Evaluation of gastric biopsies for neoplasia: differences between Japanese and Western pathologists

Unravelling interobserver variability in gastrointestinal glandular neoplasia: a contemporary study of US and Korean pathologists

AIMS

Interobserver variability in the assessment of gastric neoplasia biopsies between most Western and Eastern (predominantly represented by Japanese in the literature) pathologists has been documented. It is unknown if such variability exists between the US and Korean pathologists in the current era.

METHODS

Ten gastrointestinal (GI) pathologists from the USA (n=5) and South Korea (n=5) evaluated 100 scanned images of gastric (n=50) and colorectal (n=50) neoplasia biopsies and answered multiple questionnaires. Consensus was defined as the answer chosen by the majority. Cohen's (κc) and Fleiss' kappa (κf) values were calculated between the consensus of the two groups and among the raters, respectively.

RESULTS

Both groups reached a consensus in the majority of cases (74%-100%) with slight to perfect intergroup (κc=0.049-1.000) and no to substantial intragroup (κf=-0.083 to 0.660) agreements. For gastric neoplasia, Korean pathologists relied heavily on cytoarchitectural atypia, whereas the US pathologists focused on stromal invasion when diagnosing adenocarcinoma. For colorectal neoplasia, the Korean pathologists identified concurrent intramucosal carcinoma when diagnosing invasive adenocarcinoma, while the presence of desmoplasia was a prerequisite for the diagnosis of invasive adenocarcinoma for the US pathologists.

CONCLUSIONS

For GI neoplasia biopsy interpretation, the diagnostic approach of Korean pathologists is similar to that of Eastern/Japanese pathologists. Consensus outperformed kappa statistics in capturing the magnitude of inter-rater and intergroup reliability, highlighting the potential benefit of consensus meetings to decrease the gap between Western and Eastern diagnostic approaches.

Short Telomere Lesions with Dysplastic Metaplasia Histology May Represent Precancerous Lesions of Helicobacter pylori-Positive Gastric Mucosa

Gastric cancers are strongly associated with Helicobacter pylori infection, with intestinal metaplasia characterizing the background mucosa in most cases. However, only a subset of intestinal metaplasia cases proceed to carcinogenesis, and the characteristics of high-risk intestinal metaplasia that link it with gastric cancer are still unclear. We examined telomere reduction in five gastrectomy specimens using fluorescence in situ hybridization, and identified areas with localized telomere loss (outside of cancerous lesions), which were designated as short telomere lesions (STLs). Histological analyses indicated that STLs were characteristic of intestinal metaplasia accompanied by nuclear enlargement but lacking structural atypia, which we termed dysplastic metaplasia (DM). A review of gastric biopsy specimens from 587 H. pylori-positive patients revealed 32 cases of DM, 13 of which were classified as high-grade based on the degree of nuclear enlargement. All high-grade DM cases exhibited a telomere volume reduced to less than 60% of that of lymphocytes, increased stemness, and telomerase reverse transcriptase (TERT) expression. Two patients (15%) exhibited low levels of p53 nuclear retention. After a 10-year follow-up, 7 (54%) of the high-grade DM cases had progressed to gastric cancer. These results suggest that DM is characterized by telomere shortening, TERT expression, and stem cell proliferation, and high-grade DM is a high-grade intestinal metaplasia that likely represents a precancerous lesion of gastric cancer. High-grade DM is expected to effectively prevent progression to gastric cancer in H. pylori-positive patients.

Disparities and survival in newly diagnosed gastric cancer in Hispanic patients in the United States: a propensity score matched analysis

Background

The burden of gastric cancer involving Hispanic patients in the United States is growing as both the population and the incidence of gastric cancer in this group increases. This burden is compounded by presentation with advanced disease and socioeconomic challenges shaping cancer care. We sought to describe the demographics, socioeconomic factors, treatment, and survival experience of Hispanic patients with gastric adenocarcinoma.

Methods

Patients with gastric adenocarcinoma diagnosed between 2004 and 2015 (n=90,737) in the National Cancer Database were retrospectively identified. Patients of Hispanic ethnicity were compared against non-Hispanic white patients. Surgical cohort was further analyzed, and 1:1 propensity score matching was used to balance covariates between Hispanic and non-Hispanic white surgical patients. Survival was compared using Kaplan-Meier method. Cox regression was used to determine prognostic factors for survival.

Results

Compared to non-Hispanic white patients, Hispanic patients are more likely to be younger, female, and healthier. They were more likely to be uninsured, reside in poorer neighborhoods and reside in areas with lower rates of education. Hispanic patients were more likely to live in a metropolitan area, travel shorter distances for healthcare, and receive treatment at an academic and high volume centers. Hispanic patients were more likely to have higher stage disease presentation, higher grade tumors, lymphovascular invasion, and poorly cohesive adenocarcinoma. Hispanic patients were more likely to receive surgery, but less likely to receive adjuvant therapy. In Cox regression of all patients, unmatched surgical patients, and matched surgical patients, Hispanic ethnicity was an independent prognostic factor of improved survival.

Conclusions

Hispanic patients with gastric adenocarcinoma present with several unfavorable clinicopathologic and socioeconomic factors. Paradoxically, these patients demonstrate improved survival. Further study is warranted to characterize disease biology in this population.

T2 gallbladder cancer shows substantial survival variation between continents and this is not due to histopathologic criteria or pathologic sampling differences

Published data on survival of T2 gallbladder carcinoma (GBC) from different countries show a wide range of 5-year survival rates from 30-> 70%. Recently, studies have demonstrated substantial variation between countries in terms of their approach to sampling gallbladders, and furthermore, that pathologists from different continents apply highly variable criteria in determining stage of invasion in this organ. These findings raised the question of whether these variations in pathologic evaluation could account for the vastly different survival rates of T2 GBC reported in the literature. In this study, survival of 316 GBCs from three countries (Chile n = 137, South Korea n = 105, USA n = 74), all adequately sampled (with a minimum of five tumor sections examined) and histopathologically verified as pT2 (after consensus examination by expert pathologists from three continents), was analyzed. Chilean patients had a significantly worse prognosis based on 5-year all-cause mortality (HR: 1.89, 95% CI: 1.27-2.83, p = 0.002) and disease-specific mortality (HR: 2.41, 95% CI: 1.51-3.84, p < 0.001), compared to their South Korean counterparts, even when controlled for age and sex. Comparing the USA to South Korea, the survival differences in all-cause mortality (HR: 1.75, 95% CI: 1.12-2.75, p = 0.015) and disease-specific mortality (HR: 1.94, 95% CI: 1.14-3.31, p = 0.015) were also pronounced. The 3-year disease-specific survival rates in South Korea, the USA, and Chile were 75%, 65%, and 55%, respectively, the 5-year disease-specific survival rates were 60%, 50%, and 50%, respectively, and the overall 5-year survival rates were 55%, 45%, and 35%, respectively. In conclusion, the survival of true T2 GBC in properly classified cases is neither as good nor as bad as previously documented in the literature and shows notable geographic differences even in well-sampled cases with consensus histopathologic criteria. Future studies should focus on other potential reasons including biologic, etiopathogenetic, management-related, populational, or healthcare practice-related factors that may influence the survival differences of T2 GBC in different regions.

Endoscopic acanthosis nigricans appearance: A novel specific marker for diagnosis of low-grade intraepithelial neoplasia

BACKGROUND AND AIM

At present, there is no recognized diagnostic criteria for gastric low-grade intraepithelial neoplasia (LGIN). The purpose of this study was to determine whether an "endoscopic acanthosis nigricans appearance (EANA)" could be a useful endoscopic marker for distinguishing LGIN lesions from peripheral non-neoplastic tissues.

METHODS

A retrospective study was conducted on 638 cases of suspected superficial lesions with endoscopic images from white light endoscopy and magnifying endoscopy combined with narrow band imaging. According to the pathological results of accurate biopsies, those lesions were divided into three groups: a control group, an LGIN group, and an early gastric cancer (EGC) group.

RESULTS

According to the presence of EANAs, the sensitivity, specificity, positive predictive value, and negative predictive value for differentiating between the LGIN and control groups were 24.8%, 97.3%, 78.3%, and 76.6%, respectively. The sensitivity (84.1%) and negative predictive value (92.4%) were significantly improved by combining EANA with types IV-VI pit pattern. The intervening part and mean gray value of glands, representing microsurface features and microvascular variation, were significantly larger or higher in EANA lesions than in the surrounding non-neoplastic mucosa. LGIN with EANA was more likely to be present in lesions of type 0-IIa. In addition, the prevalence of EANAs in EGC was 16.7%.

CONCLUSION

An EANA could be used as an auxiliary indicator for a diagnosis of LGIN in suspected lesions. It could also play a potential assistive role in the diagnosis of EGC lesions.

Greater Lymph Node Retrieval Improves Survival in Node-Negative Resected Gastric Cancer in the United States

PURPOSE

Guidelines in western countries recommend retrieving ≥15 lymph nodes (LNs) during gastric cancer resection. This study sought to determine whether the number of examined lymph nodes (eLNs), a proxy for lymphadenectomy, effects survival in node-negative disease.

MATERIALS AND METHODS

The US National Cancer Database (2003-2011) was reviewed for node-negative gastric adenocarcinoma. Treatment was categorized by neoadjuvant therapy (NAT) vs. initial resection, and further stratified by eLN. Kaplan-Meier and Weibull models were used to analyze overall survival.

RESULTS

Of the 1,036 patients who received NAT, 40.5% had ≤10 eLN, and most underwent proximal gastrectomy (67.8%). In multivariate analysis, greater eLN was associated with improved survival (eLN 16-20: HR, 0.71; P=0.039, eLN 21-30: HR, 0.55; P=0.001). Of the 2,795 patients who underwent initial surgery, 42.5% had ≤10 eLN, and the majority underwent proximal gastrectomy (57.2%). In multivariate analysis, greater eLN was associated with improved survival (eLN 11-15: HR, 0.81; P=0.021, eLN 16-20: HR, 0.73; P=0.004, eLN 21-30: HR, 0.62; P<0.001, and eLN >30: HR, 0.58; P<0.001).

CONCLUSIONS

In the United States, the majority of node-negative gastrectomies include suboptimal eLN. In node-negative gastric cancer, greater LN retrieval appears to have therapeutic and prognostic value, irrespective of initial treatment, suggesting a survival benefit to meticulous lymphadenectomy.

Practical Points in Gastric Pathology

CONTEXT

-The diagnosis of gastric epithelial lesions is difficult in clinical practice, even with the recent developments and advances in endoscopic modalities, owing to the diverse morphologic features of the lesions, lack of standardized diagnostic criteria, and the high intraobserver and interobserver variabilities in the nonneoplastic (regenerative)-neoplastic spectrum.

OBJECTIVE

-To provide an overview of the current concepts and unresolved issues surrounding the diagnosis of diseases in the nonneoplastic-neoplastic spectrum, and to discuss some noteworthy properties and histologic features of gastric epithelial lesions.

DATA SOURCES

-A comprehensive assessment of the medical literature on gastric epithelial lesions was performed; we also interjected our own experiences into the discussion. Sources included original studies, review articles, and textbooks related to the field.

CONCLUSIONS

-Our literature review revealed that clear cell changes and micropapillary carcinoma components in gastric carcinomas are associated with poor clinical outcomes and should hence be included in pathologic reports. Moreover, we suggest a stepwise biopsy-endoscopic resection modality for the diagnosis of borderline neoplasia-nonneoplasia cases.

Differences in the pathological diagnosis of colorectal neoplasia between the East and the West: Present status and future perspectives from Japan

It is well known that there are discrepancies in the diagnosis of gastrointestinal neoplasia between Western and Japanese pathologists. In the West, colorectal cancer (CRC) is defined by invasion through the muscularis mucosa into the submucosa, especially depending on the presence of desmoplasia. In Japan, however, CRC is defined based on a combination of nuclear and architectural abnormalities, regardless of invasion status. As a result, intramucosal carcinoma is diagnosed as high-grade dysplasia and even intramucosal carcinoma with poorly differentiated component is classified as 'Tis' in the West. It is logical and reasonable that the term 'T1' is used to currently describe intramucosal carcinoma. Use of the term 'high-grade dysplasia' for intramucosal CRC is outdated. In order to determine appropriate clinical treatment of CRC, the various risk factors of metastasis should be fully evaluated. With improved contributions and communication between pathologists and clinicians, overtreatment and inadequate follow up can be avoided. The discrepancies in the diagnosis of CRC between Western and Japanese pathologists may be addressed by an increase in East-West exchange. In addition, in the future, molecular analysis may also be useful for establishment of standardized diagnostic criteria of CRC.

Coffee consumption and the risk of incident gastric cancer--A meta-analysis of prospective cohort studies

As several epidemiological studies on the association of coffee consumption with gastric cancer risk have produced inconsistent results, this meta-analysis was designed to synthesize current evidence of this potential relationship. We searched PubMed, EMBASE, and the Cochrane Library up to September 2014 to retrieve relevant articles. Prospective cohort studies were included if the relative risks (RRs) or hazard ratios and 95% confidence intervals (CIs) for gastric cancer according to coffee consumption were reported. Fixed- or random-effects models were used based on heterogeneity. The search yielded 13 eligible cohort studies of 3484 incident gastric cancer patients from among 1,324,559 participants. A significantly increased risk was found between gastric cardia cancer and coffee consumption (RR = 1.50, 95% CI: 1.09-2.07). Compared with Europeans (RR = 1.12, 95% CI: 0.86-1.46) and Asians (RR = 0.96, 95% CI: 0.72-1.27), Americans (RR = 1.36, 95% CI: 1.06-1.74) demonstrated a significantly positive association. However, the significant differences of the pooled results vanished after adjusting for smoking or body mass index. Our meta-analysis results suggest that a high level of coffee consumption is a risk factor for gastric cancer. However, these results should not be overinterpreted because residual confounding effects of other factors could exist.

Gastric high-grade dysplasia can be associated with submucosal invasion: evaluation of its prevalence in a series of 121 endoscopically resected specimens

Gastric neoplasms classified as high-grade dysplasia (HGD) by Western pathologists are frequently diagnosed as tubular adenocarcinoma in Japan. Here, we evaluated the prevalence of submucosal and lymphovascular invasion in a series of 125 endoscopically resected gastric neoplasms. On the basis of Western criteria, the lesions were classified as poorly cohesive carcinomas (n=4) (excluded from further analysis), low-grade dysplasia (n=4), pure HGD (n=78), HGD with tubular adenocarcinoma (n=4), and pure tubular adenocarcinoma (n=35). Submucosal invasion was found in 3.8% of the 78 HGDs, 75.0% of the 4 HGDs combined with adenocarcinoma, and 11.4% of the 35 adenocarcinomas. Venous invasion was detected in 1.3% of the 78 HGDs, 75% of the 4 HGDs combined with adenocarcinoma, and none of the 35 tubular adenocarcinomas. Lymphatic invasion was absent in HGD but noted in 25% of the HGDs combined with adenocarcinoma, and 2.9% of the tubular adenocarcinomas. Thus, we demonstrated that lesions characterized as HGD on the basis of Western criteria can be associated with submucosal and lymphovascular invasion. Endoscopic therapy has made it less crucial to differentiate between HGD and intramucosal adenocarcinoma in biopsy samples of small tubular neoplasms. However, it is important to recognize that the criteria for dysplasia currently used in the West may understate the degree of malignant potential. To limit any diagnostic discrepancy between biopsy, endoscopic resection, and surgical specimens, it is suggested that the features of HGD and adenocarcinoma be reevaluated, which may result in some lesions being classified as mucosal adenocarcinoma.

Prevention strategies for gastric cancer: a global perspective

Despite the substantial burden of gastric cancer worldwide, population strategies for primary prevention have not been introduced in any country. Recognizing the causal role of Helicobacter pylori infection, there is increasing interest in population-based programs to eradicate the infection to prevent gastric cancer. Nonetheless, the paucity of available evidence on feasibility and effectiveness has prevented implementation of this approach. There are very few secondary prevention programs based on screening with endoscopy or radiography, notably in the Republic of Korea and Japan, two of the countries with the highest incidence rates of gastric cancer. In Korea, where the organized screening program is in place, survival rate of gastric cancer is as high as 67%. More research is needed to quantify the specific contribution of the screening program to observed declines in mortality rates. Gastric cancer screening is unlikely to be feasible in many Low-Middle Income Countries where the gastric cancer burden is high. Prevention strategies are still under development and the optimal approach may differ depending on local conditions and societal values. The present review gives an overview of the etiology and burden of the disease, and possible prevention strategies for countries and regions confronted with a significant burden of disease.

Screening for and surveillance of gastric cancer

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

Unveiling lymph node metastasis in early gastric cancer

With respect to gastric cancer treatment, improvements in endoscopic techniques and novel therapeutic modalities [such as endoscopic mucosal resection (EMR) and endoscopic submucosal dissection (ESD)] have been developed. Currently, EMR/ESD procedures are widely accepted treatment modalities for early gastric cancer (EGC). These procedures are most widely accepted in Asia, including in Korea and Japan. In the present era of endoscopic resection, accurate prediction of lymph node (LN) metastasis is a critical component of selecting suitable patients for EMR/ESD. Generally, indications for EMR/ESD are based on large Japanese datasets, which indicate that there is almost no risk of LN metastasis in the subgroup of EGC cases. However, there is some controversy among investigators regarding the validity of these criteria. Further, there are currently no accurate methods to predict LN metastasis in gastric cancer (for example, radiologic methods or methods based on molecular biomarkers). We recommend the use of a 2-step method for the management of early gastric cancer using endoscopic resection. The first step is the selection of suitable patients for endoscopic resection, based on endoscopic and histopathologic findings. After endoscopic resection, additional surgical intervention could be determined on the basis of a comprehensive review of the endoscopic mucosal resection/endoscopic submucosal dissection specimen, including lymphovascular tumor emboli, tumor size, histologic type, and depth of invasion. However, evaluation of clinical application data is essential for validating this recommendation. Moreover, gastroenterologists, surgeons, and pathologists should closely collaborate and communicate during these decision-making processes.

Evidence that gastric pit dysplasia-like atypia is a neoplastic precursor lesion

Most gastric cancers develop via an intestinal metaplasia (IM)-dysplasia-carcinogenic pathway. We have noted that some patients with chronic gastritis have dysplasia-like atypia (DLA) limited to the pit epithelium but without involvement of the surface epithelium. We performed this study to determine the clinical and biological characteristics and outcome of DLA, to gain insight into its role in the pathogenesis of gastric cancer. The study consisted of 102 consecutive patients with resected gastric cancer, a separate cohort of patients (n = 166) with chronic gastritis and IM in their index gastric biopsies, and 44 controls. All specimens were evaluated for clinical and pathologic features of the cancer (in the resection cohort) and background mucosa. Of 102 patients with gastric cancer, 50 (49%) had DLA in areas of mucosa adjacent to or near either conventional dysplasia or cancer. This value was significantly higher than controls (DLA 6.8%; P < .0001). Gastric cancer patients with DLA showed a significantly higher age at presentation; intestinal-type adenocarcinoma; low-grade differentiation; stage 1 tumors; and a higher rate of chronic gastritis, IM, atrophy, and conventional dysplasia in the background mucosa compared to patients without DLA. DLA showed intestinal-type differentiation, and a higher Ki-67 rate and MUC6 positivity compared with IM. Of the 166 patients with biopsies, DLA was identified in 24 (14%). Upon follow-up, 38% of positive cases showed persistent DLA, whereas 25% progressed to conventional low-grade dysplasia. Based on these results, we conclude that DLA represents an important precursor lesion in gastric carcinogenesis and supports its interpretation as a neoplastic lesion.

Early gastric cancer: diagnosis, staging, and clinical impact. Evaluation of 530 patients. New elements for an updated definition and classification

BACKGROUND

The prevention and early diagnosis of gastric cancer permit clinicians to discover the tumor in the initial phase, during which time it can be completely eradicated, endoscopically or surgically. Since Murakami gave the definition of early gastric cancer (EGC) in 1971, many authors have identified various subtypes of EGC with different morphological characteristics and clinical behaviour.

METHODS

We evaluated retrospectively 530 patients: the median follow-up time was 10.4 months (range 0.3-29.2). All tumors were classified according to the macroscopic and microscopic criteria proposed by the Japanese Society of Gastroenterology and Endoscopy and Lauren, respectively. The infiltrative growth pattern was evaluated according to Kodama's classification. Only tumor-related death was considered as an endpoint of interest for the survival analysis.

RESULTS

The overall survival rates of our patients were 94 % (95 % CI, 92-96) and 90 % (95 % CI, 87-93) at 5 and 10 years, respectively. Only 44 patients (8.3 %) died of the disease. Kodama's type (p < 0.0001), lymph node status, both for number and pathological stage according to the 7th Edition of TNM (p < 0.0001), and depth of infiltration (p = 0.0006) were significant prognostic factors in univariate analysis. The multivariate analysis identified Kodama's PENA type (HR, 3.91; 95 % CI, 2.08-7.33; p < 0.0001) and lymph node status for more than three positive nodes versus negative nodes (HR, 12.78; 95 % CI, 5.37-30.43; p < 0.0001) as the only independent prognostic factors in our series.

CONCLUSION

Lymph node status, especially when more than three lymph nodes are involved, is the most important prognostic factor in EGC. However, it is also important to evaluate the infiltrative growth pattern of the cancers in their early phase according to Kodama's classification, considering PEN A type lesions to be more aggressive than the other EGC types. Then, we propose new elements for an updated definition and classification of EGC, with an important clinical impact on the treatment of patients.

Can we resect EGC with Signet ring cells in Europe?

PURPOSE

The proposed guideline for performing endoscopic resection of early gastric carcinoma (EGC) in Paris classification is a well-differentiated carcinoma with maximum involvement Sm1. Signet ring cell carcinomas (SRC) are excluded from this recommendation. Authors from Eastern countries have proposed extending this resection to include selected undifferentiated EGC. Via an analysis of a series of cases of signet ring carcinoma, we will discuss whether it is possible to resect EGC with signet ring cells in Europe.

METHODS

We retrospectively included patients with histological classification pT1 of EGC showing SRC. Data was extracted from the hospital gastrectomy register. Lymphadenomectomy D1.5 was performed on all patients. Histology results were retrospectively obtained from the electronic patient file.

RESULTS

Twelve patients (mean age = 55.4, four women, eight men) underwent surgery, without previous chemotherapy, between 2000 and 2012, for EGC with SRC. Mean size of the lesions was 20.2 mm (5-35 mm). Seven lesions were located in the antrum, five in the fundus. In the case of nine patients, histology showed no lymphovascular involvement. None of these nine patients presented lymph node metastases (LNM). Five patients had intramucosal carcinoma, four were classified as Sm1, one patient was Sm2, and one patient was Sm3. On surgery, the three patients with lymphovascular invasion showed LNM.

CONCLUSION

Endoscopic resection of EGC with SRC does not systematically imply complementary treatment by surgery, although criteria for endoscopic resection are difficult to determine because of the lack of data in Europe.

Pathology of gastric cancer and its precursor lesions

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

Comparisons of Gastric Cancer Treatments: East vs. West

There has been a large amount of speculation concerning the differences in the outcomes in patients who have gastric cancer in the Eastern and Western worlds. The differences in biology, surgical and adjuvant treatment have been used to explain such differences. There are clear differences observed in the histology (diffuse vs. intestinal), tumor location (proximal vs. distal), environmental exposures, dietary factors and Helicobacter pylori status. A higher incidence of gastric cancer in the East has led to screening programs, and leading to an earlier stage at presentation. Surgical treatment differs in that the extended lymph node dissection is routinely practiced in the Asian countries. Additionally, different adjuvant therapeutic regimens are used in both regions. The purpose of this review is to describe the differences in both presentation and treatment between the East and the West.

Current status of endoscopic submucosal dissection for the management of early gastric cancer: A Korean perspective

The early diagnosis of gastric cancer allows patients and physicians to pursue the option of endoscopic resection, which is significantly less invasive than conventional surgical resection. In Korea, the use of endoscopic submucosal dissection (ESD) has been increasing, and many reports on ESD have been published. In addition, Korean gastroenterologists from several hospitals performing ESD have conducted formal meetings to discuss useful information regarding ESD. Here, we discuss the Korean experience with ESD, including outcomes and prospects of endoscopic treatments.

Lymph node metastasis from intestinal-type early gastric cancer: experience in a single institution and reassessment of the extended criteria for endoscopic submucosal dissection

BACKGROUND

Given the increasing use of endoscopic resection as a therapeutic modality for cases of early gastric cancer (EGC), it is very important to define strict criteria for the use of endoscopic mucosal resection and endoscopic submucosal dissection. To date, the criteria are almost entirely based on Japanese literature evaluating the risk of lymph node (LN) metastasis in patients with EGC.

OBJECTIVE

To analyze our own experience with the factors affecting LN metastasis and to reappraise the extended criteria for endoscopic submucosal dissection.

DESIGN

Retrospective, single-center study.

SETTING

University teaching hospital.

PATIENTS

This study involved 478 patients who underwent gastrectomy with LN dissection (n = 270, mucosal [m] EGC; n = 208, submucosal [sm] EGC).

INTERVENTION

Gastrectomy with LN dissection.

MAIN OUTCOME MEASUREMENTS

LN metastasis.

RESULTS

Overall, 12.6% (60/478) of patients with EGCs presented with LN metastasis (mEGC, 3.0% [8/270], smEGC, 25.0% [52/208]). Increased size, macroscopic type (elevated), depth of invasion, and lymphovascular invasion were associated with LN metastasis. In 270 cases of mEGC, there was no relationship between clinicopathologic features and LN metastasis. In the smEGC group, size, depth of invasion, and lymphovascular emboli were associated with an increased risk of LN metastasis. Significantly, LN metastasis was noted in EGCs falling within established extended endoscopic submucosal dissection criteria, that is, intestinal-type mucosal cancer of any size without ulcer and no lymphovascular emboli (2/146 [1.4%]) or < or =3 cm with no lymphovascular emboli and irrespective of the presence of ulceration (2/126 [1.6%]) or intestinal-type submucosal cancer (sm1, <500 microm) without lymphovascular invasion and measuring < or =3 cm in size (3/20 [15.0%]).

LIMITATIONS

Retrospective review of a single-center study.

CONCLUSION

We recommend that more centers survey their experiences of LN metastasis in cases of EGC to refine the criteria for endoscopic submucosal dissection as a therapeutic modality of intestinal-type EGC.

A cohort study of missed and new cancers after esophagogastroduodenoscopy

OBJECTIVES

Little is known about missed rates of upper gastrointestinal cancer (UGC) in Western populations, with most data originating from Japanese centers quoting high missed rates of 23.5-25.8%. The objective of this study was to better define missed rates of esophagogastroduodenoscopy (EGD) and the natural history of UGC in a Western population that underwent an initial EGD without cancer, but were subsequently diagnosed with a UGC. Our hypothesis was that a normal EGD rarely misses the detection of UGC.

METHODS

This is a retrospective cohort study. A prospectively maintained electronic database was used to identify all patients who underwent EGD between 1990 and 2004 at the study institution. Patients in this cohort who were diagnosed with UGC before 2006 were identified through the Western Australian Cancer Registry. We defined missed cancers as those diagnosed within 1 year of EGD, possible missed cancers as those diagnosed 1-3 years after EGD, and new cancers as those diagnosed more than 3 years after EGD. This study had no interventions and was conducted at a tertiary referral center. The main outcome measurement included UGC.

RESULTS

Of the 28,064 EGDs performed, UGC was diagnosed subsequent to the procedure in 116 cases (0.41%). There were 29 missed cancers, 26 possible missed cancers, and 75 new cancers. Of the missed cancers, 11 were esophageal, 15 were gastric, and 3 were duodenal. In 69% (n=20) of the missed cancers, an abnormality was described at the site of malignancy. In 59% (n=17) of the missed cancers, the indication for EGD was an alarm symptom of dysphagia or suspected blood loss. In an univariate analysis, the presence of an alarm symptom was related to missed cancers, whereas operator experience, trainee participation, and usage of newer equipment were not. One of the main limitations of this study is that it was a retrospective review.

CONCLUSIONS

UGC is rare after normal EGD, confirming the high accuracy of EGD. Institutional approval was granted for the conduct of this study.

[Dysplasia in glandular digestive tissues: new concepts, new classifications]

The term of dysplasia is currently used to designate morphological alterations, identifiable at microscopic examination, revealing the existence of an unequivocally neoplastic process, at an early, non-invasive, stage of its natural history. The pathologist bears the full responsibility for the diagnosis of dysplasia, based on a broad spectrum of cytological and architectural abnormalities. It is important to grade the severity of the dysplastic lesions, in order to help guide clinical management and choose the therapeutic strategy. The Vienna classification, proposed in 2000 as a compromise between the Western and Japanese concepts, is now used for classification and grading of digestive epithelial dysplasia. The major advantages of the Vienna classification are the use of uniform terminology worldwide, achievement of good diagnostic reproducibility between pathologists and clear and consensual clinical consequences. Its use is strongly supported by the recent international recommendations.

[Evaluation of dysplasia in gastrointestinal diseases]

Dysplasia, or intraepithelial neoplasia, consists of noninvasive neoplastic cellular proliferation that may precede or accompany invasive neoplasia. Diagnosis is mainly based on histological criteria, which include cytological and structural alterations, since macroscopically identifiable lesions often do not occur. In all current classifications, dysplasia is divided in two categories, low- and high-grade, with the aim of attempting to evaluate risk and guide the therapeutic approach. The classification of the Vienna consensus aims to unity criteria and decrease interobserver variability in diagnosis. In the digestive tract, evaluation of epithelial dysplasia is especially important in four entities: Barrett's esophagus, chronic gastritis, inflammatory bowel disease, and colorectal adenomas. The criteria for diagnosis and dysplasia staging are the same in all these entities, but the therapeutic approach may vary according to the affected organ and the clinico-pathological context.

α-Methylacyl-CoA-Racemase Expression in Adenocarcinoma, Dysplasia and Non-Neoplastic Epithelium of the Stomach

Alpha-methylacyl-CoA-racemase (AMACR) is an essential enzyme in the oxidation of bile acid intermediates and branched-chain fatty acids. This study aims to examine the expression pattern, as well as diagnostic and prognostic significance, of AMACR in carcinoma, dysplasia and non-neoplastic epithelium of the stomach. A total of 158 cases, including 66 cases of gastric carcinoma (GC), 48 cases of dysplasia and 44 cases of non-neoplastic gastric mucosa, were examined by immunohistochemistry for AMACR. AMACR expression was divided into two categories: negative (negative-weak staining intensity) and positive (moderate-strong staining intensity). AMACR immunoreactivity was detected in only 2 of 44 (4.5%) cases of non-neoplastic epithelium. A significantly high frequency of AMACR expression was found in 40 of 48 (83.3%) cases of dysplasia and 34 of 66 (51.5%) carcinoma cases compared with cases of non-neoplastic epithelium (p < 0.05). The frequency of AMACR expression was significantly higher in dysplasia than in carcinoma cases (p < 0.05). AMACR expression was higher in intestinal- than diffuse-type GC (p < 0.05). In conclusion, this study suggests that AMACR immunostaining aids in distinguishing malignant or precancerous lesions from reactive epithelial atypia in gastric biopsy specimens. It also suggests that AMACR expression is more likely to be associated with intestinal-type adenocarcinoma in gastric carcinogenesis.

Salt and stress synergize H. pylori-induced gastric lesions, cell proliferation, and p21 expression in Mongolian gerbils

Our aim was to determine if salt and stress enhance Helicobacter pylori (Hp) lesions in Meriones unguiculatus. Two hundred seventy-eight pathogen-free gerbils were allocated to seven groups: Hp-Sydney strain (45), 8% higher-salt diet (38), stress (60% space reduction/water immersion; 36), Hp + salt (33), Hp + stress (34), N-methyl-N-nitro-N-nitrosoguanidine (34), and sham (58). Gerbils were sacrificed at 1 week (67), 12 weeks (73), 52 weeks (65), and 68 weeks (73). Sydney, Padova, and Lauren classifications were blindly used. Proliferation, p53, p21, and apoptosis were assessed. Follicular active gastritis (grade 2/3) was observed in 10% of Hp gerbils, 38% of Hp + salt gerbils, and 29% of Hp + stress gerbils at 52 weeks and 67%, 83%, and 43% at 68 weeks (P < 0.05). Heterotopic proliferative glands were identified in synergy groups from 52 weeks, with increases in their number and size by 68 weeks. Higher proliferative rates were observed in Hp+salt gerbils (P < 0.0001), and p21 overexpression in Hp+salt and Hp+stress gerbils (both P's < 0.0001), by 68 weeks, without p53 increases. We conclude that salt and stress synergize Hp damage and increase pseudo-invasive gland foci.

Updated diagnostic criteria on gastric epithelial dyspalsia

Large discrepancies exist between Eastern and Western countries in the diagnostic criteria for gastric epithelial dysplasia. With the purpose of a worldwide-accepted terminology and classification of precancerous lesions, Padova and Vienna classifications are established and reach a consensus that epithelial dysplasia is the earliest visible manifestation of neoplasia and the stage at which invasion has not yet occurred. So the primary term 'dysplasia' is confusing and misleading as gastric precancerous lesion. With more insight into dysplasia, new directions will be found to explore the pathogenesis, reversibility and therapy of dysplasia.

Early gastric cancer: diagnosis and less invasive treatments

The prognosis of early gastric cancer (EGC) is excellent worldwide. Incidence of EGC shows considerable geographic variation, and in high prevalence areas where diagnostic skills are adept, EGCs are not frequently overlooked. In these countries, less invasive, function-preserving treatments such as endoscopic mucosal resection and pylorus-preserving gastrectomy have become standard options. The criteria to apply conservative treatments are being expanded along with the technological improvement. Though its natural history is relatively long, EGC could be a fatal disease and should be carefully treated. Lymph node metastasis is the most important prognostic factor that should be considered in treatment selection and follow-up planning of EGC.

Increased Epithelial Cadherin Expression among Japanese Intestinal-Type Gastric Cancers Compared with Specimens from American Patients of European Descent

The different patterns of gastric cancer in the Far East and West have evolved to the extent that it has been suggested that the disease in Japan is biologically less aggressive than in the West. We studied paraffin-embedded, formalin-fixed tissue blocks from Japanese patients and American patients of European descent who had undergone gastrectomy for gastric cancer not involving the gastroesophageal junction. Specimens were staged (T stage), graded (Lauren classification), and biomarker expression (epithelial cadherin [E-cadherin], c-erbB2, Ki67, and p53) was quantified using immunohistochemistry without knowledge of the country of origin. E-cadherin was expressed in 49 per cent of malignant cells from Japanese specimens compared with 27 per cent of malignant cells from American specimens (P = 0.04). The expression of E-cadherin on diffuse cancers from the two countries was similar (34.4 in Japanese vs 41.5 in American, P = 0.92). E-cadherin expression, however, was significantly higher among intestinal cancers from the two countries: 56.3 per cent of cells from intestinal or mixed cancers from Japan (n = 32) expressed E-cadherin compared with 22.2 per cent of American specimens (n = 12; P = 0.008). c-erbB2 was expressed on a higher proportion of malignant cells from American specimens (30% vs 22%; P = 0.20). E-cadherin expression, a favorable prognostic factor, is more common in Japanese intestinal-type gastric cancer not involving the gastroesophageal junction. If the biology of gastric cancer in the Far East is less aggressive than that in the United States, it is likely that treatments need to be individualized.

Role of therapy or monitoring in preventing progression to gastric cancer

It is generally accepted that intestinal-type gastric adenocarcinoma arises through a multistep process originating with chronic gastritis, progressing through stages of atrophy, intestinal metaplasia, and dysplasia and finally invasive carcinoma. This sequential process, known as the "Correa cascade" is in many instances initiated by Helicobacter pylori infection and perpetuated by a number of environmental and host factors. Given that the development of carcinoma can be the end point of this sequential process, there is great interest in determining which if any of these steps may be reversible. Clinical studies have shown that the eradication of H. pylori can lead to resolution of chronic gastritis, and a few studies have suggested some improvement in gastric atrophy. Intestinal metaplasia, however, does not appear to be as reversible. Nevertheless, results of several intriguing studies of high-risk populations support the notion that eradication of H. pylori may decrease or delay progression to gastric carcinoma despite the inability to reverse all mucosal damage. The applicability of these findings to low-risk countries such as the United States and the United Kingdom remain uncertain. Currently, in the United States, there is no widely accepted screening program for H. pylori infection in asymptomatic individuals, and consensus regarding surveillance for gastric intestinal metaplasia or dysplasia is lacking. The purpose of this report is to evaluate the available data regarding the epidemiology of H. pylori and associated carcinoma, discuss relevant human and animal data that address eradication strategies in the prevention of gastric carcinoma, and finally discuss current recommendations regarding screening programs aimed at high-risk populations.

Observer variation of encapsulated follicular lesions of the thyroid gland

Although histologic definition of follicular thyroid lesions is readily available, application of the diagnostic criteria and personal experience may lead to disagreement among pathologists. To investigate interobserver variation in assessment of encapsulated follicular lesions, eight pathologists (four American and four Japanese) reviewed the same hematoxylin and eosin-stained slide of each of 21 cases of thyroid lesions showing encapsulation and follicular growth pattern. In 10% of the cases, there was complete agreement. At least seven pathologists agreed on the diagnosis in 29% of the cases, and at least six in 76% of the cases. American and Japanese pathologists agreed among themselves in 33% and 52% of cases, respectively. The frequency of diagnosis of adenomatous goiter among Japanese pathologists (31%) was considerably higher than that among American pathologists (6%). In contrast, the frequency of diagnosis (25%) of papillary carcinoma among American pathologists was considerably higher than that (4%) among Japanese pathologists. Our analysis revealed three main factors affecting observer variation: 1) interpretation of the significance of microfollicles intimately related to capillaries within the tumor capsule, 2) evaluation of what constituted the type of nuclear clearing indicative of papillary carcinoma, and 3) absence of clear morphologic criteria for separation of adenomatous goiter and follicular adenoma. To reduce observer variation of encapsulated follicular lesions, it will be necessary to provide more explicit criteria for diagnosis.

Early diagnosis for colorectal cancer in China

AIM

To review the present studies on early diagnosis of colorectal cancer.

METHODS

The detective rate for early cancer is 1.7%-26.1% based on various statistical data, with much higher detective rate in endoscopy. Since early cancer means invasion involved in the mucosa or submucosa, the diagnosis can only be made when the invasive depth is identified. Pathological tissue materials from both surgical operation or endoscopic resection are suitable for early cancer evaluation.

RESULTS

Incidence of polyp malignancy is 1.4%-20.4%. The various constitutive proportion of polyps may explain the different rates. Malignant incidence is higher in adenomatous polyps, that for villous polyps can reach 21.3%-58.3%. Type II early stage of colorectal carcinoma is rarely reported in China. It is shown that majority of them were not malignant, most of type IIa being adenoma or hyperplasia, and IIb being inflammatory and IIc might be the isolated ulcers. The occurrence of malignancy of type II is far lower than that of polypoid lesion. In China, the qualitative diagnosis and classification of neoplasm generally adopted the WHO standard, including surgical excision or biopsies. There is impersonal evaluation between colorectal pre-malignancy and cancer. The former emphasizes the dysplasia of nuclei and gland, while the latter is marked with cancer invasion. Diagnosis of early stage colorectal cancer in endoscopy is made with too much caution which made the detective rate much lower. Mass screening for asymptomatic subjects and follow-up for high risk population are mainly used to find the early stage colorectal cancer in China. Fecal occult blood test is also widely made as primary screening test, galactose oxygenase test of rectal mucus (T antigen), fecal occult albumin test are also used. The detective rate of colorectal cancer is 24-36.5 per 105 mass population.

CONCLUSION

Although carcinoma associated antigen in blood or stool, microsatellite DNA instability for high risk familial history, molecular biology technology for stool oncogene or antioncogene, telomerase activity and exfoliative cytological examination for tumor marker, are utilized, none of them is used in mass screening by now.

The difference in gastric cancer between Japan, USA and Europe: what are the facts? what are the suggestions?

In Japan the survival rate for gastric cancer has steadily improved over the last 30 years whilst that in the West has remained static and inferior. In this review three hypotheses are examined to explain the difference. There is little evidence to suggest genetic differences, which might result in a less aggressive cancer in Japan. Recently there has been a rise in the proportion of cancers of the gastro-oesophageal junction in the West and this has not been seen in Japan. The comparison of survival data from these two regions is problematic with different staging systems and a stage migration effect. The established surgical treatment of gastric cancer in Japan is radical gastrectomy and regional lymphadenectomy and this has been proposed as a superior treatment to the standard gastrectomy common in the West. The results for survival benefit however, have not been reproduced in randomized clinical trials. The heterogeneity of adjuvant and neoadjuvant treatment regimens in Japan and the West has led to difficulties in the interpretation of their effects. There is considerable scope for future collaboration between clinicians in the West and Japan.

Altered mucin expression in the gastrointestinal tract: a review

Early studies of changes in mucin expression in disorders of the gastrointestinal tract focused on alterations in the carbohydrate chain. This review briefly considers the various mechanisms by which such alterations may come about: (a) normal variation, (b) sialic acid alterations, (c) defective assembly of carbohydrate side-chains, (d) changed expression of core proteins and (e) epithelial metaplasia. The availability of monoclonal antibodies to mucin core proteins adds a new dimension to mucin histochemistry. It is now possible to offer explanations for traditional mucin histochemical findings on the basis of lineage-specific patterns of mucin core protein expression. Changes in core protein expression are described in inflammatory, metaplastic and neoplastic disorders of the gastrointestinal tract. The possibility that mucin change could be important in the aetiology of some diseases such as ulcerative colitis and H. pylori gastritis is considered. It is more probable, however, that changes in mucin expression are secondary to reprogramming of cellular differentiation and altered cell turnover. As such they may serve as markers to explain pathogenesis and provide novel diagnostic and prognostic information.

The pathology of epithelial pre-malignancy of the gastrointestinal tract

This chapter deals with pre-malignant epithelial lesions of the gastrointestinal tract that have the potential to become cancers. Pre-malignant lesions are divided into two types: those characterized by dysplastic mucosa and those without dysplasia. Examples of the two types are present in the oesophagus, stomach and intestine. In the oesophagus, dysplasia of the squamous epithelium is a precursor to squamous carcinoma. There are differences in interpretation between Western and Japanese pathologists in the diagnosis of oesophageal squamous lesions. Dysplasia in Barrett's oesophagus is regarded as a precursor of adenocarcinoma. The goal of endoscopic surveillance in Barrett's mucosa is the detection of high-grade dysplasia. There are several problems with our current knowledge of high-grade dysplasia and controversies regarding its management. There are differences in the interpretation of biopsies of gastric epithelial dysplasia between Japanese and Western pathologists. In the colon, pre-malignant lesions include dysplasia seen in inflammatory bowel disease and colonic adenomas. The most significant predictor of the risk of malignancy in patients with inflammatory bowel disease is the presence of dysplasia in colonic biopsies. Because of the similarity of neoplasia throughout the gastrointestinal tract, there have been attempts to unify its classification, terminology and diagnostic criteria internationally, the most recently proposed modified classification of gastrointestinal neoplasia being the Vienna classification. Dysplasia of the columnar mucosa has a similar appearance in Barrett's oesophagus, the stomach and the colon. Criteria for its histological diagnosis and grading are reviewed, with an emphasis on areas of diagnostic difficulty such as interobserver variation, and discrepancies between Western and Japanese pathologists. Implication of the presence of dysplasia that are specific to each organ site are discussed, highlighting weaknesses and controversies in current knowledge.

Dysplasia east and west

Between 1996 and 1998, several small international studies were conducted in which pathologists in group settings were asked to identify various cancers from previously prepared slides. It was hoped that these sessions would lead to international consensus with regard to terminology and help to explain the previously noted differences in diagnoses reported between Western and Japanese practitioners. This article reviews the findings of the various groups and their implications for practicing gastroenterologists.

Gastric dysplasia: the Padova international classification

A worldwide-accepted histologic, classification of the gastric carcinomatous and precancerous lesions is a prerequisite for a consistent recording of epidemiologic data and for both developing and evaluating primary and secondary preventive efforts. Different nomenclatures have been proposed for gastric precancerous lesions in eastern countries and in Japan. This article presents a classification of gastric precancerous lesions resulting from an international consensus conference involving pathologists of different countries. Five main diagnostic categories are identified. To allow comparisons with the nomenclature proposed by the Japanese Research Society for Gastric Cancer, each category was also assigned a numeric identification: 1 = normal, 2 = indefinite for dysplasia, 3 = noninvasive neoplasia, 4 = suspicious for invasive cancer, and 5 = cancer. The interobserver reproducibility of the histologic classification was tested in a series of 46 cases. By collapsing benign alterations (categories 1+2) versus noninvasive neoplasia (category 3) versus suspicious for invasive cancer and fully appearing carcinomatous lesions (categories 4+5), the general agreement value was 77.7%, whereas kappa coefficient was 0.63. By examining gastric precancerous lesions from diverse populations, the authors agreed that the gastric precancerous process is universal and the differences in nomenclatures are merely semantics. The international Padova classification of the gastric precancerous lesions is submitted to the attention of the international scientific community, which is invited to test and to improve on it.