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Aims: Gastric pyloric gland adenomas (PGAs) are rare epithelial polyps that are found more commonly in autoimmune atrophic gastritis and familial adenomatous polyposis (FAP). Little is known about the morphology and genetics of PGAs in FAP. PGAs in FAP are studied morphologically and genetically. Findings in FAP-associated PGAs are compared to sporadic PGAs and related lesions such as oxyntic gland adenoma (OGA) to increase our understanding of these rare polyps., Methods and Results: Seven PGAs and 18 fundic gland polyps (FGPs) from FAP patients were collected. KRAS and GNAS mutations were determined in six PGAs and 18 FGPs. Immunohistochemistry was applied on five PGAs to provide further confirmation of the histological subtypes and genetic alterations. Morphology of all PGAs was studied and compared to literature on sporadic PGAs and related lesions. All successfully sequenced PGAs (six of six) carried GNAS mutations and half of the successfully sequenced PGAs carried a KRAS mutation (three of six). Nuclear β-catenin was seen only in one PGA with focal high-grade dysplasia. Morphologically, PGAs in FAP showed overlapping features with OGA., Conclusion: Familial adenomatous polyposis-associated PGAs have a similar genetic background as sporadic PGAs, i.e. KRAS and GNAS mutation. Based on morphological findings in FAP associated PGAs, it is hypothesized that PGAs and OGAs are closely related lesions., Competing Interests: Disclosure/Conflict of Interest: The authors have nothing to disclose., (© 2016 John Wiley & Sons Ltd.)

Gastric polyps are found in 1% to 4% of patients undergoing gastroscopy. The vast majority are sporadic, but some gastric polyps indicate an underlying syndrome. Gastric polyps can manifest in each of the gastrointestinal polyposis syndromes, including the recently described gastric adenocarcinoma and proximal polyposis of the stomach syndrome. In addition, gastric polyps occur in Lynch syndrome and in a few rare conditions that are not primarily gastrointestinal. While some of these syndromes are clearly associated with an increased risk of gastric cancer, others are not. Interestingly, even in disorders with a well-established risk of gastric cancer, the neoplastic potential and the precursor status of these gastric polyps are not always clear. Although rare, recognition of syndromic gastric polyps is important for individual patient management. These conditions also serve as important models to study gastric homeostasis and gastric tumorigenesis., (© The Author(s) 2015.)

Background: Clinical staging of adenocarcinoma of the gastroesophageal junction (GEJ) determines the curative treatment regimen containing either neoadjuvant chemotherapy or chemoradiotherapy followed by either gastrectomy or esophagectomy. The value of current diagnostic tools is a matter of debate., Methods: A prospective database (2003-2013) was used to identify 266 consecutive patients with adenocarcinoma of the GEJ in order to evaluate the accuracy of endoscopic ultrasound (EUS) and computed tomography (CT) regarding tumor localization according to Siewert, nodal status and its consequences on treatment strategy., Results: Overall accuracy in determining tumor localization was 73% for endoscopy/EUS and 61% for CT (p = 0.018). With endoscopy/EUS, the accuracy was 97%, 66% and 75% respectively for type I, II and III. With CT this was respectively 69%, 57% and 80%. The overall accuracy for determining N-status (N0/N+) per patient was 75% for EUS and 71% for CT. Accuracy for determining a positive nodal station in patients without neoadjuvant therapy was 77% for EUS and 71% for CT (p = 0.001). Accuracy for detecting positive upper mediastinal nodes was 80-92%, whereas for peritumoral and abdominal nodes this was 50-80% in both EUS and CT. In 8/266 patients (3%) the type of surgery changed due to intraoperative findings. A radical resection was performed in 233 patients (88%)., Conclusions: Despite the suboptimal accuracy of determining tumor localization with EUS and CT, in only a small number of patients an intraoperative change of surgical treatment was needed. EUS is superior to CT in determining nodal status and tumor localization in GEJ tumors., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Currently, gastric cancer (GC) is one of the most frequently diagnosed neoplasms, with a global burden of 723000 deaths in 2012. It is the third leading cause of cancer-related death worldwide. There are numerous possible factors that stimulate the pro-carcinogenic activity of important genes. These factors include genetic susceptibility expressed in a single-nucleotide polymorphism, various acquired mutations (chromosomal instability, microsatellite instability, somatic gene mutations, epigenetic alterations) and environmental circumstances (e.g., Helicobcter pylori infection, EBV infection, diet, and smoking). Most of the aforementioned pathways overlap, and authors agree that a clear-cut pathway for GC may not exist. Thus, the categorization of carcinogenic events is complicated. Lately, it has been claimed that research on early-onset gastric carcinoma (EOGC) and hereditary GC may contribute towards unravelling some part of the mystery of the GC molecular pattern because young patients are less exposed to environmental carcinogens and because carcinogenesis in this setting may be more dependent on genetic factors. The comparison of various aspects that differ and coexist in EOGCs and conventional GCs might enable scientists to: distinguish which features in the pathway of gastric carcinogenesis are modifiable, discover specific GC markers and identify a specific target. This review provides a summary of the data published thus far concerning the molecular characteristics of GC and highlights the outstanding features of EOGC.

Gastric polyps occur in 1-4 % of patients undergoing gastroscopy. Although most are sporadic, some gastric polyps are part of an underlying hereditary syndrome. Gastric polyps can be seen in each of the well-known gastrointestinal polyposis syndromes, but also in Lynch syndrome and in several rare not primarily gastrointestinal syndromes. In addition, Gastric Adenocarcinoma and Proximal Polyposis of the Stomach (GAPPS) is a recently described heritable syndrome characterized by isolated gastric polyposis and risk of gastric cancer.Some of these syndromes are associated with an increased risk of gastric cancer, whereas others are not. However, the neoplastic potential and the precursor status of these gastric polyps are not always clear, even in syndromes with a well-established risk of gastric cancer. For instance, the neoplastic potential of Peutz-Jeghers polyps is debatable, despite the well-established risk of gastric cancer in this syndrome. Also fundic gland polyps and gastric foveolar-type adenomas in FAP carry a low risk of malignant transformation. In contrast, gastric juvenile polyps are precursor lesions of gastric cancer in juvenile polyposis syndrome through neoplastic progression of juvenile polyps in these patients.Although these hereditary syndromes with gastric polyps are rare, recognition is important for individual patient management. Furthermore, the initiation and progression of these lesions can be influenced by environmental factors such as Helicobacter Pylori infection. This makes these rare lesions an appropriate model for understanding the clonal evolution of early gastric cancer in the wider population.

Background: The advantage of laparoscopic gastrectomy compared to open gastrectomy has been established in Asian patient series with early gastric cancer. However, its feasibility in Western European patients with locally advanced gastric cancer is unknown., Methods: Between 2006 and 2014 70 consecutive patients with advanced gastric cancer underwent laparoscopic gastrectomy with D2 lymph node dissection. A Billroth II reconstruction was performed after distal gastrectomy. In case of total gastrectomy a jejunal J-pouch reconstruction was performed., Results: Total gastrectomy was performed in 56 patients and distal gastrectomy in 14 patients. Perioperative chemotherapy was administered in 45/70 (64%) patients. A radical resection was achieved in 63/70 (90%). The median number of dissected lymph nodes was 17 (2-62). The median intraoperative blood loss was 305 (30-2700) milliliters. The median postoperative hospital stay was 11 (5-91) days. The 30-day mortality was 4.3%., Conclusions: Laparoscopic gastrectomy can be performed in Western European patients with advanced gastric cancer and meets the oncologic standard with low intraoperative blood loss and short hospital stay., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

Background: For patients with an identified germline E-cadherin-1 (CDH1) mutation, prophylactic gastrectomy is the treatment of choice to eliminate the high risk of developing diffuse gastric cancer. Laparoscopic total gastrectomy with jejunal pouch reconstruction is a novel approach that may be especially suitable in these patients., Methods: Patients with a germline CDH1 mutation who underwent prophylactic laparoscopic total gastrectomy with jejunal pouch were included in our prospective database., Results: A total of 11 patients with a median age of 40 (22-61) years were included. The average operative time was 4:26 ± 0:49 h and the average blood loss was 219 ± 155 ml. Median length of hospital stay was 10 (7-27) days. In two patients, an esophagojejunal anastomotic leakage occurred (grade 4). The leakages were seen in patient numbers 2 and 3, which may be a result of a learning curve. The latter eight patients did not develop anastomotic leakage. Pulmonary complications occurred in one patient with atelectasis and in one patient with pneumonia (grade 2). The 60-day mortality rate was 0 %. Multiple foci of intramucosal diffuse gastric signet ring cell carcinoma were found in the resection specimen of 9/11 (82 %) patients. All 11/11 (100 %) resections were microscopically radical., Conclusions: Prophylactic laparoscopic total gastrectomy with jejunal pouch reconstruction in patients with a CDH1 germline mutation is feasible and safe. In 82 % of patients, foci of intramucosal diffuse gastric signet ring cell carcinoma in the resection specimen were found.

Hereditary hemochromatosis (HH) is a strong risk factor for hepatocellular cancer, and mutations in the HFE gene associated with HH and iron overload may be related to other tumors, but no studies have been reported for gastric cancer (GC). A nested case-control study was conducted within the European Prospective Investigation into Cancer and Nutrition (EPIC), including 365 incident gastric adenocarcinoma and 1284 controls matched by center, sex, age and date of blood collection. Genotype analysis was performed for two functional polymorphisms (C282Y/rs1800562 and H63D/rs1799945) and seven tagSNPs of the HFE genomic region. Association with all gastric adenocarcinoma, and according to anatomical localization and histological subtype, was assessed by means of the odds ratio (OR) and 95% confidence interval (CI) estimated by unconditional logistic regression adjusted for the matching variables. We observed a significant association for H63D with OR (per rare allele) of 1.32 (CI = 1.03-1.69). In subgroup analyses, the association was stronger for non-cardia anatomical subsite (OR = 1.60, CI = 1.16-2.21) and intestinal histological subtype (OR = 1.82, CI = 1.27-2.62). Among intestinal cases, two tagSNPs (rs1572982 and rs6918586) also showed a significant association that disappeared after adjustment for H63D. No association with tumors located in the cardia or with diffuse subtype was found for any of the nine SNPs analyzed. Our results suggest that H63D variant in HFE gene seems to be associated with GC risk of the non-cardia region and intestinal type, possibly due to its association with iron overload although a role for other mechanisms cannot be entirely ruled out.

Gastric stump carcinoma (GSC) following remote gastric surgery is widely recognized as a separate entity within the group of various types of gastric cancer. Gastrectomy is a well established risk factor for the development of GSC at a long time after the initial surgery. Both exo- as well as endogenous factors appear to be involved in the etiopathogenesis of GSC, such as achlorhydria, hypergastrinemia and biliary reflux, Epstein-Barr virus and Helicobacter pylori infection, atrophic gastritis, and also some polymorphisms in interleukin-1β and maybe cyclo-oxygenase-2. This review summarizes the literature of GSC, with special reference to reliable early diagnostics. In particular, dysplasia can be considered as a dependable morphological marker. Therefore, close endoscopic surveillance with multiple biopsies of the gastroenterostomy is recommended. Screening starting at 15 years after the initial ulcer surgery can detect tumors at a curable stage. This approach can be of special interest in Eastern European countries, where surgery for benign gastroduodenal ulcers has remained a practice for a much longer time than in Western Europe, and therefore GSC is found with higher frequency.

A genome-wide study performed in a Japanese population identified a strong association between SNP rs2294008 (Met1Thr) in the Prostate Stem Cell Antigen gene (PSCA) and diffuse-type gastric cancer (GC). This association was validated in different Asian populations, and, very recently, a study has been published in Caucasians. In this study, we analyzed the association between PSCA variation and GC risk in Caucasians from the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort. Six tagSNPs covering the PSCA gene region were genotyped in 411 incident gastric adenocarcinoma cases and 1530 matched controls from a nested case-control study in the EPIC cohort. Associations were analyzed by unconditional logistic regression, adjusting for age, sex and country. The T allele of rs2294008 in PSCA was found to be a highly significant risk factor for GC (per allele OR = 1.42, 95% CI: 1.23-1.66, p-value = 6.5 × 10(-6) ), particularly of the noncardia-type (per allele OR = 1.47, 95% CI: 1.19-1.81, p-value = 3 × 10(-4) ). At contrast with previous studies, no significant differences were observed between the diffuse (per allele OR = 1.54, 95% CI: 1.20-1.96, p-value = 5 × 10(-4) ) and the intestinal (per allele OR = 1.52, 95% CI: 1.20-1.93, p-value = 5 × 10(-4) ) GC histological subtypes. Although rs12155758 and rs9297976 were also found associated with GC, this association appeared to be due to linkage disequilibrium with rs2294008. Haplotype analysis did not provide additional information. These results confirm the association between variation in the promoter region of PSCA and GC risk in Caucasians and also indicate that the rs2294008 variant is a similar risk factor for both the diffuse and intestinal-types of GC., (Copyright © 2011 UICC.)

Hereditary diffuse gastric cancer is an autosomal dominant cancer syndrome characterized by highly penetrant diffuse gastric cancer. It is caused by germ line mutations in CDH1, encoding the cell-cell adhesion protein E-cadherin. Pancreatic ductal adenocarcinoma is one of the most dismal malignancies in humans. Although absent E-cadherin expression in pancreatic ductal adenocarcinoma is related to a higher tumor grade and a worse prognosis, there have been no reports of pancreatic ductal adenocarcinoma associated with hereditary diffuse gastric cancer. Here, we describe a patient with hereditary diffuse gastric cancer who was subsequently diagnosed with pancreatic ductal adenocarcinoma. To investigate if the previously identified CDH1 germ line mutation initiated pancreatic ductal adenocarcinoma development, we performed mutational and proteomic analyses. We conclude that the pancreatic ductal adenocarcinoma did not occur in the context of the germ line CDH1 mutation but rather appeared as a sporadic event. Immunohistochemistry ultimately proved to be the most valuable tool of investigation as persistent CDH1 staining in the pancreatic ductal adenocarcinoma unequivocally revealed E-cadherin expression., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Epigenetic events have emerged as key mechanisms in the regulation of critical biological processes and in the development of a wide variety of human malignancies, including gastric cancer (GC), however precise gene targets of aberrant DNA methylation in GC remain largely unknown. Here, we have combined pyrosequencing-based quantitative analysis of DNA methylation in 98 GC cases and 64 controls nested within the European Prospective Investigation into Cancer and Nutrition (EPIC) cohort and in cancer tissue and non-tumorigenic adjacent tissue of an independent series of GC samples. A panel of 10 cancer-associated genes (CHRNA3, DOK1, MGMT, RASSF1A, p14ARF, CDH1, MLH1, ALDH2, GNMT and MTHFR) and LINE-1 repetitive elements were included in the analysis and their association with clinicopathological characteristics (sex, age at diagnosis, anatomical sub-site, histological sub-type) was examined. Three out of the 10 genes analyzed exhibited a marked hypermethylation, whereas two genes (ALDH2 and MTHFR) showed significant hypomethylation, in gastric tumors. Among differentially methylated genes, we identified new genes (CHRNA3 and DOK1) as targets of aberrant hypermethylation in GC, suggesting that epigenetic deregulation of these genes and their corresponding cellular pathways may promote the development and progression of GC. We also found that global demethylation of tumor cell genomes occurs in GC, consistent with the notion that abnormal hypermethylation of specific genes occurs concomitantly with genome-wide hypomethylation. Age and gender had no significant influence on methylation states, but an association was observed between LINE-1 and MLH1 methylation levels with histological sub-type and anatomical sub-site. This study identifies aberrant methylation patters in specific genes in GC thus providing information that could be exploited as novel biomarkers in clinics and molecular epidemiology of GC., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Background: The recent ToGA trial results indicated that trastuzumab is a new, effective, and well-tolerated treatment for HER2-positive gastric cancer (GC). Although GC mainly affects older patients, fewer than 10% of GC patients are considered early-onset (EOGC) (presenting at the age of 45 years or younger). These EOGC show different clinicopathological and molecular profiles compared to late onset GC suggesting that they represent a separate entity within gastric carcinogenesis. In light of potential trastuzumab benefit, subpopulations of GC such as EOGC (versus late onset) should be evaluated for their frequency of amplification and overexpression using currently available techniques., Methods: Tissue microarray (TMA) blocks of 108 early onset GC and 91 late onset GC were stained by immunohistochemistry (IHC, Hercep test, DAKO) and chromogenic in situ hybridization (CISH, SPoT-Light, Invitrogen)., Results: Overall, we found only 5% HER2 high level amplification and 3% HER2 3+ overexpression (6/199). In addition, 8 patients (4%) showed a low level CISH amplification and 9 patients (4.5%) showed a 2+ IHC score. IHC and CISH showed 92% concordance and CISH showed less heterogeneity than IHC. In 2/199 cases (1%), IHC showed clinically relevant heterogeneity between TMA cores, but all cases with focal IHC 3+ expression were uniformly CISH high level amplified. Early onset GCs showed a significantly lower frequency of HER2 amplification (2%) and overexpression (0%) than late onset GCs (8% and 7% respectively) (p=0.085 and p=0.008 respectively). Proximal GC had more HER2 amplification (9% versus 3%) and overexpression (7% versus 2%) than distal tumours although this difference was not significant (p=0.181 and p=0.182 respectively). HER2 CISH showed more high level amplification in the intestinal type (7%, 16% if low-level included) compared to the mixed (5%, 5% if low-level included) and diffuse type (3%, 4% if low-level included) GCs (p=0.029). A similar association was seen for HER2 IHC and histologic type (p=0.008). Logistic regression indicated a significant association between HER2 expression and age, which remained significant when adjusted for both location and histological type., Conclusions: Even focal HER2 overexpression in GC points to uniform HER2 amplification by CISH. We show for the first time that early onset GC has a lower frequency of HER2 amplification and overexpression than late onset GC, and confirm that intestinal type GC shows the highest rate of HER2 amplification and overexpression.

Background: CDC4/FBXW7, encoding a ubiquitin ligase, maps to 4q32 and has been implicated as a tumor suppressor gene and therapeutic target in many tumor types. Mutations in colonic adenomas, and the frequent losses on 4q described in gastric cancer prompt speculation about the role of CDC4/FBXW7 in gastric carcinogenesis., Methods: We assessed the role of CDC4/FBXW7 in gastric cancer, through loss of heterozygosity (LOH) and multiplex ligation-dependent probe amplification (MLPA) on 47 flow-sorted gastric carcinomas including early-onset gastric cancers (EOGC) and xenografted conventional gastric carcinomas. Ploidy analysis was carried out on 39 EOGCs and immunohistochemistry of CDC4/FBXW7 and its substrates c-myc, c-jun, Notch and cyclin E was performed on 204 gastric carcinomas using tissue microarrays (TMAs). Sequence analysis of CDC4/FBXW7 was carried out on gastric carcinoma cell lines and xenografts., Results: Loss of heterozygosity of CDC4/FBXW7 occurred in 32% of EOGCs, and correlated with loss of expression in 26%. Loss of expression was frequent in both EOGC and conventional gastric cancers. No CDC4/FBXW7 mutations were found and loss of CDC4/FBXW7 did not correlate with ploidy status. There was a significant correlation between loss of CDC4/FBXW7 expression and upregulation of c-myc., Conclusion: Loss of CDC4/FBXW7 appears to play a role in both EOGC and conventional gastric carcinogenesis, and c-myc overexpression is likely to be an important oncogenic consequence of CDC4/FBXW7 loss.

The immensity of genes and molecules implicated in gastric carcinogenesis is overwhelming and the relevant importance of some of these molecules is too often unclear. This review serves to bring us up-to-date with the latest findings as well as to look at the larger picture in terms of how to tackle the problem of solving this multi-piece puzzle. In this review, the environmental nurturing of intestinal cancer is discussed, beginning with epidemiology (known causative factors for inducing molecular change), an update of H. pylori research, including the role of inflammation and stem cells in premalignant lesions. The role of E-cadherin in the nature (genotype) of diffuse gastric cancer is highlighted, and finally the ever growing discipline of SNP analysis (including IL1B) is discussed.

Background: COX-2 and E-cadherin, involved in invasion and metastasis, are molecules critical for gastric carcinogenesis. A relationship between them is documented in non-small cell lung and prostate cancer. We present novel evidence of a relationship between COX-2 and E-cadherin expression in gastric cancer., Methods: Using qPCR and Western blots analysis on celecoxib and PGE2 treated and untreated gastric cancer cell lines derived from tumours of the intestinal type (MKN45, MKN28, AGS3, MKN7) and immunohistochemistry of 178 gastric cancers on tissue microarrays (TMA), we examined the COX-2/E-cadherin relationship., Results: Down-regulation of COX-2 by celecoxib led to up-regulation of E-cadherin mRNA and protein levels in conventional gastric cancer cell lines, whereas expression was down regulated in the early-onset gastric cancer (EOGC) cell line. Immunohistochemistry on TMAs of 178 gastric cancers showed no correlation between COX-2 and E-cadherin expression in the conventional or early gastric cancer groups., Conclusion: The results suggest that COX-2 has an impact on transcriptional regulation of E-cadherin in gastric cancer and our findings further highlight the intriguing nature of EOGCs which appear to have a molecular phenotype distinct from conventional gastric cancer. In addition, our findings also suggest that reduction of COX-2 using nonsteroidal anti-inflammatory drugs in gastric cancer chemoprevention may only be relevant for older patients.

It has been reported that interleukin-1beta (IL-1B) genes play a crucial role in the genetic predisposition to gastric cancer although there is no information about their role in different subtypes of gastric cancer. We performed single nucleotide polymorphism analysis of IL-1B in 241 gastric cancers including early onset gastric cancers (EOGC), conventional gastric cancers, and gastric stump cancers (GSCs) as well as 100 control patients, using real-time polymerase chain reaction and sequence analysis. The C allele was present in 60% of EOGCs, 59% of conventional gastric cancers, and 90% of GSCs, compared to 62% in the control group. Interestingly, there was no difference between early onset and conventional gastric cancer with respect to the IL-1B -31T>C polymorphism distribution. A statistically significant difference in the presence of the C allele compared to the control group was found in patients with gastric stump cancer (p = 0.008) with the T allele conferring protection against gastric stump cancer. In summary, we have shown that the IL-1B -31C allele promoter polymorphism is significantly associated with gastric stump cancer compared to the control group. Although several molecular differences have been identified between conventional gastric cancer and early onset gastric cancer, the IL-1B -31 allele distribution is similar between these two groups.

COX-2 overexpression is known to be an important mechanism in gastric carcinogenesis. Previously we have found that early-onset gastric cancer has a unique COX-2 low-expressing phenotype that differs significantly from that of the frequent overexpression seen in conventional gastric cancers. To investigate whether the COX-2 -765 G>C promoter polymorphism (known to lead to a reduction of COX-2 promoter activity in the colon) may explain this difference in expression, we carried out single-nucleotide polymorphism (SNP) analysis of 241 gastric cancers, including early-onset gastric cancer, conventional gastric cancers and gastric stump cancers, as well as in 100 control patients, using real-time PCR and sequence analysis, and correlated these findings with COX-2 expression using immunohistochemistry. We found that the C allele was present in 30% of early-onset gastric cancers, 24% of conventional gastric cancer, 23% of stump cancers, in contrast to 41% in the control group. There was a statistically significant difference in the presence of the C allele in patients with gastric cancer compared with the control group (P=0.007), with the C allele being associated with protection against gastric cancer. However, there was no significant difference between the early-onset, conventional and stump gastric cancer groups. Interestingly, there was no correlation between the presence of the C allele and a difference in COX-2 expression. In summary, we show that the COX-2 -765 G allele promoter polymorphism is significantly associated with gastric cancer when compared with the normal control group, but does not appear to be related directly to COX-2 expression pattern in gastric cancer. Although early-onset gastric cancers appear to have a unique COX-2 expression pattern when compared with conventional gastric cancer, the exact mechanism by which this occurs is yet to be elucidated.

Background: Post-translational cleavage of full-length cyclin E from the N-terminus can produce low molecular weight (LMW) isoforms of cyclin E containing the C-terminus only., Aim: To assess their presence in early-onset gastric cancer (EOGC), stump cancers and conventional gastric cancers and ascertain how they influence survival in EOGC., Methods: The expression of full-length and LMW isoforms of cyclin E in 330 gastric cancers, including early-onset gastric cancer (EOGC), stump cancer and conventional gastric cancer (>45 years old) was compared using antibodies targeted to the N- and C-terminals., Results: LMW isoforms were found in 35% of EOGCs, compared to 8% of conventional gastric cancers and 4% of stump cancers; their presence was visualised in cell lines using western blot analysis. In addition, C-terminal staining was a positive predictor of survival in EOGC. In contrast, no correlation with survival was found with the N-terminal antibody which detects only full-length cyclin E., Conclusion: EOGCs have a unique molecular phenotype and LMW isoforms of cyclin E may independently influence survival in EOGC.

Bone morphogenetic protein (BMP) signaling is known to suppress oncogenesis in the small and large intestine of mice and humans. We examined the role of Bmpr1a signaling in the stomach. On conditional inactivation of Bmpr1a, mice developed neoplastic lesions specifically in the squamocolumnar and gastrointestinal transition zones. We hypothesized that the regulation of epithelial cell fate may be less well defined in these junctional zones than in the adjacent epithelium and found that the mucosa at the squamocolumnar junction in mice shows a lack of differentiated fundic gland cell types and that foveolar cells at the gastrointestinal junctional zone lack expression of the foveolar cell marker Muc5ac. Precursor cell proliferation in both transition zones was higher than in the surrounding epithelium. Our data show that BMP signaling through Bmpr1a suppresses tumorigenesis at gastric epithelial junctional zones that are distinct from the adjacent gastric epithelium in both cellular differentiation and proliferation.

We report the molecular characterization of 8 primary gastric carcinomas, corresponding xenografts, and 2 novel gastric carcinoma cell lines. We compared the tumors and cell lines, with respect to histology, immunohistochemistry, copy number, and hypermethylation of up to 38 genes using methylation-specific multiplex ligation-dependent probe amplification, and TP53 and CDH1 mutation analysis where relevant. The primary tumors and xenografts were histologically comparable and shared expression of 11 of 14 immunohistochemical markers (E-cadherin, beta-catenin, COX-2, p53, p16, TFF1, cyclin E, MLH1, SMAD4, p27, KLK3, CASR, CHFR, and DAPK1). Gains of CASR, DAPK1, and KLK3--not yet described in gastric cancer--were present in the primary tumors, xenografts, and cell lines. The most prominent losses occurred at CDKN2A (p16), CDKN2B (p15), CDKN1B (p27/KIP1), and ATM. Except for ATM, these losses were found only in the cell line or xenograft, suggesting an association with tumor progression. However, examination of p16 and p27 in 174 gastric cancers using tissue microarrays revealed no significant correlation with tumor stage or lymph node status. Further losses and hypermethylation were detected for MLH1, CHFR, RASSF1, and ESR, and were also seen in primary tumors. Loss of CHFR expression correlated significantly with the diffuse phenotype. Interestingly, we found the highest rate of methylation in primary tumors which gave rise to cell lines. In addition, both cell lines harbored mutations in CDH1, encoding E-cadherin. Xenografts and gastric cancer cell lines remain an invaluable research tool in the uncovering of the multistep progression of cancer. The frequent gains, losses, and hypermethylation reported in this study indicate that the involved genes or chromosomal regions may be relevant to gastric carcinogenesis.

Gastric cancer is thought to result from a combination of environmental factors and the accumulation of specific genetic alterations due to increasing genetic instability, and consequently affects mainly older patients. Less than 10% of patients present with the disease before 45 years of age (early onset gastric carcinoma) and these patients are believed to develop gastric carcinomas with a molecular genetic profile differing from that of sporadic carcinomas occurring at a later age. In young patients, the role of genetics is presumably greater than in older patients, with less of an impact from environmental carcinogens. As a result, hereditary gastric cancers and early onset gastric cancers can provide vital information about molecular genetic pathways in sporadic cancers and may aid in the unraveling of gastric carcinogenesis. This review focuses on the molecular genetics of gastric cancer and also focuses on early onset gastric cancers as well as familial gastric cancers such as hereditary diffuse gastric cancer. An overview of the various pathways of importance in gastric cancer, as discovered through in-vitro, primary cancer and mouse model studies, is presented and the clinical importance of CDH1 mutations is discussed.

Diffuse-type gastric carcinomas (GCs) are often difficult to characterize because of contamination of tumor samples by surrounding normal tissue. As such, information regarding chromosomal aberrations in this subtype of GCs is limited. In this study, we used representational difference analysis to pinpoint genomic amplifications occurring in diffuse-type GCs. We found nine differential products from two novel regions of amplification in two tumors: one product mapped to 19p13.1 and eight mapped to a 1.8-Mb region in chromosomal segment 11p12-13. These amplifications were confirmed using Southern blot analysis and occurred in 3/16 and 6/15 diffuse-type GCs, respectively. CD44, a well characterized cellular adhesion molecule involved in several human malignancies, is encoded by a gene located within 200 kb of the 11p12-13 amplification fragments. We confirmed that overexpression of isoform CD44v6 was correlated with amplification at 11p12-13 in 11/12 diffuse-type GCs. Since diffuse-type GCs occur more frequently in early-onset gastric carcinomas (EOGCs, presented at 45 years of age or younger) than in "conventional" GCs, and the tumors carrying the original amplifications were EOGCs, we investigated overexpression of CD44v6 in 107 EOGCs and 88 conventional GCs using tissue microarrays. We found frequent CD44v6 overexpression in both tumor groups (76% and 57% respectively) and, interestingly, significantly more cases with overexpression of CD44v6 in EOGCs than in conventional GCs (P = 0.005), irrespective of histology. These findings provide further evidence for both the relevance of CD44 in GC and for distinct molecular characteristics of EOGCs when compared with those of GCs occurring at a later age., ((c) 2006 Wiley-Liss, Inc.)

Many studies examine the molecular genetics of gastric cancer, but few look at young patients in particular and there is no comparison of molecular expression between early-onset gastric cancer (< or = 45 years old) and conventional gastric cancers. Expression of cycloxygenase-2 (COX-2) is elevated in gastric adenocarcinomas compared to non-neoplastic mucosa, and in light of studies showing reduced risk of gastric cancer in nonsteroidal anti-inflammatory drug users, we have chosen to investigate the expression of COX-2 and related molecules in 113 early-onset gastric cancers and compare it with 91 conventional gastric cancers, using tissue microarrays. These markers include molecules known to be important in conventional gastric carcinogenesis, such as E-Cadherin, p53, COX-2, Trefoil Factor-1 (TFF1), beta-catenin, p16 and c-myc; as well as molecules not yet described as being important in gastric cancer, such as the transcription factor c-jun, the COX-2 mRNA stabilizer HuR, and C/EBP-beta, a transcription factor for COX-2. All markers showed a statistically significant difference between early-onset gastric cancers and conventional gastric cancers, using a chi2 test. In particular, early-onset gastric cancers displayed a COX-2 Low, TFF1-expressing phenotype, whereas COX-2 overexpression and loss of TFF1 was found in conventional cancers, and this difference between early-onset gastric cancers and conventional cancers remained statistically significant when adjusted for location and histology (P<0.0001 and P = 0.002 respectively). We found that COX-2 overexpression correlates significantly with loss of TFF1 (P = 0.001), overexpression of C/EBP-beta (P<0.001) and cytoplasmic HuR (P = 0.016). COX-2 was significantly associated with p53 positivity (P = 0.003). Abnormalities in E-Cadherin correlated significantly with diffuse phenotype, whereas high expression of COX-2, loss of TFF1 and overexpression of C/EBP-beta correlated with the intestinal phenotype. Our results provide further evidence that early-onset gastric cancer exhibits a distinctive expression profile that may have practical implications.

Recent studies claim a critical role for RUNX3 in gastric epithelial homeostasis. However, conflicting results exist regarding RUNX3 expression in the stomach and its potential role as a tumour-suppressor gene (TSG) in gastric carcinogenesis. Our aim was to evaluate the role of RUNX3 in early-onset gastric carcinomas (EOGCs). We analysed 41 EOGCs for RUNX3 aberrations using loss of heterozygosity (LOH), fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC) analyses. LOH of markers flanking RUNX3 was relatively common, indicating that loss of the gene may play a role in gastric carcinogenesis. However, FISH analysis of selected cases and a panel of 14 gastric carcinoma-derived cell lines showed widespread presence of multiple copies of centromere 1. While RUNX3 copy numbers were generally equal to or fewer than those of centromere 1, at least two copies were present in almost all cells analysed. Accordingly, a subpopulation of tumour cells in 12/37 cases showed RUNX3 protein expression. However, expression was not detected in the adjacent nontumorous mucosa of any case. Together, these observations indicate that chromosome 1 aberrations occur frequently in EOGCs and are reflected in the LOH and IHC patterns found. Our findings refute a role for RUNX3 as a TSG in EOGCs., (Oncogene (2005) 24, 8252-8258. doi:10.1038/sj.onc.1208963; published online 1 August 2005.)

Collision tumors are thought to arise from the accidental meeting of two independent tumors. Here we present five gastroesophageal junction tumors consisting of two collision tumors and three composite tumors (characterized by two divergent lineages originating from the same neoplastic clonal proliferation), as diagnosed on histology. In an attempt to prove this distinction at a genetic level, we performed TP53 sequence analysis and p53 immunohistochemistry. In addition, loss of heterozygosity (LOH) analysis using 10 microsatellite markers was carried out. An identical TP53 mutation and a similar pattern of retention and LOH were found in both neoplastic components of the presumed collision tumors, suggesting that both components are derived from a single precursor cell that undergoes divergent differentiation in the evolution of the tumor. In the composite group, 1 case had a genetic basis for the possible diagnosis of a collision tumor, with a TP53 mutation in the adenocarcinoma component only, and a different pattern of retention and loss of heterozygosity. These findings imply that it is not possible to recognize true collision tumors from immunohistologic appearance alone and suggest that the long-standing histologic criteria for the diagnosis of these neoplasms have no molecular basis.

Gastric cancer is thought to result from a combination of environmental factors and accumulation of specific genetic alterations, and consequently mainly affects older patients (>50 years of age). Fewer than 10% of patients present with the disease before 45 years of age and these young patients are thought to develop carcinomas with a different molecular genetic profile from that of sporadic carcinomas occurring at a later age. Forty early-onset gastric carcinoma resection specimens were characterized for microsatellite instability (MSI) and loss of heterozygosity status using 22 polymorphic microsatellite markers. Twenty-four biopsies were additionally evaluated for the presence of MSI. No MSI was observed in any of the cases analysed. Losses were infrequent, but were most common for the D1S234 (26.1%) and D1S1676 (17.4%) markers, flanking the RUNX3 gene; for the p53ALU (23.1%) and TP53 (15.4%) markers, near the TP53 gene; and for the D16S2624 (17.2%) marker, near the E-cadherin (CDH1) gene. All cases with loss of CDH1, as well as 6/7 cases with loss of TP53, displayed aberrant staining of the corresponding proteins, pointing to a functional role for these proteins in early-onset gastric carcinogenesis. No germline CDH1, TP53 or RUNX3 mutations were detected in any of the cases analysed. No correlation was observed between non-functional E-cadherin and the histological type of the tumours analysed. Finally, Epstein-Barr virus was not detected in any of the cases analysed. On the basis of these results, early-onset gastric carcinomas appear to have characteristics distinct from gastric carcinomas occurring at a later age., (Copyright 2004 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.)

Background: To determine at what stage during gastric carcinogenesis Epstein-Barr virus (EBV) enters the gastric epithelial cells, the presence of EBV was investigated in two pathogenetically related but distinct forms of adenocarcinoma of the stomach-gastric carcinoma of the intact stomach (GCIS) and gastric stump carcinoma (GSC)-and their presumed precursor lesions., Patients and Methods: Eleven patients with EBV positive GCIS and eight patients with EBV positive GSC, demonstrated by the highly sensitive EBV encoded RNA 1/2 (EBER1/2) RNA in situ hybridisation (RISH) technique, were studied. Paraffin wax embedded tissue available from preoperative gastric biopsies and tumour adjacent tissue from the resection specimens containing normal gastric mucosa, inflamed gastric mucosa, and preneoplastic lesions (intestinal metaplasia and dysplasia) was investigated by EBER1/2 RISH, in addition to EBV nuclear antigen 1 (EBNA-1) and latent membrane protein 1 (LMP-1) immunohistochemistry (IHC)., Results: In both GCIS and GSC and their precursor lesions EBER1/2 transcripts were restricted to the carcinoma cells. In addition, positivity of EBNA-1 IHC was also restricted to the tumour cells. IHC for LMP-1 was negative in all cases tested., Conclusions: The absence of EBER1/2 transcripts in preneoplastic gastric lesions (intestinal metaplasia and dysplasia) and their presence in two distinct types of gastric carcinoma strongly suggest that EBV can only infect neoplastic gastric cells and thus is a late event in gastric carcinogenesis.

Background: To improve the prognosis of patients with gastric cancer it is important to develop novel treatment modalities targeting the malignant behavior of tumor cells. Concerning this, NK4, which acts as HGF-antagonist and angiogenesis inhibitor, might be a potential therapeutic agent for gastric cancer. The HGF-c-MET pathway plays a pivotal role in gastric tumor growth, invasion, metastasis and angiogenesis. Therefore, the current study investigates whether adenoviral vector-mediated NK4 gene therapy has therapeutic potential for gastric cancer., Methods: Expression of HGF and c-MET in normal and (pre-)malignant gastric tissue was studied by immunohistochemistry. The effects of adenoviral vector-mediated expression of NK4 on the biological behavior of gastric cancer cells were studied in vitro and in vivo., Results: The majority of gastric cancers, i.e. 76%, express c-MET and in all carcinomas HGF is expressed in either tumor or stromal cells. Normal gastric epithelial cells do not express either of these proteins. Transduction of gastric cancer cells with the replication-deficient adenoviral vector AdCMV.NK4 resulted in efficient production and secretion of NK4. Consequently, proliferation, migration and invasion of gastric cancer cells were significantly inhibited. In addition, significantly reduced proliferation of vascular endothelial cells and efficient inhibition of angiogenesis were achieved. Finally, treatment of established human gastric tumor xenografts with AdCMV.NK4 resulted in significant tumor growth delay and significant reduction of intratumoral microvessel density., Conclusions: The present study shows that adenoviral vector-mediated expression of NK4 is a promising strategy to treat human gastric cancer by simultaneous interfering with primary tumor growth, metastasis and angiogenesis., (Copyright 2004 John Wiley & Sons, Ltd.)

Esophageal cancer and cancer of the gastric cardia, in particular adenocarcinomas, have shown a rapid and largely unexplained increase in incidence in many developed countries around the world. These diseases have a poor prognosis and current therapies have a modest impact on survival. This review presents recent advances in the epidemiology, etiology, diagnosis, staging, prevention and treatment of resectable and advanced disease. Although significant progress has been made in these areas of research and patient management over the past years, prognosis for most patients diagnosed with esophageal cancer or cancer of the gastric cardia remains poor. New diagnostic procedures, improved surgical procedures, combined treatment modalities and new treatment modalities are being evaluated and may be expected to contribute to improved patient outcomes and better palliation of symptoms in the future., (Copyright 2004 ISDE)

Background: Adenocarcinomas of the gastric cardia and distal oesophagus are at present often considered as one clinical entity because of their comparable increasing incidence, prognosis, and optimal treatment options. However, it is still a matter of debate whether these malignancies have the same pathogenesis and genotype., Aims: The aim of this study was to analyse expression of cyclooxygenase 2 (COX-2) in cardia carcinomas, and correlate this expression with clinicopathological parameters and survival. The results were compared with the prognostic value of COX-2 found for Barrett carcinomas., Methods: Tumour sections of 134 consecutive patients undergoing potentially curative surgery for an adenocarcinoma of the gastric cardia and substantially invading the distal oesophagus were immunohistochemically stained using a COX-2 monoclonal antibody. Specimens were blindly scored based on intensity and extent of COX-2 immunopositivity., Results: COX-2 expression was negative to weak in 59% ("COX-2 low") and moderate to strong in 41% ("COX-2 high") of tumours. This was significantly lower than in Barrett carcinomas (p<0.0001). COX-2 expression was not correlated with any clinicopathological parameter. A correlation between elevated COX-2 expression and reduced survival, as described for Barrett carcinomas, was not identified for cardiac carcinomas., Conclusions: There is a difference in COX-2 expression with respect to intensity and prognostic significance between adenocarcinomas of the gastric cardia and distal oesophagus. This suggests a different pathogenesis and different genetic constitution of these two cancers. Based on these findings, the role of selective COX-2 inhibitors in the treatment of adenocarcinomas of the gastric cardia is less promising than in Barrett carcinomas.

Gastrointestinal carcinomas synthesize elevated levels of prostaglandin E(2) (PGE(2)), which has been mechanistically linked to carcinogenesis. Recently, microsomal prostaglandin E synthase-1 (mPGES-1) was cloned, which seems to be inducible and linked to cyclooxygenase-2 (Cox-2) in the biosynthesis of PGE(2). We examined expression of mPGES-1 in intestinal type gastric adenocarcinomas and in gastric cancer cell lines. The transcript for mPGES-1 was elevated in 57% (4/7) of gastric carcinomas as detected by Northern blot analysis. Moderate to strong mPGES-1 immunoreactivity was observed in 56% (5/9) of the carcinomas as detected by immunohistochemistry. Furthermore, mPGES-1 mRNA, protein and microsomal PGES activity were detected in gastric adenocarcinoma cell lines that originated from intestinal type tumors (MKN-7 and MKN-28). In contrast to Cox-2, however, expression of mPGES-1 mRNA or protein were not induced by phorbol 12-myristate 13-acetate (PMA) or interleukin-1beta (IL-1beta) in any of the gastric cancer cell lines tested (MKN-1, -7, -28, -45 and -74). Two gastric cancer cell lines (MKN-45 and MKN-74) did not express mPGES-1 and lacked microsomal PGES activity, but were still able to synthesize PGE(2). Because all gastric cell lines expressed cPGES as detected by immunoblotting, it is possible that Cox-2 can interact with cPGES or with some other yet unidentified PGES in gastric cancer cells. Furthermore, our data show that regulatory mechanisms that drive expression of mPGES-1 and Cox-2 dissociate in gastric cancer cell lines., (Copyright 2003 Wiley-Liss, Inc.)

Epidemiological studies have shown that the use of nonsteroid anti-inflammatory drugs (NSAIDs) is associated with reduced risk of gastric cancer. The best-known target of NSAIDs is the cyclooxygenase (Cox) enzyme. Two Cox genes have been cloned, of which Cox-2 has been connected with gastric carcinogenesis. Expression of Cox-2 is elevated in gastric adenocarcinomas, which correlates with several clinicopathological parameters, including depth of invasion and lymph node metastasis. This suggests that Cox-2-derived prostanoids promote aggressive behavior of adenocarcinomas of the stomach. Cox-2 expression is especially prominent in intestinal-type gastric carcinoma and it is already present in dysplastic precursor lesions of this disease, which suggests that Cox-2 contributes to gastric carcinogenesis already at the preinvasive stage. Our most recent data show that Cox-2 is expressed in gastric adenomas of trefoil factor 1 deficient mice. Treatment of these mice with a Cox-2 selective inhibitor, celecoxib, reduced the size of the adenomas. Taken together these data support efforts to initiate clinical studies to investigate the effect of Cox-2 inhibitors as chemotherapeutic agents and as adjuvant treatment modalities against gastric neoplasias.

Both Helicobacter pylori (HP) and Epstein-Barr virus (EBV) have been implicated in carcinogenesis of the stomach. Fifty-seven gastric carcinomas were tested for microsatellite instability and allelic loss at several tumor suppressor loci using 21 polymorphic microsatellite markers. Furthermore, immunohistochemistry for p53 and DPC4/SMAD4 was performed. Results were analyzed according to HP and EBV status of the tumors, as assessed by immunohistochemistry and RNA in situ hybridization, respectively. Fractional allelic loss was lower in EBV-positive carcinomas (n = 15) when compared to EBV-negative carcinomas (P < 0.001). EBV positivity was inversely associated with allelic loss at specific markers on chromosomal arms 5q (APC), 17p (TP53), and 18q (DPC4/SMAD4). Allelic loss at the TP53 locus was not encountered in EBV-positive carcinomas, but occurred in 51% of EBV-negative carcinomas (P < 0.005). Moreover, none of the EBV-positive carcinomas showed unequivocal p53 immunopositivity in contrast to 39% of the EBV-negative carcinomas (P < 0.01). EBV-status was not related to microsatellite instability. There was no correlation between HP-status and any of the molecular alterations tested. In conclusion, EBV-positive gastric carcinomas follow a distinct pathogenesis at the molecular level, in which p53 is not, or differently inactivated.

Currently, application of adenoviral vectors (AdV) in gastric cancer gene therapy would be improved by increases in the specificity of transduction. Previously, we found that epithelial cell adhesion molecule (EpCAM) was expressed on gastric tumors but not on gastric epithelium. In this study, we evaluated doubly-ablated AdV lacking native binding ability together with bispecific single-chain antibodies targeted toward EpCAM for gene therapy of gastric cancer. Specific binding to EpCAM augmented the gene transfer efficiency of doubly-ablated AdV on gastric cancer cell lines up to 144-fold, reaching levels similar to or exceeding those achieved with native AdV. In contrast, EpCAM-targeted doubly-ablated AdV-mediated gene transfer into an EpCAM-negative cell line was reduced 38-fold compared with transduction by native AdV. Most importantly, EpCAM-targeted doubly-ablated AdV showed selectivity for primary human gastric tumors versus the surrounding nonneoplastic gastric mucosa of the same patients and normal liver tissue samples. Targeting these doubly-ablated AdV toward EpCAM resulted in similar transduction efficiency as obtained with native AdV for EpCAM-expressing primary human gastric tumors, whereas transduction of gastric epithelium and liver tissue was reduced at least 10-fold. This study thus indicates that application of EpCAM-targeted doubly-ablated AdV for gastric cancer gene therapy results in a favorable tumor-over-normal tissue transduction ratio.

The prolonged use of non-steroidal anti-inflammatory drugs (NSAIDs) has been associated with a reduced risk of gastric cancer. The best-known target of these drugs is cyclooxygenase (COX); the COX-2 isoform is frequently up-regulated in gastric adenocarcinomas. Using the post-gastrectomy stomach as a model, the expression of COX-2 mRNA and protein has been investigated during tumour progression in the human stomach. COX-2 expression was comparable in gastric stump carcinomas and conventional gastric carcinomas and localized primarily to the cytoplasm of the neoplastic cells. COX-2 mRNA was elevated in biopsies containing intestinal metaplasia, as determined by reverse transcriptase polymerase chain reaction (RT-PCR). COX-2 immunopositivity became more frequent during progression from reactive epithelium to high-grade dysplasia, both in the epithelial and in the stromal cell compartment. Co-localization of COX-2-positive stromal cells was seen with CD68, alpha-smooth muscle actin (alpha-SMA), vimentin, and HLA-DR, but an as yet unidentified subpopulation of stromal cells remained. Co-localization with the macrophage marker CD68 was only observed in a minority of COX-2-positive cells. These data show that COX-2 expression is a relatively early event during carcinogenesis in the stomach. COX-2 expression increases during tumour progression in the stomach, suggesting a role for COX-2 expression in gastric tumourigenesis., (Copyright 2001 John Wiley & Sons, Ltd.)

The c-met proto-oncogene, encoding the hepatocyte growth factor receptor, can be activated by various mechanisms. These include, among others, gene amplification with concomitant overexpression and the tpr-met oncogenic rearrangement. In the case of gastric cancer, contradictory results on the presence of the tpr-met oncogenic rearrangement have been published. The current study aimed therefore to assess the prevalence of tpr-met expression in Caucasian gastric adenocarcinomas, to evaluate the importance of this oncogene in their carcinogenesis. In addition, the level of c-met expression was determined, to evaluate the role of this alternative mode of activation of the proto-oncogene. A series of Caucasian gastric adenocarcinomas (n=43) and normal gastric mucosal samples (n=14) was analysed for tpr-met and c-met expression. Expression of tpr-met mRNA in the samples was performed by two reverse transcriptase polymerase chain reaction (RT-PCR) assays, with excellent correlation. The specificity of both methods was confirmed by direct sequencing of the PCR products of the MNNG-HOS cell line, which is known to contain the rearrangement. The level of c-met expression was assessed using semi-quantitative RT-PCR assays and immunohistochemistry (IHC). None of the normal gastric mucosal or gastric adenocarcinoma samples expressed tpr-met mRNA, as determined by both RT-PCR assays. Seventy per cent of the adenocarcinomas showed overexpression of c-met, according to elevated c-met mRNA levels, compared with the expression level of normal gastric mucosa. A significant correlation was found between the level of c-met mRNA and protein expression. In conclusion, these results strongly suggest that tpr-met activation does not play a role in Caucasian gastric carcinogenesis, while overexpression of the c-met gene occurs in the majority of Caucasian gastric adenocarcinomas., (Copyright 2001 John Wiley & Sons, Ltd.)

Background: The extent of lymph node dissection can affect tumour node metastasis staging. The resulting 'stage migration' might hamper stage-by-stage comparison between different forms of oesophageal resection. The aim of this study was to assess the diagnostic impact of extended en bloc lymphadenectomy in staging (adeno)carcinoma of the mid/distal oesophagus or gastric cardia., Methods: This was a prospective study of 74 patients (67 men and seven women; median age 63 (range 40-78) years) who underwent extended oesophagectomy between 1994 and 2000., Results: A median of 31 (range 15-78) lymph nodes was resected (and identified), with a median of 5 (range 0-31) positive nodes. Twenty-seven patients (36 per cent) had tumour-positive nodes in extended fields: 15 patients (20 per cent) in the abdomen and 15 patients (20 per cent) in the mediastinum. Subcarinal nodes were most affected (19 per cent). Extended resection led to tumour upstaging in 17 patients (23 per cent); two patients had isolated positive subcarinal nodes and 15 other tumours became M1a owing to positive nodes near the coeliac axis, hepatic artery or splenic artery. Tumour positivity in paratracheal or aortopulmonary nodes occurred in 8 per cent of patients, without influencing staging., Conclusion: Extended en bloc lymphadenectomy altered staging in 17 of 74 patients (23 per cent) with adenocarcinoma of the oesophagus or cardia, mainly into M1a owing to positive coeliac nodes (20 per cent).

Data are non-existent regarding coincidental alterations in the expression of p53 and its downstream target genes MDM2 and p21(Waf1/Cip1) in gastric carcinogenesis. An immunohistochemical study was therefore performed to examine the interrelationships of p53, MDM2, and p21(Waf1/Cip1) expression in a series of Caucasian early gastric carcinomas and precursor lesions. In normal gastric mucosa, chronic gastritis, and intestinal metaplasia, the surface cells expressed p21(Waf1/Cip1) in the absence of detectable nuclear p53 and MDM2 protein. Nuclear p53 protein accumulation was found in 60 per cent of the carcinomas, with significant differences in staining characteristics between the Lauren types in the absence of detectable MDM2 protein ( p< 0.005). Nearly 80 per cent of the carcinomas expressed p21(Waf1/Cip1), irrespective of Lauren type. Stratification of the carcinomas according to histological grade and growth pattern did not result in significant differences in p53 and p21(Waf1/Cip1) expression. Finally, no significant correlation was found between overall p53 and p21(Waf1/Cip1) expression in early gastric carcinomas. It is concluded that p21(Waf1/Cip1) expression in the non-neoplastic mucosa most likely relates to cell senescence and/or terminal differentiation, perhaps even in a p53-independent manner. In view of p53/MDM2 homeostasis, the differences in p53 staining characteristics between intestinal and diffuse-type carcinomas probably result, at least in part, from a difference in the prevalence of p53 gene mutations. Moreover, p53-independent induction of p21(Waf1/Cip1) expression apparently occurs in a considerable proportion of early carcinomas. Finally, in contrast to other carcinomas, p21(Waf1/Cip1) expression is not significantly correlated with histological grade in gastric carcinomas, suggesting possible defects downstream of p21(Waf1/Cip1) as an underlying cause for this apparent discrepancy., (Copyright 1999 John Wiley & Sons, Ltd.)

Background: Due to the high variability of the epidemiology, genetics, morphology, and biologic behavior of gastric carcinoma, many classification systems are in use, e.g., the World Health Organization (WHO) classification; tumor differentiation; the criteria of Ming, Mulligan, and Laurén; and the recently introduced Goseki classification. In the authors' opinion, the TNM staging is the most valuable classification system, with a prognostic value for survival., Methods: To assess the reproducibility and usefulness of these systems in clinical practice, material from 285 gastric carcinoma patients entered in the Dutch Gastric Cancer Trial was analyzed by a panel of 5 experienced gastrointestinal pathologists. The presence of eosinophilic and lymphocytic infiltrates was analyzed in addition to the TNM staging., Results: Of the analyzed classification systems, only TNM stage, tumor differentiation, eosinophilic infiltrate, and the Goseki system contained information associated with the survival of patients with gastric carcinoma. The reproducibility was perfect for tumor differentiation (Kappa 1.00), nearly perfect for the WHO and Goseki classifications (Kappa 0.86 and 0.87, respectively), reasonably good for Laurén and lymphocytic infiltrate (Kappa 0.70), and reasonably good for eosinophilic infiltrate (Kappa 0.42)., Conclusions: Of all these systems, the Goseki classification was the only system with prognostic value that is additional to TNM staging.

Background/aims: Partial gastrectomy is a well-established pre-malignant condition. It is postulated that in the gastric stump an accelerated neoplastic process takes place, similar to that of (intestinal type) adenocarcinoma from the non-operated stomach. K-ras codon 12 mutation is one of the most frequent oncogenic alterations in human solid neoplasms. It is rare in conventional gastric carcinoma and has not been studied in gastric stump carcinoma. The aim of this study was to compare the prevalence of K-ras codon 12 point mutations in gastric stump carcinomas with those in conventional carcinomas from the non-operated stomach., Methodology: Twenty-four gastric stump carcinomas were compared with 26 conventional gastric carcinomas. Stage, histology, and demographics were comparable in both groups. Mutations in codon 12 of the K-ras gene were examined with a polymerase chain reaction (PCR)-based method and subsequent dot blot hybridization with mutation-specific probes. The results of Helicobacter pylori infection, Epstein-Barr virus infection and p53 immunohistochemistry were partially known from a previous study., Results: In one of the gastric stump carcinomas as well as in one of the conventional gastric carcinomas a K-ras codon 12 point mutation was found. p53 immunohistochemistry results were comparable in both groups. Interestingly, Helicobacter pylori infection rate and Epstein-Barr virus in situ hybridization for EBER1, as previously studied, appeared were significantly different in the two groups., Conclusions: K-ras codon 12 point mutations are rare in both gastric stump carcinomas and conventional gastric carcinomas. This supports the postulated hypothesis that the pathways of carcinogenesis in both gastric stump carcinoma and conventional gastric carcinoma share common features. However, these groups differ in infection rate of Helicobacter pylori and of Epstein-Barr virus, which suggests that some neoplastic stimuli differ as well.

Background: The prognostic value of the Laurén classification and of c-erbB-2 oncogene overexpression has been described for gastric cancer. The aim of this study was to investigate the clinical significance of these factors in adenocarcinoma of the esophagus and/or gastroesophageal junction (GEJ)., Methods: Forty-one adenocarcinomas of the esophagus and/or GEJ were reviewed for tumor stage, lymph node status, Laurén classification, and c-erbB-2 overexpression, as assessed by immunohistochemical analysis., Results: According to the Laurén classification, tumors were classified as intestinal-, mixed-, or diffuse-type (54%, 32%, and 15%, respectively). Diffuse-type tumors were associated with a significantly worse prognosis than were intestinal-type tumors (P = .018; log-rank test). The prognostic value of the Laurén classification was independent of stage (P = .048; Cox regression model). Overexpression of c-erbB-2 was detected in 24% of the tumors and was present exclusively in intestinal-type tumors and in intestinal-type areas of mixed-type tumors. Ten of the 30 stage III/IV tumors (33%) were c-erbB-2-positive, whereas none of the 11 stage I/II tumors (0%) overexpressed the oncogene product (P = .04; Fisher exact test). The prognostic value of c-erbB-2 overexpression was not independent of stage (P = .7; Cox regression model)., Conclusions: (1) The Laurén classification is an independent prognostic factor in adenocarcinoma of the esophagus and GEJ. (2) c-erbB-2 overexpression is limited to (areas of) intestinal-type tumors, indicating that intestinal- and diffuse-type tumors differ oncogenetically. (3) c-erbB-2 overexpression is associated with the stage of disease, indicating that it is a late event during tumor progression.

Data on the differences in molecular profile between H pylori-positive and H pylori-negative early gastric carcinomas, if any, are almost nonexistent. We therefore investigated whether molecular differences can be observed between H pylori-positive and H pylori-negative early gastric carcinomas. Forty-five early gastric carcinomas were analyzed for alterations in certain oncogenes (ras, MDM2, c-erbB-2, cyclin D1), the p53 tumor suppressor gene, and the e-cadherin gene. Of these 28 carcinomas were H pylori-positive, and 17 were H pylori-negative. No significant differences were found in the groups irrespective of Lauren type; ras (0% vs 0%), MDM2 (0% vs 0%), c-erbB-2 (0% vs 0%), cyclin D1 (18% vs 29%), p53 (68% vs 47%), and e-cadherin (46% vs 41%). Helicobacter pylori-positive and H pylori-negative early gastric carcinomas do not differ in molecular profile. Although they may prove different when tested for other abnormalities, our findings suggest that the acquisition of molecular alterations occurs via an H pylori independent pathway.

Inactivation of wild-type p53 during gastric carcinogenesis is usually caused by mutations within exons 5-8 of the p53 gene leading to mutated, usually immunohistochemically detectable p53 proteins. However, functional inactivation of wild-type p53, mimicking mutational inactivation, may also result from binding to overexpressed MDM2 protein. While these two mechanisms of p53 inactivation are considered to be mutually exclusive, no data exist as to whether MDM2 overexpression occurs during gastric carcinogenesis. MDM2 protein overexpression was therefore studied in relation to p53 protein accumulation in gastric carcinogenesis. Forty-five paraffin-embedded gastrectomy specimens from early gastric carcinomas were examined for the presence of chronic active gastritis, chronic atrophic gastritis, subtypes of intestinal metaplasia, and dysplasia. The Lauren type was reassessed for all early carcinomas. p53 protein accumulation was examined using the monoclonal antibody DO-7. MDM2 protein overexpression was assessed with the monoclonal antibody SMP-14. Complete absence of nuclear p53 protein accumulation was observed in chronic active gastritis, chronic atrophic gastritis, and intestinal metaplasia, irrespective of the subtype. In gastric dysplasia (one mild, two moderate, one severe), only severe dysplasia was p53-positive. Intestinal-type (n = 20) and diffuse-type early gastric carcinoma (n = 25) were p53-positive in 70 and 52 per cent of the cases, respectively. MDM2 protein overexpression was not observed during gastric carcinogenesis, either in the p53-positive or in the p53-negative cases. In conclusion, it appears that functional inactivation of wild-type p53 by MDM2 protein overexpression plays no role in (early) gastric carcinogenesis.

Aim: To evaluate similarities and differences between gastric stump cancer and conventional carcinoma in the non-operated stomach., Methods: 26 stump carcinomas were compared with 24 conventional stomach cancers. Stage, histological type, and demographics were comparable in the two groups. Expression of p53 and p21-Waf1/Cip1 was evaluated by immunohistochemical staining. Helicobacter pylori infection was evaluated by examining haematoxylin-eosin stained slides and immunohistochemistry. Epstein-Barr virus infection was evaluated by RNA in situ hybridisation., Results: Expression of p53 and p21-Waf1/Cip1 was similar in both groups and positive in more than half of the patients. H pylori infection was observed in six stump carcinomas and 17 conventional carcinomas in the intact stomach (p < 0.01). RNA in situ hybridisation (EBER1-ISH) for Epstein-Barr virus was positive in nine stump carcinomas and two carcinomas in the non-operated stomach (p < 0.05)., Conclusions: There appear to be aetiological differences between stump carcinoma and cancer in the intact stomach. Further study of these differences may improve our understanding of gastric carcinogenesis in general.

Aims: Conflicting data on c-erbB-2 overexpression in gastric carcinomas can be found in the literature with regard to overall prevalence, prognostic significance and the histological type according to Lauren. The majority of these studies have focused on advanced gastric carcinomas whereas data on c-erbB-2 overexpression in early gastric carcinomas, especially of Caucasian origin, are relatively sparse. We therefore examined a series of Caucasian early gastric carcinomas to assess overall c-erbB-2 overexpression and to correlate c-erbB-2 overexpression, if any, with the type of growth pattern and the Lauren type., Methods and Results: Forty-five paraffin-embedded gastrectomy specimens from early carcinomas were examined for the presence of chronic active gastritis, chronic atrophic gastritis, subtypes of intestinal metaplasia and dysplasia. The Lauren type and the type of growth pattern were reassessed for all early carcinomas. c-erbB-2 overexpression was assessed with monoclonal antibody 3B5 and polyclonal antibody A485. Complete absence of c-erbB-2 overexpression was observed in chronic active gastritis, chronic atrophic gastritis, subtypes of intestinal metaplasia, and dysplasia. Moreover, c-erbB-2 overexpression was found absent in both intestinal-type (n = 20) and diffuse-type early gastric carcinomas (n = 25), irrespective of growth type., Conclusions: c-erbB-2 overexpression does not play a role in the progression from normal to neoplastic gastric mucosa and should be considered as a late event in gastric carcinogenesis. Moreover, c-erbB-2 overexpression does not discriminate between intestinal and diffuse type early gastric carcinomas of Caucasian origin. Finally, it appears that mechanisms other than c-erbB-2 overexpression underlie the reported differences in biological behaviour of early gastric carcinomas with different types of growth pattern.

The aims of this study were to assess the prevalence and type of activating point mutations at codons 12, 13, and 61 of the Ki-, Ha-, and N-ras genes in a series of early gastric carcinomas in white patients and to correlate these ras gene mutations, if any, with the histological type (Lauren classification), the type of growth pattern, and with the Helicobacter pylori status. Haematoxylin and eosin and Giemsa stained sections from 45 formalin fixed, paraffin wax embedded early gastric carcinomas were used to assess the Lauren type, the type of growth pattern, and the antral H pylori status. DNA was extracted according to standard procedures. Mutations at codon 12 of the Ki-ras gene were examined with a polymerase chain reaction based restriction fragment length polymorphism (PCR-RFLP) method and dot blot hybridisation with allele-specific 32P-labelled oligodeoxynucleotide (ASO) probes. All other ras genes were analysed with specific PCR amplification and dot blot hybridisation with ASO probes. Mutations were detected by overnight autoradiography at -70 degrees C. Some 20 intestinal-type and 25 diffuse-type early gastric carcinomas were seen. According to growth pattern, there were 24 small mucosal type early gastric carcinomas, five superficial spreading type early gastric carcinomas, and 16 penetrating type early gastric carcinomas (four penetrating A type, 12 penetrating B type). H pylori was found in the antral mucosa of 28 early gastric carcinomas (62%). Activating ras gene mutations were not found. It was discovered that activating point mutations at codons 12, 13, and 61 of the Ki-, Ha-, and N-ras genes do not play a part in the development of early gastric carcinomas in white subjects, irrespective of Lauren type. Moreover, differences in biological behaviour between early carcinomas with different types of growth pattern are not related to these ras gene mutations. Finally, H pylori positive and H pylori negative gastric carcinomas cannot be discriminated on the basis of ras gene mutational analysis.

p53 Protein accumulation in early gastric carcinoma was studied in relation to the histological type (Lauren classification) and the type of growth pattern, including the chronology of p53 protein accumulation during carcinogenesis. Forty five, paraffin embedded gastrectomy specimens from early carcinomas were examined for the presence of chronic atrophic gastritis, subtypes of intestinal metaplasia, and dysplasia. The Lauren type and the type of growth pattern were reassessed for all early carcinomas. p53 Protein accumulation was examined using the monoclonal antibody DO-7. Complete absence of p53 protein accumulation was observed in normal gastric mucosa, chronic atrophic gastritis, and intestinal metaplasia, irrespective of subtype. In gastric dysplasia (one mild, two moderate, and one severe), only severe dysplasia was p53 positive. Intestinal type (n = 20) and diffuse type early gastric carcinomas (n = 25) were p53 positive in 70% and 52% of cases, respectively. Both tumour types differed significantly in the percentage of p53 positive tumour cells per tumour (p < 0.01) and in staining intensity (p < 0.05). No significant difference in p53 protein accumulation was found between early carcinomas with different types of growth pattern. It is concluded that p53 protein accumulation--usually reflecting missense p53 gene mutation--seems to be a late event in gastric carcinogenesis. Moreover, it is suggested that missense p53 gene mutation occurs in a final pathway common to both intestinal and diffuse type of early gastric carcinoma. Finally, the types of growth pattern do not seem to differ in p53 protein accumulation.

Remote partial gastrectomy for benign disease is a premalignant condition. The overall risk of gastric stump cancer is approximately a twofold increase, but patients more than 20-25 years postoperatively may have a four- to fivefold increased risk, compared to the age- and sex-matched general population. The duration of postoperative interval is the most important risk factor. For the first 10 years after initial surgery, gastric cancer risk may be reduced due to the removal of the most cancer-prone distal part of the stomach, but thereafter there is a rapid increase of the relative risk. The etiology and precise mechanism of carcinogenesis is unknown, but the time relationship with surgery suggests that the anatomical alterations induced by the operation must be important. Hypochlorhydria, reflux, diminished gastrin production, bacterial proliferation, and nitrosation are the putative contributing factors. In addition, smoking appears to contribute to a generalized cancer mortality and decreased life expectancy after peptic ulcer surgery. Digestive tract cancers other than the gastric ones which show an increased risk after peptic ulcer surgery are pancreatic and biliary tract cancers. Premalignant and precursor lesions occur more frequently in the gastric remnant after peptic ulcer surgery and endoscopic bioptic screening can detect early stump cancers at a curable stage. Large-scale screening programs of post-gastrectomy patients are nevertheless not recommended, and surveillance appears not justified.