Microsatellite Instability in Intestinal Metaplasia and Gastric Cancer

Objective: To investigate the changeable patterns of microsatellite instability(MSI)in intestinal metaplasia(IM)and gastric cancer(GC)and the role of MSI in gastric carcinogenesis. Methods: Silver staining single strand conformation polymorphism-polymeriase chain reaction(PCR-SSCP)was used to screen MSI markers at 5 loci in formalin-fixed,paraffin-embedded tissues of GC(n=30),IM(n=40)and corresponding normal gastric tissues. Results: The abnormal shifting of the single-strand DNA was identified in 7(23.3%)out of GC and in 8(20%)out of IM samples.Three(10%)tumors and one(2.5%)IM displayed high-frequency MSI(two or more loci altered).Low-frequency MSI(one loci altered)was detected in 4(13.3%)of the tumors and in 7(17.5%)IM samples.GC with MSI was associated with distal location of the tumors but age,sex,differentiation,lymph nodes metastasis and TNM stage(P=0.044).MSI was more likely detected in moderate-grade IM than in mild-grade IM tissues(34.8% versus 0; P=0.013); and MSI had a tendency to be easily detected in female with IM. Conclusion: The progressive accumulation of MSI in areas of IM may contribute to GC development,representing an important molecular event in the multistep gastric carcinogenesis.

Autoimmune gastritis studies and gastric cancer: True renaissance or bibliometric illusion

A bibliometric analysis of studies dedicated to autoimmune gastritis(AIG)recently published demonstrated a noteworthy surge in publications over the last three years.This can be explained by numerous publications from different regions of the world reporting the results of several studies that stimulated reassessment of our view of AIG as a precancerous condition.Follow-up studies and retrospective analyses showed that the risk of gastric cancer(GC)in AIG patients is much lower than expected if the patients ever being infected with Helicobacter pylori(H.pylori)were excluded.The low prevalence of precancerous lesions,such as the incomplete type of intestinal metaplasia,may explain the low risk of GC in AIG patients because the spasmolytic polypeptide-expressing metaplasia commonly observed in AIG does not involve clonal reprogramming of the gastric gland and can be considered as an adaptive change rather than a true precancerous lesion.However,changes in gastric secretion due to the progression of gastric atrophy during the course of AIG cause changes in the gastric microbiome,stimulating the growth of bacterial species such as streptococci,which may promote the development of precancerous lesions and GC.Thus,Streptococcus anginosus exhibited a robust proinflammatory response and induced the gastritis-atrophy-metaplasia-dysplasia sequence in mice,reproducing the wellestablished process for carcinogenesis associated with H.pylori.Prospective studies in H.pylori-naïve patients evaluating gastric microbiome changes during the long-term course of AIG might provide an explanation for the enigmatic increase in GC incidence in the last decades in younger cohorts,which has been reported in economically developed countries.

Helicobacter pylori infection, glandular atrophy and intestinal metaplasia in superficial gastritis, gastric erosion, erosive gastritis, gastric ulcer and early gastric cancer

AIM: To evaluate the histological features of gastric mucosa, including Helicobacter pylori infection in patients with early gastric cancer and endoscopically found superficial gastritis, gastric erosion, erosive gastritis, gastric ulcer. METHODS: The biopsy specimens were taken from the antrum, corpus and upper angulus of all the patients. Giemsa staining, improved toluidine-blue staining, and Hpylori-specific antibody immune staining were performed as appropriate for the histological diagnosis of H pylori infection. Hematoxylin-eosin staining was used for the histological diagnosis of gastric mucosa inflammation, gastric glandular atrophy and intestinal metaplasia and scored into four grades according to the Updated Sydney System. RESULTS: The overall prevalence of H pylori infection in superficial gastritis was 28.7%, in erosive gastritis 57.7%, in gastric erosion 63.3%, in gastric ulcer 80.8%, in early gastric cancer 52.4%. There was significant difference (P<0.05), except for the difference between early gastric cancer and erosive gastritis. H pylori infection rate in antrum, corpus, angulus of patients with superficial gastritis was 25.9%, 26.2%, 25.2%, respectively; in patients with erosive gastritis 46.9%, 53.5%, 49.0%, respectively; in patients with gastric erosion 52.4%, 61.5%, 52.4%, respectively; in patients with gastric ulcer 52.4%, 61.5%, 52.4%, respectively; in patients with early gastric cancer 35.0%, 50.7%, 34.6%, respectively. No significant difference was found among the different site biopsies in superficial gastritis, but in the other diseases the detected rates were higher in corpus biopsy (P<0.05). The grades of mononuclear cell infiltration and polymorphonuclear cell infiltration, in early gastric cancer patients, were significantly higher than that in superficial gastritis patients, lower than that in gastric erosion and gastric ulcer patients (P<0.01); however, there was no significant difference compared with erosive gastritis. The grades of mucosa glandular atrophy and intestinal metaplasia were significantly highest in early gastric cancer, lower in gastric ulcer, the next were erosive gastritis, gastric erosion, the lowest in superficial gastritis (P<0.01). Furthermore, 53.3% and 51.4% showed glandular atrophy and intestinal metaplasia in angular biopsy specimens, respectively; but only 40.3% and 39.9% were identified in antral biopsy, and 14.1% and 13.6% in corpus biopsy; therefore, the angulus was more reliable for the diagnosis of glandular atrophy and intestinal metaplasia compared with antrum and corpus (P<0.01). The positivity rate of glandular atrophy and intestinal metaplasia of superficial gastritis with H pyloripositivity was 50.7%, 34.1%; of erosive gastritis 76.1%, 63.0%; of gastric erosion 84.8%, 87.8%; of gastric ulcer 80.6%, 90.9%; and of early gastric cancer 85.5%, 85.3%, respectively. The positivity rate of glandular atrophy and intestinal metaplasia of superficial gastritis with H pylorinegativity was 9.9%, 6.9%; of erosive gastritis 42.5%, 42.1%; of gastric erosion 51.1%, 61.9%; of gastric ulcer 29.8%, 25.5%; and of early gastric cancer 84.0%, 86.0%, respectively. The positivity rate of glandular atrophy and intestinal metaplasia of superficial gastritis, erosive gastritis, gastric erosion, and gastric ulcer patients with H pylon positivity was significantly higher than those with H pylori negativity (P<0.01); however, there was no significant difference in patients with early gastric cancer with or without H pylori infection. CONCLUSION: The progression of the gastric pre-cancerous lesions, glandular atrophy and intestinal metaplasia in superficial gastritis, gastric erosion, erosive gastritis and gastric ulcer was strongly related to H pylori infection. In depth studies are needed to evaluate whether eradication of H pylori infection will really diminish the risk of gastric cancer.

Helicobacter pylori plays a key role in gastric adenocarcinoma induced by spasmolytic polypeptide-expressing metaplasia

Heliobacter pylori(H. pylori), a group 1 human gastric carcinogen, is significantly associated with chronic gastritis, gastric mucosal atrophy, and gastric cancer.Approximately 20% of patients infected with H. pylori develop precancerous lesions, among which metaplasia is the most critical. Except for intestinal metaplasia(IM), which is characterized by goblet cells appearing in the stomach glands, one type of mucous cell metaplasia, spasmolytic polypeptide-expressing metaplasia(SPEM), has attracted much attention. Epidemiological and clinicopathological studies suggest that SPEM may be more strongly linked to gastric adenocarcinoma than IM. SPEM, characterized by abnormal expression of trefoil factor 2, mucin 6, and Griffonia simplicifolia lectin II in the deep glands of the stomach, is caused by acute injury or inflammation. Although it is generally believed that the loss of parietal cells alone is a sufficient and direct cause of SPEM, further in-depth studies have revealed the critical role of immunosignals.There is controversy regarding whether SPEM cells originate from the transdifferentiation of mature chief cells or professional progenitors. SPEM plays a functional role in the repair of gastric epithelial injury. However, chronic inflammation and immune responses caused by H. pylori infection can induce further progression of SPEM to IM, dysplasia, and adenocarcinoma. SPEM cells upregulate the expression of whey acidic protein 4-disulfide core domain protein 2 and CD44 variant 9, which recruit M2 macrophages to the wound. Studies have revealed that interleukin-33, the most significantly upregulated cytokine in macrophages, promotes SPEM toward more advanced metaplasia. Overall, more effort is needed to reveal the specific mechanism of SPEM malignant progression driven by H.pylori infection.

Gastric cancer incidence based on endoscopic Kyoto classification of gastritis

BACKGROUND Gastric cancer(GC)incidence based on the endoscopic Kyoto classification of gastritis has not been systematically investigated using time-to-event analysis.AIM To examine GC incidence in an endoscopic surveillance cohort.METHODS This study was retrospectively conducted at the Toyoshima Endoscopy Clinic.Patients who underwent two or more esophagogastroduodenoscopies were enrolled.GC incidence was based on Kyoto classification scores,such as atrophy,intestinal metaplasia(IM),enlarged folds(EFs),nodularity,diffuse redness(DR),and total Kyoto scores.Hazard ratios(HRs)adjusted for age and sex were calculated using a Cox hazard model.RESULTS A total of 6718 patients were enrolled(median age 54.0 years;men 44.2%).During the follow-up period(max 5.02 years;median 2.56 years),GC developed in 34 patients.The average frequency of GCs per year was 0.19%.Kyoto atrophy scores 1[HR with score 0 as reference:3.66,95%confidence interval(CI):1.06 to 12.61],2(11.60,3.82-35.27),IM score 2(9.92,4.37-22.54),EF score 1(4.03,1.63-9.96),DR scores 1(6.22,2.65-14.56),and 2(10.01,3.73-26.86)were associated with GC incidence,whereas nodularity scores were not.The total Kyoto scores of 4(HR with total Kyoto scores 0-1 as reference:6.23,95%CI:1.93 to 20.13,P=0.002)and 5-8(16.45,6.29-43.03,P<0.001)were more likely to develop GC,whereas the total Kyoto scores 2-3 were not.The HR of the total Kyoto score for developing GC per 1 rank was 1.75(95%CI:1.46 to 2.09,P<0.001).CONCLUSION A high total Kyoto score(≥4)was associated with GC incidence.The endoscopy-based diagnosis of gastritis can stratify GC risk.

Narrow-band imaging with magnifying endoscopy is accurate for detecting gastric intestinal metaplasia

AIM:To investigate the predictive value of narrowband imaging with magnifying endoscopy (NBI-ME) for identifying gastric intestinal metaplasia (GIM) in unselected patients. METHODS:We prospectively evaluated consecutive patients undergoing upper endoscopy for various indications, such as epigastric discomfort/pain, anaemia, gastro-oesophageal reflux disease, suspicion of peptic ulcer disease, or chronic liver diseases. Patients underwent NBI-ME, which was performed by three blinded, experienced endoscopists. In addition, five biopsies (2 antrum, 1 angulus, and 2 corpus) were taken and examined by two pathologists unaware of the endoscopic findings to determine the presence or absence of GIM. The correlation between light blue crest (LBC) appearance and histology was measured. Moreover, we quantified the degree of LBC appearance as less than 20% (+), 20%-80% (++) and more than 80% (+++) of an image field, and the semiquantitative evaluation of LBC appearance was correlated with IM percentage from the histological findings. RESULTS:We enrolled 100 (58 F/42 M) patients who were mainly referred for gastro-esophageal reflux disease/dyspepsia (46%), cancer screening/anaemia (34%), chronic liver disease (9%), and suspected celiac disease (6%); the remaining patients were referred for other indications. The prevalence of Helicobacter pylori (H. pylori ) infection detected from the biopsies was 31%, while 67% of the patients used proton pump inhibitors. LBCs were found in the antrum of 33 patients (33%); 20 of the cases were classified as LBC+, 9 as LBC++, and 4 as LBC+++. LBCs were found in the gastric body of 6 patients (6%), with 5 of them also having LBCs in the antrum. The correlation between the appearance of LBCs and histological GIM was good, with a sensitivity of 80% (95%CI:67-92), a specificity of 96% (95%CI:93-99), a positive predictive value of 84% (95%CI:73-96), a negative predictive value of 95% (95%CI:92-98), and an accuracy of 93% (95%CI:90-97). The NBI-ME examination overlooked GIM in 8 cases, but the GIM was less than 5% in 7 of the cases. Moreover, in the 6 false positive cases, the histological examination showed the presence of reactive gastropathy (4 cases) or H. pylori active chronic gastritis (2 cases). The semiquantitative correlation between the rate of LBC appearance and the percentage of GIM was 79% (P < 0.01). CONCLUSION:NBI-ME achieved good sensitivity and specificity in recognising GIM in an unselected population. In routine clinical practice, this technique can reliably target gastric biopsies.

Microsatellite instability in gastric cancer and pre-cancerous lesions

AIM: To investigate the microsatellite instability (MSI) in cancer and pre-cancerous lesions of the stomach and its mechanisms underlying the development of gastric cancer.METHODS: Thirty-six gastric cancer samples were obtained from patients undergoing surgery. Forty-one gastric mucosa samples with dysplasia and 51 with intestinal metaplasia (IM) were obtained from patients with chronic gastritis undergoing gastro-endoscopy. Genomic DNA was extracted from the samples. Silver staining single strand conformation polymorphis-polymerize chain reaction (SSCP-PCR) was used to screen MSI markers at 5 loci (Bat-25, Bat-26, D5S346, D17S250, and D2S123)in fresh tissues and formalin-fixed, paraffin-embedded samples and their corresponding normal gastric mucosa.RESULTS: The abnormal shifting of the single-strand DNA (MSI) was identified in 21 out of 36 (58.3%) gastric cancers.Seven cases showed high-level MSI (two or more loci altered) and 14 showed low-level MSI (one locus altered).Gastric cancer with MSI had a tendency to be located in the distal stomach. MSI was also detected in 11 out of 41(26.8%) dysplasia samples and in 9 of 51 (17.6%) IM samples respectively. Three cases of dysplasia and one case of IM showed high-level MSI. Eight cases of dysplasia and 8 cases of IM displayed low-level MSI. MIS in IM was found only in moderate or severe-grade IM. No association was detected between MSI and dysplasia grade.CONCLUSION: Accumulation of MSI in dysplasia and intestinal metaplasia of gastric mucosa may be an early molecular event during gastric carcinogenesis and may contribute to the acquisition of transformed cell phenotype and the development of gastric cancer.

Helicobacter pylori associated gastric intestinal metaplasia:Treatment and surveillance

Gastric cancer(GC) is one of the leading causes of cancer related death in the world, particularly in East Asia. According to the Correa's cancer cascade, noncardia GC is usually developed through a series of mucosal changes from non-atrophic gastritis to atrophic gastritis(AG), intestinal metaplasia(IM), dysplasia and adenocarcinoma. Atrophic gastritis and IM are therefore generally considered to be pre-neoplastic gastric lesions. Helicobacter pylori(H. pylori) infection is an important initiating and promoting step of this gastric carcinogenesis cascade. Emerging long-term data showed that eradication of H. pylori reduced the risk of subsequent cancer development. It however remains confusing whether eradication of the bacterium in individuals with pre-neoplastic gastric lesions could regress these changes as well as in preventing cancer. Whilst H. pylori eradication could likely regress AG, the presence of IM may be a point of no return in this cascade. Hence, surveillance by endoscopy may be indicated in those with extensive IM or those with incomplete IM, particularly in populations with high GC risk. The optimal interval and the best tool of surveillance endoscopy remains to be determined in future studies.

Comparison of operative link for gastritis assessment, operative link on gastric intestinal metaplasia assessment, and TAIM stagings among men with atrophic gastritis

BACKGROUND Gastric cancer is the world’s third most lethal malignancy. Most gastric cancers develop through precancerous states of atrophic gastritis and intestinal metaplasia. Two staging systems, operative link for gastritis assessment(OLGA)and operative link on gastric intestinal metaplasia assessment(OLGIM), have been developed to detect high gastric cancer risk. European guidelines recommend surveillance for high-risk OLGA/OLGIM patients(stages Ⅲ–Ⅳ),and for those with advanced stage of atrophic gastritis in the whole stomach mucosa. We hypothesize, that by combining atrophy and intestinal metaplasia into one staging named TAIM, more patients with increased gastric cancer risk could be detected.AIM To evaluate the clinical value of the OLGA, OLGIM, and novel TAIM stagings as prognostic indicators for gastric cancer.METHODS In the Helsinki Gastritis Study, 22346 elderly male smokers from southwestern Finland were screened for serum pepsinogen I(PGI). Between the years 1989 and1993, men with low PGI values(PGI < 25 μg/L), were invited to undergo an oesophagogastroduodenoscopy. In this retrospective cohort study, 1147 men that underwent gastroscopy were followed for gastric cancer for a median of 13.7 years, and a maximum of 27.3 years. We developed a new staging system, TAIM,by combining the topography with the severity of atrophy or intestinal metaplasia in gastric biopsies. In TAIM staging, the gastric cancer risk is classified as low or high.RESULTS Twenty-eight gastric cancers were diagnosed during the follow-up, and the incidence rate was 1.72 per 1000 patient-years. The cancer risk associated positively with TAIM [Hazard ratio(HR) 2.70, 95%CI: 1.09–6.69, P = 0.03]. The risk increased through OLGIM stages 0-Ⅳ(0 vs Ⅳ: HR 5.72, 95%CI: 1.03–31.77, P for trend = 0.004), but not through OLGA stages 0–Ⅳ(0 vs Ⅳ: HR 5.77, 95%CI:0.67–49.77, P for trend = 0.10). The sensitivities of OLGA and OLGIM stages Ⅲ–Ⅳ were low, 21% and 32%, respectively, whereas that of TAIM high-risk was good, 79%. On the contrary, OLGA and OLGIM had high specificity, 85% and81%, respectively, but TAIM showed low specificity, 42%. In all three staging systems, the high-risk men had three-to four-times higher gastric cancer risk compared to the general male population of the same age.CONCLUSION OLGIM and TAIM stagings show prognostic value in assessing gastric cancer risk in elderly male smokers with atrophic gastritis.

Non-sequential narrow band imaging for targeted biopsy and monitoring of gastric intestinal metaplasia

AIM： To evaluate the efficacy of non-sequential narrow band imaging （NBI） for a better recognition of gastric intestinal metaplasia （GIM）. METHODS： Previously diagnosed GIM patients underwent targeted biopsy from areas with and without GIM, as indicated by NBI, twice at an interval of 1 year. The authors compared the endoscopic criteria such as light blue crest （LBC）, villous pattern （VP）, and large long crest （LLC） with standard histology. The results from two surveillance endoscopies were compared with histology results for sensitivity, specificity, positive predic-tive value （PPV）, negative predictive value （NPV）, and likelihood ratio of positive test （LR＋）. The number of early gastric cancer cases detected was also reported. RESULTS： NBI targeted biopsy was performed in 38 and 26 patients during the first and second surveillance endoscopies, respectively. There were 2 early gastric cancers detected in the first endoscopy. No cancer was detected from the second study. Surgical and endoscopic resections were successfully performed in each patient. Sensitivity, specificity, PPV, NPV, and LR＋ of all 3 endoscopic criteria during the first/second surveillances were 78.8%/91.3%, 82.5%/89.1%, 72.8%/77.8%, 86.8%/96.1, and 4.51/8.4, respectively. LBC provided the highest LR＋ over VP and LLC. CONCLUSION： Nonequential NBI is useful for GIM targeted biopsy. LBC provides the most sensitive reading. However, the optimal duration between two surveillances requires further study.

Prevalence of Helicobacter pylori infection and intestinal metaplasia in subjects who had undergone surgery for gastric adenocarcinoma in Northwest Italy

AIM： To investigate the seroprevalence of Helicobacter pylori （Hpylori） infection and its more virulent strains as well as the correlation with the histologic features among patients who had undergone surgery for gastric cancer （GC）. METHODS： Samples from 317 （184 males, 133 females, mean age 69±3.4 years） consecutive patientswho had undergone surgery for gastric non-cardia adenocarcinoma were included in the study. Five hundred and fifty-five （294 males, 261 females, mean age 57.3±4.1 years） patients consecutively admitted to the Emergency Care Unit served as control. Histological examination of tumor, lymph nodes and other tissues obtained at the time of surgery represented the diagnostic ＂gold standard＇： An enzyme immunosorbent assay was used to detect serum anti-H pylori （IgG） antibodies and Western blotting technique was utilized to search for anti-CagA protein （IgG）. RESULTS： Two hundred and sixty-one of three hundred and seventeen （82.3%） GC patients and 314/555 （56.5%） controls were seropositive for anti-H pylori （P〈0.0001; OR, 3.58; 95%CI, 2.53-5.07）. Out of the 317 cases, 267 （84.2%） were seropositive for anti-CagA antibody vs 100 out of 555 （18%） controls （P〈0.0001; OR, 24.30; 95%CI, 16.5-35.9）. There was no difference between the frequency of H pylori in intestinal type carcinoma （76.2%） and diffuse type cancer （78.8%）. Intestinal metaplasia （IM） was more frequent but not significant in the intestinal type cancer （83.4% vs 75.2% in diffuse type and 72.5% in mixed type）. Among the patients examined for IM, 39.8% had IM type Ⅰ, 8.3% type Ⅱ and 51.9% type Ⅲ （type IU vs others, P = 0.4）. CONCLUSION： This study confirms a high seroprevalence of H pylori infection in patients suffering from gastric adenocarcinoma and provides further evidence that searching for CagA status over H pylori infection might confer additional benefit in identifying populations at greater risk for this tumor.

Determination of an Appropriate Endoscopic Monitoring Interval for Patients with Gastric Precancerous Conditions in China

Objective Gastric precancerous conditions such as atrophic gastritis(AG)and intestinal metaplasia(IM)are considered independent risk factors for gastric cancer(GC).The suitable endoscopic monitoring interval is unclear when we attempt to prevent GC development.This study investigated the appropriate monitoring interval for AG/IM patients.Methods Totally,957 AG/IM patients who satisfied the criteria for evaluation between 2010 and 2020 were included in the study.Univariate and multivariate analyses were used to determine the risk factors for progression to high-grade intraepithelial neoplasia(HGIN)/GC in AG/IM patients,and to determine an appropriate endoscopic monitoring scheme.Results During follow-up,28 AG/IM patients developed gastric neoplasia lesions including gastric low-grade intraepithelial neoplasia(LGIN)(0.7%),HGIN(0.9%),and GC(1.3%).Multivariate analysis identified H.pylori infection(P=0.022)and extensive AG/IM lesions(P=0.002)as risk factors for HGIN/GC progression(P=0.025).Conclusion In our study,HGIN/GC was present in 2.2%of AG/IM patients.In AG/IM patients with extensive lesions,a 1–2-year surveillance interval is recommended for early detection of HIGN/GC in AG/IM patients with extensive lesions.

Long-term Follow-up Study on Gastric Intestinal Metaplasia Subtype and Its Relation to Expression of P53,Bcl-2 and PCNA

Objective： To investigate the correlation of typies of gastric intestinal metaplasia（IM）, expression of p53, bcl-2 and the proliferating cell nuclear antigen（PCNA）, with the lesion＇s evolution. Methods： A total of 80 patients with IM（53 male and 27 female, 35-64 years old） from an area with high-risk of gastric cancer（GC） in China were enrolled into this prospective study, including 28 cases of type Ⅰ （complete）, 25 cases of type Ⅱ （incomplete） , and 27 cases of type Ⅲ （incomplete）. Of the 80 cases, 62 cases including 19 cases of type Ⅰ, 22 type Ⅱ and 21 type Ⅲ, were followed up for 5-14 years（49 cases for 14 years, 6 for 10 years, and 7 for 5 years）. All of the 80 cases were studied immunohistochemically for the expression of p53, bcl-2 and PCNA. Results： The rate of p53-expressing cases was higher in type Ⅲ（25.9%） than in type Ⅰ（10.7%） and type Ⅱ （12.0%）, but without statistical significance（P=0.3070）. The positive rate of bcl-2 was obviously lower in type Ⅰ （21.4%） and type Ⅱ （24.0%） than in type Ⅲ（37.0%）, but not statistically significant（P=0.4223）. We observed difference in PCNA labelling index （LI） between type Ⅱ and type Ⅲ（P=0.0037）, and the difference was particularly significant in type Ⅰ as compared with type Ⅲ（P〈0.0001）. There was no statistical significance between type I and type II （P=0.0616）. Evolution into GC was detected in 0%, 4.5%, and 14.3% of type Ⅰ, type Ⅱ, and type Ⅲ IM cases, respectively. Progression to dysplasia was detected in 31.6%, 18.2%, and 14.3% of type Ⅰ, type Ⅱ, and type Ⅲ IM cases, respectively. Persistence of IM was documented in 31.6%, 45.5%, and 42.9% of type Ⅰ, type Ⅱ, and type Ⅲ IM cases, respectively. Regression of IM was documented in 36.8%, 31.8%, and 28.6% of type Ⅰ, type Ⅱ, and type ⅢIM cases, respectively. In progressive, persistent and regressive groups, the positive rates of p53 were 17.6%, 16.0% and 15.0%, bcl-2 were 29.4%, 36.0% and 25.0%, and PCNA LIs were 24.953±14.477, 23.752±12.934 and 25.105±10.055, respectively. There were no significant differences between the groups. Conclusion： The present follow-up study indicated that type Ⅲ had a higher risk for development of cancer than type Ⅰ or Ⅱ. PCNA LI was significantly higher in type Ⅲthan in type Ⅰ and Ⅱ, suggesting that cell proliferation in type Ⅲwas more active. Our data also indicated that the expression of p53 and bcl-2 had no apparent association with the particular type and the expression of p53, bcl-2 and PCNA had no apparent correlation with evolution of IM. Further studies with a larger sample size are needed to verify present observation.

Gastric intestinal metaplasia development in African American predominant United States population

BACKGROUND Gastric cancer significantly contributes to cancer mortality globally.Gastric intestinal metaplasia(GIM)is a stage in the Correa cascade and a premalignant lesion of gastric cancer.The natural history of GIM formation and progression over time is not fully understood.Currently,there are no clear guidelines on GIM surveillance or management in the United States.AIM To investigate factors associated with GIM development over time in African American-predominant study population.METHODS This is a retrospective longitudinal study in a single tertiary hospital in Washington DC.We retrieved upper esophagogastroduodenoscopies(EGDs)with gastric biopsies from the pathology department database from January 2015 to December 2020.Patients included in the study had undergone two or more EGDswith gastric biopsy.Patients with no GIM at baseline were followed up until they developed GIM or until the last available EGD.Exclusion criteria consisted of patients age<18,pregnancy,previous diagnosis of gastric cancer,and missing data including pathology results or endoscopy reports.The study population was divided into two groups based on GIM status.Univariate and multivariate Cox regression was used to estimate the hazard induced by patient demographics,EGD findings,and Helicobacter pylori(H.pylori)status on the GIM status.RESULTS Of 2375 patients who had at least 1 EGD with gastric biopsy,579 patients were included in the study.138 patients developed GIM during the study follow-up period of 1087 d on average,compared to 857 d in patients without GIM(P=0.247).The average age of GIM group was 64 years compared to 56 years in the non-GIM group(P<0.001).In the GIM group,adding one year to the age increases the risk for GIM formation by 4%(P<0.001).Over time,African Americans,Hispanic,and other ethnicities/races had an increased risk of GIM compared to Caucasians with a hazard ratio(HR)of 2.12(1.16,3.87),2.79(1.09,7.13),and 3.19(1.5,6.76)respectively.No gender difference was observed between the study populations.Gastritis was associated with an increased risk for GIM development with an HR of 1.62(1.07,2.44).On the other hand,H.pylori infection did not increase the risk for GIM.CONCLUSION An increase in age and non-Caucasian race/ethnicity are associated with an increased risk of GIM formation.The effect of H.pylori on GIM is limited in low prevalence areas.

Confocal laser endomicroscopy as a new diagnostic tool for poorly differentiated gastric adenocarcinoma

Gastric cancer(GC)is a multifactorial disease,where both environmental and genetic features can have an impact on its occurrence and development.GC represents one of the leading causes of cancer-related deaths worldwide.GC is most frequent in males and is believed to arise from a series of premalignant lesions.The detection of GC at an early stage is crucial because early GC,which is an invasive stomach cancer confined to the mucosal or submucosal lining,may be curable with a reported 5-year survival rate of more than 90%.Advanced GC usually has a poor prognosis despite current treatment standards.The diagnostic efficacy of conventional endoscopy(with light endoscopy)is currently limited.Confocal laser endomicroscopy is a novel imaging technique that allows real-time in vivo histological examination of mucosal surfaces during endoscopy.Confocal laser endomicroscopy may be of great importance in the surveillance of precancerous gastric lesions and in the diagnosis of GC.In this editorial we commented on the article about this topic published by Lou et al in the recent issue of the World Journal of Clinical Cases.

Identifying high-risk individuals for gastric cancer surveillance from western and eastern perspectives: Lessons to learn and possibility to develop an integrated approach for daily practice

Current evidence shows that individuals with gastric dysplasia, severe and extensive gastric atrophy, extensive gastric intestinal metaplasia and the incomplete subtype of intestinal metaplasia are at high risk for gastric cancer(GC) development. There are several approaches to identifying these subjects,including noninvasive methods, esophagogastroduodenoscopy and histology.The main approach in Western countries is histology-based while that in Eastern countries with a high prevalence of GC is endoscopy-based. Regarding asymptomatic individuals, the key issues in selecting applicable approaches are the ability to reduce GC mortality and the cost-effectiveness of the approach. At present, population-based screening programs have only been applied in a few Asian countries with a high risk of GC. Pre-endoscopic risk assessment based on demographic and clinical features, such as ethnicity, age, gender, smoking and Helicobacter pylori status, is helpful for identifying subjects with high pre-test probability for a possibly cost-effective approach, especially in intermediate-and low-risk countries. Regarding symptomatic patients with indications for esophagogastroduodenoscopy, the importance of opportunistic screening should be emphasized. The combination of endoscopic and histological approaches should always be considered as endoscopy provides a real-time assessment of the patient’s risk level. In addition, imaging enhanced endoscopy(IEE) has been shown to facilitate targeted biopsies resulting in better correlation between endoscopic and histological findings. Currently, the use of IEE is recommended for endoscopic examinations, and the Operative Link for Gastric Intestinal Metaplasia or Operative Link on Gastritis Assessment grading systems are recommended for histological examinations whenever available. However,resource limitations are an important barrier in many regions worldwide. Thus,for an approach to be applicable in real-life practice, it should be not only evidence-based but also resource-sensitive. In this review, we discuss the current understanding and approaches to identifying high-risk individuals from western and eastern perspectives, as well as the possibility of an integrated, resourcesensitive approach.

Follow-up of intestinal metaplasia in the stomach: When, how and why

Gastric cancer remains the second most frequent cause of cancer-related mortality in the world. Screening programs in some Asian countries are impractical in the majority of other countries worldwide. Therefore, follow-up of precancerous lesions is advisable for secondary gastric cancer prevention. Intestinal metaplasia (IM) is recognized as a precancerous lesion for gastric cancer, increasing the risk by 6-fold. IM is highly prevalent in the general population, being detected in nearly 1 of every 4 patients undergoing upper endoscopy. The IM prevalence rate is significantly higher in patients with Helicobacter pylori (H. pylori) infection, in first-degree relatives of gastric cancer patients, in smokers and it increases with patient age. IM is the "breaking point" in the gastric carcinogenesis cascade and does not appear to regress following H. pylori eradication, although the cure of infection may slow its progression. Gastric cancer risk is higher in patients with incomplete-type IM, in those with both antral and gastric body involvement, and the risk significantly increases with IM extension over 20% of the gastric mucosa. Scheduled endoscopic control could be cost-effective in IM patients, depending on the yearly incidence of gastric cancer in IM patients, the stage of gastric cancer at diagnosis discovered at surveillance, and the cost of endoscopy. As a pragmatic behavior, yearly endoscopic control would appear justified in all IM patients with at least one of these conditions: (1) IM extension > 20%; (2) the presence of incomplete type IM; (3) first-degree relative of gastric cancer patients; and (4) smokers. In the remaining IM patients, a less intensive (2-3 years) could be proposed.

Helicobacter pylori associated chronic gastritis,clinical syndromes,precancerous lesions,and pathogenesis of gastric cancer development

Helicobacter pylori (H. pylori) infection is well known to be associated with the development of precancerous lesions such as chronic atrophic gastritis (AG), or gastric intestinal metaplasia (GIM), and cancer. Various molecular alterations are identified not only in gastric cancer (GC) but also in precancerous lesions. H. pylori treatment seems to improve AG and GIM, but still remains controversial. In contrast, many studies, including meta-analysis, show that H. pylori eradication reduces GC. Molecular markers detected by genetic and epigenetic alterations related to carcinogenesis reverse following H. pylori eradication. This indicates that these changes may be an important factor in the identification of high risk patients for cancer development. Patients who underwent endoscopic treatment of GC are at high risk for development of metachronous GC. A randomized controlled trial from Japan concluded that prophylactic eradication of H. pylori after endoscopic resection should be used to prevent the development of metachronous GC, but recent retrospective studies did not show the tendency. Patients with precancerous lesions (molecular alterations) that do not reverse after H. pylori treatment, represent the &#x0201c;point of no return&#x0201d; and may be at high risk for the development of GC. Therefore, earlier H. pylori eradication should be considered for preventing GC development prior to the appearance of precancerous lesions.

Endoscopic Kyoto classification of Helicobacter pylori infection and gastric cancer risk diagnosis

Recent advances in endoscopic technology allow detailed observation of the gastric mucosa.Today,endoscopy is used in the diagnosis of gastritis to determine the presence/absence of Helicobacter pylori(H.pylori)infection and evaluate gastric cancer risk.In 2013,the Japan Gastroenterological Endoscopy Society advocated the Kyoto classification,a new grading system for endoscopic gastritis.The Kyoto classification organized endoscopic findings related to H.pylori infection.The Kyoto classification score is the sum of scores for five endoscopic findings(atrophy,intestinal metaplasia,enlarged folds,nodularity,and diffuse redness with or without regular arrangement of collecting venules)and ranges from 0 to 8.Atrophy,intestinal metaplasia,enlarged folds,and nodularity contribute to gastric cancer risk.Diffuse redness and regular arrangement of collecting venules are related to H.pylori infection status.In subjects without a history of H.pylori eradication,the infection rates in those with Kyoto scores of 0,1,and≥2 were 1.5%,45%,and 82%,respectively.A Kyoto classification score of 0 indicates no H.pylori infection.A Kyoto classification score of 2 or more indicates H.pylori infection.Kyoto classification scores of patients with and without gastric cancer were 4.8 and 3.8,respectively.A Kyoto classification score of 4 or more might indicate gastric cancer risk.

Risk of gastric cancer development after eradication of Helicobacter pylori

Helicobacter pylori(H. pylori) infection is the most important risk factor for gastric cancer(gc) development through the correa's gastric carcinogenesis cascade. However, H. pylori eradication alone does not eliminate gc, as pre-neoplastic lesions(atrophic gastritis, intestinal metaplasia and dysplasia) may have already developed in some patients. It is therefore necessary to identify patients at high-risk for gastric cancer after H. pylori eradication to streamline the management plan. If the patients have not undergone endoscopy with histologic assessment, the identification of certain clinical risk factors and non-invasive testing(serum pepsinogen) can predict the risk of atrophic gastritis. For those with suspected atrophic gastritis, further risk stratification by endoscopy with histologic assessment according to validated histologic staging systems would be advisable. Patients with higher stages may require long-term endoscopic surveillance. Apart from secondary prevention to reduce deaths by diagnosing gc at an early stage, identifying medications that could potentially modify the gc risk would be desirable. The potential roles of a number of medications have been suggested by various studies, including proton pump inhibitors(PPIs), aspirin, statins and metformin. However, there are currently no randomized clinical trials to address the impact of these medications on gc risk after H. pylori eradication. In addition, most of these studies failed to adjust for the effect of concurrent medications on gc risk. Recently, large population-based retrospective cohort studies have shown that PPIs were associated with an increased gc risk after H. pylori eradication, while aspirin was associated with a lower risk. The roles of other agents in reducing gc risk after H. pylori eradication remain to be determined.