate (kappa = 0.53, 0.57 and 0.41, respectively, p < 0.0001), but almost perfect for intestinal metaplasia (kappa = 0.82, 0.80 and 0.81, respectively, p < 0.0001). However, interobserver agreement between general pathologists was poor for atrophy, but moderate for intestinal metaplasia. OLGIM staging provided the highest interobserver agreement, but a substantial proportion of potentially high-risk individuals would be missed if only OLGIM staging is applied. Therefore, we recommend to use a combination of OLGA and OLGIM for staging of chronic gastritis.

An educational intervention to improve the endoscopist's ability to correctly diagnose small gastric lesions using magnifying endoscopy with narrow-band imaging

BACKGROUND

Magnifying endoscopy with narrow-band imaging (ME-NBI) and a simple and systematic classification system based on microvascular and microsurface patterns, the "VS" classification system (VSCS), have been shown to be useful for the diagnosis of early gastric cancer. The aim of this study was to clarify whether an educational lecture about the VSCS improves performance with ME-NBI.

METHODS

Sixty-four gastrointestinal endoscopists took the 1st exam before receiving the lecture about the VSCS, the 2nd exam immediately after the lecture, and the 3rd exam 2 months after the lecture. We compared the VSCS-based diagnostic accuracy among the participants before and after the lecture.

RESULTS

The proportion of correct diagnoses was significantly higher, at 70.8% in the 2nd exam than in the 1st exam, at 53.1% (P<0.001). The correct diagnosis rate in the 3rd exam was significantly lower than that in the 2nd exam (60.9% vs. 70.8%; P<0.001) but was still higher than that in the 1st exam (60.9% vs. 53.1%; P<0.001). The difference in proportion of correct diagnosis between the 2nd and the 3rd exams was smaller among routine ME-NBI practitioners (n=6; 79.2% and 76.1%, respectively), compared to that among non-routine practitioners (n=34; 71.6% and 59.8%, respectively) or non-practitioners (n=24; 67.5% and 58.8%, respectively).

CONCLUSION

This study revealed that an educational intervention increased correct diagnosis rate of small gastric lesions using the VSCS, diagnosis criteria based on ME-NBI and also showed that the routine use of the modality and the diagnosis criteria was necessary to maintain diagnostic skills.

Strategies for eliminating death from gastric cancer in Japan

In Japan, efforts have been directed toward improving the detection of early gastric cancer by double contrast radiography and endoscopy, since early cancer has a good prognosis, resulting in Japan having the world's best diagnostic system for early gastric cancer. The 5-year survival rate of gastric cancer patients in Japan is much higher than in Western countries by the development of endoscopic treatment for early gastric cancer. In February 2013, Japanese national health insurance cover for H. pylori eradication therapy was expanded to patients with H. pylori-associated gastritis, a type of chronic gastritis. H. pylori-associated gastritis causes gastric and duodenal ulcers and gastric polyps, therefore, providing treatment for this gastritis is likely to substantially decrease the prevalence of both gastric and duodenal ulcer and gastric cancer. Patients with gastritis are tested for H. pylori infection and those who are positive receive eradication therapy followed by periodic endoscopic surveillance. If such an approach is pursued further in Japan, gastric cancer deaths will show a dramatic decline after 10-20 years.

Roadmap to eliminate gastric cancer with Helicobacter pylori eradication and consecutive surveillance in Japan

In Japan, the annual number of deaths from gastric cancer is approximately 50,000 and there has been no change over the last 50 years. So far, all efforts have been directed toward improving the detection of early gastric cancer by barium X-ray and endoscopy, since early cancer has a good prognosis, resulting in Japan having the best diagnostic capability for early gastric cancer worldwide. The 5-year survival rate of gastric cancer patients exceeds 60 % in Japan and is much higher than that in Europe and the US (20 %) because of this superior diagnosis of early gastric cancer. In February 2013, national health insurance coverage for Helicobacter pylori eradication therapy to treat H. pylori-associated chronic gastritis became available in Japan. H. pylori-associated gastritis leads to development of gastric and duodenal ulcers and gastric polyps. Therefore, providing treatment for gastritis is likely to substantially decrease the prevalence of both gastric and duodenal ulcers and polyps. Because treatment for H. pylori-associated gastritis, which leads to atrophic gastritis and gastric cancer, is now covered by health insurance in Japan, a strategy to eliminate gastric cancer-related deaths by taking advantage of this innovation was planned. According to this strategy, patients with gastritis will be investigated for H. pylori infection and those who are positive will receive eradication therapy followed by periodic surveillance. If this strategy is implemented, deaths from gastric cancer in Japan will decrease dramatically after 10-20 years.

A cost-effectiveness analysis evaluating endoscopic surveillance for gastric cancer for populations with low to intermediate risk

BACKGROUND

Gastric cancer (GC) surveillance based on oesophagogastroduodenoscopy (OGD) appears to be a promising strategy for GC prevention. By evaluating the cost-effectiveness of endoscopic surveillance in Singaporean Chinese, this study aimed to inform the implementation of such a program in a population with a low to intermediate GC risk.

METHODS

USING A REFERENCE STRATEGY OF NO OGD INTERVENTION, WE EVALUATED FOUR STRATEGIES: 2-yearly OGD surveillance, annual OGD surveillance, 2-yearly OGD screening and 2-yearly screening plus annual surveillance in Singaporean Chinese aged 50-69 years. From a perspective of the healthcare system, Markov models were built to simulate the life experience of the target population. The models projected discounted lifetime costs ($), quality adjusted life year (QALY), and incremental cost-effectiveness ratio (ICER) indicating the cost-effectiveness of each strategy against a Singapore willingness-to-pay of $46,200/QALY. Deterministic and probabilistic sensitivity analyses were used to identify the influential variables and their associated thresholds, and to quantify the influence of parameter uncertainties respectively.

RESULTS

With an ICER of $44,098/QALY, the annual OGD surveillance was the optimal strategy while the 2-yearly surveillance was the most cost-effective strategy (ICER = $25,949/QALY). The screening-based strategies were either extendedly dominated or cost-ineffective. The cost-effectiveness heterogeneity of the four strategies was observed across age-gender subgroups. Eight influential parameters were identified each with their specific thresholds to define the choice of optimal strategy. Accounting for the model uncertainties, the probability that the annual surveillance is the optimal strategy in Singapore was 44.5%.

CONCLUSION

Endoscopic surveillance is potentially cost-effective in the prevention of GC for populations at low to intermediate risk. Regarding program implementation, a detailed analysis of influential factors and their associated thresholds is necessary. Multiple strategies should be considered in order to recommend the right strategy for the right population.

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.

Management of gastric polyps: an endoscopy-based approach

The endoscopic finding of a gastric polyp and the histopathologic report that follows may leave clinicians with questions that have not been addressed in formal guidelines: do all polyps need to be excised, or can they just be sampled for biopsy? If so, which ones and how many should be sampled? What follow-up evaluation is needed, if any? This review relies on the existing literature and our collective experience to provide practical answers to these questions. Fundic gland polyps, now the most frequent gastric polyps in Western countries because of widespread use of proton pump inhibitors, and hyperplastic polyps, the second most common polyps notable for their association with gastritis and their low but important potential for harboring dysplastic or neoplastic foci, are discussed in greater detail. Adenomas have had their name changed to raised intraepithelial neoplasia and are decreasing in parallel with Helicobacter pylori infection; however, they do retain their importance as harbingers of gastric cancer, particularly in East Asia. Gastrointestinal stromal tumors have low incidence and no known associations, but their malignant potential is high; early diagnosis and proper management are crucial. Although rare and benign, inflammatory fibroid polyps need to recognized, particularly by pathologists, to avoid misdiagnosis. Gastric neuroendocrine tumors (carcinoids) are important because of their association with either atrophic gastritis or the multiple endocrine neoplasia syndromes; those that do not arise in these backgrounds have high malignant potential and require aggressive management. The review concludes with some practical suggestions on how to approach gastric polyps detected at endoscopy.

Staging of intestinal- and diffuse-type gastric cancers with the OLGA and OLGIM staging systems

BACKGROUND

Operative link on gastritis assessment (OLGA) and Operative link on gastric intestinal metaplasia assessment (OLGIM) staging systems have been proposed for gastric cancer (GC) risk estimation.

AIM

To validate the OLGA and OLGIM staging systems in a region with high risk of GC.

METHODS

This retrospective study included 474 GC patients and age- and sex-matched health screening control persons in a cancer centre hospital. We classified gastritis patterns according to the OLGA and OLGIM systems using the histological database that a pathologist prospectively evaluated using the updated Sydney system. GC risk according to the OLGA and OLGIM stages was evaluated using logistic regression analysis.

RESULTS

More GC patients had OLGA stages III-IV (46.2%) than controls (26.6%, P < 0.001), particularly among patients with intestinal-type GCs (62.2%) compared with diffuse-type GCs (30.9%). OLGA stages III and IV were significantly associated with increased risk of GC [odds ratios (ORs), 2.09; P = 0.008 and 2.04; P = 0.014 respectively] in multivariate analysis. The association was more significant for intestinal-type (ORs, 4.76; P = 0.001 and 4.19; P = 0.002 respectively), but not diffuse-type GC. OLGIM stages from I to IV were significantly associated with increased risk of both intestinal-type (ORs, 3.64, 5.15, 7.89 and 13.20 respectively) and diffuse-type GC (ORs, 1.84, 2.59, 5.08 and 6.32 respectively) with a significantly increasing trend.

CONCLUSION

As high OLGA and OLGIM stages are independent risk factors for gastric cancer, the staging systems may be useful for risk assessment in high-risk regions, especially for intestinal-type gastric cancer.

Biomarkers of Helicobacter pylori-associated gastric cancer

Helicobacter pylori-associated gastric cancer is a major cause of morbidity and mortality worldwide, and is predicted to become even more common in developing countries as the population ages. Since gastric cancer develops slowly over years to decades, and typically progresses though a series of well-defined histologic stages, cancer biomarkers have potential to identify asymptomatic individuals in whom surgery might be curative, or even those for whom antibiotics to eradicate H. pylori could prevent neoplastic transformation. Here we describe some of the challenges of biomarker discovery, summarize current approaches to biomarkers of gastric cancer, and explore some recent novel strategies.

Helicobacter pylori infection: selected aspects in clinical management

PURPOSE OF REVIEW

This review focuses on new aspects of recently published guidelines for the management of Helicobacter pylori infection as well as progress in diagnostic tests and treatment regimens. We also discuss new strategies for gastric cancer prevention.

RECENT FINDINGS

The general recommendation to treat H. pylori infection whenever diagnosed still faces resistance for reasons that are pertinent to the diversity of related clinical outcomes and to the complexity of eradication regimens. Thus, new updated guidelines for the management of H. pylori infection have been released in several continents. Progress has been made in molecular diagnostic tests for the detection of antibiotic resistance and serological tests for the detection of advanced gastric atrophic changes. Effective quadruple therapies in various combinations of 'traditional drugs' have been introduced with sequential or concomitant order of administration. Moreover, traditional drugs in a new galenic formulation have been introduced to overcome increasing H. pylori antibiotic resistance. Effective strategies for gastric cancer prevention have been adopted in some countries with high gastric cancer incidence, and have successfully contributed to lower the gastric cancer incidence. A screen-and-treat strategy for individuals at increased risk for gastric cancer needs to be further explored also in areas with low/moderate incidence of gastric cancer.

SUMMARY

New guidelines share many universal similarities across countries but respect and emphasize specific needs and requirements in individual communities. Various combinations of traditional drugs have been successfully introduced to overcome the increasing H. pylori antibiotic resistance. Gastric cancer prevention by a screen and treat strategy showed promising results.

Screening for gastric cancer and surveillance of premalignant lesions: a systematic review of cost-effectiveness studies

BACKGROUND

Cost-effectiveness studies are highly dependent on the models, settings, and variables used and should be based on systematic reviews. We systematically reviewed cost-effectiveness studies that address screening for gastric cancer and/or surveillance of precancerous conditions and lesions.

MATERIALS AND METHODS

A systematic review of cost-effectiveness studies was performed by conducting a sensitive search in seven databases (PubMed, Scopus, Web of Science, Current Contents Connect, Centre for Reviews and Dissemination, Academic Search Complete, and CINAHL Plus), independently evaluated by two investigators. Articles were evaluated for type of study, perspective, model, intervention, incremental cost-effectiveness ratio, clinical or cost variables, and quality, according to published guidelines.

RESULTS

From 2395 abstracts, 23 articles were included: 19 concerning population screening and 4 on following up premalignant lesions. Studies on Helicobacter pylori screening concluded that serology was cost-effective, depending on cancer incidence and endoscopy cost (incremental cost-effectiveness ratio: 6264-25,881), and eradication after endoscopic resection was also cost-effective (dominant) based on one study. Studies on imaging screening concluded that endoscopy was more cost-effective than no screening (incremental cost-effectiveness ratio: 3376-26,836). Articles on follow-up of premalignant lesions reported conflicting results (incremental cost-effectiveness ratio: 1868-72,519 for intestinal metaplasia; 18,600-39,800 for dysplasia). Quality assessment revealed a unanimous lack of a detailed systematic review and fulfillment of a median number of 23 items (20-26) of 35 possible ones.

CONCLUSIONS

The available evidence shows that Helicobacter pylori serology or endoscopic population screening is cost-effective, while endoscopic surveillance of premalignant gastric lesions presents conflicting results. Better implementation of published guidelines and accomplishment of systematic detailed reviews are needed.

Systematic review of the diagnosis of gastric premalignant conditions and neoplasia with high-resolution endoscopic technologies

AIM. The aim of the article is to systematically review the current evidence on the diagnostic use of narrow band imaging (NBI), flexible spectral imaging color enhancement (FICE) and endoscopic image enhancement technology i-scan endoscopies for gastric precancerous and cancerous lesions. MATERIALS AND METHODS. Original manuscripts were searched in PubMed until October 2012. Pertinent data were collected and pooled diagnostic accuracy measures were estimated when possible. RESULTs. In total, 38 studies were evaluated. Thirty-one studies were included for NBI and 7 studies for FICE assessment in this systematic review. No article was found meeting inclusion criteria for i-scan endoscopy. The most defined and evaluated outcomes were cancer-related (n = 26). Quality Assessment of Diagnostic Accuracy Studies score varied from 9 to 12 (out of 14). Only few studies assessed the interobserver reliability. On a patient level analysis, NBI's pooled sensitivity, specificity and diagnostic odds ratio were 0.67 (95% CI: 0.61-0.73), 0.81 (95% CI: 0.76-0.85) and 22.71 (95% CI: 12.53-41.1), respectively for diagnosing normal mucosa; 0.86 (95% CI: 0.82-0.90), 0.77 (95% CI: 0.73-0.80) and 17.01 (95% CI: 1.4-207.2) for intestinal metaplasia and 0.90 (95% CI: 0.84-0.94), 0.83 (95% CI: 0.80-0.86) and 47.61 (95% CI: 4.61-491.34) for dysplasia. Owing to the insufficient data and different definitions, we could not aggregate the results for FICE. CONCLUSION. Gastric pattern descriptions have been proposed for NBI and FICE studies by gathering all descriptions in one single description. The classification systems varied between studies, a single description of gastric mucosal features with HR--scopes or at least per technology--will have to be agreed on.

Surveillance of gastric intestinal metaplasia for the prevention of gastric cancer

BACKGROUND

Adenocarcinoma of the stomach is the second leading cause of cancer related death in the world. Gastric intestinal metaplasia (GIM) is a recognised premalignant condition of the stomach. It has been described as occurring in up to one in five patients in western countries. Although there is a definite risk of progression from GIM to cancer, published guidelines and statements differ as to the utility and structure of surveillance programs for this condition.

OBJECTIVES

To see whether or not endoscopic or biochemical surveillance of patients with gastric intestinal metaplasia (GIM) could result in increased detection of dysplasia and early gastric cancer to decrease gastric cancer mortality.

SEARCH METHODS

We performed a search of the following electronic databases from inception to October 2012: CENTRAL, EMBASE, MEDLINE and LILACS. We handsearched for abstracts from relevant conferences.

SELECTION CRITERIA

Randomised controlled trials only were included.

DATA COLLECTION AND ANALYSIS

No studies met the inclusion criteria.

MAIN RESULTS

No studies met the inclusion criteria.

AUTHORS' CONCLUSIONS

There is a lack of randomised data on the utility of surveillance of GIM. The observational data from non-randomised studies are discussed and would suggest that although a randomised trial would be a desirable undertaking to attain the highest grade of clinical evidence, given the ethical and acceptability issues involved, further non-randomised clinical studies focussing on surveillance protocols and the role of Helicobacter pylori eradication may be a more pragmatic means of addressing the core clinical question.

Helicobacter pylori: gastric cancer and extragastric malignancies - clinical aspects

The best opportunity to reduce gastric cancer (GC)-related mortality remains prevention. Mass eradication of Helicobacter pylori infection in a Taiwanese population >30 years of age reduced GC incidence with an effectiveness of 25% (rate ratio 0.753, 95% CI 0.372-1.524). In the Shandong intervention trial conducted on a Chinese population aged 35-64 years, cancer incidence was reduced by 39% in subjects who received H. pylori treatment compared with the placebo group after 14.7 years of follow-up (absolute risk 3.0 vs 4.6%; odds ratio 0.61, 95% CI 0.38-0.96; p = .03). A high incidence of severe gastric atrophic changes and noninvasive gastric neoplasia has been reported in a Portuguese case-control study on first-degree relatives of patients with early-onset gastric carcinoma (i.e., diagnosed before 45 years), which emphasizes again the importance of GC screening in this population. For patients with advanced GC, new targeted therapies to improve survival are under scrutiny. Trastuzumab resistance may be present from early on, or develop during trastuzumab therapy in patients with GC, and an overexpression of the HER2/neu protein. New molecules to overcome trastuzumab resistance are also being evaluated. The association between H. pylori-induced gastritis and an increased risk of developing colonic neoplasms has been confirmed in a recent study, but the causality for this intriguing association has still to be clarified.

First-degree relatives of early-onset gastric cancer patients show a high risk for gastric cancer: phenotype and genotype profile

First-degree relatives (FDR) of early-onset gastric cancer (EOGC) is presumed to be a population with a distinct molecular and phenotypic profile, regarding the prevalence of gastric premalignant conditions and the association with Helicobacter pylori infection and host proinflammatory gene polymorphisms. A case-control study was conducted with FDR of EOGC patients (n = 103) and age and gender matched controls (n = 101; ranging from spouses to neighbors and dyspeptics). Upper endoscopy was performed, Operative Link on Gastritis Assessment (OLGA) system used for staging and H. pylori (cagA and vacA) and host IL1B-511, IL1RN intron2 VNTR and IFNGR1-56 genotyping. Seventy percent of cases showed atrophy, while 19 % presented with high-stage gastritis (OLGA stage III or IV) (p < 0.001); gastric dysplasia was present in seven cases (vs none in controls) (p = 0.007). In cases, H. pylori was present in 82 % (vs 62 % in controls; p = 0.004) with vacA s1 and vacA m1 + strains significantly associated with the presence of atrophy; individuals homozygous for IL1B-511*T present a significantly higher risk for dysplasia. An increased global prevalence of IFNGR1-56*T/*T polymorphism (37 % in cases vs 24 % in controls; p = 0.03) was observed with no association with atrophic changes or dysplasia. All trends observed were kept when comparing FDR of EOGC with spouses, neighbors, or dyspeptic controls. We demonstrated that FDR of EOGC patients have an increased prevalence of high-risk OLGA stages and dysplasia that seem to be associated with high virulence H. pylori strains and pro-inflammatory host genotypes, including a possible population-specific risk marker. FDR of EOGC patients may merit specific management through endoscopic and histopathological adequate assessment of gastric mucosa and surveillance.

Helicobacter pylori infection in Europe: current perspectives

There is a commonly held perception that Helicobacter pylori related diseases are declining, however these are still associated with a high risk of morbidity and mortality. In recent years worrying themes have emerged such as increasing levels of antibiotic resistance and falling cure rates which illustrate there is no room for complacency with respect to H. pylori. In addition there are many significant issues which have not been elucidated regarding the role played by H. pylori in very serious pathologies such as gastric and esophageal cancer and other more benign disorders common in the developed world such as gastroesophageal reflux disease, functional dyspepsia and perhaps obesity which carry a significant impact both economically and as regards to symptoms. Future guidelines aimed at European practitioners and patients will need to address the questions raised by these issues as well as the more familiar areas such as constituents and duration of therapy.

Red-flag technologies in gastric neoplasia

Given its morbidity and mortality, the early detection and diagnosis of gastric cancer is an area of intense research focus. This article reviews the emerging use of enhanced endoscopic imaging technologies in the detection and management of gastric cancer. The combined use of white-light endoscopy with enhanced imaging technologies, such as magnification narrow-band imaging, chromoendoscopy, and autofluorescence endoscopy, demonstrates promise in the improved ability to detect and delineate gastric neoplasia. However, widespread clinical use is still limited, mainly because of the restricted availability of the technologies.

Gastric cáncer: Overview

Gastric cancer ranks fourth in incidence and second in mortality among all cancers worldwide. Despite the decrease in incidence in some regions of the world, gastric cancer continues to present a major clinical challenge due to most cases being diagnosed in advanced stages with poor prognosis and limited treatment options. The development of gastric cancer is a complex and multifactorial process involving a number of etiological factors and multiple genetic and epigenetic alterations. Among the predisposing factors are: Helicobacter pylori infection, high salt intake, smoking, and in a small percentage of patients, a familial genetic component. More than 95% of stomach cancer cases are adenocarcinomas, which are classified into two major histologic types: intestinal and diffuse. Intestinal type adenocarcinoma is preceded by a sequence of gastric lesions known as Correa´s cascade and is the histologic type associated with the global decrease in gastric cancer rates. Diffuse type adenocarcinomas have a more aggressive behavior and worse prognosis than those of the intestinal type. According to the anatomical location, adenocarcinomas are classified as proximal (originating in the cardia) and distal (originating in the body and antrum). This classification seems to recognize two different clinical entities. Surgical resection of the tumor at an early stage is the only effective treatment method. Therefore, the identification and surveillance of patients at risk may play a significant role in survival rates. Anti-Helicobacter pylori therapy has been shown to be an effective measure in the prevention of gastric cancer.

Interobserver variation in assessment of gastric premalignant lesions: higher agreement for intestinal metaplasia than for atrophy

BACKGROUND

Either atrophy or intestinal metaplasia of the gastric mucosa are considered premalignant lesions. The new operative link for gastritis assessment staging system is based on the detection of atrophy, and the operative link for assessment of intestinal metaplasia staging system is based on the detection of intestinal metaplasia. Good interobserver agreement is necessary for identification of any premalignant condition.

AIMS

The aim of this study was to compare the agreement between findings of gastric atrophy and intestinal metaplasia by expert and general pathologists and to analyze the possible reasons behind any possible disagreement.

METHODS

Patients with dyspeptic symptoms, aged 55 years and above, without previous Helicobacter pylori eradication were enrolled and analyzed according to the updated Sydney Classification by two expert pathologists and an experienced general pathologist; the results were compared with the consensus driven by the two experts.

RESULTS

Gastric biopsy specimens from 121 patients (91 women) were included in the analysis; the mean age of the patients was 67.4 years. H. pylori infection was present in 61.2% of patients. The level of agreement between the general pathologist and the two experts (κ-value) was 0.12, 0.46, and 0.87, respectively, for detecting atrophy in the corpus; 0.77, 0.77, and 0.65, respectively, for detecting intestinal metaplasia in the corpus; 0.06, 0.51, and 0.54, respectively, for detecting atrophy in the antrum; and 0.69, 0.85, and 0.79, respectively, for detecting metaplasia in the antrum.

CONCLUSION

The agreement was substantially higher for intestinal metaplasia than for atrophy. This could result in discrepancies when the operative link for gastritis assessment and operative link for assessment of intestinal metaplasia staging systems are applied and can be caused by differences in the criteria used to define atrophy.

Pathology of gastric cancer and its precursor lesions

Gastric cancers are a histologically heterogenous group of neoplasms arising from unique epidemiologic and molecular backgrounds. There is accumulating evidence that the intestinal type of gastric adenocarcinoma develops through a multistep process beginning with chronic gastritis triggered primarily by Helicobacter pylori and progressing through atrophy, intestinal metaplasia, and dysplasia (intraepithelial neoplasia) to carcinoma. Loss of E-cadherin expression resulting from CDH1 gene alterations is the primary carcinogenetic event in hereditary diffuse gastric cancer. Proximal gastric adenocarcinomas likely result from either gastroesophageal reflux or H pylori gastritis. This article provides an update of the histologic, immunohistochemical, and molecular pathways of gastric cancer and its precursors.