Gastric Intestinal Metaplasia: Real Culprit or Innocent Bystander as a Precancerous Condition for Gastric Cancer?

Gastric intestinal metaplasia (GIM), which denotes conversion of gastric mucosa into an intestinal phenotype, can occur in all regions of the stomach, including cardiac, fundic, and pyloric mucosa. Since the earliest description of GIM, its association with gastric cancer of the differentiated (intestinal) type has been a well-recognized concern. Many epidemiologic studies have confirmed GIM to be significantly associated with subsequent gastric cancer development. Helicobacter pylori, the principal etiologic factor for gastric cancer, plays the most important role in predisposing to GIM. Although the role of GIM in the stepwise progression model of gastric carcinogenesis (the so-called "Correa cascade") has come into question recently, we review the scientific evidence that strongly supports this long-standing model and propose a new progression model that builds on the Correa cascade. Eradication of H pylori is the most important method for preventing gastric cancer globally, but the effect of eradication on established GIM, is limited, if any. Endoscopic surveillance for GIM may, therefore, be necessary, especially when there is extensive corpus GIM. Recent advances in image-enhanced endoscopy with integrated artificial intelligence have facilitated the identification of GIM and neoplastic lesions, which will impact preventive strategies in the near future.

Gastric dysplastic lesions in Helicobacter pylori-naïve stomach: Foveolar-type adenoma and intestinal-type dysplasia.

Reports of Helicobacter pylori (Hp)-naïve gastric neoplasm (HpNGN) cases have been rapidly increasing due to the recent increase in the Hp-naïve population in Japan. Most HpNGNs exhibit the gastric immunophenotype and a low malignant potential regardless of histological type. Especially, foveolar-type gastric adenoma (FGA) and intestinal-type gastric dysplasia (IGD) rarely progress to invasive carcinoma. FGA is a foveolar epithelial neoplasm that occurs in the fundic gland (oxyntic gland) mucosa and is classified as the flat type or raspberry type (FGA-RA). The flat type is a large, whitish flatly elevated lesion while FGA-RA is a small reddish polyp. Genomically, the flat type is characterized by APC and KRAS gene mutations and FGA-RA by a common single nucleotide variant in the KLF4 gene. This KLF4 single-nucleotide variant reportedly induces gastric foveolar epithelial tumorigenesis and activates both cell proliferation and apoptosis, leading to its slow-growing nature. IGD consists of an intestinalized epithelial dysplasia that develops in the pyloric gland mucosa, characterized as a superficial depressed lesion surrounded by raised mucosa showing a gastritis-like appearance. Immunohistochemically, it exhibits an intestinal or gastrointestinal phenotype and, frequently, p53 overexpression. Thus, IGD shows unique characteristics in HpNGNs and a potential multistep tumorigenic process.

Endoscopic differential diagnosis between foveolar-type gastric adenoma and gastric hyperplastic polyps in Helicobacter pylori-naïve patients.

BACKGROUND: Foveolar-type gastric adenoma (FGA) occurs in Helicobacter pylori (Hp)-naïve individuals and morphologically mimics Hp-naïve gastric hyperplastic polyp (HpN-GHP). FGA is often difficult to distinguish from HpN-GHP even by biopsy, due to its low-grade histologic atypia. We conducted a retrospective study to create an endoscopic diagnostic index. METHODS: We analyzed 51 FGAs in 41 patients and 36 HpN-GHPs in 24 patients. All lesions were photographed by white-light endoscopy (WLE) and narrow-band imaging with magnification endoscopy (NBIME). Three experts and three non-experts reviewed the WLE and WLE+NBIME images to assess six items for lesion diagnosis. We analyzed correlations between the diagnostic items and histologic features and compared the diagnostic accuracy between modalities. We created a composite diagnostic index and calculated its accuracy and consistency. RESULTS: FGAs more frequently showed the following features vs. HpN-GHPs: bright-red color (94.1% vs. 44.4%), peripheral hyperplasia (58.8% vs. 8.3%), papillary/gyrus-like microstructure (96.1% vs. 33.3%), visible capillaries (70.6% vs. 38.9%), and demarcation line (98.0% vs. 41.7%) (P < 0.05). White-zone thickening was seen only in HpN-GHPs (52.8%). Diagnostic accuracy (mean, WLE vs. WLE+NBIME) was 90.8 ± 1.1% vs. 93.5 ± 2.4% (P = 0.15) for experts and 88.5 ± 3.0% vs. 86.6 ± 3.5% (P = 0.51) for non-experts. When satisfying the four criteria (bright-red color, papillary/gyrus-like microstructure, demarcation line, and absent white-zone thickening), sensitivity and specificity for FGA were 90.2% and 94.4%, respectively, with a kappa value of ≥ 0.6 for interobserver diagnostic agreement. CONCLUSIONS: Composite diagnostic index contributes to the reproducible, accurate, preoperative differential diagnosis of FGA and HpN-GHP.

Mutual association between family history of gastric and colorectal cancer and risk of gastric and colorectal cancer.

BACKGROUND AND AIM: We evaluated the associations between gastric cancer (GC) family history (FH) and colorectal cancer (CRC) risk and between CRC FH and GC/gastric adenoma risk. METHODS: We used data of participants who underwent national cancer screening between 2013 and 2014. Participants with GC or CRC FH in first-degree relatives (n = 1 172 750) and those without cancer FH (n = 3 518 250) were matched 1:3 by age and gender. RESULTS: Of the 1 172 750 participants with a FH, 871 104, 264 040, and 37 606 had FHs of only GC, only CRC, and both GC and CRC, respectively. The median follow-up time was 4.8 years. GC and CRC FHs were associated with increased GC and CRC risks, respectively. GC FH was associated with CRC risk (adjusted hazard ratio 1.05; 95% confidence interval [CI] 1.01-1.10), whereas CRC FH was not associated with the risk of GC or gastric adenoma. However, gastric adenoma risk increased 1.62-fold (95% CI 1.40-1.87) in participants with FHs of both GC and CRC, demonstrating a significant difference with the 1.39-fold (95% CI 1.34-1.44) increase in participants with only GC FH. Furthermore, GC risk increased by 5.32 times (95% CI 1.74-16.24) in participants with FHs of both GC and CRC in both parents and siblings. CONCLUSIONS: GC FH was significantly associated with a 5% increase in CRC risk. Although CRC FH did not increase GC risk, FH of both GC and CRC further increased the risk of gastric adenoma. FHs of GC and CRC may affect each other's neoplastic lesion risk.

Prevalence and endoscopic treatment outcomes of upper gastrointestinal neoplasms in familial adenomatous polyposis.

BACKGROUND: Although upper gastrointestinal (GI) neoplasms are not rare in patients with familial adenomatous polyposis (FAP), few studies have focused on them and the long-term outcomes of their treatment by endoscopy. Therefore, we aimed to investigate the prevalence and endoscopic treatment outcomes of upper GI neoplasms in patients with FAP. METHODS: Among 215 patients diagnosed with FAP between January 1991 and December 2019, 208 who underwent esophagogastroduodenoscopy were eligible. The clinical features and endoscopic treatment outcomes of upper GI neoplasms were retrospectively investigated and analyzed. RESULTS: Among the enrolled patients, 113 (54.3%) had one or more upper GI neoplasms: gastric adenoma (n = 34), gastric cancer (n = 7), nonampullary duodenal adenoma (n = 86), and ampullary adenoma (n = 53). Among patients with gastric neoplasms (n = 37), 24 (64.9%) underwent treatment (endoscopic treatment: 22, surgery: 2). No tumor-related mortality occurred during median follow-up of 106 months (interquartile range [IQR] 63-174). Endoscopic treatment was performed in 47 (54.7%) of 86 patients with nonampullary duodenal adenoma and in 32 (60.4%) of 53 patients with ampullary adenoma. No patient underwent surgery for duodenal neoplasms, and no tumor-related mortality occurred during median follow-up of 88 months (IQR 42-145). The proportion of patients with increased Spigelman stage at 2 years after the initial diagnosis or treatment was significantly higher in untreated group than in the group treated for duodenal neoplasms (27.3% vs. 0.0%, p = 0.001). CONCLUSION: Endoscopic surveillance in FAP patients is important for the detection and treatment of upper GI neoplasms in early stage. In particular, endoscopic therapy for duodenal neoplasms can reduce the severity of duodenal polyposis.

Gastric Adenoma: A High Incidence Rate of Developing Carcinoma and Risk of Metachronous Gastric Cancer according to Long-Term Follow-Up.

INTRODUCTION: Gastric adenomas are histologically defined as benign epithelial tumors. While some of them remain adenomas for a long time, others progress to carcinomas. However, long-term outcomes of such cases are not entirely clear. Here, we explored the risk factors and incidence of developing carcinoma from gastric adenoma as well as metachronous gastric cancer. METHODS: This study was conducted at a facility that adopted a follow-up strategy for gastric adenoma. Lesions histologically diagnosed as gastric intestinal-type adenomas between January 2004 and December 2016 were analyzed. Clinicopathological data were collected from patients' medical records, and histological changes from adenoma to carcinoma during endoscopic follow-up and risk factors of cancer development were evaluated. RESULTS: This study involved 409 lesions from 376 patients. The analysis of the development of gastric cancer from adenoma and metachronous gastric cancer was ultimately performed for 282 lesions from 258 patients and 269 lesions from 246 patients, respectively, due to different follow-up periods. The 5-year rate of carcinoma development was 34.0%. Risk factors for carcinoma development upon multivariate analysis were lesion size ≥15 mm and morphological depression. All cases with both factors developed gastric carcinoma, and 50.5% of those with either factor developed carcinoma within 5 years. Gastric adenoma was accompanied by metachronous gastric cancer in 1.5% of the patients annually. The only risk factor for metachronous gastric carcinoma was primary adenoma progressing to carcinoma during the follow-up period. DISCUSSION/CONCLUSION: Given the high rate of carcinoma development in patients with risk factors, resection of gastric adenoma should be considered during the initial examination. Careful observation and follow-up should also be conducted to detect not only changes in the primary adenoma but also the occurrence of metachronous carcinoma, especially in cases of adenoma progressing to carcinoma.

Changing Trends in Gastric Polyps.

BACKGROUND: The prevalence of gastric polyps varies around the world reflecting regional associations. We describe demographic features of patients with gastric polyp diagnosis treated between 1980 and 2016 at a referral center in Mexico City and analyzed trends of polyp subtype. MATERIALS AND METHODS: We conducted a blind review of archival slides of gastric biopsies with polyp diagnosis from the years 1980, 1990, 2000, 2010, and 2016. Initial diagnosis; patient's gender, age and symptoms; and number and location of lesions were recorded. Blind slide review and trend analysis were performed. RESULTS: In 3887 gastric biopsies, 192 patients (4.93%) with epithelial polyps were identified. The median age of patients was 58 years; 73% were female. Polyps were single in 143/192 cases (74.4%), almost 67% in the oxyntic mucosa, and 85% were associated with dyspepsia. The prevalence was 0.5%, 1.6%, 1.9%, 4.6%, and 9.6% for the years 1980, 1990, 2000, 2010, and 2016, respectively, resulting in a rising trend in the prevalence of epithelial polyps of 380% in 46 years. Fundic gland polyps (FGPs) had a global frequency of 66.6% (128/192). They were identified for the first time in the third period of the study, with a frequency of 28.6% (6/21), 66.6% (35/53), and 78.3% (87/111) for the years 2000, 2010, and 2016, respectively. Contrary, hyperplastic polyps (HPs) decreased 20%. A relative prevalence of 3.29%, 0.97%, and 0.15% was observed for FGP, HP, and gastric adenoma, respectively. DISCUSSION: The 1400% change of FGP explains the increased prevalence of gastric polyps. Chronic treatment with proton pump inhibitors and Helicobacter pylori eradication are possible explanations.

Probe-based confocal endomicroscopy is accurate for differentiating gastric lesions in patients in a Western center.

OBJECTIVE: Probe-based confocal laser endomicroscopy (pCLE) technique may improve the diagnosis of gastric mucosal lesions allowing acquisition of high-resolution in vivo images at the cellular and microvascular levels. This study aims to evaluate the accuracy of pCLE for the differential diagnosis of non-neoplastic and neoplastic gastric lesions. METHODS: Twenty gastric mucosal lesions from 10 patients were evaluated during endoscopic procedure and were examined by pCLE. Diagnostic pCLE was followed by biopsies or endoscopic resection of suspected lesions. A senior pathologist evaluated the specimens and was blinded to the pCLE results. RESULTS: Patients' mean age was 68.3 (range, 42-83) years and six were men. Thirteen suspicious flat or elevated lesions (classified as 0-Is, 0-IIa or 0-IIa + IIc) and seven pre-malignant lesions (atrophy and intestinal metaplasia) were evaluated. One patient was studied during his long-term follow-up after partial gastrectomy and presented severe atrophy, intestinal metaplasia, and xanthomas at the stump mucosa. The location of gastric lesions was in the body (n=10 lesions), the antrum (n=9) and the incisura angularis (n=1). All neoplastic lesions and all but one benign lesion were properly diagnosed by pCLE. pCLE incorrectly diagnosed one small antrum lesion as adenoma, however the final diagnosis was intestinal metaplasia. The final histological diagnosis was neoplastic in 9 and benign lesions in 11. In this small case series, pCLE accuracy was 95% (19/20 lesions). CONCLUSIONS: pCLE is accurate for real time histology of gastric lesions. pCLE may change the management of patients with gastric mucosal lesions, guiding biopsies and endoscopic resection, and avoiding further diagnostic workup or unnecessary therapy.

Morphology and genetics of pyloric gland adenomas in familial adenomatous polyposis.

AIMS: Gastric pyloric gland adenomas (PGAs) are rare epithelial polyps that are found more commonly in autoimmune atrophic gastritis and familial adenomatous polyposis (FAP). Little is known about the morphology and genetics of PGAs in FAP. PGAs in FAP are studied morphologically and genetically. Findings in FAP-associated PGAs are compared to sporadic PGAs and related lesions such as oxyntic gland adenoma (OGA) to increase our understanding of these rare polyps. METHODS AND RESULTS: Seven PGAs and 18 fundic gland polyps (FGPs) from FAP patients were collected. KRAS and GNAS mutations were determined in six PGAs and 18 FGPs. Immunohistochemistry was applied on five PGAs to provide further confirmation of the histological subtypes and genetic alterations. Morphology of all PGAs was studied and compared to literature on sporadic PGAs and related lesions. All successfully sequenced PGAs (six of six) carried GNAS mutations and half of the successfully sequenced PGAs carried a KRAS mutation (three of six). Nuclear ß-catenin was seen only in one PGA with focal high-grade dysplasia. Morphologically, PGAs in FAP showed overlapping features with OGA. CONCLUSION: Familial adenomatous polyposis-associated PGAs have a similar genetic background as sporadic PGAs, i.e. KRAS and GNAS mutation. Based on morphological findings in FAP associated PGAs, it is hypothesized that PGAs and OGAs are closely related lesions.

Long-term follow-up study of gastric adenoma; tumor-associated macrophages are associated to carcinoma development in gastric adenoma.

BACKGROUND: Some gastric adenomas may progress to adenocarcinoma in a short time, but others remain as adenoma for a long time. METHODS: Among 1138 cases diagnosed as adenoma by biopsy at Kure Medical Association Hospital between 1990 and 2010, 51 adenomas were enrolled. Of these, 28 adenomas (group A) were followed for 60 months or longer with no progression to adenocarcinoma within 60 months, and the other 23 adenomas (group B) were upgraded to carcinoma by consecutive biopsies performed within 1 year after the first biopsy. These adenomas were compared clinicopathologically and immunohistochemically. RESULTS: Macroscopically, the mean size of group B adenomas was significantly larger than that of group A adenomas (18.6 vs. 9.9 mm) at the first biopsy. The frequency of a depressed area in the adenoma was significantly higher in group B than group A. Microscopically none of group A but 7 (30.4%) of 23 group B adenomas showed severe atypia. Each of a highly proliferative gland measured by Ki-67 labeling, cellular atypical grade, gastric phenotype defined by MUC5AC and MUC6 and CD204-positive tumor-associated macrophage (TAM) was a significant risk factor for adenocarcinoma development in gastric adenoma by univariate analysis. Only moderate or severe atypia of adenoma cells and the TAM number in the stroma of adenomas were independent risk factors by multivariate analysis. CONCLUSIONS: As independent risk factors, cellular atypia may reconfirm the importance of morphological analysis, and the TAM number may indicate the significance of TAM function in gastric adenoma.

[Gastric adenoma of pyloric type associated with familial adenomatous polyposis: A rare histological type not to be overlooked]. / Adénome gastrique de type pylorique au cours de la polypose adénomateuse familiale : une entité rare à ne pas méconnaître.

We report here two cases of gastric adenomas of pyloric type diagnosed during the follow-up of familial adenomatous polyposis (FAP). This rare histological lesion has been only recently described in this particular context and its clinical and pathological spectrum remains to be evaluated. Our two cases were very different in their clinical and endoscopic presentation. In the first patient, the lesion was diagnosed late during the evolution of FAP; it was very large and protruded above the adjacent mucosa; because of its large size, its treatment proved to be difficult. In the second patient, the lesion was discovered incidentally in gastric biopsies, early in the course of FAP. Both lesions presented the characteristic morphological and immunohistochemical features of pyloric adenoma, including the expression of MUC6. Both showed evidence of dysplasia, including high-grade dysplasia in the largest lesion. Pyloric adenoma belongs to the spectrum of gastric polyps associated with FAP; its prognosis and evolution remain to be evaluated.

The new modified ABCD method for gastric neoplasm screening.

BACKGROUND: The ABCD screening method was developed for risk stratification of gastric cancer. It is unclear whether the ABCD method can predict the risk of gastric neoplasms, including gastric adenomas, as observed for gastric cancer. We aimed to devise a modified ABCD method for predicting gastric neoplasms. METHODS: We reviewed 562 patients who had undergone upper gastrointestinal tract endoscopy and whose serum IgG anti-Helicobacter pylori antibody, gastrin, and pepsinogen (PG) I and PG II data were available. Patients were classified into the following four groups: H. pylori antibody negative and normal PG level (group A), H. pylori antibody positive and normal PG level (group B), H. pylori antibody positive and low PG level (group C), and H. pylori antibody negative and low PG level (group D). RESULTS: The PG I/PG II ratio was lower in patients with gastric neoplasms than in patients without these lesions (gastric adenoma vs gastric cancer vs no neoplasm, 3.7 ± 2.0 vs 3.8 ± 1.8 vs 4.9 ± 2.1, P < 0.001). The optimal cutoff values of the PG I/PG II ratio for predicting gastric neoplasms were 3.1 for H. pylori antibody negative patients and 4.1 for H. pylori antibody positive patients. A higher group grade was associated with a significantly higher proportion of gastric neoplasms [odds ratio (95 % confidence interval), group A, reference; group B, 1.783 (1.007-3.156); group C, 3.807 (2.382-6.085); and group D, 5.862 (2.427-14.155)]. CONCLUSIONS: The modified ABCD method using two different cutoff values according to the H. pylori antibody status was useful for predicting the presence of gastric neoplasms. This method might be a supplementary screening tool for both gastric adenoma and gastric cancer. However, further studies will be required to provide a definitive conclusion.

Upper gastrointestinal tumours in Japanese familial adenomatous polyposis patients.

OBJECTIVE: The upper gastrointestinal characteristics in Japanese familial adenomatous polyposis patients have not yet been clarified. The aim of the present study was to elucidate these characteristics in Japanese familial adenomatous polyposis patients. METHODS: This study was conducted by the study group for familial adenomatous polyposis in the Japanese Society for Cancer of the Colon and Rectum. Familial adenomatous polyposis patients who underwent surgical resection from 2000 to 2012 were included in the study. RESULTS: In total, 303 familial adenomatous polyposis patients were enrolled, with 265 cases of classical familial adenomatous polyposis (≥100 adenomas) and 38 cases of attenuated familial adenomatous polyposis (<100 adenomas). Fundic gland polyps were significantly more common in classical familial adenomatous polyposis than in attenuated familial adenomatous polyposis; however, gastric cancer was significantly less common in classical familial adenomatous polyposis than in attenuated familial adenomatous polyposis. Gastric cancer and duodenal adenoma were significantly more common in familial adenomatous polyposis patients with gastric adenoma than in those without gastric adenoma. Duodenal cancer was detected in 7 of 72 familial adenomatous polyposis patients with duodenal adenoma. The median tumour risk in 50-year-old familial adenomatous polyposis patients was 55.3, 21.8, 3.8, 39.2 and 7.7% for fundic gland polyp, gastric adenoma, gastric cancer, duodenal adenoma and duodenal cancer, respectively. CONCLUSIONS: Upper gastrointestinal tumours/polyps were frequently found in familial adenomatous polyposis patients, and their incidences were correlated; however, the frequency of gastric cancer in Japanese familial adenomatous polyposis patients was similar to that in the general population.

Dense-type crypt opening seen on magnifying endoscopy with narrow-band imaging is a feature of gastric adenoma.

BACKGROUND: Magnifying endoscopy with narrow-band imaging (ME-NBI) can visualize crypt openings (CO) as slit-like structures in gastric epithelial neoplasia. Visualization of numerous CO is characteristic of low-grade adenoma (LGA). The aim of the present study was to investigate whether visualization of CO by ME-NBI is useful for discriminating between LGA and early gastric cancer (EGC). PATIENTS AND METHODS: Fifty-one superficial elevated-type gastric neoplasias (10 LGA and 41 EGC) were retrospectively evaluated. The presence of CO and the number of CO were evaluated in endoscopic photos obtained at high-power endoscopic magnification by ME-NBI. The optimal cut-off value for the number of CO visualized to discriminate between LGA and EGC was determined by receiver operating characteristic curve analysis. RESULTS: The mean number of CO visualized was significantly larger in the LGA group than in the EGC group (31.2, 95% confidence interval [CI] 16.3-46.1 vs 6.3, 95% CI 3.6-9.0; P < 0.001). When the cut-off for the number of CO visualized was set at 20, the sensitivity, specificity, and accuracy of dense-type CO for discriminating between LGA and EGC were 90.0%, 87.8%, and 88.2%, respectively. CONCLUSION: Determining the number of CO visualized in superficial elevated-type gastric neoplasias by ME-NBI appears to be a useful method for discriminating between LGA and EGC.

Association between low-dose aspirin and the risk of gastric cancer and adenoma according to a family history of gastric cancer.

This study aimed to evaluate the association between low-dose aspirin use and the risk of GC and gastric adenoma according to a family history of GC. We conducted a population-based study of 7,596,003 participants screened for GC between 2013 and 2014. Aspirin users and non-users were matched in a 1:1 ratio through propensity score matching (PSM). After PSM, 51,818 participants with a family history of GC and 359,840 without a family history of GC were analyzed (mean follow-up periods: 4.9 ± 0.8 and 4.8 ± 0.8 years, respectively). In patients with a family history of GC, aspirin use was significantly associated with a reduced risk of GC (adjusted hazard ratio [aHR]=0.80; 95 % confidence interval [CI]=0.65-0.995) and gastric adenoma (aHR=0.81; 95% CI=0.69-0.94). In those without a family history of GC, aspirin use was associated with a reduced risk of gastric adenoma (aHR = 0.92; 95 % CI = 0.86-0.98), but not with that of GC (aHR = 0.99; 95 % CI = 0.90-1.08). Low-dose aspirin use was associated with a reduced risk of gastric adenoma, regardless of a family history of GC, and may play a role in the early stages of gastric carcinogenesis. However, the association between aspirin and GC was only observed in those with a family history of GC.

Risk of gastric adenoma and adenocarcinoma in patients with familial adenomatous polyposis in Japan: a nationwide multicenter study.

BACKGROUND: Patients with familial adenomatous polyposis (FAP) have an increased risk of developing gastric neoplasms. However, the clinical course of FAP with these gastric lesions has not yet been fully clarified. The present study aimed to clarify the changes in the incidence risk of developing gastric adenoma or gastric cancer during the lifespan of patients with FAP. METHODS: Four hundred forty-three patients with data regarding gastric adenoma and gastric cancer retrospectively registered in a nationwide Japanese multicenter study were enrolled. The cumulative incidences and hazard rates (HRs) of gastric neoplasms were evaluated. RESULTS: The cumulative incidence rates in 50-year-old patients with FAP were 22.8% for gastric adenoma and 7.6% for gastric cancer, respectively. No significant association was found between gastric neoplasms and the colonic phenotype. The peak age for the HR of gastric adenoma was 65 years, with the highest HR (0.043). Regarding the incidence of gastric cancer, the HR increased moderately up to the age of 40 years, but the increase accelerated from the age of 50 years (HR = 0.0067). CONCLUSION: Careful surveillance of the upper gastrointestinal tract in elderly patients with FAP, such as shortening the interval of follow-up according to age, may be helpful for early diagnosis of gastric cancer.

Risk Factors for Developing Metachronous Superficial Gastric Epithelial Neoplasms after Endoscopic Submucosal Dissection.

Background: Although endoscopic submucosal dissection (ESD) provides a high rate of curative resection, the remaining gastric mucosa after ESD is at risk for metachronous superficial gastric epithelial neoplasms (MSGENs). It leaves room for risk factors for developing MSGENs after ESD. This study aimed to identify clinicopathological risk factors for the occurrence of MSGENs, and to evaluate the association of Helicobacter pylori (H. pylori) with the MSGENs. Methods: We conducted a retrospective cohort study including 369 patients with 382 lesions that underwent ESD for adenoma/early gastric cancer. Results: Twenty-seven MSGENs occurred. The subjects were divided into MSGEN and not-MSGEN groups. There was a significantly higher frequency of histological intestinal metaplasia (HIM) and initial neoplasm location in the upper or middle parts (INUM) in the MSGEN group. The HIM and INUM groups had a significantly higher cumulative incidence of MSGENs. We compared 27 patients from the MSGEN group and 27 patients from the not-MSGEN group that were matched to the MSGEN group for variables including HIM and INUM. There was a significantly higher frequency of the spontaneous disappearance of H. pylori in the MSGEN group. Conclusions: HIM, INUM, and the spontaneous disappearance of H. pylori may be clinicopathological risk factors for developing MSGENs after ESD.

Clinical features of gastric adenoma detected within 3 years after negative screening endoscopy in Korea.

Background: Early detection and management of gastric adenoma are important for preventing gastric cancer. The present study aimed to evaluate the predictors of missed gastric adenoma on screening endoscopy in Korea and identify the risk factors associated with interval precancerous gastric lesions. Methods: All cases of gastric adenomas diagnosed via screening endoscopy between 2007 and 2019 were reviewed. Among them, those who had undergone endoscopy within 3 years were included in the present study. Missed gastric adenoma was defined as gastric adenoma diagnosed within 3 years after negative screening endoscopy. Results: In total, 295 cases of gastric adenoma were identified. Of these, 95 (32.2%) were missed gastric adenoma cases (mean age, 60.6 years; average interval between final and index endoscopies, 12.6 months); the remaining 200 (67.8%) were newly detected adenoma cases. Univariate analysis revealed that male sex, endoscopist experience, observation time, and presence of gastric intestinal metaplasia (pathologically proven) were associated with missed gastric adenoma. Multivariate analysis revealed that gastric intestinal metaplasia (odds ratio [OR], 2.736; 95% confidence interval [CI], 1.320-5.667; P = 0.007) and shorter observation time of the index screening endoscopy (B, -0.011; OR, 0.990; 95% CI, 0.986-0.993; P < 0.001) were independent risk factors for missed gastric adenoma. The optimal cut-off for the observation time for detecting gastric adenoma was 3.53 minutes (area under curve, 0.738; 95% CI, 0.677-0.799; P < 0.001). Conclusions: Gastric intestinal metaplasia is an indication of missed gastric adenoma. Therefore, careful inspection of gastric mucosa with gastric intestinal metaplasia and proper observation time can lower the possibility of missing the gastric adenoma during screening.

Effect of Helicobacter pylori Eradication Treatment on Metachronous Gastric Neoplasm Prevention Following Endoscopic Submucosal Dissection for Gastric Adenoma.

The long-term effect of Helicobacter pylori eradication on metachronous gastric neoplasm prevention after endoscopic submucosal dissection (ESD) of gastric adenoma is unclear. This study included patients with confirmed H. pylori infection after ESD with curative resection for gastric adenoma. Patients were divided based on the success of H. pylori eradication treatment into two groups: eradication and non-eradication. Patients with any newly detected lesion within 1 year after ESD and recurrence at the ESD site were excluded from the analysis. Further, 1:1 propensity score matching was also performed to eliminate baseline differences between the two groups. H. pylori eradication treatment was administered to 673 patients after ESD (163 in the successful eradication group and 510 in the non-eradication group). During the median follow-up periods of 25 and 39 months in the eradication and non-eradication groups, metachronous gastric neoplasm was identified in 6 (3.7%) and 22 patients (4.3%), respectively. Adjusted Cox analysis revealed that H. pylori eradication was not associated with increased risk of metachronous gastric neoplasm after ESD. Kaplan-Meier analysis in the matched population yielded similar findings (p = 0.546). H. pylori eradication treatment was not associated with metachronous gastric neoplasm after ESD with curative resection for gastric adenoma.

Photodynamic Diagnosis for the Identification of Intestinal-Type Gastric Cancers and High-Grade Adenomas.

Gastric cancer is the second most common cancer in Japan. The incidence of gastric cancer remains high owing to the increase in the elderly population. Endoscopy outperforms radiography in identifying early gastric cancer (EGC). Furthermore, image-enhanced endoscopy (IEE) has been developed and implemented worldwide in clinical practice. Magnifying IEE images can help to visualize the microvascular pattern and microstructure architecture, which is used for the characterization of EGC. However, accurate endoscopic diagnosis requires the experience and skill of endoscopists, making an objective and simple diagnostic method desirable. In this retrospective study, we investigated the diagnostic yield of 5-aminolevulinic acid (5-ALA)-mediated photodynamic diagnosis (PDD) for identifying gastric cancers and high-grade adenomas. In total, 52 lesions from 43 patients were ultimately included in the study. We detected 5-ALA-mediated protoporphyrin IX fluorescence in 45 of the 52 lesions that were initially intended for PDD, resulting in a detection rate of 86.5%, whereas each signet ring cell carcinoma was negative using 5-ALA PDD. In eight of the patients with multiple lesions, 17 lesions were identified using 5-ALA PDD. Again, we took biopsies from six areas that we suspected as new lesions. While 4 lesions were gastric neoplasms resected by endoscopic submucosal dissection, two other lesions were normal. Preoperative 5-ALA-PDD could provide additional diagnostic yields to detect such multiple lesions simultaneously. No severe adverse events were observed. Prospective multicenter studies are warranted to confirm the usefulness of 5-ALA PDD for EGC identification.