Intestinal-type Cancer Research Articles

Value of the neoadjuvant chemotherapy with PET/CT metabolic tumor volume (MTV) in advanced gastric cancer of intestinal type

Objective To investigate the feasibility and effectiveness of 18 F-FDG PET/CT in neoadjuvant chemotherapy (NAC) response in the patients with resectable advanced gastric cancer of intestinal type.Methods Forty-one patients (28 males and 13 females) with gastric cancer of intestinal type were recruited in this study.All patients received NAC and radical gastric resection,FDG PET/CT was performed before and after NAC and the histopathologic response were detected by postoperative histopathology.The reduction rates of SUVmax and MTV after NAC at primary tumor were calculated and the correlations with histopathologic grades of regression were analyzed using the Spearman correlation analysis.Prediction of pathologic response by SUVmax and MTV was assessed using ROC analysis.x2 test and Z test were also used to analyze the accuracy of Response Evaluation Criteria in Solid Tumors (RECIST) 1.0 and reduction rate of SUVmax for predicting the pathologic response after NAC.Results Twenty patients had effective outcomes according to the histopatholgic response and others didn't.Both of the two metabolic parameters showed significant correlation with the histopathologic grades of regression,while the correlation factor of tumor MTV reduction rate was higher (r=0.763,P＜0.01) than that of SUVmax reduction rate (r=0.434,P＜0.01).The AUC for predicting response was 0.789 with SUVmax reduction rate and 0.943 with MTV reduction rate (Z=2.1 14,P＜0.05).The cutoff value of MTV reduction rate was set to 49.4％ for the highest accuracy for prediction of histopathologic response with a sensitivity of 90.0％ (18/20) and specificity of 90.5％ (19/21).The MTV with PET/CT was a better predictor for histopathologic response than that of RECIST 1.0 criteria (accuracy:90.2％(37/41) vs 80.5％(33/41);x2=7.14,P＜0.05).Conclusions 18F-FDG PET/CT MTV can be used as an important indicator for assessment of NAC response in patients with resectable advanced gastric cancer of intestinal type. Key words: Stomach neoplasms; Drug therapy; Tomography, emission-computed; Tomography, X-ray computed; Deoxyglucose

Quantitative measurement of organic acids in tissues from gastric cancer patients indicates increased glucose metabolism in gastric cancer.

The levels of organic acids representing metabolic pathway end products are important indicators of physiological status, and may be associated with metabolic changes in cancer. The aim of this study is to investigate the levels of organic acids in cancerous and normal tissues from gastric cancer patients and to confirm the role of metabolic alterations in gastric carcinogenesis. Organic acids in normal and cancerous tissues from forty-five patients with gastric adenocarcinoma were investigated by gas chromatography-mass spectrometry in selected ion monitoring mode as methoxime/tert-butyldimethylsilyl derivatives. We analysed the significant differences in the levels of organic acids in normal and cancer tissues and investigated the correlation of these levels in cancer tissues with clinicopathological features. The levels of Krebs cycle components, including α-ketoglutaric acid, succinic acid, fumaric acid, malic acid and oxaloacetic acid, were significantly increased in cancer tissues compared to normal tissues. In addition, the levels of glycolytic products, including pyruvic acid and lactic acid, as well as the levels of ketone bodies, including 3-hydroxybutyric acid, were also significantly increased in cancer tissues compared to normal tissues. The levels of ketone bodies in cancer tissues with differentiated histology and in intestinal-type cancer tissues were significantly increased. The organic acid profiling analysis described here may be a generally useful clinical tool for understanding the complexity of metabolic events in gastric adenocarcinoma, and organic acids may have potential as metabolic markers for the future discovery of diagnostic and therapeutic modalities.

Sa1874 Incidence of Gastric Intestinal Metaplasia in Patients With Negative Helicobacter pylori

G A A b st ra ct s and / or surgery for histological examination and sub-classification of adenocarcinomas according to Lauren into diffuse, intestinal or mixed type. Fasting blood samples were collected preoperatively for determination of serum gastrin by radioimmunoassay (upper normal range 40 pM) and Helicobacter pylori (H pylori) serology. Tumor localization was determined after macroscopic and histological examination and classified as antrum, corpus and overlapping. Results: Patients with localization of the carcinoma in the gastric corpus (n=45) had significantly higher serum gastrin than patients with carcinoma localized to the antrum (n=32) (100.7±27.5 vs. 17.1±2.6 pM, p=0.004). There was no significant difference in serum gastrin between patients with intestinal type (n=49) carcinoma compared to diffuse type (n=46) carcinoma (49.7±16 vs 58.0±21 pM, p=0.33), while patients withmixed histological type (n=7) had gastrin 98.7±50.6 pM, (p=0.29 vs. intestinal type). Among patients with tumor localized to the corpus, those with diffuse type carcinoma tended to have higher serum gastrin than patients with intestinal type (131.6±61 vs. 78.4±37 pM, p =0.29). H pylori positive patients tended to have higher serum gastrin than HP negative patients (69.4±22.4 pM vs. 32.3±11.0 pM, p=0.29), but H pylori status did not differ between diffuse and intestinal type cancers (82.6% vs. 68.7% positive patients, p=0.26). Conclusions: Patients with adenocarcinomas localized to the gastric corpus had higher serum gastrin that patient with localization of carcinoma in the antrum. The histological subtype did not seem to be influenced by serum gastrin concentrations. The findings support the hypothesis that hypergastrinemia, as seen in animal models also promotes carcinogenesis in patients.

267 Macrophages Promote the Progression of Metaplasia in the Stomach Following Acute Parietal Cell Loss

Adenocarcinoma in the human stomach evolves in the setting of Helicobacter pylori-induced oxyntic atrophy and chronic mucous cell metaplasia. Two types of metaplasia associated with development of intestinal-type cancers are observed in the human stomach: intestinal metaplasia (IM; intestinal type goblet cells in the stomach) and Spasmolytic Polypeptide (TFF2) Expressing Metaplasia (SPEM; with the presence of antral type TFF2-expressing mucous cells in the oxyntic region). Our previous study showed that SPEM developed from transdifferentiation of mature chief cells, rather than originating from aberrant differentiation of resident progenitor cells. Recent investigations have noted evidence for increased Ras activity in up to a third of gastric cancers. Thus, we have hypothesized that activated Ras, specifically induced in mature chief cells, elicits transdifferentiation of chief cells into SPEM and progression of SPEM to more intestinalized metaplasia. To test this hypothesis, we have examined a novel mouse model of metaplasia in the stomach in Mist1-CreERT2Tg/+;LSLK-Ras(G12D)Tg/+;mT/mGTg/+ mice. Tamoxifen (TAM) treatment induces the expression of activated K-Ras specifically in mature chief cells and marks the K-Ras-induced chief cells with GFP as a lineage tracer. This mouse model rapidly develops SPEM and IM within 3 months, following TAM induction of activated K-Ras expression in mature chief cells. At 1 week post TAM treatment, we found several groups of metaplastic glands between normal oxyntic glands that were positive for SPEM markers. At 3 months post TAM treatment, oxyntic glands were replaced withmetaplastic glands that showed highly proliferative mucous cell populations at the bases and the cells in the metaplastic glands were strongly positive for clusterin and TFF3 with distinct goblet cell morphologies, and also positive for Pdx1. Some glands were positive for IM markers such as villin and Cdx1. The mice at 4 months post TAM treatment developed severe inflammation, metaplasia, dysplasia and the invasive adenocarcinoma. Consistent with active K-Ras expression, cells with nuclear expression of phospho-ERK1/2 were also observed at the bases of metaplastic glands. Interestingly, we observed that the metaplastic glands were positive for GFP, indicating that they were derived from transdifferentiation of Cre-induced chief cells. Therefore, the induction of activated Ras specifically in mature chief cells initially leads to transdifferentiation of chief cells into SPEM followed by evolution of goblet cell IM and eventual neoplastic lesions. These studies demonstrate that expression of activated Ras in Chief cells can lead to the development of the entire spectrum of metaplastic and neoplastic lineages leading to gastric cancer.

266 Active Kras Leads to Rapid Transdifferentiation of Gastric Chief Cells Into Metaplasia With Progression to Dysplasia and Invasive Cancer

Adenocarcinoma in the human stomach evolves in the setting of Helicobacter pylori-induced oxyntic atrophy and chronic mucous cell metaplasia. Two types of metaplasia associated with development of intestinal-type cancers are observed in the human stomach: intestinal metaplasia (IM; intestinal type goblet cells in the stomach) and Spasmolytic Polypeptide (TFF2) Expressing Metaplasia (SPEM; with the presence of antral type TFF2-expressing mucous cells in the oxyntic region). Our previous study showed that SPEM developed from transdifferentiation of mature chief cells, rather than originating from aberrant differentiation of resident progenitor cells. Recent investigations have noted evidence for increased Ras activity in up to a third of gastric cancers. Thus, we have hypothesized that activated Ras, specifically induced in mature chief cells, elicits transdifferentiation of chief cells into SPEM and progression of SPEM to more intestinalized metaplasia. To test this hypothesis, we have examined a novel mouse model of metaplasia in the stomach in Mist1-CreERT2Tg/+;LSLK-Ras(G12D)Tg/+;mT/mGTg/+ mice. Tamoxifen (TAM) treatment induces the expression of activated K-Ras specifically in mature chief cells and marks the K-Ras-induced chief cells with GFP as a lineage tracer. This mouse model rapidly develops SPEM and IM within 3 months, following TAM induction of activated K-Ras expression in mature chief cells. At 1 week post TAM treatment, we found several groups of metaplastic glands between normal oxyntic glands that were positive for SPEM markers. At 3 months post TAM treatment, oxyntic glands were replaced withmetaplastic glands that showed highly proliferative mucous cell populations at the bases and the cells in the metaplastic glands were strongly positive for clusterin and TFF3 with distinct goblet cell morphologies, and also positive for Pdx1. Some glands were positive for IM markers such as villin and Cdx1. The mice at 4 months post TAM treatment developed severe inflammation, metaplasia, dysplasia and the invasive adenocarcinoma. Consistent with active K-Ras expression, cells with nuclear expression of phospho-ERK1/2 were also observed at the bases of metaplastic glands. Interestingly, we observed that the metaplastic glands were positive for GFP, indicating that they were derived from transdifferentiation of Cre-induced chief cells. Therefore, the induction of activated Ras specifically in mature chief cells initially leads to transdifferentiation of chief cells into SPEM followed by evolution of goblet cell IM and eventual neoplastic lesions. These studies demonstrate that expression of activated Ras in Chief cells can lead to the development of the entire spectrum of metaplastic and neoplastic lineages leading to gastric cancer.

The Niche Component Periostin Is Produced by Cancer-Associated Fibroblasts, Supporting Growth of Gastric Cancer through ERK Activation

Overexpression of periostin (POSTN), an extracellular matrix protein, has been observed in several cancers. We investigated the importance of POSTN in gastric cancer. Genome-wide gene expression analysis using publicly available microarray data sets revealed significantly high POSTN expression in cancer tissues from stage II-IV gastric cancer, compared with background normal tissues. The POSTN/vimentin mRNA expression ratio was highly associated with gene groups that regulate the cell cycle and cell proliferation. IHC showed that periglandular POSTN deposition, comprising linear deposition abutting the glandular epithelial cells in normal mucosa, disappeared during intestinal gastric cancer progression. Stromal POSTN deposition was also detected at the invasive front of intestinal-type and diffuse-type cancers. In situ hybridization confirmed POSTN mRNA in cancer-associated fibroblasts, but not in tumor cells themselves. POSTN enhanced the in vitro growth of OCUM-2MLN and OCUM-12 diffuse-type gastric cancer cell lines, accompanied by the activation of ERK. Furthermore, coinoculation of gastric cancer cells with POSTN-expressing NIH3T3 mouse fibroblast cells facilitated tumor formation. The OCUM-2MLN orthotopic inoculation model demonstrated that tumors of the gastric wall in Postn(-/-) mice were significantly smaller than those in wild-type mice. Ki-67 and p-ERK positive rates were both lower in Postn(-/-) mice. These findings suggest that POSTN produced by cancer-associated fibroblasts constitutes a growth-supportive microenvironment for gastric cancer.

High Lactate Dehydrogenase 5 Expression Correlates with High Tumoral and Stromal Vascular Endothelial Growth Factor Expression in Gastric Cancer

Background: Lactate dehydrogenase 5 (LDH5) is a major lactate dehydrogenase isoenzyme catalyzing the transformation of pyruvate to lactate to provide anaerobic energy. Vascular endothelial growth factor (VEGF) is expressed in both tumor and stromal cells in gastric cancer. Our aim was to study the prognostic effect of LDH5, and tumoral and stromal expression of the angiogenic factor VEGF in gastric cancer, and the intercorrelation of tissue expression of both factors. Methods: Tissue microarray analysis of 382 consecutive gastric cancer resection specimens was used for immunohistochemistry of LDH5 and VEGF, and expression of LDH5, tumoral VEGF, and stromal VEGF was categorized into low and high groups. Results: High expression was observed for LDH5 in 57.9% (219/378), tumoral VEGF in 35.7% (136/381), and stromal VEGF in 58.5% (223/381) of the specimens. Regarding high expression of LDH5 and VEGF, significant associations with intestinal type, advanced gastric cancer, lymph node metastasis, higher TNM stage, and upper-third location were noted. Positive intercorrelations occurred among the expression of LDH5 and VEGF. Results of survival analyses revealed a significant association of high expression of LDH5 and VEGF with lower survival (overall and disease-free survival). Five-year survival rates were significantly lower in tumors with high LDH5 and tumoral VEGF expression in diffuse- or mixed-type cancers and high expression of stromal VEGF in intestinal-type cancer. Conclusion: The results of our study showed that high LDH5 and VEGF expression in both tumor and stroma was a prognostic factor for patients with gastric cancers, especially diffuse- or mixed-type cancers. Therefore, LDH5 expression may play a role in the regulation of tumoral and stromal VEGF expression in gastric cancer. Our results suggest the potential use of LDH5 expression as a biomarker for response to VEGF-targeted therapy.

Up-regulation of CLDN1 in gastric cancer is correlated with reduced survival

BackgroundThe genetic changes in gastric adenocarcinoma are extremely complex and reliable tumor markers have not yet been identified. There are also remarkable geographical differences in the distribution of this disease. Our aim was to identify the most differentially regulated genes in 20 gastric adenocarcinomas from a Norwegian selection, compared to matched normal mucosa, and we have related our findings to prognosis, survival and chronic Helicobacter pylori infection.MethodsBiopsies from gastric adenocarcinomas and adjacent normal gastric mucosa were obtained from 20 patients immediately following surgical resection of the tumor. Whole genome, cDNA microarray analysis was performed on the RNA isolated from the sample pairs to compare the gene expression profiles between the tumor against matched mucosa. The samples were microscopically examined to classify gastritis. The presence of H. pylori was examined using microscopy and immunohistochemistry.Results130 genes showed differential regulation above a predefined cut-off level. Interleukin-8 (IL-8) and Claudin-1 (CLDN1) were the most consistently up-regulated genes in the tumors. Very high CLDN1 expression in the tumor was identified as an independent and significant predictor gene of reduced post-operative survival. There were distinctly different expression profiles between the tumor group and the control mucosa group, and the histological subsets of mixed type, diffuse type and intestinal type cancer demonstrated further sub-clustering. Up-regulated genes were mapped to cell-adhesion, collagen-related processes and angiogenesis, whereas normal intestinal functions such as digestion and excretion were associated with down-regulated genes. We relate the current findings to our previous study on the gene response of gastric epithelial cells to H. pylori infection.ConclusionsCLDN1 was highly up-regulated in gastric cancer, and CLDN1 expression was independently associated with a poor post-operative prognosis, and may have important prognostic value. IL-8 and CLDN1 may represent central links between the gene response seen in acute H. pylori infection of gastric epithelial cells, and ultimately gastric cancer.

HER2 Status in Gastric and Gastroesophageal Junction Cancer Assessed by Local and Central Laboratories: Chinese Results of the HER-EAGLE Study

Trastuzumab has been approved for human epidermal growth factor receptor 2 (HER2)-positive advanced gastric and gastroesophageal junction cancers (GC and GJC) in combination with chemotherapy. The aim of this HER2 early/advanced gastric epidemiology (HER-EAGLE) study was to evaluate the frequency of HER2 over-expression and to evaluate agreement on HER2 status assessment in GC and GJC patients in local laboratories versus a central laboratory in China. Tumor samples from 734 GC or GJC patients who were enrolled at 11 different hospitals in China were examined. HER2 status was assessed by immunohistochemistry (IHC), and followed by dual-color silver-enhanced in Situ hybridization (DSISH) in IHC 2+ cases. Clinicopathologic characteristics were collected from all of the patients. HER2-positive tumors were identified in 12.0% (88/734) of the GC and GJC cases. There were significantly higher rates of HER2 positivity in patients with GJC (GJC: 18.1%, GC: 9.7%, P=0.002), and intestinal-type cancers using the Lauren classification (intestinal: 23.6%, diffuse/mixed: 4.3%, P<0.0001). No significant difference in HER2 positivity was identified between resection and biopsy samples, or between early and advanced disease stages. The agreement between local laboratories and the central laboratory on HER2 status scoring was good (kappa=0.86). The main reason of HER2 status discordance between local and the central laboratories was IHC result mis-interpretation in local laboratories. These results suggest that IHC followed by DSISH testing is an accurate and cost-effective procedure in China.

Is Colonoscopic Screening Necessary for Patients with Gastric Adenoma or Cancer?

Since colorectal adenoma or cancer is commonly associated with gastric adenoma or cancer, early colorectal adenoma detection can affect the survival of gastric adenoma or cancer patients. The purpose here was to investigate the colorectal adenoma or cancer prevalence and evaluate the necessity for screening colonoscopy in gastric adenoma or cancer patients. From September 2005 through August 2010, 857 patients younger than 70 years who had gastric adenoma or cancer were enrolled. Healthy age- and sex-matched controls were selected from the general screening population. The prevalence and risk of colorectal adenoma or cancer were compared between the participants and the controls. Data from 416 patients in the gastric neoplasm group (123 with gastric adenoma and 293 with gastric cancer) and 416 healthy control group participants were included in the statistical analysis. The presence of gastric adenoma or cancer was an independent risk factor for colorectal neoplasm (OR = 1.348, 95 % CI = 1.001-1.815). Patients with diffuse type gastric cancer had a lower prevalence of colorectal adenoma or cancer than those with gastric adenoma or intestinal type cancer. In gastric cancer patients younger than 50 years, intestinal type histology was significantly associated with colorectal adenoma or cancer (OR = 3.838, 95 % CI = 1.077-13.677). The colorectal adenoma or cancer risk was significantly increased in patients with gastric adenoma or cancer. Therefore, screening colonoscopy should be considered for gastric adenoma or cancer patients including young patients, in the case of intestinal type gastric cancer.

Expression analysis of MET, EGFR, and HER2, and K-ras mutation status in patients with stage II/III gastric cancer enrolled in the ACTS-GC study.

40 Background: Exploratory biomarker analysis was conducted to identify factors related to outcomes of patients enrolled in the ACTS-GC study, a randomized controlled trial comparing surgery followed by adjuvant S-1 therapy with surgery alone in 1,059 patients with stage II/III gastric cancer. Methods: Formalin-fixed paraffin-embedded specimens obtained from 105 patients, an institutional subset of this biomarker study of 829 patients, were extensively examined for EGFR and HER2 by immunohistochemistry (IHC), MET amplification by FISH, and K-ras mutation status (codon 12, 13) by PNA-enriched direct sequencing. The expressions of 63 genes involved in pyrimidine metabolic pathway, growth factor signaling pathway, apoptosis, DNA repair, etc., were measured by quantitative real-time RT-PCR. The relations of the expressions of these genes to clinicopathological features such as histological type, T grade, N grade, tumor stage, gender, and age were also investigated. Results: The rates of K-ras mutation, EGFR overexpression, HER2 overexpression, and MET amplification were 6.7% (7/105), 14.3% (15/105), 11.4% (12/105), and 21.0% (22/105), respectively. These factors were almost mutually exclusive. Co-expressions were seen in 2 (EGFR &amp; HER2), 4 (HER2 &amp; MET), 5 (MET and EGFR) and 1 (EGFR &amp; HER2 &amp; MET) of the 105 patients. MET amplification and EGFR overexpression were associated with worse outcomes. In contrast, KRAS and HER2 status were not associated with overall survival or relapse-free survival. Expression levels of PCAM1, ESR1, MUC2, CAV1, ITGB3, and APC mRNA were significantly higher in diffuse-type cancer than in intestinal-type cancer, whereas expression levels of HER2, E2F1, LDHA and TOP2A mRNA were significantly higher in intestinal-type than in diffuse-type cancer (FDR P&lt;0.05). Associations of other clinically significant genes with clinicopathological features other than histologic type were not screened. Conclusions: Many clinical, pathological, molecular, and genetic factors have been investigated with a growing understanding of the molecular pathogenesis of gastric cancer. We review and discuss such prognostic markers in the ACTS-GC study.

Stem Cells, Self-Renewal and Cancer of the Gastric Epithelium

The gastric mucosa and its glands show continuous bidirectional self-renewal via differentiation from stem and progenitor cells. Here, two types of gastric units, i.e., fundic and antral units, form delicate homeostatic systems. This review focuses on recent developments concerning the different types of gastric stem cells, the central function of parietal cells as organizing centres of fundic units, the stepwise differentiation of zymogenic cells via trans-differentiation of mucous neck cells, and unexpected differences between fundic and antral surface mucous cells. Within the last years, the central role of Sonic hedgehog (Shh) for correct self-renewal of fundic units has become much clearer. Furthermore, also the knowledge concerning the genesis of gastric cancer increased substantially. Here, chronic inflammation leads to dysregulated differentiation processes and finally to cancer. Remarkable progress has been made particularly concerning the genesis of two metaplastic cell lineages, i.e., the TFF2/spasmolytic polypeptide expressing metaplasia (SPEM) and intestinal metaplasia, which both arise in intestinal-type cancers in fundic units by dysregulated trans-differentiation of the zymogenic cell lineage. Additionally, Shh has been recognized as a target for inflammatory processes and an important player for innate immunity processes. Thus, stem cells, self-renewal, and gastric cancer are intimately linked.

Stem Cells, Self-Renewal and Cancer of the Gastric Epithelium

The gastric mucosa and its glands show continuous bidirectional self-renewal via differentiation from stem and progenitor cells. Here, two types of gastric units, i.e., fundic and antral units, form delicate homeostatic systems. This review focuses on recent developments concerning the different types of gastric stem cells, the central function of parietal cells as organizing centres of fundic units, the stepwise differentiation of zymogenic cells via trans-differentiation of mucous neck cells, and unexpected differences between fundic and antral surface mucous cells. Within the last years, the central role of Sonic hedgehog (Shh) for correct self-renewal of fundic units has become much clearer. Furthermore, also the knowledge concerning the genesis of gastric cancer increased substantially. Here, chronic inflammation leads to dysregulated differentiation processes and finally to cancer. Remarkable progress has been made particularly concerning the genesis of two metaplastic cell lineages, i.e., the TFF2/spasmolytic polypeptide expressing metaplasia (SPEM) and intestinal metaplasia, which both arise in intestinal-type cancers in fundic units by dysregulated trans-differentiation of the zymogenic cell lineage. Additionally, Shh has been recognized as a target for inflammatory processes and an important player for innate immunity processes. Thus, stem cells, self-renewal, and gastric cancer are intimately linked.

Prognostic significance of membrane-associated mucins 1 and 4 in gastric adenocarcinoma

Aberrant expression of mucins is likely associated with cancer biology as alterations in the expression and/or glycosylation patterns of various mucins have been noted. Expression of the mucin family in gastric cancers has been reported in numerous studies, but the results are conflicting. Therefore, we investigated the potential use of mucin (MUC)1 and 4 as prognostic markers in gastric cancer according to histological subtype. Three-hundred and sixty-five gastric adenocarcinoma patients who underwent surgical resection were selected for this study. Among the 365 gastric cancer samples tested here, 34% consisted of early gastric cancer and 66% were advanced. In terms of location, 68.7% of the cohort had intestinal-type cancer and 30.7% had diffuse-type. We constructed tissue microarrays with formalin-fixed paraffin-embedded blocks of gastric cancer and these micro-arrays were evaluated for phenotypic expression of MUC1/4 using monoclonal antibodies. Two-hundred and ninety-two patients (92.7%) were positive for MUC1 and 216 (60.5%) were positive for MUC4. MUC1 expression was not correlated with any other clinicopathological variables such as age, gender, depth of invasion, lymph node metastasis, Lauren classification or recurrence. However, loss of MUC4 expression was significantly correlated with recurrence (p=0.033). MUC4 expression was also significantly correlated with better disease-free survival (p=0.049) and particularly in the intestinal-type (p=0.018). Our present findings demonstrated that loss of MUC4 expression can be used as a prognostic marker in gastric cancer. Loss of MUC4 expression is a prognostic indicator of increased recurrence and poor disease-free survival in patients with gastric cancer.

Association between common genetic variant of HRH2 and gastric cancer risk

Histamine plays important physiological roles in the upper gastrointestinal tract and acts via the H2 receptor. The -1018 G>A (rs2067474) in an enhancer element of the promoter and non-synonymous rs79385261 (Asn46Thr) were identified in HRH2. We attempted to clarify the associations of these polymorphisms with gastric carcinogenesis. The study was performed in 321 patients with gastric cancer and 599 subjects with no evidence of gastric malignancies on upper gastroduodenal endoscopy. The genotypes were determined using a one-tube multiplex PCR-SSCP method. The degree of gastritis was assessed in 496 subjects and serum pepsinogen (PG) I/II levels were measured in 124 subjects without gastric cancer. The minor allele of Asn46Thr could not be detected. The frequencies of the -1018 A allele in the non-GC and GC groups were 13.5% and 8.26%, respectively (p=0.00077). Overall, -1018 GG homozygotes had an increased risk for developing gastric cancer (OR 1.68; 95% CI 1.17-2.42; p=0.0052), especially intestinal type cancer (OR 1.94; 95% CI 1.23-3.08; p=0.0047). In subjects aged >60 years, the adjusted risk for gastric cancer among individuals who were -1018 GG homozygotes was 1.87 (range 1.19-2.93; p=0.0065) compared with A carriers. In the gastric cancer cases located in the antrum and at comparative advanced stage, -1018 GG homozygosity was a significantly increased risk factor. In subjects >60 years, the metaplasia score was significantly higher in -1018 GG homozygotes than A carriers. Both atrophy and metaplasia scores were significantly increased with age only in -1018 GG homozygotes. The PG I/II ratio was significantly decreased in H.pylori positive GG homozygotes than negative GG homozygotes and positive A carriers. Our results suggest that -1018 GG homozygosity of HRH2 may be associated with the severity of gastric mucosal atrophy. This genotype has an increased risk for the subsequent development of gastric cancer, especially intestinal type, at advanced age.

Abstract 4540: Pyruvate kinase M2 (PKM2) associated with poor prognosis in gastric signet ring cell carcinoma

Abstract Background: PKM2 (M2 isoform of pyruvate kinase) was identified as a driver of aerobic glycolysis, leading to cell growth and tumor development. PKM2 is usually known to overexpress in cancer, however, there are still remaining questions about the function and the potential as anti-cancer treatment target. We investigated the expression status of PKM2 in gastric cancer tissues and evaluated the possibility of biomarker and anticancer target. Methods: Paraffin-embedded tissue microarray blocks of gastric adenocarcinoma tissue specimens were obtained from 363 gastric cancer patients. All patients underwent curative gastric resection from 1999 to 2007 and distributed from stage I to IV and their clinical characteristics were collected. IHC (Immunohistochemical) assay was performed to evaluate PKM2 expression levels. The correlation of PKM2 expression level with gastric cancer prognosis / stage / histology was evaluated. Results: In our previous microarray study using 60 gastric cancer tissues, we identified PKM2 mRNA overexpressed in cancer tissue than non-cancer tissue (P&amp;lt;0.01). In IHC assays, PKM2 expression level was classified to score 0 (negative, n=185), 1 (weak positive, n=136), and 2 (strong positive, n=42). 49% of gastric cancer tissues presented PKM2 expression (weak or strong positive). PKM2 expression had no relation with prognosis (p=0.913, recurrence free survival) and TNM stage (p=0.825). Intestinal and diffuse type cancer manifested different PKM2 expression pattern and signet ring cell carcinoma manifested 26.6% PKM2 expression. Within same Lauren classification, there was no significant difference of prognosis according to PKM2 expression except signet ring cell carcinoma. In signet ring cell cancer (n=78), PKM2 expression was related to poor overall survival (p=0.029) Conclusion: PKM2 protein expression was not correlated with gastric cancer prognosis. Only in signet ring cell gastric cancer, overexpressed PKM2 was associated with poor overall survival. The role of PKM2 should be further verified in signet ring cell gastric cancer model to find clinical significance in this subtype of gastric cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4540. doi:1538-7445.AM2012-4540

HER-2/neu Overexpression is an Independent Prognostic Factor for Intestinal-type and Early-stage Gastric Cancer Patients

To evaluate the HER-2/neu protein level by immunohistochemistry (IHC) and its gene amplification by fluorescence in situ hybridization (FISH) in gastric cancer samples, and the relevance to the prognosis of gastric cancer patients. HER-2/neu overexpression and gene amplification were examined with semiquantitative standardized IHC in 775 formalin-fixed paraffin-embedded gastric cancer samples, and 252 of these cases were analyzed with FISH. Of the 775 gastric cancer samples examined by IHC, a total of 88 (11%) cases were positive for HER-2/neu overexpression at a score of 3+; another 44 (6%) cases were equivocal with a score of 2+; and the rest 643 (83%) cases were negative scored as 0/1+. Intestinal-type and early-stage cancers exhibited higher rate of HER-2/neu overexpression than those of diffuse/mixed-type and advanced cancers (P<0.05). Intestinal-type and early-stage cancers with HER-2/neu overexpression also exhibited short 5 year survival rates (21% vs. 47%, P=0.027; 29% vs. 60%, P=0.037) than HER-2/neu-negative cases, but not in the diffuse/mixed-type and advanced stage cancers. By FISH analysis, it was shown that 70% (60/86) of IHC 3+ had HER-2/neu gene amplication. In contrast, only 14% (6/43) of IHC 2+ cases, and 2.5% (3) of the 120 cases with IHC 0/1+ randomly selected showed HER-2/neu gene amplification. HER-2/neu overexpression may be used as an independent prognostic factor for intestinal-type and early-stage gastric cancer patients. IHC 3+ and 2+ cases should be further detected by FISH to assess HER-2/neu gene status. Patients with HER-2/neu amplification also might constitute potential candidates for targeted therapy with trastuzumab.

Serological assessment of gastric mucosal atrophy in gastric cancer

BackgroundNon-invasive tools for gastric cancer screening and diagnosis are lacking. Serological testing with the detection of pepsinogen 1 (PG1), pepsinogen 2 (PG2) and gastrin 17 (G17) offers the possibility to detect preneoplastic gastric mucosal conditions. Aim of this study was to assess the performance of these serological tests in the presence of gastric neoplasia.MethodsHistological and serological samples of 118 patients with gastric cancer have been assessed for tumor specific characteristics (Laurén type, localisation), degree of mucosal abnormalities (intestinal metaplasia, atrophy) and serological parameters (PG1, PG2, PG1/2-ratio, G17, H. pylori IgG, CagA status). Association of the general factors to the different serological values have been statistically analyzed.ResultsPatients with intestinal type gastric cancer had lower PG1 levels and a lower PG1/2-ratio compared to those with diffuse type cancer (p = 0.003). The serum levels of PG2 itself and G17 were not significantly altered. H. pylori infection in general had no influence on the levels of PG1, PG2 and G17 in the serum of gastric cancer patients. There was a trend towards lower PG1 levels in case of positive CagA-status (p = 0.058). The degree of both intestinal metaplasia and atrophy correlated inversely with serum levels for PG1 and the PG1/2-ratio (p < 0.01). Laurén-specific analysis revealed that this is only true for intestinal type tumors. Univariate ANOVA revealed atrophy and CagA-status as the only independent factors for low PG1 and a low PG1/2-ratio.ConclusionsGlandular atrophy and a positive CagA status are determinant factors for decreased pepsinogen 1 levels in the serum of patients with gastric cancer. The serological assessment of gastric atrophy by analysis of serum pepsinogen is only adequate for patients with intestinal type cancer.

Evaluation of the clinical relevance of hrgA gene in patients with Helicobacter pylori infection.

Patients with gastric cancer in some Asian populations were infected more frequently with hrgA-positive H. pylori. The aim of this study was to examine the usefulness of hrgA to predict the clinical outcome of H. pylori infection. Forty four patients with gastric cancer (35 intestinal and 9 diffuse type cancer) and 51 control subjects were studied. Presence of hrgA gene in H. pylori strains isolated from biopsy specimens was examined by PCR. Biopsy specimens were also obtained for histological assessment of gastritis. Nine of 44 patients with gastric cancer (20.4%) and 11 of 51 control subjects (21.6%) were infected with hrgA-positive strain (NS). In patients with gastric cancer, prevalence of hrgA-positive strain was 20.0% in patients with intestinal type cancer (7/35) and 22.2% with diffuse type cancer (2/9) (NS). In control subjects, the prevalence of hrgA-positive infection was not associated with gastric mucosal inflammatory infiltration and glandular atrophy. Infection with hrgA-positive strain was not frequent among patients with gastric cancer. Presence of hrgA gene would not be a useful marker to predict clinical outcome of patients infected with H. pylori in this series of Japanese patients.

Gastric cancer risk according to the distribution of intestinal metaplasia and neutrophil infiltration

Gastritis and intestinal metaplasia (IM) have long been known to be risk factors for and precursors of gastric cancer. We aimed to elucidate the association between gastric cancer risk and the distribution of precancerous lesions in the stomach by histological analyses. We analyzed patients from whom two biopsy specimens (one from the antrum and one from the corpus) were obtained by upper gastrointestinal endoscopy. Specimens were assessed for Helicobacter pylori, IM, and neutrophil infiltration (NI). Patients were classified into three groups based on the presence of IM. Patients were also classified into four groups based on the presence of NI. The prevalence of gastric cancer was compared between groups. A total of 1395 patients were analyzed. Of these, 54 had gastric cancer (34 intestinal and 20 diffuse type). A multivariate analysis showed that male sex and the distribution of IM were independent risk factors for intestinal-type cancer. Compared with patients without IM (n = 1005), the odds ratio (OR) for patients with IM in the antrum only (n = 240) was 2.34 (95% confidence interval: 1.08-4.96), and that for patients with IM in the corpus (n = 150) was 5.84 (2.92-11.8). However, NI was related to diffuse-type cancer. Compared with patients without NI (n = 899), the OR for patients with NI in the corpus only (n = 122) was 3.66 (1.02-12.2). The histological pattern and distribution of gastric mucosal change assessed by two biopsy specimens were related to gastric cancer.