Long-term follow-up study on gastric adenoma and its relation to gastric protruded carcinoma

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.

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 villous adenoma: a case report and review of the literature

BACKGROUND

Villous adenoma is the one subtype of adenomatous polyp that is very uncommon in the stomach. Data regarding clinical characteristics, natural history, and prognosis were scarce.

CASE PRESENTATION

This report presented an 87-year-old Thai woman with a large gastric villous adenoma incidentally revealed in a computed tomography of chest for the evaluation of right pleural effusion. The esophagogastroduodenoscopy demonstrated a huge, glossy, proliferative polypoid mass involving gastric cardia, fundus, and a lesser curve of the upper body. The pathological report confirmed villous adenoma with low grade dysplasia. Although surgical resection was suggested, the patient denied any treatment due to advanced age and multiple comorbidities. She was generally well after 12 months of clinical and radiologic surveillance.

CONCLUSION

From literature review, only 14 cases of gastric villous adenoma were reported to date. Most of the lesions were large and symptomatic. Malignancy presented in 43% of the cases. Nevertheless, our patient remained asymptomatic without surgical removal following a 12-month period.

Gastrik polipler: 10 yıllık endoskopik işlemin retrospektif analizi

Objective: Gastric polyps are gastric mucosal protrusions that are usually asymptomatic and detected incidentally during upper gastrointestinal system endoscopy. In this study, the incidence, location and general characteristics of gastric polyps were evaluated. Materials and methods: Upper gastrointestinal system endoscopies performed in a tertiary hospital for a period of ten years were evaluated retrospectively. Demographic characteristics of the patients, gastroscopy indications, morphological and histological characteristics of polyps were recorded. Results: Gastric polyps were found in 347 (1.4%) of a total of 25230 gastroscopy patients. The mean age of the patients was 61.04 ± 15.05 and 64.3% were female. 124 (35.7%) of the patients were male and 223 (64.3%) were female. The most common endoscopic indication (74.1%) of the patients with polyps was dyspepsia. Most of the polyps (55.3%) were smaller than 5 mm and the most common site was the antrum. Hyperplastic polyp (44.4%) was detected the most. 42.9% of the patients with polyps were positive for Helicobacter pylori. In addition, 58% of adenomatous polyps were accompanied by dysplasia. Conclusion: Hyperplastic polyps were the most common polyp type in our population. Full excision of polyps over 5 mm (especially adenomatous polyps) is recommended instead of biopsy, as they may contain dysplasia foci. In addition, it was thought that taking polyps smaller than 5 mm into endoscopic follow-up without excision was more cost-effective.

Endoscopic tissue sampling - Part 1: Upper gastrointestinal and hepatopancreatobiliary tracts. European Society of Gastrointestinal Endoscopy (ESGE) Guideline

1: ESGE recommends that, where there is a suspicion of eosinophilic esophagitis, at least six biopsies should be taken, two to four biopsies from the distal esophagus and two to four biopsies from the proximal esophagus, targeting areas with endoscopic mucosal abnormalities. Distal and proximal biopsies should be placed in separate containers.Strong recommendation, low quality of evidence. 2: ESGE recommends obtaining six biopsies, including from the base and edge of the esophageal ulcers, for histologic analysis in patients with suspected viral esophagitis.Strong recommendation, low quality of evidence. 3: ESGE recommends at least six biopsies are taken in cases of suspected advanced esophageal cancer and suspected advanced gastric cancer.Strong recommendation, moderate quality of evidence. 4: ESGE recommends taking only one to two targeted biopsies for lesions in the esophagus or stomach that are potentially amenable to endoscopic resection (Paris classification 0-I, 0-II) in order to confirm the diagnosis and not compromise subsequent endoscopic resection.Strong recommendation, low quality of evidence. 5: ESGE recommends obtaining two biopsies from the antrum and two from the corpus in patients with suspected Helicobacter pylori infection and for gastritis staging.Strong recommendation, low quality of evidence. 6: ESGE recommends biopsies from or, if endoscopically resectable, resection of gastric adenomas.Strong recommendation, moderate quality of evidence. 7: ESGE recommends fine-needle aspiration (FNA) and fine-needle biopsy (FNB) needles equally for sampling of solid pancreatic masses.Strong recommendation, high quality evidence. 8: ESGE suggests performing peroral cholangioscopy (POC) and/or endoscopic ultrasound (EUS)-guided tissue acquisition in indeterminate biliary strictures. For proximal and intrinsic strictures, POC is preferred. For distal and extrinsic strictures, EUS-guided sampling is preferred, with POC where this is not diagnostic.Weak recommendation, low quality evidence. 9: ESGE suggests obtaining possible non-neoplastic biopsies before sampling suspected malignant lesions to prevent intraluminal spread of malignant disease.Weak recommendation, low quality of evidence. 10: ESGE suggests dividing EUS-FNA material into smears (two per pass) and liquid-based cytology (LBC), or the whole of the EUS-FNA material can be processed as LBC, depending on local experience.Weak recommendation, low quality evidence.

The Usefulness of Argon Plasma Coagulation Compared with Endoscopic Submucosal Dissection to Treat Gastric Adenoma

Background/Aims

To date, the best therapeutic modality for gastric adenoma, especially low-grade adenoma, has not been established. The aim of this study was to assess the usefulness of argon plasma coagulation (APC) in treating gastric adenoma compared with endoscopic submucosal dissection (ESD).

Methods

We included 210 patients with gastric adenoma, who underwent treatment with either APC (97 patients) or ESD (113 patients). The clinical and pathologic characteristics, mean duration of hospital stay, complications, and recurrence rates between the two groups were compared.

Results

The mean adenoma size was 0.9 cm and 1.1 cm in the APC group and ESD group, respectively (p<0.001). The mean duration of hospital stay was significantly shorter in the APC group than in the ESD group (1.6 days vs. 5.8 days, p<0.001). Complications did not occur in the APC group. However, one case of perforation (0.9%) and 6 cases of bleeding (5.3%) occurred in the ESD group. The recurrence rates were 15.3% (15/97 patients) in the APC group and 3.5% (4/113 patients) in the ESD group (p=0.003). The proportion of hospitalization was less in the APC group (43.3%, 42/97) than in the ESD group (100.0%, 113/113) (p<0.001). Medical expense was less in the APC group (377,172 won) than in the ESD group (1,430,610 won) (p<0.001).

Conclusions

The findings of this study suggest that APC is a safe treatment method for gastric adenoma without serious complications. However, regular endoscopic follow-up is necessary to detect any residual or recurrent lesions due to the relatively high rate of local recurrence after APC.

The Expression of MCM7 is a Useful Biomarker in the Early Diagnostic of Gastric Cancer

The aim of this study was to investigate the expression of minichromosome maintenance complex component 7 (MCM7) in gastric mucosal lesions, further to find its potential effect as a biomarker to distinguish intraepithelial neoplasia from gastric mucosal lesions. MCM7 and Ki67 were detected in 93 cases of gastric mucosal lesions by immunohistochemistry. MCM7 and Ki67 expression in GT were lowest compared with other groups (P<0.001), meanwhile there were significant differences compared with Group IM and other groups in MCM7 and Ki67 expression (P<0.001). MCM7 and Ki67 expression in GSC were highest (P<0.05). Groups of LGN, HGN and GIC had no significant differences in MCM7 expression (P>0.05), but there was significant difference compared with Group LGN and Group GIC in Ki67 expression (P<0.05). MCM7 expression elevated with tumor grade increasing and had positive correlation with Ki67 significantly (r=0.940, P<0.001). Furthermore, in some cases, some tumor cells were immunoreactive to MCM7 but negative to Ki67. So we concluded that MCM7 is helpful for us to make differential diagnosis in pathological grade, MCM7 combination of Ki67 may serve as more sensitive proliferation markers for evaluation of gastric carcinoma and precancerous lesions.

Efficacy of endoscopic mucosal resections for the management of small gastric adenomas with low-grade dysplasia

OBJECTIVE

Gastric adenoma with low-grade dysplasia (LGD) can progress to gastric cancer; however, the optimal therapeutic modality for LGD has not been established. The aim of this study was to assess the efficacy, safety of and local recurrence following endoscopic mucosal resection (EMR) for LGD. Specifically, we compared EMR with circumferential precutting (EMR-P) and EMR using a dual-channel endoscope (EMR-D) for the treatment of LGD ≤2 cm.

MATERIALS AND METHODS

A total of 158 lesions from 147 patients with LGD treated by EMR were retrospectively analyzed. The en bloc resection rate, complete resection rate, procedure time, complication rate and local recurrence rate were compared between EMR-P and EMR-D.

RESULTS

The en bloc resection and complete resection rates of EMR were 91.1% and 90.5%, respectively. The bleeding and perforation rates were 1.3% and 1.3%, respectively. The local recurrence rate following EMR was 2.2%. The en bloc resection and complete resection rates did not differ between EMR-P and EMR-D (88.2% vs. 92.5%, p = not significant (NS); and 90.2% vs. 90.7%, p = NS, respectively). The procedure time was significantly longer for EMR-P compared with EMR-D (16 (5-141) vs. 7 (2-48) min, p < 0.001), and the complication rate was significantly higher for EMR-P (7.8% vs. 0.0%, p = 0.010). Local recurrence was not found in EMR-P, whereas the recurrence rate was 3.2% in EMR-D.

CONCLUSION

EMR is an effective method for the treatment of LGD ≤2 cm. Compared with EMR-P, EMR-D appears to be the more effective, technically simple and safer method.

Endoscopic Raman Spectroscopy for Molecular Fingerprinting of Gastric Cancer: Principle to Implementation

Currently, positive endoscopic biopsy is the standard criterion for gastric cancer diagnosis but is invasive, often inconsistent, and delayed although early detection and early treatment is the most important policy. Raman spectroscopy is a spectroscopic technique based on inelastic scattering of monochromatic light. Raman spectrum represents molecular composition of the interrogated volume providing a direct molecular fingerprint. Several investigations revealed that Raman spectroscopy can differentiate normal, dysplastic, and adenocarcinoma gastric tissue with high sensitivity and specificity. Moreover, this technique can indentify malignant ulcer and showed the capability to analyze the carcinogenesis process. Automated on-line Raman spectral diagnostic system raised possibility to use Raman spectroscopy in clinical field. Raman spectroscopy can be applied in many fields such as guiding a target biopsy, optical biopsy in bleeding prone situation, and delineating the margin of the lesion. With wide field technology, Raman spectroscopy is expected to have specific role in our future clinical field.

Combination of Paris and Vienna classifications may optimize follow-up of gastric epithelial neoplasia patients

Background

The aim of this study was to evaluate the efficiency of the combination of Paris and Vienna classifications in a follow-up study of gastric epithelial neoplasia (GEN) patients.

Material/Methods

This study was conducted between January 2003 and September 2010, during which 170 biopsy-proven GEN patients were followed up by gastroenterologists and pathologists according to our follow-up regimen (modified Vienna classification).

Results

In total, 161 patients with low-grade neoplasia (LGN) and 9 patients with high-grade neoplasia (HGN) were randomly enrolled in our study. Eighteen patients with depressed appearance were observed, of which 9 patients had HGN and 9 patients had low-grade dysplasia (LGD). Three patients with type 0-IIa were observed with low-grade adenoma (LGA), and type 0–I was observed in 2 patients with LGN. Endoscopic or surgical treatments were performed to avoid potential malignancy or bleeding. Two patients with ulcer lesions, 2 patients with non-depressed type 0 appearance, and 3 patients without visible lesions were shown to have higher-grade lesions during follow-up. The misdiagnosis rate of forceps biopsy – 62.07% – was determined by comparing pre- and post-resection diagnoses of 29 patients.

Conclusions

The combination of the Paris and Vienna classifications for GEN may optimize the follow-up routines for patients with suspicious precancerous lesions and may significantly improve the detection of early gastric cancer (EGC) while helping gastroenterologists select the best therapy option.

Gastric epithelial dysplasia: characteristics and long-term follow-up results after endoscopic resection according to morphological categorization

Background

Gastric epithelial dysplasia (GED) can be morphologically categorized into adenomatous and foveolar types. To date, there have been few studies on the clinical characteristics of GEDs according to the morphologic types. Therefore, we here aimed to elucidate the clinicopathologic characteristics of patients with GED and the long-term follow-up results after endoscopic resection according to the morphologic characteristics of GEDs.

Methods

A total of 357 patients who underwent endoscopic resection for GEDs at Pusan National University Hospital between January 2008 and December 2009 were included in the study. GEDs were morphologically categorized into adenomatous, foveolar, and hybrid types on histologic examination. The clinicopathologic characteristics of patients with GEDs and outcomes of endoscopic resection were analyzed.

Results

Patients with GED were divided into 3 groups: adenomatous (n = 167, 46.8%), foveolar (n = 103, 28.9%), and hybrid (n = 87, 24.3%) types. Compared to the adenomatous type, foveolar type lesions were more frequently located in the antrum/pylorus, flat/depressed lesions, and normal/reddish in color; and showed more frequent high-grade dysplasia. During the follow–up period (median, 37.3 months), the overall incidence of synchronous and metachronous lesions was 20.8% and 20.1%, respectively; of these, the incidence of synchronous and metachronous gastric cancer was 8.7% and 5.4%, respectively. There were no significant differences in the incidence of synchronous and metachronous lesions according to morphologic types.

Conclusion

GEDs appear to have different clinicopathologic characteristics according to morphologic types. Irrespective of the morphology, synchronous and metachronous gastric cancers are commonly found after endoscopic resection of GEDs. Therefore, close follow-up surveillance after endoscopic resection of GEDs should be performed for all patients.

Antral hyperplastic polyp: A rare cause of gastric outlet obstruction

INTRODUCTION

Gastric polyps are usually found incidentally during upper gastrointestinal endoscopic examinations. These polyps are generally benign, with hyperplasia being the most common. While gastric polyps are often asymptomatic, they can cause gastric outlet obstruction.

PRESENTATION OF CASE

A 64 years-old female patient presented to our polyclinic with a history of approximately 2 months of weakness, occasional early nausea, vomiting after meals and epigastric pain. A polypoid lesion of approximately 25mm in diameter was detected in the antral area of the stomach, which prolapsed through the pylorus into the duodenal bulbus, and subsequently caused gastric outlet obstruction, as revealed by upper gastrointestinal endoscopy of the patient. The polyp was retrieved from the pyloric canal into the stomach with the aid of a tripod, and snare polypectomy was performed.

DISCUSSION

Currently, widespread use of endoscopy has led to an increase in the frequency of detecting hyperplastic polyps. While most gastric polyps are asymptomatic, they can cause iron deficiency anemia, acute pancreatitis and more commonly, gastric outlet obstruction because of their antral location. Although there are no precise principles in the treatment of asymptomatic polyps, polyps >5mm should be removed due to the possibility of malignant transformation.

CONCLUSION

According to the medical evidence, polypectomy is required for gastric hyperplastic polyps because of the risks of complication and malignancy. These cases can be successfully treated endoscopically.

Molecular markers of mucosa harboring gastric adenomas

CONTEXT

Gastric adenoma is a precursor lesion of the adenocarcinoma.

OBJECTIVE

To characterize gastric adenomas according to the mucin immunoexpression and to evaluate the immunoexpression of p53, p16ink4a, BCL-2, cyclin D, Ki-67, in the adenoma and in the gastric mucosa harboring adenoma.

METHODS

Forty gastric specimens from 20 patients were classified as intestinal (MUC2-goblet cell mucin) or foveolar (MUC5AC-gastric-foveolar mucin) adenomas. Immunohistochemistry was performed using streptavidin-biotin-complex method.

RESULTS

Twelve (60%) patients were men. The mean age was 67.9±12.9 years-old. Intestinal adenomas were detected in 13 (65%) patients and gastric type in 7 (35%). Low-grade dysplasia was present in 13 (65%) of the adenomas, high-grade in 3 (15%), and adenocarcinoma within the polyp in 4 (20%). Six (30%) patients had synchronous adenocarcinoma. p53 immunoexpression was observed in 6/20 (30%) of adenomas, and in 2/6 (33.3%) of synchronous tumors. There was an association between p53 immunoexpression and intestinal type of adenoma/tumor, P=0.04. There was no association between p16ink4a, Bcl-2, cyclin D and Ki-67 and adenoma clinicopathological characteristics.

CONCLUSION

Immunohistochemistry may be useful to classify the adenomas subtypes and may define the pathway of adenoma to carcinoma sequence.

Discrepancy between endoscopic forceps biopsy and endoscopic resection in gastric epithelial neoplasia

BACKGROUND

Endoscopic forceps biopsy (EFB) is a major diagnostic procedure for gastric epithelial neoplasia (GEN). However, discrepancy between the result of EFB and endoscopic resection (ER) is not uncommon. Thus, there is controversy over whether specimens obtained by EFB are optimal for diagnosis of GEN. We investigated the discrepancy between EFB and ER in the diagnosis of GEN.

METHODS

A total of 1,850 GEN cases were histologically diagnosed with EFB, including 954 low-grade dysplasias (LGDs), 315 high-grade dysplasias (HGDs), and 581 carcinomas. Following diagnosis with EFB, all patients were treated with ER. We retrospectively reviewed the pathologic findings and patient characteristics and analyzed predictors for the discrepancy between the two procedures (largest diameter, number of biopsy fragments, number of biopsy fragments/largest diameter, location, macroscopic type, color, surface unevenness, and erosion).

RESULTS

The overall discrepancy rate between EFB and ER was 31.7 % (587/1,850). Among the discordant group, 440 (23.9 %) cases showed a higher grade of disease after ER; 229 of the 954 LGDs (24.0 %) were diagnosed as HGD or carcinoma, 166 of the 315 HGDs (52.7 %) as carcinoma, and 45 of the 581 differentiated carcinomas (7.7 %) as undifferentiated carcinoma. In the LGD group with EFB, the largest diameter (≥1.8 cm; P < 0.001), surface unevenness (P = 0.014), and depressed macroscopic type (P < 0.001) were factors associated with discrepancy. In the carcinoma group with EFB, flat macroscopic type (P = 0.043) was the only significant factor. In the HGD group with EFB, there were no significant factors for discrepancy.

CONCLUSIONS

EFB can be insufficient for diagnosing GENs, and ER can be considered not only as treatment but also as a diagnostic modality in GEN. It is especially pertinent to all cases of HGD regardless of their endoscopic features and to cases of LGDs with the largest lesion diameter ≥1.8 cm, surface unevenness, or a depressed macroscopic type.

Serrated adenoma of the stomach: Case report and literature review

Gastric serrated adenomas are histologically characterized by protruding glands with lateral saw tooth-like indentations lined with stratified dysplastic cells containing abundant eosinophilic cytoplasm. Since the first case of gastric serrated adenoma found in 2001, 18 additional cases have been reported. Gastric serrated adenomas have a particular proclivity to progress to invasive carcinoma; 75% or 15 of the 20 cases now in record - including the present one - exhibited invasive carcinoma. The 20(th) case of gastric serrated adenoma reported here differs from the preceding ones in as much as it evolved in a patient with Lynch syndrome, implying that this adenoma phenotype may develop not only sporadically but also in patients with hereditary traits.

Narrow band imaging versus white light gastroscopy in detecting potentially premalignant gastric lesions: a randomized prospective crossover study

BACKGROUND AND AIMS

Narrow band imaging (NBI) detects mucosal surface details (pit pattern) as well as the microvasculature pattern of mucosa. In premalignant conditions the pattern and regularity of pits and microvasculature are altered. We aimed to assess whether NBI is superior to conventional white light gastroscopy (WLG) in detecting potentially premalignant gastric lesions.

PATIENTS AND METHODS

We conducted a randomized prospective crossover study from January 2009 to July 2009. Patients above 45 years of age with dyspepsia in absence of alarm symptoms underwent gastric mucosal examination using WLG and NBI in the same session by different endoscopists who were blinded to each other's endoscopy findings. Biopsy was taken if required at the end of the second gastroscopy after a third observer reviewed reports of both scopists. The yield of gastric potentially premalignant lesions (atrophic gastritis, intestinal metaplasia, dysplasia, adenomatous polyp) was compared for both procedures.

RESULTS

Two hundred [mean age 52.3 (6.4) years, males-66 %] patients participated in the study. Thirty-two patients were diagnosed to have potentially premalignant lesions using both modalities. No patient had early gastric cancer. WLG detected lesions in 17 patients (atrophic gastritis in 12, atrophic gastritis with intestinal metaplasia in 5) and NBI in 31 patients (atrophic gastritis in 22, atrophic gastritis with intestinal metaplasia in 9). The sensitivity of lesion detection by NBI was significantly higher than WLG (p = 0.001).

CONCLUSIONS

NBI was superior to WLG for detection of atrophic gastritis and intestinal metaplasia.

Argon plasma coagulation is safe and effective for treating smaller gastric lesions with low-grade dysplasia: a comparison with endoscopic submucosal dissection

BACKGROUND AND AIMS

The best therapeutic modality has not been established for gastric low-grade adenomas or dysplasia (LGD), which can progress to invasive carcinoma despite a low risk. This study aims to investigate the clinical efficacy, safety, and local recurrence after argon plasma coagulation (APC) treatment of gastric LGD compared with endoscopic submucosal dissection (ESD).

PATIENTS AND METHODS

A total of 320 patients with gastric LGD ≤ 2.0 cm treated with APC or ESD between 2004 and 2011 were retrospectively analyzed. We compared local recurrence rate, complication rate, procedure time, and admission to hospital between APC and ESD groups.

RESULTS

Of the 320 patients, 116 patients were treated with APC and 204 with ESD. During follow-up, local recurrence was more common in the APC group (3.8 %, 4/106) than the ESD group (0.5 %, 1/188; log-rank test P = 0.036). However, all patients with local recurrence (n = 5) were treated by additional APC, and followed up without further recurrences. ESD was complicated by two perforations (1.0 %, 2/204) compared with no perforations in the APC group (0 %, 0/116). Bleeding complications were not different between the APC (1.7 %, 2/116) and ESD (2.0 %, 4/204) groups. Procedure time was shorter in the APC (7.8 ± 5.1 min) than the ESD (53.1 ± 38.1 min) group (P < 0.001). The proportion of hospitalization was less in the APC group (31.0 %, 36/116) than the ESD group (100.0 %, 204/204) (P < 0.001).

CONCLUSIONS

APC can be a good treatment option for patients with LGD ≤ 2.0 cm.

Magnifying endoscopy with narrow-band imaging helps determine the management of gastric adenomas

BACKGROUND

There are no clear clinical criteria for the management of gastric lesions diagnosed as adenomas (Vienna classification category 3) by pre-treatment biopsy. In the present study, we examined the feasibility of magnifying endoscopy with narrow-band imaging (ME-NBI) in discriminating early gastric cancers (Vienna classification category 4 or 5) from adenomas in lesions diagnosed as adenomas by pre-treatment biopsy.

METHODS

This was a single-center cross-sectional retrospective study at a tertiary referral center. One hundred thirty-seven consecutive cases of gastric lesions diagnosed as adenomas in pre-treatment forceps biopsy were examined with conventional non-magnifying endoscopy under white light, non-magnifying chromoendoscopy, and ME-NBI. We investigated the association between the final pathological diagnoses (carcinoma or adenoma) and the following factors: lesion size (mm), color (red or white), macroscopic type (depressed or others), presence of ulceration, and positive ME-NBI finding. The presence of an irregular microvascular pattern or an irregular microsurface pattern with a demarcation line between the lesion and the surrounding area was regarded as a positive ME-NBI finding.

RESULTS

Lesion size was significantly larger in carcinomas than adenomas (P = 0.005). Depressed lesion (P = 0.011), red color (P < 0.001), and positive ME-NBI finding (P < 0.001) were significant predictive factors for carcinoma. Multivariate logistic regression confirmed that red color (odds ratio [OR] 3.04, 95% confidence interval [CI] 1.26-7.34, P = 0.14) and a positive ME-NBI finding (OR 13.68, 95% CI 5.69-32.88, P < 0.001) were independent predictive factors for carcinomas. A positive ME-NBI finding was the strongest predictive factor.

CONCLUSIONS

ME-NBI is useful in planning the management of lesions diagnosed as adenomas by pre-treatment forceps biopsy.

Endoscopic submucosal dissection as a treatment for gastric adenomatous polyps: predictive factors for early gastric cancer

OBJECTIVE

Endoscopic forceps biopsy (EFB) sampling of gastric adenoma may provide inadequate specimens for a correct diagnosis and lead to inappropriate follow-up strategies for adenomas or missed carcinoma foci. The aim of this study was to determine the diagnostic concordance between an EFB and resected gastric adenomatous polyps by endoscopic submucosal dissection (ESD) and to know the efficacy of ESD for the treatment of gastric adenomatous polyps.

MATERIAL AND METHODS

Between November 2008 and May 2011, 413 ESDs were carried out at Pusan National University Yangsan Hospital. After exclusion, 282 cases were enrolled. The clinicopathological features, complete resection rate, procedure time, complication rate and associated factors for early gastric cancer (EGC) prediction were analyzed.

RESULTS

The mean age was 62.13 ± 8.91 years. Submucosal dissection results showed that the discrepancy rate between endoscopic biopsy and pathology of resected specimens was 32.9% (93/282). Additionally, 71 cases (25.2%) were adenocarcinomas. Among low-grade dysplasia (LGD) from EFB, 23 cases (11.8%) were adenocarcinomas after ESD. Among high-grade dysplasia (HGD) from EFB, 48 cases (55.2%) were adenocarcinomas after ESD. EFB procedure times were longer in the HGD group than in the LGD group (24.90 vs. 29.88 min, p = 0.017). In multivariate analysis, HGD from EFB, surface redness and lesion diameter were the significant predictive factors for EGC.

CONCLUSIONS

Gastric adenomatous polyps should be removed by endoscopic resection regardless of histopathological type. ESD is a useful method for complete resection of gastric adenomas, regardless of size and location.

Clinical characterization of gastric lesions initially diagnosed as low-grade adenomas on forceps biopsy

AIM

The aim of this study was to elucidate characteristics of gastric lesions that are initially diagnosed as low-grade adenomas and to establish appropriate treatment.

METHODS

We retrospectively reviewed 231 lesions initially diagnosed as gastric adenomas. All forceps biopsy samples were histologically diagnosed as category 3 low-grade adenomas according to the revised Vienna Classification. All patients underwent endoscopic resection with endoscopic findings and post-resection diagnoses evaluated subsequently.

RESULTS

Sixty-three lesions were initially diagnosed as depressed adenomas, and 168 lesions were diagnosed as protruding adenomas. The depressed lesions were significantly smaller (11.6 ± 5.0 mm) than the protruding lesions (17.0 ± 10.8 mm) (P < 0.001). Diagnoses reclassified to category 4 mucosal high-grade neoplasia (i.e. high-grade adenoma, adenocarcinoma in adenoma and adenocarcinoma) were more frequent among depressed lesions (52.4%) than among protruding lesions (31.0%) (P = 0.004). Multivariate analysis of all 231 lesions showed that lesion size larger than 20 mm (P < 0.001) and depressed appearance (including central depression) (P < 0.001) were significant independent factors suggesting cancer. For the 168 protruding lesions, lesion size larger than 20 mm (P < 0.001) and central depression (P < 0.001) were significant independent factors suggesting cancer. For the 63 depressed lesions, lesion size larger than 15 mm (P = 0.016) and a moth-eaten appearance (P = 0.017) were significant independent factors in the pre-treatment diagnosis of cancer.

CONCLUSIONS

Adenocarcinoma lesions were often found in depressed lesions and protruding lesions with central depression. Endoscopic resection for total biopsy is recommended, even if forceps biopsy indicates low-grade adenoma, as pre-treatment biopsy may be inadequate for an accurate histological diagnosis.

Spectrum of final pathological diagnosis of gastric adenoma after endoscopic resection

AIM: To investigate how many discrepancies occur in patients before and after endoscopic treatment of referred adenoma and the reason for these results.

METHODS: We retrospectively reviewed data from 554 cases of 534 patients who were referred from primary care centres for adenoma treatment and treated for endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) at Chungnam National University Hospital, from July 2006 to June 2009. Re-endoscopy was examined in 142 cases and biopsy was performed in 108 cases prior to treatment. Three endoscopists (1, 2 and 3) performed all EMRs or ESDs and three pathologists (1, 2 and 3) diagnosed most of the cases. Transfer notes, medical records and endoscopic pictures of these cases were retrospectively reviewed and analyzed.

RESULTS: Adenocarcinoma was 72 (13.0%) cases in total 554 cases after endoscopic treatment of referred adenoma. When the grade of dysplasia was high (55.0%), biopsy number was more than three (22.7%), size was no smaller than 2.0 cm (23.2%), morphologic type was depressed (35.8%) or yamada type IV (100%), and color was red (30.9%) or mixed-or-undetermined (25.0%), it had much more malignancy rate than the others (P < 0.05). All 18 cases diagnosed as adenocarcinoma in the re-endoscopic forceps biopsy were performed by endoscopist 1. There were different malignancy rates according to the pathologist (P = 0.027).

CONCLUSION: High grade dysplasia is the most im-portant factor for predicting malignancy as a final pathologic diagnosis before treating the referred gastric adenoma. This discrepancy can occur mainly through inappropriately selecting a biopsy site where cancer cells do not exist, but it also depends on the pathologist to some extent.

Differential LINE-1 Hypomethylation of Gastric Low-Grade Dysplasia from High Grade Dysplasia and Intramucosal Cancer

Background/Aims

Gastric epithelial dysplasia is considered a precancerous lesion with a variable clinical course. There is disagreement, however, regarding histology-based diagnoses, which has led to confusion in choosing a therapeutic plan. New objective markers are needed to determine which lesions progress to true malignancy. We measured LINE-1 methylation levels, which have been reported to strongly correlate with the global methylation level in gastric epithelial dysplasia and intramucosal cancer.

Methods

A total of 145 tissue samples were analyzed by two histopathologists. All tissues were excised by therapeutic endoscopic mucosal resection and paired with adjacent normal tissue samples. A modified long interspersed nucleotide elements-combined bisulfite restriction analysis (COBRA-LINE-1) method was used.

Results

Gastric epithelial dysplasia and intramucosal cancer tissues had significantly lower levels of LINE-1 methylation than adjacent normal gastric tissues. High-grade dysplasia and intramucosal cancer were distinguishable from low-grade dysplasia based on LINE-1 methylation levels. Furthermore, the distinction could be determined with high sensitivity and specificity, as shown by the receiver operating characteristic (ROC) curve (AUC, 0.82; 95% confidence interval, 0.74 to 0.88).

Conclusions

LINE-1 methylation levels may provide a diagnostic tool for identifying high-grade dysplasia and intramucosal cancer.

Geminin, Ki67, and minichromosome maintenance 2 in gastric hyperplastic polyps, adenomas, and intestinal-type carcinomas: pathobiological significance

BACKGROUND

Geminin negatively regulates Cdt1 and induces the formation of prereplicative complexes by loading mini-chromosome maintenance proteins (Mcm) onto chromatin and limiting DNA replication to once per cell cycle. Recent studies have suggested that geminin expression is a marker of the S/G2/M phase of the cell cycle and is associated with a poor prognosis in various human malignancies. This study aimed to clarify the pathobiological role of geminin in intestinal-type gastric carcinoma, and its relationships with minichromosome maintenance 2 (Mcm2) and Ki67 expression.

METHODS

We performed western blot analysis of seven human gastric cancer cell lines, and immunohistochemical analysis of 72 gastric mucosal lesions and 128 surgically removed advanced intestinal-type gastric carcinomas. Double-labeling immuno-fluorescence was performed to identify the coexpression of geminin and Ki67.

RESULTS

Geminin was detected in all cell lines. Geminin labeling indices (LIs) in hyperplastic polyps, low-grade adenomas, high-grade adenomas, and intestinal-type adenocarcinomas were 3.9%, 10.5%, 18.6%, and 27.2%, respectively. The equivalent LIs for Ki67 and Mcm2 were 17.7%, 42.2%, 52.6%, and 59.7%; and 26.7%, 70.0%, 67.8%, and 77.8%, respectively. Double-labeling immunofluorescence revealed coexpression of geminin and Ki67 in both normal and tumor cells. The LI for geminin was significantly correlated with N stage, International Union Against Cancer (UICC) stage, Mcm2 LI, and Ki67 LI. Patients in stages I-IV and stage III with higher LIs for geminin (>25%) had significantly worse prognoses (P < 0.05 and P < 0.04, respectively). Univariate Cox regression analysis indicated that the overall survival of stage I-IV tumors was significantly correlated with high geminin LIs (relative risk [RR] = 1.94; P = 0.04).

CONCLUSIONS

Geminin expression might reflect the biological nature of gastric intramucosal neoplasms and could be a possible prognostic marker in advanced intestinal-type gastric carcinomas.

Genetic instability in gastric epithelial neoplasias categorized by the revised vienna classification

BACKGROUND/AIMS

The aim of this study was to determine the structural chromosomal aberrations, such as loss of heterozygosity (LOH) and microsatellite instability (MSI), at multiple tumor suppressor gene loci in gastric epithelial neoplasia categorized by the revised Vienna classification.

METHODS

All tissue samples were excised by endoscopic mucosal resection. Sixty category 3 (low-grade adenoma) tissue samples and 51 category 4 samples (high-grade adenoma and intramucosal carcinoma with adenoma) were examined at the 7 sets of microsatellite loci linked to the tumor suppressor gene locus.

RESULTS

For category 3 and 4 tissue samples, there were no differences in the frequencies of LOH-positive chromosomes or the extent of chromosomal loss. The Helicobacter-pylori (H. pylori)-positive rate was significantly higher in MSI-positive category 4 samples than in category 3 samples (p=0.04). The frequency of MSI positivity was significantly higher in category 4 samples than in category 3 samples (p=0.003).

CONCLUSIONS

H. pylori infection is associated with genetic instability of the premalignant lesion. MSI occurs in the early stages of gastric carcinogenesis and its occurrence increases during malignant transformation. Detection of MSI in premalignant gastric lesions may be a surveillant of risk of malignant transformation.

Risk factors in malignant transformation of gastric epithelial neoplasia categorized by the revised Vienna classification: endoscopic, pathological, and immunophenotypic features

BACKGROUND

According to the revised Vienna classification, the surgical removal of gastric epithelial neoplasia category 3 (low-grade dysplasia) lesions is not necessary, whereas the removal of category 4 lesions (high-grade dysplasia and intramucosal cancer) is obligatory. However, approximately 15%-30% of low-grade adenomas/dysplasia progress to high-grade lesions or adenocarcinoma, and it is difficult to determine which lesions will advance to true malignancy. The aim of this study was to evaluate the endoscopic, pathological, and immunophenotypic differences between category 3 and 4 lesions according to the revised Vienna classification.

METHODS

All tissue samples were excised by endoscopic mucosal resection. Fifty-two category 3 tissue samples and 54 category 4 samples were evaluated by endoscopic findings; by pathology examination of the surrounding mucosa; and by CD10, MUC2, MUC5AC, MUC6, and RUNX3 immunohistochemical staining.

RESULTS

Univariate analysis showed that the size of the lesion, color change, ulceration, gastritis score of the surrounding mucosa, and positive expression of MUC6 were associated with category 4 lesions. Multivariate analysis showed that the size of the lesion, ulceration, and positive expression of MUC6 were strongly associated with category 4 lesions.

CONCLUSION

Lesions more than 17 mm in diameter or lesions that are associated with ulceration have the potential for malignant transformation. Positive immunoreactivity for MUC6 appears to be a complementary marker for malignant transformation of gastric epithelial neoplasia.

The usefulness of magnifying endoscopy with narrow-band imaging to distinguish carcinoma in flat elevated lesions in the stomach diagnosed as adenoma by using biopsy samples

BACKGROUND

Therapeutic strategies for flat elevated (0-IIa) lesions in the stomach diagnosed as adenoma by biopsy are currently not established, because some difficulties have previously been reported in the evaluation of vascular patterns alone for the differential diagnosis between adenoma and carcinoma.

OBJECTIVE

We attempted to evaluate the 0-IIa lesions diagnosed as adenoma by using magnifying endoscopy with narrow-band imaging (MENBI) to distinguish them as either adenoma or carcinoma.

SETTING

Department of Gastroenterology, Fujita Health University.

PATIENTS

Fourteen adenomatous lesions (6 adenomas and 8 carcinomas confirmed postoperatively) diagnosed with preoperative biopsies from patients who had undergone endoscopic submucosal dissection were evaluated.

INTERVENTIONS

We selected 5 sites per lesion for MENBI. Selected sites were divided into superficial structures (SSs) and irregular microvascular patterns (IMVPs).

MAIN OUTCOME MEASUREMENTS

The rate of SSs and IMVPs in adenoma and carcinoma.

RESULTS

Significant SSs were tubular in the adenoma and unclear in the carcinoma. Regarding IMVP subcategories, (1) slight intrastructual irregular microvascular patterns (ISIMVPs) accounted for 97%, (2) severe ISIMVPs accounted for 0%, (3) fine networks accounted for 3%, and (4) corkscrews accounted for 0% of cases in the adenomas. The corresponding proportions in the carcinomas were (1) 40%, (2) 15%, (3) 45%, and (4) 0%. Severe ISIMVPs and fine networks were significant findings for carcinomas.

LIMITATIONS

The number of cases was limited.

CONCLUSIONS

Our combined evaluation method using MENBI offers the ability to establish proper therapeutic strategies for lesions that are difficult to identify as adenoma or carcinoma.

Do we need colonoscopy in patients with gastric adenomas? The risk of colorectal adenoma in patients with gastric adenomas

BACKGROUND

Gastric polyps are found frequently in various colonic polyposis syndromes. Genetic alterations of several genes occur in gastric adenomas and colorectal adenomas. However, it is unknown whether patients with gastric adenomas are at higher risk for colorectal adenomas.

OBJECTIVE

To investigate the prevalence rate of colorectal adenoma in patients with gastric adenomas and to determine the association between the presence of gastric adenomas and synchronous colorectal adenomas.

DESIGN

A retrospective, cross-sectional, case-control study.

SETTING

Single center: Center for Health Promotion of Samsung Medical Center.

PATIENTS

This study involved 87 patients with gastric adenomas and 174 sex-matched and age-matched controls among 19,019 participants who underwent EGD and colonoscopy simultaneously or within 6 months of each other from January 2001 to December 2008 at the Center for Health Promotion of Samsung Medical Center.

INTERVENTION

EGD and colonoscopy.

MAIN OUTCOME MEASUREMENTS

The prevalence rate of colorectal adenoma in patients with gastric adenomas.

RESULTS

The 87 gastric adenoma patients included 72 men and 15 women. Colorectal adenomas were identified in 42 (48.3%) of 87 cases and in 58 (33.3%) of 174 controls (P = .022). The prevalence of colorectal adenoma was significantly higher in the gastric adenoma group than in the control group. The mean size and number of colorectal adenomas were not significantly different between the two groups. The majority of colorectal adenomas were located in distal colonic segments in the gastric adenoma group in contrast with proximal colonic segments in the control group. Multivariate logistic regression analysis revealed that independent risk factors for colorectal adenoma were the presence of gastric adenomas (odds ratio [OR], .915; 95% confidence interval [CI], 1.044-3.513) and increasing age over 55 years (OR, 2.943; 95% CI, 1.558-5.560).

LIMITATIONS

Lack of data on previous colorectal adenomas and possible confounding factors such as hyperlipidemia or diabetes mellitus.

CONCLUSION

The risk of colorectal adenoma increases significantly in patients with gastric adenomas and in patients over age 55. A screening colonoscopy may be necessary for patients with gastric adenomas to detect colorectal adenomas.

Argon plasma coagulation with submucosal saline injection for gastric adenoma on outpatient basis

Gastric adenoma with low-grade dysplasia (LGD) is a less progressive disease than with high-grade dysplasia; nevertheless, a certain portion of lesions can progress. The purpose of this study was to evaluate the effectiveness of argon plasma coagulation (APC) with submucosa saline injections (APC-SSI) for gastric adenoma with LGD on an outpatient department (OPD) basis. We included 57 patients with 64 lesions of gastric adenoma with LGD. Endoscopic type was flat elevated in 58 lesions and central depressed in 6 lesions. Normal saline was injected into the submucosa under the lesion before APC. APC was performed to the lesion and its surrounding mucosa. After treatment, patients underwent regular endoscopy follow-ups. One case each of pneumoperitoneum and Mallory-Weiss tearing occurred and could be managed with conservative care. One case of overt bleeding occurred after 2 weeks and was treated with APC. After 19.5 months of follow-up, four residual adenomas (6.3%) were found and treated with additional APC-SSI. Fourteen metachronous lesions were noted in eight patients (14.0%). Twelve lesions were adenoma with LGD and two lesions were intramucosal adenocarcinoma. APC-SSI is an effective and safe treatment modality for gastric adenoma with LGD on an OPD basis and it is recommended for patients with risk factors of endoscopic mucosal resection (EMR). After treatment of gastric adenoma, meticulous follow-up endoscopy is recommended for detection of metachronous lesions.

Polyps in the gastrointestinal tract: discrepancy between endoscopic forceps biopsies and resected specimens

BACKGROUND AND AIM

An endoscopic forceps biopsy (EFB) carries the risk of missing the neoplastic foci within a polyp as only a small portion of the lesion is sampled using this technique. Accordingly, the histological examination of specimens obtained by an EFB is of limited accuracy and patient management based on the histological findings is controversial. The aim of this prospective study was to determine the diagnostic concordance between an EFB and resected tissues of gastric and colon polyps.

METHODS

Between January 2006 and October 2007, 1312 gastrointestinal polyps from 896 patients were resected in our hospital. Patients with polyps of epithelial origin of at least 8 mm in diameter and not associated with polyposis syndromes were included in the study. Polyps of nonepithelial origin were excluded. One thousand two hundred and sixty-four polyps of epithelial origin [gastric polyps (n=268) and colon polyps (n=996)] obtained from 813 patients met the inclusion criteria. All patients underwent an EFB and resection of the polyp by endoscopic mucosal resection and endoscopic submucosal dissection.

RESULTS

Multiple polyps existed in 31.6% of the patients. The pathological diagnoses of resected gastric polyps were as follows: adenomas with low-grade dysplasia, 46 (17.2%); adenomas with high-grade dysplasia, 42 (15.7%); hyperplastic polyps, 126 (47.0%); chronic inflammatory polyps, 29 (10.8%); and adenocarcinomas, 25 (9.3%). The discrepancy rate between an EFB and the pathology of the resected gastric polyps was 39.2% (the Kendall's tau-b and the kappa coefficient for agreement between the EFB and resected specimens of gastric polyps were 0.577 and 0.472, respectively; P value <0.001). No relationship between the size of the gastric polyp and the concordance rate was observed. The pathological diagnoses of the resected colon polyps were as follows: adenomas with low-grade dysplasia, 559 (56.1%); adenomas with high-grade dysplasia, 229 (23.0%); hyperplastic polyps, 44 (4.4%); adenocarcinomas, 53 (5.3%); and inflammatory polyps, 111 (11.1%). The discrepancy rate between the EFB and the pathology of the resected colon polyps was 39.8%. (the Kendall's tau-b and the kappa coefficient for agreement between the EFB and the resected specimens of the colon polyps were 0.479 and 0.293, respectively; P value <0.001). No relationship between the size of the colon polyp and the concordance rate was observed.

CONCLUSION

Considerable discrepancies were observed in histological findings between the EFB and the resected specimens. Therefore, complete removal of the entire polyp is recommended to confirm the diagnosis, to remove precancerous lesions, and to develop an optimal management plan.

White opaque substance within superficial elevated gastric neoplasia as visualized by magnification endoscopy with narrow-band imaging: a new optical sign for differentiating between adenoma and carcinoma

BACKGROUND

The microvascular pattern (MVP) as visualized by magnification endoscopy (ME) is a reliable marker for differentiating between benign and malignant gastric flat lesions. However, in cases of gastric neoplasia of 0-IIa type, it is sometimes impossible to visualize the MVP because a white opaque substance (WOS) obscures the subepithelial MVP.

OBJECTIVE

To investigate whether the morphology of the WOS could be a useful optical sign for discriminating between adenoma and carcinoma.

SETTING

Single tertiary referral center.

MATERIALS

Forty-six gastric neoplasias of only 0-IIa type (18 adenomas and 28 early carcinomas) were evaluated.

INTERVENTION

The prevalence and the morphology of the WOS as visualized by ME with narrow-band imaging (NBI) according to histologic type (adenoma vs carcinoma).

MAIN OUTCOME MEASUREMENTS

The WOS is more frequently present in adenomas than in carcinomas. With regard to the morphology of the WOS, 100% of the examples of WOS within adenomas demonstrated a regular distribution; in contrast, 83% of the examples of WOS within carcinomas showed an irregular distribution.

RESULTS

In cases in which a neoplasia of 0-IIa type showed either WOS with a regular distribution or a regular MVP, the sensitivity and specificity for discriminating adenoma from carcinoma were 94% and 96%, respectively.

LIMITATIONS

The number of cases was limited. The WOS has not yet been characterized by chemical analysis.

CONCLUSION

In cases in which the WOS is observed, rather than assessing the MVP, morphologic analysis of the WOS could be an alternative new optical sign for discriminating adenoma from carcinoma when using ME with NBI.

Gastric polyps: classification and management

Gastric polyps can be broadly defined as luminal lesions projecting above the plane of the mucosal surface. They are relatively frequent in routine pathology practice, where the main goal is to rule out the possibility of malignancy. Various subtypes of gastric polyps are recognized and generally divided into nonneoplastic and neoplastic. We will review herein only a limited subset of gastric polyps representing the most common or, sometimes, challenging.

Endoscopic characteristics of gastric adenomas suggesting carcinomatous transformation

BACKGROUND

Currently, endoscopic resections, including endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD), are widely performed for the management of gastric neoplasia. This study aimed to evaluate the potential predictive factors for carcinomas on the basis of endoscopic features.

METHODS

This study investigated 114 samples from 114 patients. Gastric adenoma was diagnosed initially for all the patients. The endoscopic findings were reviewed for location, size, gross appearance, surface nodularity, ulceration, surface color, and number of biopsy samples. These variables were analyzed and compared between an adenoma group (51 cases) and a carcinoma group (63 cases) on the basis of postresection diagnosis.

RESULTS

The mean age of the patients was 62 years (range, 43-82 years), and 83 of the patients were men. The diameter of the lesions was 14.6 +/- 8.2 mm in the adenoma group and 15.4 +/- 7.4 mm in the carcinoma group. Depressed type, combined high-grade dysplasia, red discoloration, and mucosal ulceration were significant variables associated with carcinomas. In the multivariate analysis, combined high-grade dysplasia was a significant independent predictor of carcinomas.

CONCLUSIONS

The results suggest that patients with high-grade dysplasia on forceps biopsies should be considered candidates for endoscopic resection. Characteristics of gastric adenomas such as a depressed type, red color, and ulceration that may have foci of carcinomas in other parts of the adenomas also should be considered for endoscopic resection.

Gastric adenomas: relationship between clinicopathological findings, Helicobacter pylori infection, APC mutations and COX-2 expression

Gastric adenomas are rare neoplastic growths characterized by localized polypoid proliferations of dysplastic epithelium that tend to progress to infiltrating adenocarcinoma. Therefore, the identification of molecular markers that could reliably recognize adenomas at risk of progression is advocated in the clinical management. In this study we investigated, in a series of gastric adenoma specimens from an area at high risk of gastric cancer, the relationship between clinicopathological characteristics of adenoma and Helicobacter pylori infection, APC mutational status, and COX-2 and the down-stream enzyme mPGES1 expression. Helicobacter pylori infection, detected in 24%, and 33% by histology and PCR analyses, respectively, did not show any relationship with growth pattern, localization, size, dysplasia grade and presence of synchronous cancer. Pathogenetic mutations of MCR region (codons 1269-1589) of the APC gene were detected only in one case corresponding to a single, small size, low grade, H. pylori-negative adenoma. The expression of COX-2 largely matched that of mPGES(1). Both were overexpressed in 79% of cases showing a relationship with high-grade dysplasia, size >10 mm and presence of a synchronous carcinoma. In conclusion, COX-2 may play a key role in the development and progression of gastric adenoma and could be an attractive target in the management of gastric adenoma at major risk of cancer development.

Early diagnosis of early gastric cancer

The prognosis of gastric cancer is closely related to the stage of disease at diagnosis. Early gastric cancer, whereby disease is limited to mucosa and submucosa, confers a survival rate of greater than 90% in 5 years in many centres. Gastric cancer is still a major cause of cancer mortality worldwide. In high incidence areas such as Japan, screening of asymptomatic population has been advocated. However, in Western countries, mass screening is not cost-effective. Hence, strategy has been directed to screen symptomatic individuals who are at higher risk of gastric cancer. Most patients with early gastric cancer present with symptoms indistinguishable from benign peptic ulcer disease. Screening for this group of patients improves detection rate of early gastric cancer and therefore its prognosis. Endoscopy for surveillance of premalignant lesions has been explored with this objective in mind. Serology testing for biomarkers such as pepsinogen, anti-Helicobacter pylori antibody and gastrin has been studied as an alternative to endoscopy. There is compelling evidence for the role of H. pylori in the initiation of Correa's cascade (stepwise progression from chronic active gastritis, atrophic gastritis, intestinal metaplasia, dysplasia and finally adenocarcinoma). Regression of premalignant lesions has been demonstrated with H. pylori eradication. However, it is not known whether this might effectively prevent gastric cancer in either low or high-risk population.

Histologic characteristics of gastric polyps in Korea: Emphasis on discrepancy between endoscopic forceps biopsy and endoscopic mucosal resection specimen

AIM: To investigate histological characteristics of gastric polyps in the Korean population.

METHODS: We reviewed endoscopic photographs and medical records of patients with gastric polyps who underwent endoscopic mucosal resection from April 1996 through February 2003.

RESULTS: A total of 85 gastric polyps from 74 patients were reviewed. Male-to-female ratio was 1:1.96. Mean age was 59.9 ± 10.8 years. Multiple polyps were observed in 10.8%. Gastric polyps occurred most frequently in the antrum (58.8%). Pathological results on resected specimens were as follows: tubular adenoma 45.9%, hyperplastic polyp 31.8%, inflammatory polyp 9.4%, hamartoma 3.5%, fundic gland polyp 2.4%, tubulovillous adenoma 2.4%, adenocarcinoma 2.4%, dysplasia 1.1%, and mucosal pseudolipomatosis 1.1%. Discrepancy rate between endoscopic biopsy and pathology of resected specimens was 27.1%. There was no relationship between the size of the polyp and concordance rate.

CONCLUSION: There is considerable discrepancy in histologic findings between endoscopic forceps biopsy and resected specimens. Approaches to review of the histology of an entire polyp should be performed, especially when an adenoma is suspected.

Epigenetic alterations in gastric carcinogenesis

Gastric cancer is believed to result in part from the accumulation of multiple genetic alterations leading to oncogene overexpression and tumor suppressor loss. Epigenetic alterations as a distinct and crucial mechanism to silence a variety of methylated tissue-specific and imprinted genes, have been extensively studied in gastric carcinoma and play important roles in gastric carcinogenesis. This review will briefly discuss the basic aspects of DNA methylation and CpG island methylation, in particular the epigenetic alterations of certain critical genes implicated in gastric carcinogenesis and its relevance of clinical implications.

Endoscopic excision of a prolapsing malignant polyp which caused intermittent gastric outlet obstruction

A 69-year-old male with chronic lymphocytic leukemia presented with iron deficiency anemia and post-prandial abdominal fullness. Endoscopy showed a large polyp on a stalk, protruding through the pylorus into the duodenum causing intermittent gastric outlet obstruction. While prolapsing gastric antral polyps are usually benign and hyperplastic, inflammatory or regenerative in type, excisional snare polypectomy here led to complete resolution of his symptoms, but showed a malignant polyp.

Analysis of mucin, p53 protein and Ki-67 expressions in gastric differentiated-type intramucosal neoplastic lesions obtained from endoscopic mucosal resection samples: a proposal for a new classification of intramucosal neoplastic lesions based on nuclear atypia

There are differing views between Western and Japanese pathologists on the use of histological criteria to classify gastrointestinal tumors. It is therefore a priority to create a new histological classification of the stomach in order to resolve the confusion. Expression patterns were examined of mucin (MUC2, CD10, MUC5AC, pyloric gland-type mucin), p53 protein, and Ki-67 in tumor cells according to the following new classification system for differentiated-type intramucosal neoplastic lesions of the stomach, based on nuclear atypia: borderline neoplasia (adenoma (including dysplasia), indefinite tumor of adenoma or low-grade cancer, and low-grade cancer) and definite carcinoma (intermediate cancer, and high-grade cancer). The resulting grades were: adenoma, 23; indefinite tumor for adenoma or low-grade cancer, 6; low-grade cancer, 28; intermediate cancer, 48; high-grade cancer, 20. While the frequency of intestinal-type borderline neoplasias was higher than that of definite carcinomas, the mixed-type of definite carcinomas occurred with higher frequency than borderline neoplasias. The p53 protein overexpression and the Ki-67-positive rate increased with an increase in the grade assigned according to the new classification. The correlated expression levels of p53 protein, Ki-67, and various mucins, support the conclusion that this classification of intramucosal neoplastic lesions is useful for obtaining a consensus diagnosis of gastric intramucosal neoplasia between pathologists and gastrointestinal clinicians.

Three independent genetic profiles based on mucin expression in early differentiated-type gastric cancers--a new concept of genetic carcinogenesis of early differentiated-type adenocarcinomas

Recent molecular studies have shown that the genetic profiles of differentiated-type adenocarcinomas of the stomach are associated with distinct cellular mucin phenotypes (gastric- intestinal- and mixed-phenotypes). Therefore, we examined whether these cellular mucin phenotypes reflect specific molecular genetic alterations, and whether the phenotypes can be used to help categorize the intramucosal neoplasias of gastric tumors. We subclassified tumors into four cellular phenotypes using immunohistochemical mucin analysis. In all, 62 early gastric carcinomas (gastric-phenotype, 13; intestinal-phenotype, 17; mixed-phenotype, 31; unclassified-phenotype, 1) were examined using a combination of polymerase chain reaction microsatellite assays and immunohistochemical analysis in order to detect chromosomal allelic losses of multiple cancer-related chromosomal loci (1p, 3p. 4p, 5q, 8p, 9p, 13p, 17p, 18q and 22q), microsatellite instability (MSI), and overexpression of the p53 protein. In addition, we analyzed the relationship between MSI status and hMLH1 promoter hypermethylation, which is thought to be a cause of high MSI status. For gastric phenotype cancers, the frequency of 3p allelic loss was higher than that of other microsatellite markers, whereas 5q allelic loss was frequently found in intestinal phenotype cancers. The genetic profile of mixed phenotype cancers is comprised of two distinct genetic types: LOH and MSI types. In the former, 5q, 3p and 18q allelic losses are seen frequently in intramucosal carcinomas. On the other hand, 17p, 1p and 9p allelic losses are associated with the development of submucosal carcinomas. MSI was observed only in mixed phenotype cancers (six of 31 mixed phenotype cancers). Overexpression of the p53 protein is common in differentiated-type gastric cancers. In addition, the MSI status of the tumor cells was correlated with the extent of hypermethylation of the hMLH1 promoter. We suggest that the cellular mucin phenotypes of the differentiated-type adenocarcinomas result from distinct genetic alterations.

Frequent CpG island methylation in precursor lesions and early gastric adenocarcinomas

Gastric carcinogenesis involves multiple genetic and epigenetic alterations. Epigenetic silencing of tumor-related genes due to CpG island methylation (CIM) has been recently reported in gastric cancer, but the role in precursor lesions is not well understood. We analysed the methylation status of the tumor suppressor gene p16, the DNA mismatch repair gene hMLH1, and four CpG islands (MINT1, MINT2, MINT25, and MINT31) using methylation-specific polymerase chain reaction in 35 polypoid adenomas and 46 flat dysplasias unassociated with carcinoma, 34 early adenocarcinomas (T1N0M0) and associated adenomas/dysplasias, and corresponding adjacent non-neoplastic mucosa. The extent of CIM was defined by the fraction of methylated loci (methylation index), and compared with previously characterized genetic alterations (microsatellite instability (MSI) and APC gene mutation). We found that methylation of p16 was more frequent in adenocarcinoma-associated dysplasias/adenomas (29%) and adenocarcinomas (44%) as compared to flat dysplasias (4%) and adenomas (18%) unassociated with adenocarcinoma (P=0.001). The mean methylation index increased from normal/chronic gastritis (CG) mucosa (0.09) to intestinal metaplasia (IM) (0.16), flat dysplasias (0.40) or polypoid adenomas (0.41) unassociated with carcinoma, dysplasias/adenomas associated with carcinoma (0.44), and adenocarcinomas (0.44). There was no difference in frequencies of high-level CpG island methylation (CIM-H, methylation index > or =0.5) among flat dysplasias (50%) and polypoid adenomas (51%) unassociated with carcinoma, dysplasias/adenomas associated with adenocarcinoma (47%), and adenocarcinoma (47%). CIM-H was present in 15% of IM, but not in normal/CG mucosa. There was a significant correlation between methylation of hMLH1 and high-level of microsatellite instability (MSI-H): methylation of hMLH1 was present in 71% of MSI-H tumors, but only 8% of MSI-low tumors and 13% of microsatellite-stable tumors (P=0.0001). There was no statistical difference between methylation index and APC mutation. Our results indicate that concurrent promoter methylation is an early and frequent event in gastric tumorigenesis, including both MSI-H and microsatellite-stable neoplasms. Methylation of the p16 gene may contribute to the malignant transformation of gastric precursor lesions.

Differential gene-expression profiles associated with gastric adenoma

Gastric adenomas may eventually progress to adenocarcinomas at varying rates. The purpose of the present study was to identify gene-expression profiles linked to the heterogeneous nature of gastric adenoma as compared to adenocarcinoma. Suppression subtractive hybridisation analysis was performed to extract relevant genes from two cases of low- and high-grade gastric adenomas. The identified genes were quantified by RT-PCR in 14 low-grade adenoma, nine high-grade adenoma and nine adenocarcinoma samples, followed by hierarchical clustering analysis to separate tumours into groups according to their gene-expression profiles. Nine genes previously implicated in carcinogenesis in a variety of organs, including three genes related to gastric adenocarcinoma, were identified. The overexpression of these genes in gastric adenoma has not been reported previously. The clustering analysis of these nine genes across 32 cases identified three groups, one of which consisted primarily of adenocarcinomas, whereas the other two groups consisted of adenomas. One group of adenomas, characterised by larger tumour size, exhibited gene-expression profiles of an intestinal cell lineage implicated in the pathogenesis of an intestinal-type gastric adenocarcinoma. Another adenoma group consisting of low-grade adenomas with smaller tumour size exhibited a unique expression profile. In conclusion, clustering analysis of expression profiles using a limited number of genes may serve as molecular markers for gastric adenoma with different biological properties. Although the prognostic values of these gene-expression profiles need to be evaluated in further follow-up study of adenoma cases, these findings add new insights to (a) our understanding of the pathogenesis of gastric tumours, (b) the development of specific tumour markers for clinical practice, and (c) the design of novel therapeutic targets.

Defining the pathologic diagnosis of metaplasia, atrophy, dysplasia, and gastric adenocarcinoma

Epidemiologic and pathologic studies have confirmed that the development of gastric cancer spans over several decades starting with Helicobacter pylori chronic active gastritis followed, over time and only in a subset of patients, with the development of intestinal metaplasia and atrophy, dysplasia, and finally gastric adenocarcinoma. It has also been established that the pathogenesis of gastric cancer is a multifactorial process in which both environmental and host-related factors play significant role. Improvement in upper endoscopic techniques make possible the detection of not only early gastric cancers but also the mucosal alterations that predate malignant degeneration. A better understanding of the gastric carcinogenic sequence will allow us to better identify the patients at risk and to implement preventive strategies. We review the histopathologic steps that predate the development of gastric cancer and evaluate the risks of transformation that they confer.