Gastric carcinoma

Diagnostic performance of virtual gastroscopy using MDCT in early gastric cancer compared with 2D axial CT: focusing on interobserver variation

OBJECTIVE

The objective of our study was to assess the diagnostic performance of virtual gastroscopy using MDCT for the detection of early gastric cancer (EGC) compared with 2D axial CT, focusing on interobserver reliability.

MATERIALS AND METHODS

During an 11-month period, we performed CT examinations of 94 consecutive patients with EGC and a control group composed of 68 patients without EGC. Three radiologists retrospectively interpreted the 2D axial CT and virtual gastroscopy images. Diagnostic performances were compared within each observer using the area under the receiver operating characteristic curve (A(z)). Sensitivity and specificity were also calculated for each individual observer. The simple kappa statistic was used to evaluate interobserver reliability in the detection of EGC.

RESULTS

The diagnostic performance for overall lesion detection in patients with EGC was significantly higher with virtual gastroscopy (A(z) = 0.829-0.885) than with 2D axial CT (A(z) = 0.734-0.793) (p < 0.001). The sensitivity and specificity of virtual gastroscopy for EGC were 78.7-84.0% and 83.8-91.2%, respectively. The sensitivity and specificity of 2D axial CT for EGC were 62.8-69.2% and 83.8-92.7%, respectively. Virtual gastroscopy showed a higher sensitivity for EGC than 2D axial CT (p < 0.001). The interobserver reliabilities showed moderate to substantial agreement (kappa = 0.40-0.74 for 2D axial CT, kappa = 0.57-0.71 for virtual gastroscopy).

CONCLUSION

Virtual gastroscopy showed excellent results with a good interobserver reliability for the detection of EGC compared with 2D axial CT.

MAD1 (mitotic arrest deficiency 1) is a candidate for a tumor suppressor gene in human stomach

Mitotic arrest deficiency 1 (MAD1) is a component of the spindle checkpoint factors that monitor fidelity of chromosomal segregation. We previously confirmed that the level of MAD1 protein was decreased in gastric carcinoma compared with non-tumoral mucosa by conducting proteome-based analyses (Nishigaki R, Osaki M, Hiratsuka M, Toda T, Murakami K, Jeang KT, Ito H, Inoue T, Oshimura M, Proteomics 5:3205-3213, 29). In this study, an immunohistochemical analysis was performed to examine MAD1 expression histologically in gastric mucosa and tumor. MAD1 was detected in the supranuclear portion of normal epithelial, intestinal metaplasia, and adenoma cells, but its expression was not restricted to any specific area in carcinoma cells. Lower levels of expression were noted in 16 (47.1%) of 34 adenomas and in 52 (60.5%) of 86 carcinomas, whereas all normal mucosae and intestinal metaplasias were grouped into cases with higher level of expression. Moreover, the expression of MAD1 was significantly lower in advanced carcinomas than early carcinomas and in intestinal than diffuse type, respectively (P < 0.05). Exogenous expression of wild-type MAD1, but not the mutant MAD1, inhibited cell proliferation and resulted in G2/M accumulation in MKN-1, a gastric carcinoma cell line. Taken together, our findings suggest that the MAD1 gene could be a candidate tumor suppressor gene and that down-regulation of MAD1 expression contribute to tumorigenesis in human stomach.

Treatment and prognosis of gastric stump carcinoma in comparison with primary proximal gastric cancer

BACKGROUND

The intention of this study was to evaluate the outcome of patients with gastric stump cancer (GSC) in comparison with patients treated for primary proximal gastric cancer (PPGC).

METHODS

Nineteen patients with GSC undergoing surgery between January 1989 and August 2005 were compared with 194 PPGC patients treated during the same time period. Various factors such as epidemiologic data, type of treatment, and histopathologic data were evaluated in the analysis.

RESULTS

The overall 5-year disease-specific survival was 42% for resected GSC patients in comparison with 37% for resected PPGC patients. There was no statistically significant difference in the survival rate detected between these 2 groups. On multivariate analysis the infiltration of the gastrojejunal anastomosis by the carcinoma was shown to be a significant predictor for the outcome of patients with GSC.

CONCLUSIONS

In summary, no significant difference in the outcome between GSC and PPGC has been detected.

The role of minimal access surgery for metastasectomy and cytoreduction

This article summarizes findings about the applicability of minimal-access techniques for thoracic and upper gastrointestinal cancers, including those affecting the lung, liver, stomach, and adrenal gland. If metastasectomy and cytoreductive surgery are rapidly evolving, minimal-access surgery in this setting is in its introductory stages. Nevertheless, minimal-access metastasectomy and cytoreductive surgery harbor great potential for selected patients, but further clinical studies are needed.

Regulation of Helicobacter pylori cagA expression in response to salt

Helicobacter pylori infection and a high dietary salt intake are risk factors for the development of gastric adenocarcinoma. In this study, we tested the hypothesis that high salt concentrations might alter gene expression in H. pylori. Transcriptional profiling experiments indicated that the expression of multiple H. pylori genes, including cagA, was regulated in response to the concentrations of sodium chloride present in the bacterial culture medium. Increased expression of cagA in response to high salt conditions was confirmed by the use of transcriptional reporter strains and by immunoblotting. H. pylori CagA is translocated into gastric epithelial cells via a type IV secretion pathway, and on entry into target cells, CagA undergoes tyrosine phosphorylation and causes multiple cellular alterations. Coculture of gastric epithelial cells with H. pylori grown under high salt conditions resulted in increased tyrosine-phosphorylated CagA and increased secretion of interleukin-8 by the epithelial cells compared with coculture of the cells with H. pylori grown under low salt conditions. Up-regulation of H. pylori cagA expression in response to high salt concentrations may be a factor that contributes to the development of gastric adenocarcinoma.

Features of Gastric Neoplasm Detected during the Screening Examination

BACKGROUND/AIMS

Gastric cancer is the leading malignancy in Korea and early detection through the health screening seems to be important. The aims of this study were to investigate the features of gastric neoplasms detected during screening, and to figure out the risk factors of these lesions.

METHODS

From October 2003 to September 2005, subjects who visited Seoul National University Hospital Healthcare System Gangnam Center for health check-up were included in the study. The program included a questionnaire and tests including anti-Helicobacter pylori (H. pylori) antibody, esophagogastroduodenoscopy or double contrast upper gastrointestinal study. To figure out the risk factors, an age and gender-matched, four-fold sized control group was selected from the subjects.

RESULTS

Of 25, 432 subjects, 122 cases of gastric neoplasms were detected including 61 adenocarcinoma (45 early gastric cancers), 53 adenoma, 7 mucosa-associated lymphoid tissue lymphoma, and one metastatic cancer. There was no significant statistical difference in basal characteristics of the subjects between gastric adenocarcinoma and adenoma. When comparing with the control group those without gastric neoplasms, smoking history, family history of stomach cancer, and H. pylori seropositivity were found to be significant risk factors for gastric neoplasms. Metabolic syndrome was more prevalent in adenoma than in the control (p<0.05).

CONCLUSIONS

The health screening may be beneficial in early detection of gastric cancer. In addition, metabolic syndrome might be related with gastric adenoma.

Frequent loss of heterozygosity at 8p22 chromosomal region in diffuse type of gastric cancer

AIM: To study the loss of heterozygosity (LOH) at 8p21-23 locus in diffuse gastric cancer.

METHODS: To evaluate the involvement of this region in gastric cancer, we used eight microsatellite markers covering two Mb of mentioned region, to perform a high-resolution analysis of allele loss in 42 cases of late diffuse gastric adenocarcinoma.

RESULTS: Six of these STS makers: D8S1149, D8S1645, D8S1643, D8S1508, D8S1591, and D8S1145 showed 36%, 28%, 37%, 41%, 44% and 53% LOH, respectively.

CONCLUSION: A critical region of loss, close to the NAT2 locus and relatively far from FEZ1 gene currently postulated as tumor suppressor gene in this region.

An analysis on the proportion of gastric cancer in Qinghai region from 1994 to 2003

AIM: To study the clinicopathologic variation trend of gastric cancer during the past ten years.

METHODS: A total of 1765 gastric cancer patients diagnosed with endoscopy and pathologic examination were included in this study. The cases were divided into 2 groups. Group A comprised patients during 1994 to 1998, while group B consisted of ones during 1999 to 2003. Statistical comparison analyses on the age, sex of patients, distribution and histological type of gastric cancer were performed.

RESULTS: The male to female ratio was 3.33 : 1 in group A, and 3.29 : 1 in group B. The proportion of the male was evidently higher than that of the female in both groups (P < 0.05). The proportion of patients with different ages was 12.86% (< 40 years old), 45.04% (40-60 years old) and 42.10% (> 60 years old), respectively. The patients over 40 years old showed a higher ratio than the others. In comparison with group B, the proportion of patients aged 40 to 60 years in group A was increased (χ² = 6.116, P = 0.013), while that of patients over 60 years old was decreased (χ² = 4.983, P = 0.026). In both groups, gastric carcinoma occurred mainly at gastric body, antrum and cardia part. As compared with group A, there was an increase in the proportion of gastric cancer at fundus (χ² = 6.116, P = 0.01) while a corresponding decrease in the proportion of pyloric carcinoma (χ² = 6.116, P = 0.007) in group B. The familiar tissue types in both groups were lowly- and moderately-differentiated adenocarcinoma.

CONCLUSION: The age of gastric cancer patients is going up, and there is a trend towards proximal stomach in the location of gastric cancer.

Impact of hospital volume on recurrence and survival after surgery for gastric cancer

BACKGROUND

Some, but not all, studies using registry data have suggested a small but significant long-term survival advantage following a curative surgical resection of gastric cancer at hospitals where the volume of such surgeries is high. However, because such data may be significantly influenced by the impact of postoperative mortality, and may be imbalanced for factors important to survival, the true nature of this relationship remains uncertain.

METHODS

We conducted a nested volume-outcome study in a sample of 448 surgical survivors with stage IB through IV (M0) gastric and gastroesophageal junction adenocarcinoma, previously randomized to adjuvant chemoradiation after surgery or surgery alone, to measure the effect of hospital surgical volume, as assessed by Medicare claims data, on overall survival and gastric cancer recurrence.

RESULTS

In this selected sample of postoperative survivors, hospital surgical volume was not predictive of overall survival (P = 0.46) or disease-free survival (P = 0.43) at a median follow-up of 8.9 years. However, patients who underwent either a D1 or D2 dissection at a high- or moderate-volume center experienced an adjusted hazard ratio of 0.80 (95% CI, 0.53-1.20) for overall survival and 0.78 (95% CI, 0.53-1.14) for disease-free survival compared with those patients resected at a low-volume hospital; these results were not statistically significant. When a D0 resection was performed, hospital procedure volume showed no impact on survival.

CONCLUSIONS

Excluding the impact of perioperative mortality by utilizing prospectively recorded data from a large postoperative adjuvant trial, hospital procedure volume had no overall effect on long-term gastric cancer survival. The potential benefit of moderate- to high-volume centers for patients who underwent a D1 or D2 dissection requires confirmation in larger studies.

5-fluorouracil, mitomycin-C, and polysaccharide-K adjuvant chemoimmunotherapy for locally advanced gastric cancer: the prognostic significance of frequent perineural invasion

BACKGROUND/AIMS

Although adjuvant chemotherapy has demonstrated small but significant survival benefit in locally advanced gastric cancer in several meta-analyses, optimal chemotherapy regimen remains to be determined.

METHODOLOGY

We retrospectively analyzed the survival of 207 gastric cancer patients (stage IB: 19, II: 65, IIIA: 58, IIIB: 28, IV: 37) who underwent 5-fluorouracil (5-FU), mitomycin-C (MMC), and polysaccharide-K (PSK) chemoimmunotherapy (CITX) after curative resection (FM group). The survival of FM group was compared with that of historical control cohort of 103 patients with almost identical stage distribution who received 5-FU and doxorubicin-based chemotherapy (FA group).

RESULTS

Five-year disease-free survival and overall survival (OS) of FM group were 58.7% and 59.1%, respectively. Frequent perineural invasion was significantly associated with poor OS (p = 0.01) in multivariate analysis. There was no statistically significant difference in 5-year OS (59.1% vs. 56.2%, p = 0.637) between FM and FA groups. FM group showed superior 5-year OS (84.4% vs. 67.6%, p = 0.019) compared with FA group in stage IB or II patients without significant difference (p = 0.222) in stage IIIA to IV.

CONCLUSIONS

5-FU, MMC, and PSK CITX is as effective as 5-FU and doxorubicin-based chemotherapy. Moreover, frequent perineural invasion seems to be an important poor prognostic factor.

Potential tumor markers for human gastric cancer: an elevation of glycan:sulfotransferases and a concomitant loss of alpha1,2-fucosyltransferase activities

PURPOSE

Several reports indicate a complexity in glycosyltransferase activities which lead to several tumor associated carbohydrate structures in gastric carcinoma. The present study was aimed to identify the carbohydrate associated transferases which exhibit the most marked and consistent change of activity in gastric tumorigenesis.

METHODS

We examined the levels of fucosyl, beta-galactosyl-, beta-N-acetylgalactosaminyl, sialyl- and glycan:sulfotransferase activities, which generate the outer ends of oligosaccharide chains in tumorous and adjacent normal gastric tissues of the same patient in ten gastric carcinoma cases by using well defined specific synthetic acceptors utilized in our several earlier published studies as referenced in the text (e.g. Chandrasekaran et al. in J Biol Chem 279:10032-10041, 2004; Biochemistry 44:15619-15635, 2005; Carbohydr Res 341:983-994, 2006).

RESULTS

Among glycosyltransferases only alpha1,2-fucosyltransferase (FT) was unique in showing a remarkable 40-90% decrease of activity in seven cases. Uniquely several fold elevation of Gal3Sulfo-T(2) (1.9 --> 156.7 fold) and Gal3Sulfo-T(4) (2.4 --> 149.0 fold) activities in all ten cases and moderate elevation of GlcNAc6Sulfo-T (1.3 --> 37.5 fold) activities in nine cases were identified. Poorly differentiated Signet ring cell carcinoma expresses mainly Gal3Sulfo-T(2) activity whereas poorly differentiated adenocarcinoma express predominantly Gal3Sulfo-T(4) activity and also GlcNAc6Sulfo-T activity. But, very low level of these sulfotransferase activities were identified in moderately differentiated gastric carcinomas as well as non-epithelial gastric stromal sarcoma.

CONCLUSION

Up regulation of glycan:sulfotransferase activities and down regulation of alpha1,2-fucosyltransferase activity are apparently associated with human gastric tumorigenesis.

Frequent reduced expression of alpha-1B-adrenergic receptor caused by aberrant promoter methylation in gastric cancers

Recent studies have suggested that epigenetic inactivation of tumour-related genes by promoter methylation participates in the development of gastric cancer. We newly identified the frequently aberrant promoter methylation of alpha-1B-adrenergic receptor (ADRA1B) in colorectal cancer by methylation-sensitive representational difference analysis (MS-RDA) and examined the methylation status of the ADRA1B promoter in 34 paired samples of colorectal cancer and surrounding epithelial tissue, and 34 paired samples of gastric cancer and surrounding epithelial tissue. In colorectal cancers, only four of 34 (11.8%) tumours showed ADRA1B promoter methylation. In contrast, ADRA1B promoter methylation was detected in 24 of 34 (70.6%) gastric cancers and in 14 of 34 (41.2%) surrounding epithelial tissues. The frequency of ADRA1B promoter methylation was higher in gastric epithelial tissues with intestinal metaplasia (41.6%) than in those without intestinal metaplasia (25.0%). Reverse transcription–PCR detected reduced ADRA1B expression in 12 of 18 (66.7%) gastric cancers, and its promoter methylation was detected in 11 of these 12 (91.7%) gastric cancers with reduced ADRA1B expression. Thus, ADRA1B promoter is frequently methylated in gastric cancer. Our results suggest that the ADRA1B gene is an important tumour-related gene frequently involved in the development and progression of gastric cancer.

Results following resection for stage IV gastric cancer; are better outcomes observed in selected patient subgroups?

BACKGROUND

Patients who present with stage IV gastric cancer are not commonly managed with surgical resection as effective palliation can usually be accomplished with systemic chemotherapy, endoscopic stenting, or surgical bypass procedures. Given the inherent morbidity and mortality associated with gastrectomy, palliative resection for stage IV gastric cancer should be reserved for ideal surgical candidates who are most likely to benefit from the procedure. The purpose of this study is to review outcomes following resection for stage IV gastric cancer, and to identify criteria predictive of improved outcomes following gastrectomy in this setting.

METHODS

A retrospective review of a prospective GI oncology database was conducted. Sixty-three patients with stage IV gastric cancer managed with surgical resection between 1989 and 2001 were identified. Variables including demographic data, patterns of distant spread (ex: peritoneal, lymphatic, hematogenous), location of tumor, and type of gastrectomy were utilized to conduct survival analyses.

RESULTS

Actuarial survival for all patients at one and 3-year intervals was 52% and 12%, respectively. Improved survival was observed for patients of East Asian race (median survival 20 vs. 12 months, P < 0.05, students t-test) and age less than 60 years (median survival 15 vs. 12 months, P < 0.05). This trend was also illustrated by Kaplan-Meier survival analysis. Other variables including pattern of distant spread, location of tumor, and type of gastrectomy were not associated with a significant difference in survival. Both East Asian race and age less than 60 years were statistically significant predictors of improved survival when assessed by univariate regression analysis. When variables were analyzed in a multivariate regression analysis, Asian race and age <60 both lost their statistical significance as independent predictors of improved survival.

CONCLUSIONS

Long-term survival for patients with stage IV gastric cancer who are managed with surgical resection is achievable. Patient specific variables including East Asian race and age less than 60 years appear to be associated with prolonged survival when assessed by comparison of means, Kaplan-Meier analysis, and univariate regression analysis. However, multivariate regression analysis failed to demonstrate these factors as independent predictors of improved outcome. In conclusion, highly selected acceptable risk surgical candidates with stage IV gastric cancer should be considered for management with surgical resection in clinically appropriate scenarios.

Improvement of cancer-targeting therapy, using nanocarriers for intractable solid tumors by inhibition of TGF-beta signaling

Transforming growth factor (TGF)-beta plays a pivotal role in regulation of progression of cancer through effects on tumor microenvironment as well as on cancer cells. TGF-beta inhibitors have recently been shown to prevent the growth and metastasis of certain cancers. However, there may be adverse effects caused by TGF-beta signaling inhibition, including the induction of cancers by the repression of TGF-beta-mediated growth inhibition. Here, we present an application of a short-acting, small-molecule TGF-beta type I receptor (TbetaR-I) inhibitor at a low dose in treating several experimental intractable solid tumors, including pancreatic adenocarcinoma and diffuse-type gastric cancer, characterized by hypovascularity and thick fibrosis in tumor microenvironments. Low-dose TbetaR-I inhibitor altered neither TGF-beta signaling in cancer cells nor the amount of fibrotic components. However, it decreased pericyte coverage of the endothelium without reducing endothelial area specifically in tumor neovasculature and promoted accumulation of macromolecules, including anticancer nanocarriers, in the tumors. Compared with the absence of TbetaR-I inhibitor, anticancer nanocarriers exhibited potent growth-inhibitory effects on these cancers in the presence of TbetaR-I inhibitor. The use of TbetaR-I inhibitor combined with nanocarriers may thus be of significant clinical and practical importance in treating intractable solid cancers.

Proteomic analysis of cancer tissues: shedding light on carcinogenesis and possible biomarkers

Lung, gastric, colorectal, pancreatic, and esophageal cancers, as well as hepatocellular carcinoma (HCC), were the six most common and highly fatal cancers for Japanese men in Japan in 2003, while for women uterine cervical cancer could also be added to this list. To identify diagnostic or therapeutic biomarkers for these cancers, investigators are nowadays performing proteomic analyses of cancer tissues and cells, and revealing a large number of molecules which are diagnostic, prognostic and informative of carcinogenesis. From reports of proteomic analyses of cancerous tissues and noncancerous tissues sampled from HCC, and pancreatic, esophageal, gastric, colorectal, lung and uterine cervical cancers, we classified the proteins into digestive enzymes, growth factors, cell adhesion molecules, calcium-binding proteins, proteases, protease inhibitors, transporter proteins, structural molecules, apoptosis inhibitor, molecular chaperone, as well as proteins related to cell growth, cell differentiation, cell transformation, tumor invasion, carcinogen metabolism, and others. The aim of this study was to understand carcinogenesis of major cancers from a proteomics perspective using samples from cancer patients, and to elucidate their tumor biomarkers.

Gene polymorphisms of folate metabolizing enzymes and the risk of gastric cancer

Multiple studies have reported an association between disturbances of folate metabolism and increased risk of gastric cancer, including low intake of folate, low levels of folate in blood or genetic factors affecting folate metabolism. Among the genetic factors, in particular a common polymorphism in the gene encoding for 5,10-methylenetetrahydrofolate reductase (MTHFR C677T) has been linked to gastric cancer. Other polymorphisms in folate-metabolising genes have been less frequently investigated. Therefore, we analyzed this polymorphism, the glutamate carboxypeptidase (GCP) II C1561T and the reduced folate carrier (RFC) G80A in a case-control study involving 106 patients with histologically confirmed and characterized gastric cancer with adjustment for other established risk factors for gastric cancer in comparison to 106 age- and sex-matched controls. Neither the MTHFR nor the GCP gene polymorphisms showed an association to cancer diagnosis, to tumor stage, grade of differentiation or Lauren type. However, non-cardia cancers were more likely to exhibit the 80GA and 80AA RFC genotypes, compared to cancers of the gastric cardia (adjusted OR 0.28; 95% CI=0.11-0.71). Thus, gene polymorphisms of the RFC gene might contribute to an increased risk of developing distal gastric cancer.

Napoleon Bonaparte's gastric cancer: a clinicopathologic approach to staging, pathogenesis, and etiology

BACKGROUND

Numerous hypotheses on the cause of Napoleon Bonaparte's death have been proposed, including hereditary gastric cancer, arsenic poisoning, and inappropriate medical treatment. We aimed to determine the etiology and pathogenesis of Napoleon's illness by a comparison of historical information with current clinicopathologic knowledge.

INVESTIGATIONS

Evaluation of Napoleon's clinical history, original autopsy reports, and of historical documents. The clinicopathologic data from 135 gastric cancer patients were used for comparison with the data available on Napoleon.

DIAGNOSIS

At least T3N1M0 (stage IIIA) gastric cancer. Napoleon's tumor extended from the cardia to the pylorus (>10 cm) without infiltration of adjacent structures, which provides strong evidence for at least stage T3. The N1 stage was determined by the presence of several enlarged and hardened regional (perigastric) lymph nodes, and the M0 stage by the absence of distant metastasis. Analysis of the available historical documents indicates that Napoleon's main risk factor might have been Helicobacter pylori infection rather than a familial predisposition.

CONCLUSIONS

Our analysis suggests that Napoleon's illness was a sporadic gastric carcinoma of advanced stage. Patients with such tumors have a notoriously poor prognosis.

Radiologische Bildgebung des oberen Gastrointestinaltraktes

CT, and multi-detector row computed tomography in particular, play a very important role in staging malignant tumors of the stomach. The optimized technique of so called "Hydro-CT", including distension to the gastric wall with 1-1.5 l oral contrast media, mainly water, has fostered the diagnostic value of CT in the diagnosis of diseases of the stomach. By using the "Hydro-CT" technique, the detection rate for gastric carcinoma is now between 89% and 94%, and for liver metastasis between 85% and 92%. For overall T staging, the sensitivity is rather low at between 43% and 65%, and for the lymph nodes between 64 and 88%. Depending on tumor type, multislice computed tomography (MSCT) supplies morphological details for defining the type of lesion (polyps, gastritis, lymphoma, gastrointestinal stromal tumours, carcinoma). Nevertheless, a definite differential diagnosis remains difficult. In addition, multiplanar reconstruction (MPR), derived from multi-detector row computed tomography data sets, is very helpful in localizing these pathologies and demonstrating their anatomic relationship to adjacent organs and vascular structures. MRI plays no major part in the diagnostic evaluation of the upper GI-tract.

Prevalence and evaluation of B12 deficiency in patients with autoimmune thyroid disease

BACKGROUND

Patients with autoimmune thyroid disease (AITD) have a higher prevalence of pernicious anemia compared with the general population. Clinical signs of B12 deficiency may be subtle and missed, particularly in patients with known autoimmune disease. We assessed the prevalence of vitamin B12 deficiency in patients with AITD and whether their evaluation may be simplified by measuring fasting gastrin levels.

METHODS

Serum B12 levels was measured in 115 patients with AITD (7 men and 108 women), with a mean age of 47 +/- 15 years. In patients with low serum B12 levels (< or =133 pmol/L), fasting serum gastrin and parietal cell antibodies (PCA) were measured.

RESULTS

Thirty-two patients (28%) with AITD had low B12 levels. Fasting serum gastrin was measured in 26 and was higher than normal in 8 patients. PCA were also measured in 27 patients with B12 deficiency and were positive in 8 patients. Five patients with high gastrin levels underwent gastroscopy with biopsy, and atrophic gastritis was diagnosed in all. The prevalence of pernicious anemia as assessed by high serum gastrin levels in patients with low B12 was 31%.

CONCLUSIONS

Patients with AITD have a high prevalence of B12 deficiency and particularly of pernicious anemia. The evaluation of B12 deficiency can be simplified by measuring fasting serum gastrin and, if elevated, referring the patient for gastroscopy.

Paraneoplastic syndrome, infection or arthritis: Difficulties in diagnosis

Many different diseases have overlapping clinical symptoms. A major challenge in daily clinical practice is to differentiate between diseases associated with systemic inflammation, such as neoplasia, infection and autoimmune disease. We report on a 46-year-old Caucasian male with a 3-month history of rheumatoid arthritis presenting with dramatic weight loss and dysphagia. Computer tomography revealed multiple lesions in the liver and the spleen, strongly suggesting malignant disease of unknown origin. Surprisingly, on biopsy, the liver lesions drained pus. Workup revealed that the abscesses resulted from gastric perforation, which was the consequence of NSAR therapy for rheumatoid arthritis. Antibiotic therapy was initiated, abscesses diminished and dysfunctional deglutition improved. This unique case demonstrates in a dramatic way the difficulties in daily clinical practice to differentiate between paraneoplasia, infection and autoimmune disease and the potentially life-threatening consequences of their therapy.

High incidence of microscopic gastrointestinal stromal tumors in the stomach

Gastrointestinal stromal tumors (GISTs) are rare mesenchymal neoplasms with an annual incidence of approximately 10 to 20 per 1 million cases. Although pathologists have often observed incidental small GISTs in the stomach resected from patients with gastric cancer, no report on the real incidence of gastric GISTs is available. In this study, 100 whole stomachs resected from patients with gastric cancer were sectioned at 5-mm intervals and hematoxylin and eosin-stained slides (a mean of 130 slides for each case) were examined for microscopic GISTs. KIT (CD117), CD34, and desmin expression of the incidental tumors was evaluated by immunohistochemistry, and genomic DNA extracted from formalin-fixed and paraffin-embedded tumor tissues was analyzed for c-kit gene mutations in exon 11. In 35 of the 100 whole stomachs, we found 50 microscopic GISTs, all of which were positive for KIT and/or CD34 and negative for desmin. Most microscopic GISTs (45/50, 90%) were located in the upper stomach. Two of the 25 (8%) microscopic GISTs had c-kit gene mutations. Fifty-one leiomyomas with positive expression for desmin were observed in 28 of the 100 stomachs. Both leiomyomas and GISTs were found in 12 stomachs. These results indicate that microscopic GISTs are common in the upper portion of the stomach. Considering the annual incidence of clinical GISTs, only few microscopic GISTs may grow into a clinical size with malignant potential. Further studies are required to clarify the genetic events responsible for the transformation of microscopic GISTs to clinical GISTs.

Thymidylate synthase and dihydropyrimidine dehydrogenase are related to histological effects of 5-fluorouracil and cisplatin neoadjuvant chemotherapy for primary gastric cancer patients

Thymidylate synthase (TS), dihydropyrimidine dehydrogenase (DPD), and vascular endothelial growth factor (VEGF) are associated with the effect of 5-fluorouracil (5-FU) based adjuvant chemotherapy. However, very few studies have investigated the relationship between these factors and 5-FU neoadjuvant chemotherapy for primary gastric cancer patients. In this study, we studied the correlation between these markers and the histological chemotherapeutic effect in advanced gastric cancer with neoadjuvant chemotherapy.

METHODS

Sixty-two primary advanced gastric cancer patients were recruited into the study. One cycle of continuous infusion of 5-FU (300 mg/m2/day, 14 days) plus drip infusion of cisplatin (15 mg/m2/day, Day one and Day two) was performed as neoadjuvant chemotherapy. Histological chemotherapeutic responses of the resected specimens were classified into responders and nonresponders. TS, DPD, VEGF expressions both before and after neoadjuvant chemotherapy were examined immunohistochemically.

RESULTS

There was an association between the TS-low group and the responders (p < 0.05); the DPD-low group and the responders in both biopsy and surgical specimens (p < 0.01). A combination of the low-TS and low-DPD group was further associated with responders (p < 0.01). The immunoexpressions of biopsied and surgical specimens were significantly associated with each other.

CONCLUSION

Neoadjuvant chemotherapy for primary gastric cancer with one cycle of 5-FU and cisplatin was associated with histological findings in patients with low baseline TS and DPD. This dual determination may predict for efficacy of neoadjuvant treatment with these drugs.

Molecular screening of gastric cancer by proteome analysis

Gastric cancer affects annually more than 800,000 individuals worldwide and remains a challenge for clinicians and oncologists. Most patients with gastric cancer are diagnosed in advanced stages, when a curative resection is impossible, which leads to an overall poor prognosis. Finding new diagnostic and treatment procedures is of paramount importance to improve patient prognosis, which will be improved most dramatically by techniques that allow the detection of gastric cancer in its early stages. So far the value of conventional tumour markers such as Ca72-4 or carcinoembryonic antigen is limited, and even markers developed from molecular biological studies on the carcinogenesis of gastric cancer, such as E-cadherin and others, have not proved to be of adequate sensitivity and specificity to allow the early detection of gastric cancer. With the development of innovative diagnostic tools, such as proteome analysis, new biomarkers may be identified that may allow early diagnosis and thus screening for gastric cancer, particularly in at-risk patient populations. Recent studies have indicated that these biomarkers may be derived from the tumour itself or reflect a specific metabolic or immunological response to cancer that can be used to find gastric cancer patients at an early and putatively curative stage of the disease.

Diffuse gastric cancer

Gastric cancer is one of the leading causes of cancer deaths around the world. This article provides an overview of gastric cancer using a unique case study involving a New Zealand Maori family genetically predisposed to diffuse gastric cancer. The pathophysiology of diffuse gastric cancer, including prognosis, diagnosis, and treatment, along with important patient considerations is highlighted.

Tamoxifen exposure and risk of oesophageal and gastric adenocarcinoma: a population-based cohort study of breast cancer patients in Sweden

In a population-based cohort study of all women aged over 50 years with breast cancer in the Swedish Cancer Register in 1961–2003, those diagnosed before 31 December 1987 were regarded as unexposed to tamoxifen, whereas those diagnosed after that date were considered potentially exposed. Crosslinkages within the Cancer Register and the Registers of Death and Emigration enabled follow-up. Standardised incidence ratios (SIRs) of oesophageal and gastric cancer represented relative risks. Among 138 885 cohort members contributing with 1 075 724 person-years of follow-up, we found a nonsignificantly increased risk of oesophageal adenocarcinoma during the potential tamoxifen exposure period (SIR 1.60, 95% confidence interval (CI) 0.83–3.08), but the risk estimates decreased with increasing latency interval. No association was observed during the unexposed period. No increased risk of cardia adenocarcinoma was identified in either period. The risk of non-cardia gastric adenocarcinoma was increased in the potential tamoxifen period (SIR 1.27, 1.03–1.57), and almost doubled (SIR 1.86, 95% CI 1.10–3.14) in the period of longest latency (10–14 years). The corresponding overall SIR was increased in the unexposed group also, but here SIR did not increase with longer latency intervals. An increased risk of tobacco-related tumours, that is, oesophageal squamous-cell carcinoma and lung cancer, was limited to the unexposed cohort, indicating that confounding by smoking might explain the increased SIR during the unexposed period. We concluded that there might be a link between tamoxifen and risk of non-cardia gastric adenocarcinoma.

Plasminogen activator inhibitor-1 as a potential marker for the malignancy of gastric cancer

To test the hypothesis that plasminogen activator inhibitor-1 (PAI-1) may serve as a candidate marker for the malignancy of gastric cancer, we carried out quantitative reverse transcription-polymerase chain reaction for the PAI-1 gene and evaluated the possible relationship between PAI-1 gene expression levels and clinicopathological findings in gastric cancer. A significant increase in PAI-1 expression scores was observed in lymph node metastasis-positive gastric cancers (2.11 +/- 0.35) compared to metastasis-negative cancers (0.33 +/- 0.49) (P = 0.0048), as well as in distant metastasis-positive gastric cancers (3.68 +/- 0.58) compared to metastasis-negative cancers (1.20 +/- 0.32). The PAI-1 expression score markedly increased with tumor stage (P < 0.0001; ANOVA test). Moreover, multivariate analysis revealed the PAI-1 expression score to be a strong and independent prognostic factor for gastric cancer (P = 0.0450). These results suggested that PAI-1 might serve as a new and promising parameter for the prediction of prognosis in gastric cancer.

Gastric cancer patients at high-risk of having synchronous cancer

AIM: To identify patients with a high-risk of having a synchronous cancer among gastric cancer patients.

METHODS: We retrospectively analyzed the prospective gastric cancer database at the National Cancer Center, Korea from December 2000 to December 2004. The clinicopathological characteristics of patients with synchronous cancers and those of patients without synchronous cancers were compared. Multivariate analysis was performed to identify the risk factors for the presence of a synchronous cancer in gastric cancer patients.

RESULTS: 111 of 3 291 gastric cancer patients (3.4%) registered in the database had a synchronous cancer. Among these 111 patients, 109 had a single synchronous cancer and 2 patients had two synchronous cancers. The most common form of synchronous cancer was colorectal cancer (42 patients, 37.2%) followed by lung cancer (21 patients, 18.6%). Multivariate analyses revealed that elderly patients with differentiated early gastric cancer have a higher probability of a synchronous cancer.

CONCLUSION: Synchronous cancers in gastric cancer patients are not infrequent. The physicians should try to find synchronous cancers in gastric cancer patients, especially in the elderly with a differentiated early gastric cancer.

The emerging role of oxaliplatin in the treatment of gastric cancer

Gastric cancer is often diagnosed in locally advanced or metastatic stages and, therefore, of poor prognosis. Many controversies exist about surgery, neoadjuvant, adjuvant and palliative treatments of gastric cancer. So we need to explore a variety of novel management options including the use of new agents and new combinations. Some of these agents include oral fluoropyrimidine, irinotecan, docetaxel and oxaliplatin. Oxaliplatin is a diaminocyclohexane-platinum compound that is significantly different from cisplatin and carboplatin with respect to its activity and toxicity. Oxaliplatin is an alkylating agent inhibiting DNA replication by forming adducts between two adjacent guanines or guanine and adenine molecules. However, the adducts of oxaliplatin appear to be more effective than cisplatin adducts in regard to the inhibition of DNA synthesis. In contrast to cisplatin, oxaliplatin has demonstrated efficacy alone and in combination with 5-fluorouracil in advanced colorectal cancer. Many studies are ongoing to test the combination in noncolorectal gastrointestinal tumors and other malignancies. This review focuses on the increasing amount of data concerning the clinical activity of oxaliplatin-based regimens in advanced gastric cancer.

Analysis of hopQ alleles in East Asian and Western strains of Helicobacter pylori

Helicobacter pylori hopQ (omp27) alleles exhibit a high level of genetic diversity, and certain hopQ genotypes have been associated with an increased risk for peptic ulcer disease. In this study, we analyzed hopQ alleles in H. pylori strains from East Asia and the United States. Phylogenetic analysis indicated the presence of two highly divergent families of hopQ alleles, without evidence of extensive recombination. Type I hopQ alleles from Western and Asian H. pylori strains were similar, and markedly different from type II hopQ alleles. Analyses of synonymous and non-synonymous nucleotide substitutions suggested that there is a positive selection for HopQ amino acid diversity. Type II hopQ alleles were identified commonly in Western H. pylori strains, but rarely in East Asian strains. Nearly all of the East Asian strains analyzed were cagA-positive and contained type I hopQ alleles. Geographic variation in the genetic characteristics of H. pylori strains may be a factor contributing to geographic variation in gastric cancer incidence.

Promoter methylation of helicase-like transcription factor is associated with the early stages of gastric cancer with family history

BACKGROUND

To investigate the clinicopathological significance of promoter methylation of the helicase-like transcription factor (HLTF) in primary gastric cancer.

PATIENTS AND METHODS

Two-hundred fifty six patients participated in this study. Methylation status of HLTF gene was evaluated in fresh-frozen tissues by the methylation-specific polymerase chain reaction. All statistical analyses were two-sided, with a 5% type I error rate.

RESULTS

Aberrant methylation of HLTF was found in 98 (38%) of 256 gastric cancer patients. HLTF methylation was significantly associated with a family history in the early stages of gastric cancer, regardless of histologic types. In intestinal-type cases, HLTF methylation occurred in 15 (56%) of 27 patients with family histories, and in 26 (31%) of 85 patients without family histories (P = 0.02). In diffuse-type cases, patients with family histories were also found to exhibit a higher prevalence of HLTF methylation than those without family histories (61% vs. 34%; P = 0.009). HLTF methylation in both of the histologic types occurred in about 70-90% of the early stage cases in which the patient had a family history and in 15-30% of cases in which the patient did not have a family history. In our multivariate logistic regression analysis, the stage 1-2 cases with family histories were determined to carry a higher risk of HLTF methylation than did the stage 3-4 cases without family histories in both the intestinal-type (OR = 6.01, 95% CI = 1.20-30.01, P = 0.02) and the diffuse-type cancers (OR = 8.25, 95% CI = 1.67-40.86, P = 0.009).

CONCLUSIONS

These results suggest that HLTF methylation may play a crucial role in the early stages of gastric carcinogenesis in patients with family histories and may be a valuable susceptible marker for the risk of gastric cancer in individuals with family histories.

Gene expression profiling of gastric cancer by microarray combined with laser capture microdissection

AIM

To examine the gene expression profile of gastric cancer (GC) by combination of laser capture microdissection (LCM) and microarray and to correlate the profiling with histological subtypes.

METHODS

Using LCM, pure cancer cells were procured from 45 cancerous tissues. After procurement of about 5000 cells, total RNA was extracted and the quality of RNA was determined before further amplification and hybridization. One microgram of amplified RNA was converted to cDNA and hybridized to cDNA microarray.

RESULTS

Among 45 cases, only 21 were qualified for their RNAs. A total of 62 arrays were performed. These included 42 arrays for cancer (21 cases with dye-swab duplication) and 20 arrays for non-tumorous cells (10 cases with dye-swab duplication) with universal reference. Analyzed data showed 504 genes were differentially expressed and could distinguish cancerous and non-cancerous groups with more than 99% accuracy. Of the 504 genes, trefoil factors 1, 2, and 3 were in the list and their expression patterns were consistent with previous reports. Immunohistochemical staining of trefoil factor 1 was also consistent with the array data. Analyses of the tumor group with these 504 genes showed that there were 3 subgroups of GC that did not correspond to any current classification system, including Lauren's classification.

CONCLUSION

By using LCM, linear amplification of RNA, and cDNA microarray, we have identified a panel of genes that have the power to discriminate between GC and non-cancer groups. The new molecular classification and the identified novel genes in gastric carcinogenesis deserve further investigations to elucidate their clinicopathological significance.

Hormone replacement therapy and risks of oesophageal and gastric adenocarcinomas

Oesophageal and gastric adenocarcinoma share an unexplained male predominance, which would be explained by the hypothesis that oestrogens are protective in this respect. We carried out a nested case–control study of hormone replacement therapy (HRT) among 299 women with oesophageal cancer, 313 with gastric cancer, and 3191 randomly selected control women, frequency matched by age and calendar year in the General Practitioners Research Database in the United Kingdom. Data were adjusted for age, calendar year, tobacco smoking, alcohol consumption, body mass index, hysterectomy, and upper gastrointestinal disorders. Among 1 619 563 person-years of follow-up, more than 50% reduced risk of gastric adenocarcinoma was found among users of HRT compared to nonusers (odds ratio (OR), 0.48, 95% confidence interval (CI) 0.29–0.79). This inverse association appeared to be stronger for gastric noncardia (OR 0.34, 95% CI 0.14–0.78) and weaker for gastric cardia tumours (OR 0.68, 95% CI 0.23–2.01). There was no association between HRT and oesophageal adenocarcinoma (OR 1.17, 95% CI 0.41–3.32).

Early gastric cancer: virtual gastroscopy

Gastric cancer is one of the most common cancers and one of the most frequent causes of cancer-related deaths worldwide. Early detection and accurate preoperative staging of early gastric cancer (ECG) offers the best prognosis and is essential for planning optimal therapy such as endoscopic mucosal resection or gastric resection. Recent advances in computed tomographic technology and three-dimensional imaging software have enabled more accurate gastric imaging. Virtual gastroscopy (VG) is helpful in the detection and evaluation of EGC in the same way as gastroscopy. VG has a wider field of view than conventional gastroscopy, the angle of the virtual cancer can be adjusted omnidirectionally, and it has no blind point because retrospective reconstruction is available. Thus, VG is a promising method for evaluating gastric lesions despite its limitations. This report describes the clinical usefulness of VG with multidetector row computed tomography for EGC and axial computed tomography.

Differences in genomic instability between intestinal- and diffuse-type gastric cancer

BACKGROUND

Microsatellite instability (MSI) and loss of heterozygosity (LOH) are lesions in the genome found with different frequencies in gastric carcinomas (GCAs). Despite a great body of studies, no systematic approach to the detailed classification of MSI and LOH in the two major types of GCA has been published.

METHODS

Thirty-seven advanced GCAs, 25 intestinal-type (IGCAs) and 12 diffuse-type (DGCAs), were assayed with 15 autosomal tetranucleotide markers on 14 chromosomal arms. The observed frequencies and types of microsatellite alterations allowed stratification into subgroups, i.e., high- and low-grade MSI (MSI-H, MSI-L) or microsatellite-stable (MSS), and high- or low-grade, or non-detectable LOH (LOH-H, LOH-L, LOH-N).

RESULTS

Collectively, the markers detected MSI-H tumors with sensitivity equal to that of BAT-26 (a single marker highly specific for MSI-H). Likewise, the markers detected LOH at chromosomal arms 5q, 18q, and 21q with a sensitivity equal to markers used previously. Seven (19%) MSI-H and six (16%) LOH-H tumors were found, with a significant association (P = 0.027) with IGCA: 92% of MSI-H and LOH-H occurred in IGCA patients only. Conversely, in DGCA, a significantly higher prevalence of a stable (LOH-N/MSS) phenotype was found as compared with IGCA (75.1% vs 28.0%; P = 0.035). The MSI-L phenotype was found in 57.9% of non-MSI-H IGCA tumors and was associated significantly (P = 0.015) with LOH-H.

CONCLUSION

A clear difference in genomic instability between IGCA and DGCA was found. In IGCA, the MSI and LOH pathways were more commonly involved, whereas in DGCA, a stable phenotype was predominant. As a novel finding, MSI-L as a true phenomenon and its association with LOH was observed in IGCA.

Prognostic significance of peritoneal lavage cytology in gastric cancer in Singapore

BACKGROUND

Peritoneal lavage cytology has been included as part of the staging process in the 13th edition of the Japanese Classification of Gastric Cancer. However, this procedure has neither been studied nor established in our population. We aimed to evaluate its prognostic relevance among our patients with gastric cancer.

METHODS

A total of 142 consecutive patients with gastric carcinoma were recruited prospectively. All had histologically proven gastric carcinomas and had undergone laparotomy and intraoperative peritoneal lavage for cytological examination at Singapore General Hospital. The fluid recovered was centrifuged and stained by the Papanicolau method. All patients were followed up with endpoints of cancer recurrence and mortality.

RESULTS

There were 91 men and 51 women; 36 patients (25.4%) had positive peritoneal lavage. Patients with advanced macroscopic features, presence of vascular invasion, nodal involvement, advanced depth of tumor invasion and metastatic disease tended to have positive lavage, by univariate logistic regression analysis. Despite curative resections, patients with positive cytology had a more dismal disease-free survival (mean, 27 months vs 53 months; P < 0.0001 by log rank test) and higher recurrence rate (54.5% vs 19.3%; P = 0.007 by log rank test). There was also a trend towards earlier recurrences (median, 8 months vs 11 months; P = 0.37). By multivariate Cox regression stepwise analysis, advanced depth of tumor invasion and positive lavage cytology were found to be independent poor prognostic factors for disease-free survival.

CONCLUSION

Positive peritoneal lavage cytology correlated well with advanced features of gastric cancer. It is an independent poor prognostic factor and the procedure should be routinely performed. Integration of lavage status into our current staging systems may serve as a guide for adjuvant therapeutic options to improve the survival of gastric cancer in our population.

Linear stapling of the short gastric vessels reduces blood loss and splenectomy at oesophageal and gastric surgery

BACKGROUND

Increased operative blood loss, blood transfusion and nontherapeutic splenectomy negatively influence postoperative morbidity and mortality following esophageal or gastric resection. A critical point at which blood loss and iatrogenic splenic injury occurs is at the time of division of the short gastric vessels. We examined the efficacy of using a laparoscopic linear cutting stapler (developed for minimal access surgery) to divide with the short gastric vessels at open surgery.

METHODS

Fifty-six patients were included. In 28 consecutive patients the linear stapler was used when dividing the short gastric vessels. These were compared to 28 matched controls (short gastric vessels were divided between hemostats and ligated). In the two patient groups, patient age, body mass index, and preoperative hemoglobin levels were similar.

RESULTS

Operation time, splenectomy rates, blood transfusion, and mean transfusion volume were all significantly reduced in the group where the stapler was used.

CONCLUSION

Use of a linear cutting stapler reduced operation time, blood product use, and incidental splenectomy in patients undergoing radical open esophageal and gastric surgery.

Epstein-Barr virus (EBV) infection and p53 protein expression in gastric carcinoma

In the presented studies p53 protein expression was evaluated in samples of gastric carcinoma originating from 32 selected adult patients (with documented diagnosis of adenocarcinoma of the stomach and without the presence of Helicobacter pylori infection). Among the patients 14 individuals carried EBV-positive gastric carcinoma (group 1) while the 18 remaining patients carried EBV-negative gastric carcinoma (group 2). EBV infection was detected testing the tissue material for the presence of EBER by RNA in situ hybridization (ISH) and testing sera of the patients for EBV-specific antibodies. Expression of p53 protein was analysed using immunohistochemistry. Presence of p53 protein was noted in 9 (64.3%) cases of EBV-positive gastric cancer (group 1) and in 10 (55.5%) cases of EBV-negative gastric cancer (group 2). No significant differences were detected in the frequencies of p53 protein expression in the two studied groups. The results permit to conclude that abnormalities in p53 in gastric cancer are independent of EBV infection, even if EBV may participate in development of the tumour.

Survival of Young Patients after Gastrectomy for Gastric Cancer

It has been suggested that gastric cancer has a worse prognosis in young patients, but the data are controversial. The aim of this study was to compare the 5-year survivals after gastrectomy for gastric cancer in two groups of patients (those < or = 45 years of age and those (> 45 years) and to determine some of the prognostic factors. The 5-year survival was significantly better for patients < or = 45 years of age. Survival was also better for young patients with a curative resection and also for those with lymph node metastases. However, survival was not significantly different for the two groups when the resection was not curative and when the lymph nodes were not involved. Survival was no different for the two groups when compared at each stage, although a multivariate analysis showed that age > 45 years, moderate or poor degree of differentiation of the tumor, advanced tumors, the presence of lymph node involvement, and a noncurative resection were independent negative prognostic factors. Long-term survival after gastrectomy for gastric cancer depends on the stage of the disease; the age of the patient is not a decisive factor.

A phase II trial of irinotecan in patients with previously untreated advanced esophageal and gastric adenocarcinoma

Chemotherapy options for esophagogastric adenocarcinoma remain limited. Irinotecan has demonstrated broad activity in a variety of epithelial malignancies. Forty-six patients with previously untreated, measurable, unresectable, or metastatic esophagogastric adenocarcinoma were enrolled. Patients received irinotecan (125 mg/m2 intravenously over 90 min weekly) for 4 consecutive weeks followed by a 2-week rest. Forty-three patients received at least one treatment and were evaluable for response and toxicity. One complete and five partial responses were observed, for an overall response rate of 14% (95% CI, 4-24%). Median survival for all 43 patients was 6.4 months (95% CI, 4.6-8.2 months). Grade 3 to 4 toxicity included 10 patients (23%) with neutropenia, 13 patients (30%) with late diarrhea, 6 patients (14%) with vomiting, and 6 patients (14%) with fatigue. We conclude that although single-agent irinotecan is an active agent for esophagogastric adenocarcinoma, the schedule utilized in this trial is associated with moderate toxicity. When used as a single-agent, a tri-weekly schedule may be preferable for this patient population.

Evaluation of the diagnostic accuracy of gastroscopy to detect gastric tumours: clinicopathological features and prognosis of patients with gastric cancer missed on endoscopy

OBJECTIVES

Some gastric cancers are missed during diagnostic gastroscopy, but data are sparse on the clinical characteristics of patients with missed gastric cancers and on the accuracy of gastroscopy for detecting these tumours. We evaluated the number, clinicopathological characteristics, and survival of patients with missed gastric cancers, and the sensitivity and specificity of gastroscopy to detect these tumours.

METHODS

Data on gastric cancers detected in 1996-2001 in a single hospital referral area were obtained from the National Cancer Registry. Patient files were examined to identify those who underwent gastroscopy less than 3.5 years before a cancer diagnosis.

RESULTS

Of the 284 gastric cancer patients, 13 (4.6%) had undergone gastroscopy in the previous 3.5 years; their mean age was 72.4 years at the time of the first gastroscopy. The median delay in cancer diagnosis was 11.5 months. Histologically, all patients had gastric carcinoma. The sensitivity and specificity of gastroscopy for diagnosing gastric cancer were 0.93 and 1.00, respectively. Among the deceased patients, no difference was observed in the survival of cases with non-missed (n = 191) and missed (n = 10) carcinoma: 9.4 versus 7.3 months (P = 0.15).

CONCLUSION

A small proportion of gastric carcinomas are missed on gastroscopy, causing a significant delay in diagnosis. However, the prognoses of patients with missed and non-missed gastric carcinoma were equally poor.

Epstein-Barr virus-associated gastric carcinoma: Evidence of age-dependence among a Mexican population

AIM: To investigate features of Epstein-Barr virus (EBV)-associated gastric carcinoma (EBVaGC) among a Mexican population.

METHODS: Cases of primary gastric adenocarcinoma were retrieved from the files of the Departments of Pathology at the Instituto Nacional de Cancerología and the Instituto Nacional de la Nutrición in Mexico City. The anatomic site of the gastric neoplasia was identified, and carcinomas were histologically classified as intestinal and diffuse types and subclassified as proposed by the Japanese Research Society for Gastric Cancer. EBV-encoded small non-polyadenylated RNA-1 (EBER-1) in situ hybridization was conducted to determine the presence of EBV in neoplastic cells.

RESULTS: We studied 330 consecutive, non-selected, primary gastric carcinomas. Among these, there were 173 male and 157 female patients (male/female ratio 1.1/1). EBER-1 was detected in 24 (7.3%) cases (male/female ratio: 1.2/1). The mean age for the entire group was 58.1 years (range: 20-88 years), whereas the mean age for patients harboring EBER-1-positive gastric carcinomas was 65.3 years (range: 50-84 years). Age and histological type showed statistically significant differences, when EBER-1-positive and -negative gastric carcinomas were compared. EBER-1 was detected in hyperplastic- and dysplastic-gastric mucosa surrounding two EBER-1-negative carcinomas, respectively.

CONCLUSION: Among Latin-American countries, Mexico has the lowest frequency of EBVaGC. Indeed, the Mexican population >50 years of age was selectively affected. Ethnic variations are responsible for the epidemiologic behavior of EBVaGC among the worldwide population.

Gastric cancer screening of a high-risk population in Japan using serum pepsinogen and barium digital radiography

With the aim of developing more efficient gastric cancer screening programs for use in Japan, we studied a new screening program that combines serum pepsinogen (PG) testing and barium digital radiography (DR). A total of 17 647 middle-aged male subjects underwent workplace screening over a 7-year period using a combination of PG testing and DR. This program's effectiveness, as well as other characteristics of the program, was analyzed. Forty-nine cases of gastric cancer were detected (comprising 88% early cancer cases). The detection rate was 0.28%, and the positive predictive value was 0.85%. The PG test detected 63.3% of cases, DR detected 69.4% of cases, and both tests were positive in 32.7% of cancer cases. The two methods were almost equally effective, and were considerably more effective than conventional screening using photofluorography. Each screening method detected a distinct gastric cancer subgroup; the PG test efficiently detected asymptomatic small early cancer with intestinal type histology, while DR was efficient at detecting cancers with depressed or ulcerated morphology and diffuse type histology. The cost for the detection of a single cancer was much less than that for conventional screening. In fact, it is possible to further reduce the cost of detecting a single cancer to a cost comparable to that of surgically resecting a single gastric cancer. Thus, it is probable that a highly efficient gastric cancer screening system can be implemented by combining the two screening methods. Such a screening program would be beneficial in a population at high risk for gastric cancer.

Inhibitory effect of etodolac, a selective cyclooxygenase-2 inhibitor, on stomach carcinogenesis in Helicobacter pylori-infected Mongolian gerbils

The effect of the selective COX-2 inhibitor, etodolac, on Helicobacter pylori (Hp)-associated stomach carcinogenesis was investigated in Mongolian gerbils (MGs). Hp-infected MGs were fed for 23 weeks with drinking water containing 10 ppm N-methyl-N-nitrosourea. They were then switched to distilled water and placed on a diet containing 5-30 mg/kg/day etodolac for 30 weeks. We found that etodolac dose-dependently inhibited the development of gastric cancer, and no cancer was detected at a dose of 30 mg/kg/day. Etodolac did not affect the extent of inflammatory cell infiltration or oxidative DNA damage, but it significantly inhibited mucosal cell proliferation and dose-dependently repressed the development of intestinal metaplasia in the stomachs of Hp-infected MGs. These results suggest that COX-2 is a key molecule in inflammation-mediated stomach carcinogenesis and that chemoprevention of stomach cancer should be possible by controlling COX-2 expression or activity.

Glutathione S-transferase M1, T1 and P1 genetic polymorphisms, cigarette smoking and gastric cancer risk

Glutathione S-transferases (GSTs) belong to a superfamily of detoxification enzymes that provide critical defences against a large variety of chemical carcinogens and environmental toxicants. GSTs are present in most epithelial tissues of the human gastrointestinal tract. We investigated associations between genetic variability in specific GST genes (GSTM1, GSTT1 and GSTP1), the interaction with cigarette smoking and susceptibility to gastric cancer. The GSTM1, GSTT1 and GSTP1 polymorphisms were determined using real-time polymerase chain reaction (PCR) and fluorescence resonance energy transfer with Light Cycler Instrument. The study included 70 patients with gastric cancer and 204 controls. Associations between specific genotypes and the development of gastric cancer were examined by use of logistic regression to calculate odds ratios (OR) and 95% confidence intervals (CI). The GSTM1 homozygous null genotype was associated with an increased risk of developing gastric cancer (OR = 1.73; 95% CI = 1.10-3.04). GSTT1 homozygous null genotype and GSTP1 genotypes were not associated with the risk of gastric cancer. Also there was no difference between cases and controls in the frequency of val-105 and ile-105 alleles (p = 0.07). After grouping according to smoking status, GSTM1 null genotype was associated with an increased gastric cancer risk for smokers (OR = 2.15; 95% CI, 1.02-4.52). There were no significant differences in the distributions of any of the other GST gene combinations. Our findings suggest that the GSTM1 null genotype may be associated with an increased susceptibility to gastric cancer.

Overexpression of cathepsin B in gastric cancer identified by proteome analysis

We aimed to validate an analytical approach based on proteomics on gastric cancer specimens for the identification of new putative diagnostic or prognostic markers. Primary screening was performed on gastrectomy specimens obtained from ten consecutive patients with gastric cancer. Gastric epithelial cells were obtained with an epithelial cell enrichment technique, homogenized and then separated by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). The differential protein expression pattern was verified stepwise by Western blotting and immunohistochemistry on samples from 28 and 46 cancer patients, respectively. The putative clinical applicability and prognostic use were tested by an enzyme-linked immunoabsorbent assay on serum samples obtained from 149 cancer patients. One hundred-ninety-one differentially expressed protein spots were found by 2-D PAGE and identified by mass spectrometry, including cathepsin B, which was over-expressed in six (60%) patients. Western blotting confirmed that the active form of cathepsin B is over-expressed, while immunohistochemistry showed strong cytoplasmic staining in cancer tissues of 45 (98%) patients. The serum level of cathepsin B was increased in patients with gastric cancer compared to healthy controls (P = 0.0026) and correlated with T-category and the presence of distant metastases (P < 0.05). Serum levels above 129 pmol x L(-1) were associated with a reduced survival rate (P = 0.0297). Proteome analysis is a valuable tool for the identification of prognostic markers in gastric cancer: Increased cathepsin B serum levels are associated with advanced tumor stages and progressive disease, which enables the classification of some gastric cancer patients into a subgroup that should undergo aggressive therapy.