Primary adenocarcinomas of lower esophagus, esophagogastric junction and gastric cardia: in special reference to China

BBOX1-AS1 promotes gastric cardia adenocarcinoma progression via interaction with CtBP2 to facilitate the epithelial-mesenchymal transition process

It is recognized that lncRNA BBOX1-AS1 exerts a crucial oncogenic property in several cancer types. However, the functions and underlying mechanisms of BBOX1-AS1 in the epithelial-mesenchymal transition (EMT) process of gastric cardia adenocarcinoma (GCA) have remained unclarified. The findings of this study demonstrated that GCA tissues had elevated BBOX1-AS1 expression levels, which was associated with a worse prognosis in GCA patients. BBOX1-AS1 dramatically enhanced cell proliferation, invasion, and TGF-β1-induced the EMT process in vitro. Further mechanism analysis revealed that BBOX1-AS1 could combine with CtBP2 and strengthen the interaction of CtBP2 and ZEB1. BBOX1-AS1 might regulate the E-cadherin expression through CtBP2/ZEB1 transcriptional complex-mediated transcriptional repression, further affecting the activation of the Wnt/β-catenin pathway and the EMT process. Overall, our findings demonstrate that BBOX1-AS1 might act as an lncRNA associated with EMT for facilitating GCA advancement via interaction with CtBP2 to facilitate the activation of Wnt/β-catenin pathway and the EMT process, which indicated that it might function as an exploitable treatment target for GCA patients.

Novel metabolic biomarker for early detection and diagnosis to the patients with gastric cardia adenocarcinoma

BACKGROUND

Gastric cardia adenocarcinoma (GCA) is classified as Siewert type II adenocarcinoma at the esophagogastric junction in Western countries. The majority of GCA patients do not exhibit early warning symptoms, leading to over 90% of diagnoses at an advanced stage, resulting in a grim prognosis, with less than a 20% 5-year survival rate.

METHOD

Metabolic features of 276 GCA and 588 healthy controls were characterized through a widely-targeted metabolomics by UPLC-MS/MS analysis. This study encompasses a joint pathway analysis utilizing identified metabolites, survival analysis in both early and advanced stages, as well as high and negative and low expression of HER2 immunohistochemistry staining. Machine learning techniques and Cox regression models were employed to construct a diagnostic panel.

RESULTS

A total of 25 differential metabolites were consistently identified in both discovery and validation sets based on criteria of p < 0.05, (VIP) ≥ 1, and FC ≥ 2 or FC ≤ 0.5. Early-stage GCA patients exhibited a more favorable prognosis compared to those in advanced stages. HER2 overexpression was associated with a more positive outcome compared to the negative and low expression groups. Metabolite panel demonstrated a robust diagnostic performance with AUC of 0.869 in discovery set and 0.900 in validation set.

CONCLUSIONS

A total of 25 common and stable differential metabolites may hold promise as liquid non-invasive indicators for GCA diagnosis. HER2 may function as a tumor suppressor gene in GCA, as its overexpression is associated with improved survival. The downregulation of bile acid metabolism in GCA may offer valuable theoretical insights and innovative approaches for precision-targeted treatments in GCA patients.

Focal amplifications are associated with chromothripsis events and diverse prognoses in gastric cardia adenocarcinoma

The role of focal amplifications and extrachromosomal DNA (ecDNA) is unknown in gastric cardia adenocarcinoma (GCA). Here, we identify frequent focal amplifications and ecDNAs in Chinese GCA patient samples, and find focal amplifications in the GCA cohort are associated with the chromothripsis process and may be induced by accumulated DNA damage due to local dietary habits. We observe diverse correlations between the presence of oncogene focal amplifications and prognosis, where ERBB2 focal amplifications positively correlate with prognosis and EGFR focal amplifications negatively correlate with prognosis. Large-scale ERBB2 immunohistochemistry results from 1668 GCA patients show survival probability of ERBB2 positive patients is lower than that of ERBB2 negative patients when their surviving time is under 2 years, however, the tendency is opposite when their surviving time is longer than 2 years. Our observations indicate that the ERBB2 focal amplifications may represent a good prognostic marker in GCA patients.

Long Non-coding RNA LINC01503 Promotes Gastric Cardia Adenocarcinoma Progression via miR-133a-5p/VIM Axis and EMT Process

BACKGROUND

LINC01503 has been reported to act as a candidate oncogenic lncRNA in several types of human cancer. However, the functions and underlying mechanisms of LINC01503 in gastric cardia adenocarcinoma (GCA) remain unclear.

AIMS

To investigate the roles and underlying mechanisms of LINC01503 in GCA progression.

MATERIALS AND METHODS

Gene expressions were detected by quantitative real-time PCR (qRT-PCR). Gain-of-function assays were performed to evaluate the function of LINC01503 in gastric cancer cells. Bioinformatics analysis, luciferase reporter assay, and RIP assay were performed to identify associations among LINC01503, miR-133a-5p, and VIM.

RESULTS

The expression level of LINC01503 was significantly elevated in GCA tissues and cell lines. High expression of LINC01503 was correlated with lymph node metastasis, TNM stage, and poor prognosis of GCA patients. Knockdown of LINC01503 significantly reduced proliferation, migration, and invasion ability in GC cells. LINC01503 might function as a competing endogenous RNA (ceRNA) via sponging miR-133a-5p to upregulate the expression of VIM. Furthermore, overexpression of LINC01503 promoted the progression of epithelial mesenchymal transition (EMT) in vitro.

CONCLUSION

LINC01503 serves as an oncogenic lncRNA to promote GCA progression via affecting LINC01503/miR-133a-5p/VIM axis and EMT process. LINC01503 not only has a critical role in GCA progression but also provide a novel potential biomarker in predicting prognosis for GCA patients.

Characterization of 500 Chinese patients with cervical esophageal cancer by clinicopathological and treatment outcomes

Objective: There are no comprehensive studies on survival outcomes and optimal treatment protocols for cervical esophageal cancer (CEC), due to its rare clinical prevalence. Our objective was to determine the relationship between pathological characteristics, treatment protocols, and survival outcomes in Chinese CEC patients.

Methods: A total of 500 Chinese CEC patients were selected from our 500,000 esophageal and gastric cardia carcinoma database (1973–2018). There were two main groups: patients treated with surgery, and patients receiving non-surgical treatments (radiotherapy, radiochemotherapy, and chemotherapy). The Chi-square test and Kaplan–Meier method were used to compare the continuous variables and survival.

Results: Among the 500 CEC patients, 278 (55.6%) were male, and the median age was 60.9 ± 9.4 years. A total of 496 patients (99.2%) were diagnosed with squamous cell carcinoma. In 171 (34.2%) patients who received surgery, 22 (12.9%) had undergone laryngectomy. In 322 (64.4%) patients who received non-surgical treatments, 245 (76.1%) received radiotherapy. Stratified survival analysis showed that only T stage was related with survival outcomes for CEC patients in the surgical group, and the outcomes between laryngectomy and non-laryngectomy patients were similar. It was noteworthy that the 5-year survival rate was similar in CEC patients among the different groups treated with surgery, radiotherapy, chemotherapy, or radiochemotherapy (P = 0.244).

Conclusions: The CEC patients had similar survival outcomes after curative esophagectomy and radiotherapy, including those with or without total laryngectomy. These findings suggest that radiotherapy could be the initial choice for treatment of Chinese CEC patients.

Helicobacter pylori and gastric cardia cancer: What do we know about their relationship?

The incidence of gastric cardia cancer is increasing around the world. Since the discovery of Helicobacter pylori (H. pylori), numerous studies have proved that it is a causative factor for many kinds of digestive system tumors. Although the literature on gastric cardia cancer and H. pylori is not scarce, there are still many controversies on the relationship between gastric cardia cancer and H. pylori. Many Western research results showed that there was a negative or no correlation between H. pylori infection and gastric cardia cancer, but in several studies in Asian countries, such as China, H. pylori was demonstrated to be a risk factor for gastric cardia cancer. Therefore, we intended to analyze the related studies to find out the relationship between H. pylori and gastric cardia cancer and find out the causes of the above controversies. We also conducted a meta-analysis of the relationship between cagA positive expression of H. pylori and gastric cardia cancer, to find out whether there is an effect between those two. The primary purpose of this paper was to explore the relationship between gastric cardia cancer and H. pylori. Through analysis, the study showed the reasons for the controversies mentioned above: (1) Geographical factors could affect the relationship between H. pylori and gastric cardia cancer; (2) The definition of gastric cardia cancer in various studies is inconsistent. The result of a meta-analysis about the relationship between H. pylori virulence factor cagA and gastric cardia cancer showed that there was no relationship between these two.

A clinical metabolomics-based biomarker signature as an approach for early diagnosis of gastric cardia adenocarcinoma

Gastric cardia adenocarcinoma (GCA) has a high mortality rate worldwide; however, current early diagnostic methods lack efficacy. Therefore, the aim of the present study was to identify potential biomarkers for the early diagnosis of GCA. Global metabolic profiles were obtained from plasma samples collected from 21 patients with GCA and 48 healthy controls using ultra-performance liquid chromatography/quadrupole-time-of-flight mass spectrometry. The orthogonal partial least squares discrimination analysis model was applied to distinguish patients with GCA from healthy controls and to identify potential biomarkers. Metabolic pathway analysis was performed using MetaboAnalyst (version 4.0) and revealed that ‘glycerophospholipid metabolism’, ‘linoleic acid metabolism’, ‘fatty acid biosynthesis’ and ‘primary bile acid biosynthesis’ were significantly associated with GCA. In addition, an early diagnostic model for GCA was established based on the relative levels of four key biomarkers, including phosphorylcholine, glycocholic acid, L-acetylcarnitine and arachidonic acid. The area under the receiver operating characteristic curve revealed that the diagnostic model had a sensitivity and specificity of 0.977 and 0.952, respectively. The present study demonstrated that metabolomics may aid the identification of the mechanisms underlying the pathogenesis of GCA. In addition, the proposed diagnostic method may serve as a promising approach for the early diagnosis of GCA.

Expression and Significance of MyD88 in Patients With Gastric Cardia Cancer in a High-Incidence Area of China

Background: Gastric cardia cancer (GCC) arises in the area of the stomach adjoining the esophageal-gastric junction and has unique risk factors. It was suggested that the involvement of Helicobacter pylori is associated with GCC from high-risk population. Myeloid differentiation factor 88 (MyD88) is a crucial adaptor molecule in Toll-like signaling pathway recognizing H. pylori. Its role in GCC has not been elucidated yet. In this study, our purpose is to investigate the expression and significance of MyD88 in GCC tissue. Methods: Expression of MyD88 and nuclear factor κB (NF-κB) p105/p50 and infection of H. pylori were detected by immunohistochemistry in gastric cardia tissue. The correlation of MyD88 expression to NF-κB p105/p50 expression, H. pylori infection, and clinicopathologic characteristics in gastric cardia tissue was analyzed. The involvement of MyD88 in patient prognosis was also analyzed. Results: Our data showed that the expression of MyD88 elevated from normal mucosa to inflammation (p = 0.071). The expression of MyD88 was enhanced in GCC tissues by contrast to non-malignant cardia mucosa (p = 0.025). What's more, overexpression of MyD88 was detected in intestinal-type adenocarcinoma with inflammation. Patients with high MyD88 staining revealed a better differentiation (p = 0.02). MyD88 also positively correlated with NF-κB p105/p50 expression (p = 0.012) in cancer tissue. Expression of MyD88 was increased but not significantly in biopsies with H. pylori infection compared with non-infected biopsies. Multivariate analyses revealed lymph node metastasis but not MyD88 expression was an independent predictor for patient survival. Conclusion: These findings provide pathological evidence that upregulating MyD88 and inducing inflammation might be involved in gastric cardia carcinogenesis in high-risk population. MyD88 plays a role in gastric cardia carcinogenesis with NF-κB pathway activation. Higher MyD88 expression is not a major prognostic determinant in GCC, but it may relate to the tumor cell differentiation.

Risk factors predisposing to cardia gastric adenocarcinoma: Insights and new perspectives

Recent decades have seen an alarming increase in the incidence of cardia gastric adenocarcinoma (CGA) while noncardia gastric adenocarcinoma (NCGA) has decreased. In 2012, 260 000 CGA cases (age‐standardised rate (ASR); 3.3/100 000) and 691 000 NCGA cases (ASR; 8.8/100 000) were reported worldwide. Compared with women, men had greater rates for both the subsites, especially for CGA. Recently, four molecular subtypes of GC have been proposed by the Cancer Genome Atlas (TCGA) and the Asian Cancer Research Group (ACRG); however, these classifications do not take into account predisposing germline variants and their possible interaction with somatic alterations in carcinogenesis. The etiology of adenocarcinoma of the cardia and the gastroesophageal junction (GEJ) is not known. It is thought that CGA is distinct from adenocarcinomas located in the esophagus or distal stomach, both epidemiologically and biologically. Moreover, CGA is often identified in the advanced stage having a poor prognosis. Therefore, understanding the risk and the role of predisposing factors in etiology of CGA can inform clinical practice and counseling for risk reduction. In this paper, we showed that GC family history, lifestyle, demographics, gastroesophageal reflux disease, Helicobacter pylori infection, and multiple genetic and epigenetic risk factors as well as several predisposing conditions may underlie susceptibility to CGA. However, several genome‐wide association studies (GWASs) should be conducted to identify novel high‐penetrance genes and pathways as well as causal germline variants predisposing to CGA. They must include different ethnic groups, especially from high‐incidence countries for CGA, because some risk loci are ancestry‐specific. In parallel, statistical methods can be developed to identify cancer predisposition genes (CPGs) from tumor sequencing data. It is also necessary to find novel long noncoding RNAs related to the risk of CGA. Taken altogether, new cancer risk prediction models, including all genetic and nongenetic factors influencing risk, should be developed to facilitate risk assessment, disease prevention, and early diagnosis and intervention of CGA in the future.

MiR-6872 host gene SEMA3B and its antisense lncRNA SEMA3B-AS1 function synergistically to suppress gastric cardia adenocarcinoma progression

BACKGROUND

Semaphorin 3B (SEMA3B) is frequently inactivated in several carcinomas. However, as the host gene of miR-6872, the roles of SEMA3B, antisense lncRNA SEMA3B-AS1, and miR-6872 in gastric cardia adenocarcinoma (GCA) tumorigenesis have not been clarified.

METHODS

The expression levels of SEMA3B, SEMA3B-AS1, and miR-6872 were respectively detected by qRT-PCR, western blot, or immunohistochemical staining assays. The methylation status was determined by BGS and BS-MSP methods. In vitro assays were preformed to explore the biological effects of SEMA3B, SEMA3B-AS1, and miR-6872-5p in gastric cancer cells. Chromatin immunoprecipitation assay was used to detect the binding of protein to DNA. The interaction of SEMA3B-AS1 with MLL4 was identified by RNA immunoprecipitation and RNA pull-down assays.

RESULTS

Frequent downregulation of SEMA3B, SEMA3B-AS1, and miR-6872 was detected in GCA tissues and gastric cancer cells. Aberrant hypermethylation of the promoter region was more tumor specific and was negatively correlated with the expression level of SEMA3B, SEMA3B-AS1, and miR-6872-5p. Transcription factor Sp1 activated SEMA3B or SEMA3B-AS1 transcription and CpG sites hypermethylation within promoter region eliminated Sp1 binding ability. Overexpression of SEMA3B and SEMA3B-AS1 inhibited gastric cancer cell proliferation, migration, and invasion in vitro. SEMA3B-AS1 induced the expression of SEMA3B by interacting with MLL4. ZNF143 might be the target gene of miR-6872-5p and miR-6872-5p functioning synergistically with SEMA3B to suppress cell invasion. Furthermore, SEMA3B, SEMA3B-AS1, and miR-6872-5p expression levels were associated with GCA patients' survival.

CONCLUSIONS

SEMA3B, SEMA3B-AS1, and miR-6872 may act as tumor suppressors and may serve as potential targets for antitumor therapy.

Aberrant methylation-mediated downregulation of long noncoding RNA C5orf66-AS1 promotes the development of gastric cardia adenocarcinoma

As a long non-coding RNA, C5orf66-AS1 is located at 5q31.1. Downregulation and aberrant hypermethylation of C5orf66-AS1 have been detected in a limited several tumors. However, the biological role and distribution of methylated CpG sites of C5orf66-AS1 in gastric cardia adenocarcinoma (GCA) development and prognosis are poorly clarified. The present study was to investigate the expression status and function of C5orf66-AS1 in GCA, and to detect the distribution of methylated CpG sites within the three CpG islands of the promoter and gene body of C5orf66-AS1, further to clarify its prognostic value in GCA patients. C5orf66-AS1 was significantly downregulated in GCA tissues and cell lines, and the expression level was associated with TNM stage, pathological differentiation, lymph node metastasis, and distant metastasis or recurrence. The expression level of C5orf66-AS1 was significantly increased in cancer cells after treated with 5-Aza-dC. Further methylation analysis demonstrated that the aberrant hypermethylation of the regions around the transcription start site of C5orf66-AS1 was more tumor specific and was associated with its expression. Moreover, Sp1 may upregulate C5orf66-AS1 expression and CpG sites hypermethylation within the binding sites may abrogate Sp1 binding. In addition, C5orf66-AS1 inhibited gastric cancer cell proliferation and invasion, and the dysregulation and hypermethylation of the regions around the transcription start site of C5orf66-AS1 were associated with poorer GCA patients' survival. These findings suggest that aberrant hypermethylation-mediated downregulation of C5orf66-AS1 may play important roles in GCA tumorigenesis and C5orf66-AS1 may serve as a potential prognostic marker in predicting GCA patients' survival.

Cancer survival in Cixian of China, 2003-2013: a population-based study

Cixian is one of the high‐risk areas for upper gastrointestinal cancer in China and the world. From 2005, comprehensive population‐based screening for upper gastrointestinal cancers has been conducted in Cixian. The aim of this study was to investigate population‐based cancer survival from 2003 to 2013 and to explore the effect of screening on upper gastrointestinal cancer survival in Cixian. Observed survival was estimated using the life table method. The expected survival from the general population was calculated using all‐cause mortality data from the population of Cixian with the EdererII method. Cixian cancer registry, with a total coverage of 6.88 million person years, recorded 19,628 cancer patients diagnosed during 2003–2013. In Cixian, from 2003 to 2013, there were 19,628 newly cancer cases and 13,984 cancer deaths, with an incidence rate of 285.37/100,000 and mortality rate of 203.31/100,000. The overall five‐year relative cancer survival for patients diagnosed in Cixian in 2003–2013 was 22.53%. The relative survival for all cancers combined in Cixian had an overall upward trend from 2003 to 2013. Among upper gastrointestinal cancer in Cixian, the five‐year relative survival for cardia gastric cancer was highest at 30.42%, followed by oesophageal cancer at 25.37% and noncardia gastric cancer at 18.93%. In 2013, the five‐year relative survival for oesophageal cancer, cardia gastric cancer, and noncardia gastric cancer patients aged 45–69 years was 39.97% (95% CI: 34.52–45.43%), 51.74% (95% CI: 42.09–60.86%), and 37.43% (95% CI: 26.93–48.17%), respectively, the absolute values increasing 14.11%, 16.71%, and 14.92% compared with that in 2003. There is an increasing trend in overall survival for upper gastrointestinal cancer with early screening and treatment of cancer in Cixian.

Promoter hypermethylation-mediated downregulation of miR-770 and its host gene MEG3, a long non-coding RNA, in the development of gastric cardia adenocarcinoma

Maternally expressed gene 3 (MEG3) is an imprinted gene located at 14q32 which encodes an lncRNA and is downregulated in an expanding list of cancer cell lines and primary human cancers. The miR-770 is transcribed from the intronic sequence of MEG3 and MEG3 may be the host gene for miR-770. However, the biological role of MEG3 and miR-770 in gastric cardia adenocarcinoma (GCA) development and prognosis is poorly defined. The present study was to investigate the function and methylation status of MEG3 in GCA, and further to detect the functional association of miR-770 and its host gene MEG3 in GCA carcinogenesis and prognosis. MEG3 and miR-770 was significantly downregulated in GCA patients and cell lines, and their expression was associated with TNM stage and lymph node metastasis. Overexpression of MEG3 and miR-770 inhibited gastric cancer cell proliferation and invasion in vitro. Furthermore, the expression level of MEG3 and miR-770 was significantly increased in cancer cells after treated with 5-Aza-dC. The aberrant hypermethylation of proximal promoter and enhancer region of MEG3 was detected in GCA tissues. In addition, the proximal promoter and enhancer region hypermethylation and dysregulation of MEG3 and miR-770 were associated with poorer GCA patients' survival. These findings suggest that miR-770 and its host gene MEG3 may play tumor suppressor role and hypermethylation of proximal promoter and enhancer region may be one of the critical mechanisms in inactivation of MEG3 and miR-770 in GCA development. MEG3 and miR-770 may be used as potential biomarkers in predicting GCA patients' prognosis.

Expression of CDX2 in gastric cardia adenocarcinoma and its correlation with H. pylori and cell proliferation

BACKGROUND

Gastric cardia cancer (GCC) is located in the distal stomach, and strongly correlates with atrophic gastritis and Helicobacter pylori (H.pylori) infection. Caudal-related homeobox transcription factor 2 (CDX2) is homeobox gene encoding an intestine-specific transcription factor usually expressed in the intestinal epithelium cells. However, in several recent published papers, CDX2 was found to be aberrantly expressed in gastric, thyroid and ovarian cancer.

RESULTS

Higher expression of CDX2 was found in GCC tissues in comparison with non-malignant cardia mucosa (p<0.05). Moreover, immunohistochemical analysis demonstrated that CDX2 expression correlated with lymphatic metastasis. In addition, we found that CDX2 expression progressively increased with the level of H. pylori infection (p<0.05), and also correlated with cell proliferation, based on Ki67 staining.

METHODS

To investigate the relationship between CDX2, cell proliferation and H. pylori infection, we detected CDX2, Ki62 and H.pylori expression in 83 non-malignant gastric cardia mucosacases and 60 GCC specimens in the Chaoshan area, a high-risk region for esophageal and gastric cardia cancer.

CONCLUSION

These findings provide pathological evidence that H. pylori infectionis a driving force of gastric cardia carcinogenesis by upregulating CDX2 and inducing inflammation. These results provide new pathological evidence that H. pylori infection induces GCC tumorigenesis.

Differences in Clinicopathology of Early Gastric Carcinoma between Proximal and Distal Location in 438 Chinese Patients

Early gastric carcinoma (EGC) in Chinese patients remains poorly understood and endoscopic therapy has not been well established. Here, we compared endoscopic and clinicopathologic features between early proximal gastric carcinoma (PGC, n = 131) and distal gastric carcinoma (DGC, n = 307) in consecutive 438 EGCs diagnosed with the WHO criteria. By endoscopy, PGCs showed protruding and elevated patterns in 61.9%, while depressed and excavated patterns in 33.6%, which were significantly different from those (32.6% and 64.5%) in DGCs. PGCs were significantly smaller (1.9 cm in average, versus 2.2 cm in DGCs), invaded deeper (22.9% into SM2, versus 13% in DGCs), but had fewer (2.9%, versus 16.7% in DGCs) lymph node metastases. Papillary adenocarcinoma was significantly more frequent (32.1%, versus 12.1% in DGCs), as were mucinous and neuroendocrine carcinomas, carcinoma with lymphoid stroma (6.9%, versus 1.6% in DGCs); but poorly cohesive carcinoma was significantly less frequent (5.3%, versus 35.8% in DGCs). The overall 5-year survival rate was 92.9% in EGCs, and PGC patients showed shorter (42.4 months, versus 48.3 in DGCs) survival. Papillary and micropapillary adenocarcinomas and nodal metastasis were independent risk factors for worse survival in EGCs. EGCs in Chinese were heterogeneous with significant differences in endoscopy and clinicopathology between PGC and DGC.

Variant TP53BP1 rs560191 G>C is associated with risk of gastric cardia adenocarcinoma in a Chinese Han population

OBJECTIVE

To investigate the association between gastric cardia adenocarcinoma (GCA) and ten functional single nucleotide polymorphisms (SNPs), including TP53BP1 rs560191 G>C, CASP8 rs1035142 G>T, CASP7 rs3127075 G>C, CASP7 rs7907519 C>A, and six C1orf10/CRNN variants. We performed a hospital-based case-control study to evaluate the genetic effects of these SNPs.

METHODS

Two hundred and forty-three GCA cases and 476 controls were enrolled in this study. A custom-by-design 48-Plex SNPscan(TM) Kit was used to determine their genotypes.

RESULTS

When the TP53BP1 rs560191 GG homozygote genotype was used as the reference group, the GC genotype was associated with a significantly increased risk of GCA. The CC genotype was not associated with the risk of GCA compared with the GG genotype. None of the CASP8 rs1035142 G>T, CASP7 rs3127075 G>C, CASP7 rs7907519 C>A or the six C1orf10/CRNN polymorphisms showed a significant difference in genotype distributions between the cases and the controls.

CONCLUSIONS

The results demonstrated that the functional polymorphism TP53BP1 rs560191 G>C might contribute to GCA susceptibility. However, the statistical power of our study was limited. Large, well-designed studies and further functional investigations are needed to confirm our findings.

Changing trends in the proportions of small (≤ 2 cm) proximal and non-proximal gastric carcinomas treated at a high-volume tertiary medical center in China

OBJECTIVE

Guided by the recently established histological criteria of the gastroesophageal junction (GEJ), we aimed to investigate and compare trends in the proportions of small (≤ 2 cm) proximal gastric carcinoma (PGC) vs non-PGC (NPGC) in Chinese patients over an 8-year period.

METHODS

The study was conducted with consecutive surgical resected specimens of small PGC that was located within 3 cm below the GEJ and NPGC (located at all other gastric regions) treated at a single medical center in China. Differences in proportions between the two groups were compared.

RESULTS

Among all 313 cases, 111 (35.5%) were classified as PGC and the remaining 202 (64.5%) as NPGC. Patients with PGC were significantly elder than those with NPGC, and none aged younger than 40 years. The proportions of PGC significantly and progressively increased from 16% in 2004 to 45% in 2011, in contrast to a steady decreasing trend for NPGC from 84% to 55% over the same period. The difference in trends between the two groups approached, but was not at a statistically significant level (P = 0.08). Proportions of small cancers in the gastric corpus and in female patients remained low and stable, in contrast to a significantly higher proportion in male patients (P < 0.05).

CONCLUSIONS

Our data showed a significantly upward-shifting trend in the proportions of small PGC, primarily in elderly male patients, in contrast to a downward shifting trend in NPGC over the most recent 8-year period in Chinese patients.

Detection of autoantibodies to a panel of tumor-associated antigens for the diagnosis values of gastric cardia adenocarcinoma

To evaluate the diagnostic values of using autoantibodies in sera to a panel of eight tumor-associated antigens (TAAs) of P53, Koc, P62, C-myc, IMP1, Survivn, P16 and Cyclin B1 full-length recombinant proteins for early detection of patients with gastric cardia adenocarcinoma (GCA) and high-risk subjects screening. Enzyme-linked immunosorbent assay was used to detect autoantibodies against the eight selected TAAs in 383 sera samples from four groups, including 140 subjects with normal gastric cardia epithelia (NOR), 76 patients with chronic atrophic gastritis (CAG), 79 patients with gastric cardia dysplasia (DYS) and 88 patients with GCA. In addition, the expression of the eight antigens was analyzed in gastric cardia tissues by immunohistochemical method. The individual autoantibodies to six TAAs (P53, P62, IMP1, Survivn P16 and Cyclin B1) were significantly higher in sera from patients with GCA than that in normal subjects (P < 0.05). When autoantibody assay successively accumulated to seven TAAs (P53, Koc, P62, C-myc, IMP1, Survivn and P16), a stepwise increased detection frequency of autoantibodies was found in the four sera groups (13% in NOR, 39% in CAG, 46% in DYS, and 64% in GCA, respectively), the risks to CAG, DYS and GCA steadily increased about 4.4-, 5.7- and 12.0-fold. The sensitivity and the specificity for autoantibodies against the seven TAAs in diagnosing GCA reached up to 64% and 87%, respectively. The area under the receiver operating characteristic curve for the seven anti-TAA autoantibodies was 0.73 (95%CI: 0.68-0.78) No more increase in sensitivity was found with the addition of new anti-TAA autoantibodies. A combination detection of autoantibodies to TAAs might be helpful to distinguish GCA patients from normal subjects and the patients with gastric cardia precancerous lesions. In addition, further studies in patients with GCA and precancerous lesions using enlarged TAA panels might improve the sensitivity and specificity of cancer detection and high-risk subjects screening.

The role of glycogen synthase kinase 3-β in immunity and cell cycle: implications in esophageal cancer

Esophageal cancer (EC) is one of the most aggressive gastrointestinal malignancies, possessing an insidious onset and a poor prognosis. Numerous transcription factors and inflammatory mediators have been reported to play a pivotal role in the initiation and progression of this cancer. However, the specifics of the signaling network responsible for said factors, especially which elements are the critical regulators, are still being elucidated. Glycogen synthesis kinases 3 (GSK3)β was originally regarded as a kinase regulating glucose metabolism. Accumulating evidence demonstrated that it also played an essential role in a variety of cellular processes including proliferation, differentiation, inflammation, motility, and survival by regulating various transcription factors such as c-Jun, AP-1, β-catenin, CREB, and NF-κB. Aberrant regulation of GSK3β has been shown to promote cell growth in some cancers, while suppressing it in others, and thus may play an important role in the development of EC. This review will discuss our current understanding of GSK3β signaling, and its control of the expression and activation of various transcription factors that mediate the inflammatory response. We will also explore some of the known mediators of EC progression, and based on current literature, elucidate the potential roles and implications of GSK3 in this disease.

Comparison of gastro-oesophageal junction carcinomas in Chinese versus American patients

AIMS

To compare the clinical and pathological features of gastro-oesophageal junction (GEJ) carcinomas in Chinese and American patients.

METHODS AND RESULTS

Eighty consecutive patients with a GEJ carcinoma (43 from mainland China, and 37 from the USA) were evaluated for association with Barrett oesophagus (BO), chronic Helicobacter pylori gastritis, intestinal metaplasia, and outcome. GEJ carcinomas were defined as tumours that were located within 20 mm of, and crossed, the GEJ. Overall, GEJ carcinomas from Chinese patients revealed significantly more frequent location in the proximal stomach, higher pathological stage, larger size, younger patient age, and association with chronic H. pylori gastritis. In contrast, GEJ cancers from American patients showed a strong association with distal oesophageal location, BO, and associated intestinal metaplasia and dysplasia. Pathologically, GEJ carcinomas from American patients were predominantly adenocarcinomas, whereas Chinese patients showed a higher proportion of mucinous, adenosquamous, acinar or neuroendocrine tumours. Overall, 3- and 5-year survival rates were statistically similar between both patient groups, but upon multivariate analysis, Chinese patients showed statistically better survival rates for stage III tumours.

CONCLUSIONS

Most GEJ carcinomas in patients from China represent proximal gastric cancers associated with chronic H. pylori gastritis, and BO-associated carcinomas are rare among this patient population.

Delayed caspase-8 activation and enhanced integrin β1-activated FAK underpins anoikis in oesophageal carcinoma cells harbouring mt p53-R175H

FAK (focal adhesion kinase)-mediated signalling reportedly suppresses caspase-8 activation and, as a consequence, rescues epithelial cells from Fas-mediated anoikis. Critical was the use of a HOSCC (human oesophageal squamous carcinoma) cell line harbouring mt (mutant) p53-R175H and displaying resistance to detachment and Tyr397 dephosphorylation of FAK. Here we show, although caspase-8 activation is delayed in the mt p53-R175H cell line, comparable apoptotic events evidenced in the wt (wild type) p53 HOSCC cell lines could be induced in the mt p53-R175H cell line by strengthening the apoptotic stimulus. Significant to anoikis-related regulation, the delay in caspase-8 activation was accompanied by the maintenance of FAK Tyr397 phosphorylation, integrin β1-associated FAK and a FAK/caspase-8 complex. Thus, mt p53-R175H may desensitize tumours to Fas-mediated anchorage-independent death via a FAK-dependent mechanism.

Adenocarcinoma versus carcinoma epidermóide: análise de 306 pacientes em hospital universitário

RACIONAL: A literatura médica tem registrado aumento progressivo e significativo da prevalência do adenocarcinoma do esôfago nos últimos anos e este fato tem importância epidemiológica nos tratamentos a serem instituídos, na evolução e prognóstico dos doentes. OBJETIVO: Analisar dados epidemiológicos dos carcinomas epidermóides e adenocarcinomas. MÉTODOS: Estudo retrospectivo dos tumores de esôfago em hospital universitário analisando a prevalência dos carcinomas epidermóides e adenocarcinomas, suas respectivas localizações, tipos histopatológicos, os hábitos, as características de cor, sexo, idade e procedência dos doentes. Foram revistos os prontuários dos doentes operados e tratados por adenocarcinomas e carcinomas epidermóides do esôfago no período de 1983 a 2010. RESULTADOS: Foram estudados 306 doentes assim distribuídos: 192 (62,7%) portadores de carcinoma espinocelular e 114 (37,3%) de adenocarcinoma de esôfago. Todos foram submetidos à ressecção cirúrgica (esofagectomia) com intenção curativa. Entre os casos com carcinoma espinocelular os dados obtidos foram: 80,7% brancos, 11,5% pardos, 7,8% negros, 88,0% do gênero masculino, 12,0% do feminino, média de idade 54,7 anos, 88,0% tabagistas e 77,7% etilistas. Entre os doentes com adenocarcinoma os dados obtidos foram: 92,1% brancos, 6,1% pardos, 1,8% negros, 85,1% homens, 14,9% mulheres, média de idade 57,9 anos, 66,7% tabagistas e 45,6% etilistas. CONCLUSÃO: O adenocarcinoma de esôfago tem apresentado incidência mais elevada nos últimos anos e este fato tem importância epidemiológica, nos tratamentos a serem instituídos, na evolução e prognóstico dos doentes.

How to classify adenocarcinomas of the esophagogastric junction: as esophageal or gastric cancer?

BACKGROUND

To evaluate whether so-called cardiac adenocarcinomas (adenocarcinomas of the esophagogastric junction type II and III, ie AEG II and III) are better staged as cancers of the esophagus or as cancers of the stomach.

METHODS

A single-center cohort of 1141 patients operated for AEG II and III is staged according to the seventh edition of the TNM classification for cancers of the esophagus and cancers of the stomach. Kaplan-Meier and Cox regression analyses are used to evaluate the prognostic performance of these 2 staging schemes.

RESULTS

For so-called cardiac adenocarcinomas, the esophageal T classification is monotone. That is, it defines subgroups with continuous decreasing survival with increasing T stage. And it is distinct. That is, survival of these monotonic subgroups differs significantly. The gastric T classification is monotone but not distinct for pT2 versus pT3 (P=0.641) and for pT4a versus pT4b tumors (P=0.130). The type of infiltrated adjacent structure matters with significant differences in prognosis between the esophageal subgroups T4a and T4b (P<0.001). For the N classification, both the esophageal and gastric schemes are monotone and distinct, with decreasing prognosis with increasing number of lymph node metastases. The subclassification of N3a and N3b disease according to the gastric scheme defines 2 subgroups with significant differences in prognosis (P<0.01). Both the gastric and esophageal schemes include heterogeneous stage groups (2 and 1, respectively) and are not distinctive between several stage groups (4 and 3, respectively).

CONCLUSIONS

Neither the esophageal nor the gastric scheme proves to be clearly superior over the other, and neither is perfect for AEG II and III. Our analysis includes further hints that so-called cardiac adenocarcinomas have different biological properties compared with genuine gastric and genuine esophageal cancers.

Gastric cardiac carcinomas involving the esophagus are more adequately staged as gastric cancers by the 7th edition of the American Joint Commission on Cancer Staging System

The aim of this study was to compare the 7th with the 6th edition of the American Joint Commission on Cancer Staging System for prognostic stratification of gastric cardiac carcinomas involving the esophagus. We retrospectively compared differences in pathological stages with patient survival between the 7th and the 6th staging systems in 142 consecutive resection cases of this cancer. Patient median age was 65 years. The male-female ratio was 3.3. The epicenter of all tumors was within 5 cm below the gastroesophageal junction. The median tumor size was 5.0 cm. Most tumors (79%) were typical adenocarcinomas and the rest showed uncommon histology types. Using the guidelines for gastric cancer, this group of cancer was better stratified by the 7th than the 6th edition of the staging system, especially for pathological nodal (pN) and overall stage pIIIC. Patients with celiac axis nodal disease had the 5-year survival rate worse than those staged at pN3A and pIIIA. Patients staged at pT3 and pN3B had the 5-year survival rate worse than those at pM1 and pIV. We showed that the overall stage of gastric cardiac carcinomas was better stratified by gastric than by esophageal cancer grouping. We conclude that these tumors are better stratified with the 7th than the 6th edition of the gastric staging system, especially for pIII cancers, and better staged by the new gastric than esophageal cancer staging system. We propose that the staging of these tumors be reverted to gastric grouping and combine pT3 and pN3B into the overall stage pIV.

A combined proteomics and metabolomics profiling of gastric cardia cancer reveals characteristic dysregulations in glucose metabolism

Gastric cardia cancer (GCC), which occurs at the gastric-esophageal boundary, is one of the most malignant tumors. Despite its high mortality and morbidity, the molecular mechanism of initiation and progression of this disease is largely unknown. In this study, using proteomics and metabolomics approaches, we found that the level of several enzymes and their related metabolic intermediates involved in glucose metabolism were deregulated in GCC. Among these enzymes, two subunits controlling pyruvic acid efflux, lactate dehydrogenase A (LDHA) and pyruvate dehydrogenase B (PDHB), were further analyzed in vitro. Either down-regulation of LDH subunit LDHA or overexpression of PDH subunit PDHB could force pyruvic acid into the Krebs cycle rather than the glycolysis process in AGS gastric cancer cells, which inhibited cell growth and cell migration. Our results reflect an important glucose metabolic signature, especially the dysregulation of pyruvic acid efflux in the development of GCC. Forced transition from glycolysis to the Krebs cycle had an inhibitory effect on GCC progression, providing potential therapeutic targets for this disease.

Polymorphism of IL-8 in 251 allele and gastric cancer susceptibility: a meta-analysis

BACKGROUND

The relationship of gastric cancer to the presence of interleukin-8 (IL-8) 251 T/A has been reported with conflicting results.

AIM

To further explore the association of IL-8 251 allele polymorphism with gastric cancer susceptibility.

METHODS

We performed an extensive search of relevant studies and carried out a meta-analysis, including ten studies with 2,195 gastric cancer cases and 3,505 controls, to obtain a more precise estimate.

RESULTS

The combined results based on all studies showed that the IL-8 251 allele AA genotype was a risk factor for gastric cancer [AA versus TT: odds ratio (OR) = 1.363, 95% confidence interval (CI): 1.199-1.527]. In subgroup analysis, a clear effect of AA in IL-8 251 allele was shown in Asians (AA versus TT: OR = 1.593, 95% CI: 1.013-2.173) but not in Caucasians or Mexicans. When stratified by Lauren classification, we found that the IL-8 251 allele TA and AA polymorphism was significantly associated with the diffuse type of gastric cancer (TA versus TT: OR = 1.448, 95% CI: 1.177-1.720; AA versus TT: OR = 1.586, 95% CI: 1.128-2.044). The IL-8 251 AA genotype was found to be a risk factor for cardiac gastric cancer (AA versus TT: OR = 1.840, 95% CI: 1.112-2.568) but not for noncardiac gastric cancer.

CONCLUSIONS

This meta-analysis suggested that IL-8 251 allele A>T polymorphism might be a risk factor for gastric cancer.

Neurofilament heavy polypeptide regulates the Akt-beta-catenin pathway in human esophageal squamous cell carcinoma

Aerobic glycolysis and mitochondrial dysfunction are common features of aggressive cancer growth. We observed promoter methylation and loss of expression in neurofilament heavy polypeptide (NEFH) in a significant proportion of primary esophageal squamous cell carcinoma (ESCC) samples that were of a high tumor grade and advanced stage. RNA interference-mediated knockdown of NEFH accelerated ESCC cell growth in culture and increased tumorigenicity in vivo, whereas forced expression of NEFH significantly inhibited cell growth and colony formation. Loss of NEFH caused up-regulation of pyruvate kinase-M2 type and down-regulation of pyruvate dehydrogenase, via activation of the Akt/beta-catenin pathway, resulting in enhanced aerobic glycolysis and mitochondrial dysfunction. The acceleration of glycolysis and mitochondrial dysfunction in NEFH-knockdown cells was suppressed in the absence of beta-catenin expression, and was decreased by the treatment of 2-Deoxyglucose, a glycolytic inhibitor, or API-2, an Akt inhibitor. Loss of NEFH activates the Akt/beta-catenin pathway and increases glycolysis and mitochondrial dysfunction. Cancer cells with methylated NEFH can be targeted for destruction with specific inhibitors of deregulated downstream pathways.

Cancer mortality in a Chinese population exposed to hexavalent chromium in drinking water

BACKGROUND

In 1987, investigators in Liaoning Province, China, reported that mortality rates for all cancer, stomach cancer, and lung cancer in 1970-1978 were higher in villages with hexavalent chromium (Cr+6)-contaminated drinking water than in the general population. The investigators reported rates, but did not report statistical measures of association or precision.

METHODS

Using reports and other communications from investigators at the local Jinzhou Health and Anti-Epidemic Station, we obtained data on Cr+6 contamination of groundwater and cancer mortality in 9 study regions near a ferrochromium factory. We estimated: (1) person-years at risk in the study regions, based on census and population growth rate data, (2) mortality counts, based on estimated person-years at risk and previously reported mortality rates, and (3) rate ratios and 95% confidence intervals.

RESULTS

The all-cancer mortality rate in the combined 5 study regions with Cr+6-contaminated water was negligibly elevated in comparison with the rate in the 4 combined study regions without contaminated water (rate ratio = 1.13; 95% confidence interval = 0.86-1.46), but was somewhat more elevated in comparison with the whole province (1.23; 0.97-1.53). Stomach cancer mortality in the regions with contaminated water was more substantially elevated in comparison with the regions without contaminated water (1.82; 1.11-2.91) and the whole province (1.69; 1.12-2.44). Lung cancer mortality was slightly elevated in comparison with the unexposed study regions (1.15; 0.62-2.07), and more strongly elevated in comparison with the whole province (1.78; 1.03-2.87). Mortality from other cancers combined was not elevated in comparison with either the unexposed study regions (0.86; 0.53-1.36) or the whole province (0.92; 0.58-1.38).

CONCLUSIONS

While these data are limited, they are consistent with increased stomach cancer risk in a population exposed to Crz=6 in drinking water.

Connective tissue growth factor is overexpressed in esophageal squamous cell carcinoma and promotes tumorigenicity through beta-catenin-T-cell factor/Lef signaling

Connective tissue growth factor (CTGF or CCN2), a member of the CCN family, is involved in diverse biological processes such as cell adhesion, proliferation, and angiogenesis. In this study, we show that overexpression of CTGF occurred in a significant proportion of esophageal squamous cell carcinoma (ESCC) samples that were of a high tumor grade and metastatic. Forced expression of CTGF in Eca109 ESCC cells accelerated their growth in culture and significantly increased tumor formation in nude mice, whereas RNA interference-mediated knockdown of CTGF in ESCC cells significantly inhibited cell growth and colony formation, as well as tumorigenicity in vivo. Moreover, overexpression of CTGF in ESCC cells resulted in the accumulation and nuclear translocation of beta-catenin, leading to activation of beta-catenin-T-cell factor (TCF)/Lef signaling. Up-regulation of c-Myc and cyclin D1, two target genes of beta-catenin-TCF/Lef signaling, was also observed in the CTGF-overexpressing cells. These effects of CTGF in ESCC cells were abolished by transfection with either dominant negative beta-catenin or dominant negative TCF4. Furthermore, we identified a beta-catenin-TCF/Lef-binding site (TBE) in the promoter region of CTGF and found that CTGF is a transcriptional target of beta-catenin-TCF/Lef signaling. Taken together, these results revealed that the interaction of CTGF and beta-catenin-TCF/Lef forms a positive feedback loop, which could contribute to the tumorigenicity of ESCC.

Polymorphisms of glutathione S-transferase M1, T1 and P1 in patients with reflux esophagitis and Barrett's esophagus

Reflux esophagitis (RE) and Barrett's esophagus (BE) belong to the most common esophageal complications of gastroesophageal reflux disease. Glutathione S-transferase (GST) enzymes play an important role in cellular protection against oxidative stress and toxic foreign chemicals. Therefore, we investigated the hypothesis that polymorphisms in genes for these detoxifying enzymes could influence susceptibility to RE and BE. GSTM1, GSTT1 and GSTP1 loci were analyzed by PCR-based methods in 64 patients with RE (and an additional group of 22 subjects with BE as the fourth grade of esophagitis) and 173 unrelated controls. There were no significant differences in the distributions of GSTM1 and GSTT1 genotypes between the controls and patients with RE or BE. Similarly, frequencies of GSTP1 alleles were non-significantly different between the control and RE groups. However, GSTP1 B allele carriers were more frequent among the patients with BE compared to those in the reflux esophagitis group (P=0.04, OR=2.10, 95% CI 0.99-4.44) and most significantly when compared to the controls (P=0.0067, Pcorr<0.05, OR=2.56, 95%CI 1.30-5.05). Although the GSTM1 and GSTT1 genes did not show any relationship with reflux disease, the GSTP1 gene might be one of the risk factors associated with susceptibility to RE, especially to BE.

The histopathologic spectrum of carcinomas involving the gastroesophageal junction in the Chinese

Carcinomas involving the gastroesophageal junction are common in China. The histopathologic characteristics of these cancers have not been systematically investigated. Reported are 41 such resected cancers from Chinese patients (30 men, 11 women). Their mean age was 62 years. The mean tumor size was 4.4 cm (range, 2 to 9 cm), and 58% were poorly differentiated. An unusual spectrum of tumor differentiation was observed, including adenocarcinomas (83%), adenosquamous (32%), colloid (2%), signet-ring (10%), squamous (5%), oncocytic (7%), pancreatic acinar (12%), and neuroendocrine (5%) carcinomas. Cancers with multiple types of differentiation in the same tumor were identified in 37 cases (90%). The adjacent gastric cardiac mucosa showed hyperplasia, oncocytic, and pancreatic acinar metaplasia, and mild chronic inflammation. Dysplasia was uncommon (n = 6). Barrett esophagus was not identified. Carcinomas involving the gastroesophageal junction in the Chinese are morphologically distinct, heterogeneous, and may be of esophageal origin.

Expression of ATP7B in human gastric cardiac carcinomas in comparison with distal gastric carcinomas

AIM: To analyze expression of ATP7B in gastric cardiac adenocarcinomas, its clinicopathologic significance, in comparison with distal gastric adenocarcinomas.

METHODS: Immunohistochemical avidin-biotin peroxidase complex method was applied to detect the expression of ATP7B in 49 cases of cardiac carcinomas, the corresponding adjacent non-neoplastic epithelium and 55 cases of distal gastric carcinomas.

RESULTS: The proportion of ATP7B positive samples in gastric cardiac carcinomas (51.0%, 25 of 49) was significantly higher than that in the corresponding adjacent non-neoplastic epithelium (22.4%, 11 of 49) (P = 0.003). ATP7B expression in poorly differentiated gastric cardiac carcinomas was significantly higher than that in well/moderately differentiated gastric cardiac carcinomas (P = 0.030). ATP7B expression in gastric cardiac carcinomas was independent of age, tumor size, nodal stage and metastasis status. ATP7B protein was detected in 30.9% (17/55 cases) of distal gastric carcinomas, markedly lower than that in gastric cardiac carcinomas (P = 0.037).

CONCLUSION: ATP7B protein is frequently overexpressed in gastric cardiac carcinomas, and correlated with the differentiation of cardiac carcinoma. ATP7B expression in gastric cardiac carcinomas is significantly higher than that in distal gastric carcinomas, which might partially explain the difference of chemotherapy response and prognosis between these two gastric carcinomas.

Age effects and temporal trends in adenocarcinoma of the esophagus and gastric cardia (United States)

A number of hypotheses have been advanced to explain the rapid increase of the incidence of esophageal adenocarcinoma in the US. A major problem in identifying and understanding the nature of this increase is the difficulty in untangling age effects from temporal trends due to cohort and period effects. To address this problem, we have developed multi-stage carcinogenesis models that describe the age-specific incidence of adenocarcinoma of the esophagus and of the gastric cardia with separate adjustments for temporal trends. These models explicitly incorporate important features of the cancers, such as the metaplastic conversion of normal esophagus to Barrett's esophagus (BE). We fit these models separately to the incidence of adenocarcinoma of the esophagus and of the gastric cardia reported in the Surveillance Epidemiology and End Results (SEER) registry over the period 1973-2000. We conclude that the incidence of both cancers is consistent with a sequence that posits a tissue conversion step in the target organ followed by a multi-stage process with three rate-limiting events, the first two leading to an initiated cell that can expand clonally into a premalignant lesion, and the third converting an initiated cell into a malignant cell. Temporal trends in the incidence of both cancers are dominated by dramatically increasing period effects.

Comparative genomic hybridization: comparison between esophageal squamous cell carcinoma and gastric cardia adenocarcinoma from a high-incidence area for both cancers in Henan, northern China

Esophageal squamous cell carcinoma (SCC) remains the leading cause of cancer related deaths in Linzhou (formerly Linxian), the highest incidence area for esophageal cancer (EC) in Henan, northern China. In China, gastric cardia adenocarcinoma (GCA) shares very similar geographic distribution with SCC, suggesting the possibility of similar risk factors involved in SCC and GCA carcinogenesis in these areas. However, the underlying genetic alterations for esophageal and gastric cardia carcinogenesis, especially for the molecular difference between SCC and GCA, are largely unknown. The present study was thus undertaken to determine the difference in chromosomal aberrations in SCC (n = 37) and GCA (n = 31) using the comparative genomic hybridization method (CGH). All the patients were from Linzhou, Henan, a high-risk geographic region for both SCC and GCA. CGH results showed that chromosomal aberrations with different degrees were identified both in SCC and GCA. In SCC, chromosomal profile of DNA copy number was characterized by most frequently detected gains at 8q (29/37, 78%), 3q (24/37, 65%) and 5p (19/37, 51%); and frequently detected losses at 3p (21/37, 57%), 8p and 9q (14/37, 38%). In GCA, the frequently detected gains were identified at 20q (13/31, 42%), 6q (12/31, 39%) and 8q (11/31, 35%); the DNA copy number losses in GCA occurred frequently at 17p (17/31, 55%), 19p (15/31, 48%) and 1p (14/31, 45%). Statistically, there were evident differences between SCC and GCA in DNA copy number gains at 8q, 3q, 5p and 20q (P < 0.05) and in losses at 3p, 8p, 5q, 17p and 18q (P < 0.05). Gains at 8q were frequently observed in both SCC and GCA. Gains at 3q and 8p were frequently observed in TNM stage III of both SCC and GCA. The present CGH results provide candidate regions that may contain specific related genes involved in SCC and GCA in the Linzhou population. Gains at 8q, 3q and 5p and losses at 3p, 8p and 9q were specifically implicated in SCC; gains at 20q, 6q and 8q and losses at 17p, 19p and 1p were specifically implicated in GCA; gains at 8q were implicated in both SCC and GCA.

Genetic polymorphisms in glutathione S-transferases T1, M1 and P1 and susceptibility to reflux esophagitis

Recent studies indicate that the prevalence of reflux esophagitis (RE) in China is increasing. RE is one of the most common esophageal complications associated with gastroesophageal reflux disease (GERD) and RE-Barrett's esophagus-esophageal adenocarcinoma (EAC) sequence has been considered as an histogenesis model for EAC in Western countries. RE is only present in a subset of patients with GERD, suggesting an altered susceptibility to RE may exist in these GERD individuals. However, the genetic changes related with high susceptibility to RE is largely unknown. The polymorphisms in glutathione S-transferases (GSTs) T1, M1 and P1 have been reported with high susceptibity to esophageal cancer in Chinese people. The present case-control study was thus undertaken to characterize the genetic polymorphisms of GSTs and their correlation with susceptibility to RE. One hundred and nine patients with RE, 97 patients with nonerosive reflux disease (NERD) and 97 normal controls were recruited in this study. All the subjects were from Beijing, China, and received endoscopic examination and questionnaires for RE. Genomic DNA was extracted from the lymphocytes of peripheral blood for each subject. Genotypes of the GSTM1 and GSTT1 genes were analyzed by a multiplex PCR method. A-->G polymorphism of codon 104 of the GSTP1 gene was detected using PCR-based restriction fragment length polymorphisms (RFLP). The variant GSTP1 genotypes (*A/*Bomicron*B/*B) was found with a high frequency in the case with RE (40%), and followed by NERD (25%) and normal control (22%). The differences were statistically significant (P < 0.05). The risk for RE increased 2.42-fold [odds ratio (OR); 95% confidence interval (95% CI), 2.42 (1.22-4.80)] in the subjects with variant GSTP1 genotype. The subjects with positive variant GSTP1 genotypes and negative H. pylori infection showed increasing tendency for risk of RE [OR (95% CI), 2.67 (1.06-6.70)]. However, the subjects with GSTT1 and GSTM1 polymorphisms did not show any correlation with high risk for RE or NERD. No significant interactions were identified between the variant GSTs and cigarette smoking, or alcohol drinking and subtype of RE. The present result suggests that GSTP1 genetic polymorphism may be one of the high susceptibility factors involved in the mechanisms of RE. H. pylori infection may play a protective role against RE.

Differences and similarities of adenocarcinomas of the esophagus and esophagogastric junction

During the last few decades there has been an alarming rise in the incidence of tumors originating at the esophagogastric junction (EGJ) [1]. The reason for this is unknown. Tumors of the EGJ can be categorized in two types of cancer divided according to their anatomical origin: distal esophageal adenocarcinoma and adenocarcinoma of the gastric cardia. However, due to their location, in the transitional zone of the esophagus and stomach, there is constant debate about the proper classification, staging, and management of these tumors. The etiology of distal esophageal adenocarcinoma is clearly related to gastroesophageal reflux disease (GERD) and the development of a Barrett's esophagus [2]. The etiology of adenocarcinoma of the gastric cardia is less well understood. In the present paper, we will discuss the clinical characteristics and clinical management of esophagogastric tumors. Special attention will be given to differences and similarities of adenocarcinomas of the gastric cardia and distal esophagus.

Distinction between short-segment Barrett’s esophageal and cardiac intestinal metaplasia

AIM: To investigate the roles of mucin histochemistry, cytokeratin 7/20 (CK7/20) immunoreactivity, clinical characteristics and endoscopy to distinguish short-segment Barrett’s esophageal (SSBE) from cardiac intestinal metaplasia (CIM).

METHODS: High iron diamine/Alcian blue (HID/AB) mucin-histochemical staining and immunohistochemical staining were used to classify intestinal metaplasia (IM) and to determine CK7/20 immunoreactivity pattern in SSBE and CIM, respectively, and these results were compared with endoscopical diagnosis and the positive rate of gastroesophageal reflux disease (GERD) symptoms and H pylori infection. Long-segment Barrett’s esophageal and IM of gastric antrum were designed as control.

RESULTS: The prevalence of type III IM was significantly higher in SSBE than in CIM (63.33% vs 23.08%, P<0.005). The CK7/20 immunoreactivity in SSBE showed mainly Barrett’s pattern (76.66%), and the GERD symptoms in most cases which showed Barrett’s pattern were positive, whereas H pylori infection was negative. However, the CK7/20 immunoreactivity in CIM was gastric pattern preponderantly (61.54%), but there were 23.08% cases that showed Barrett’s pattern. H pylori infection in all cases which showed gastric pattern was significantly higher than those which showed Barrett’s pattern (63.83% vs 19.30%, P<0.005), whereas the GERD symptoms in gastric pattern were significantly lower than that in Barrett’s pattern (21.28% vs 85.96%, P<0.005).

CONCLUSION: Distinction of SSBE from CIM should not be based on a single method; however, the combination of clinical characteristics, histology, mucin histochemistry, CK7/20 immunoreactivity, and endoscopic biopsy should be applied. Type III IM, presence of GERD symptoms, and Barrett’s CK7/20 immunoreactivity pattern may support the diagnosis of SSBE, whereas non-type III IM, positive H pylori infection, and gastric CK7/20 immunoreactivity pattern may imply CIM.

The molecular mechanisms of oesophageal cancer

Apoptosis is a process of programmed cell death, which is as essential as cell growth, for the maintenance of homeostasis. When these processes loose integration such as cancer, then uncontrolled cell growth occurs. Cancer of the oesophagus ranks as the ninth most common malignancy in the world, and recent evidence shows that its incidence is increasing. Prognosis of this disease is poor, with an overall 5-year survival rate of less than 10%. Unraveling the mechanisms or developing animal models for oesophageal carcinoma have thus far not been successful. It is believed that oesophageal cancer has an intricate molecular mechanism of evading apoptosis by the down-regulation of Bax, up-regulation of Bcl-2, Bcl-xl and Survivin, mutation of p53 and alteration in Fas expression. A great deal of research has been performed in order to determine the key genes that initiate and promote the growth of oesophageal cancer. This review focuses on apoptosis and candidate genes linked to the development of oesophageal cancer, which it is hoped may provide diagnostic and therapeutic tools, and potential therapeutic strategies for the management of this carcinoma.

Variants of the IL8 and IL8RB Genes and Risk for Gastric Cardia Adenocarcinoma and Esophageal Squamous Cell Carcinoma

The population of Linxian in north central China is at high risk for gastric cardia adenocarcinoma (GCC) and esophageal squamous cell carcinoma (ESCC), and chronic inflammation may contribute to this risk. Interleukin-8 (IL8), a potent chemoattractant, has three well-characterized single nucleotide polymorphisms (SNP), one (−251) of which alters transcriptional activity. Four well-described SNPs in the two IL8 receptors, IL8RA and IL8RB, have been associated with inflammation. We conducted a case-cohort study in the Nutrition Intervention Trials (Linxian, China) to assess the association between these SNPs and incident GCC (n = 90) and ESCC (n = 131). IL8, IL8RA, and IL8RB SNPs were analyzed using a multiplex assay system, haplotypes were constructed, and risks were estimated using Cox proportional hazards models. The homozygous variants of IL8 −251 and +396 were associated with 2-fold increased relative risks for GCC, but the highest risk observed was for the AGT/AGC haplotype of IL8 −251/+396/+781 (relative risk, 4.14; 95% confidence interval, 1.31-13.1). Variation within IL8 was not associated with ESCC. Few subjects had variation at the IL8RA SNP and no significant associations were observed for IL8RB SNPs or haplotypes with either GCC or ESCC. We conclude that variation in IL8 seems to increase the risk for GCC but not ESCC in this high-risk population. These variants could confer an altered IL8 expression pattern or interact with environmental factors to increase the risk for inflammation and GCC.

High incidence of adenocarcinoma arising from the right side of the gastric cardia in NW Iran

BACKGROUND

In the West, the subsite incidence of gastric cancer has changed in recent decades, with cancer of the cardia increasing in incidence and that of the more distal stomach decreasing. NW Iran has a very high incidence of upper gastrointestinal cancer and we have examined the anatomical site specific incidence in this geographical region.

METHOD AND MATERIALS

Of 33 718 patients who visited our clinic from March 2000 to Jan 2003, 3119 (9.3%) with persistent upper gastrointestinal symptoms underwent upper gastrointestinal fibreoptic endoscopy. Exact tumour site, subsite, and axial view were determined. Demographic data including age, sex, and place of residence were assessed. Using matched data from the cancer registry and endoscopic survey, age standardised rates (ASR) for all subsites were calculated.

RESULTS

Upper gastrointestinal cancer was diagnosed histologically in 499 patients (16.0%). The most frequent site was the gastric cardia (126 (25.3%)) followed by the oesophageal body (90 (18.0%)), antrum (82 (16.4%)), corpus (74 (14.8%)), distal oesophagus (57 (11.4%)), gastro-oesophageal junction (47 (9.4%)), and proximal oesophagus (22 (4.4%)). From axial views of the cardia, 51.4% and 6.8% of tumours were found to originate from the lesser and greater curve, respectively. ASR for gastric cancer were 51.2 in males and 15.4 in females. Cardia cancer with ASR of 26.4 in males and 8.6 in females was the major component of gastric cancer.

CONCLUSION

NW Iran is a geographical region with a very high incidence of cardia cancer and with the great majority originating from the right side of the cardia. This suggests a locally acting luminal carcinogen. Studying the aetiology of this cancer in NW Iran is likely to increase our understanding of the rising incidence of this cancer throughout the Western world.

MAPK signal transduction and apoptosis of human gastric carcinoma cells induced by liposomes of survivin antisense oligonucleotide

AIM: To study the relation of mitogen-activated protein kinase (MAPK) signal transduction and apoptosis of human gastric carcinoma cells HS-746T induced by liposomes of survivin antisense oligonucleotide (ASODN).

METHODS: Survivin ASODN was designed and synthesised to transfect human gastric carcinoma cells HS-746T. The cultured cells were divided into 6 groups: vacuity control group, liposome and sense oligonucleotide (SODN) group, 100, 200 and 400 nmoL/L ASODN group and P38MAPK, extracellular signal-regulated kinase 1/2 (ERK1/2) inhibitor groups. Apoptotic index (AI) and proliferative index (PI) were examined by flow cytometry after transfection 2, 4, 8, 12, 24 and 48 h. RT-PCR, immunocytochemical stain, Western blot, immuno-precipitation and kinase activity assay were used to detect protein expression and activity of P38MAPK, ERK1/2, survivin and survivin mRNA after transfection.

RESULTS: Expression of ERK1/2 and P38MAPK has not significantly different among vacuity control group, liposomes group and SODN group. The apoptotic cells increased in anisoconcentration survivin ASODN groups and AI was higher than that of other control group. Apoptotic cells decreased in P38MAPK inhibitor group while increased in ERK1/2. The protein and mRNA expression of survivin decreased when transfection concentration was increased. The phosphorylated and nonphosphorylated ERK1/ 2 showed a dose-and time-dependent decrease whereas protein level of p38MAPK remained unchanged, but activity increased.

CONCLUSION: Survivin ASODN can induce apoptosis of human gastric carcinoma cells in vitro though MAPK signal transduction including activating apoptosis-related signal P38MAPK and suppressing proliferation-related signal ERK1/2.

Effect of body mass index on adenocarcinoma of gastric cardia

AIM: Obesity has been proved as one of the main risk factors for gastric cardia adenocarcinoma (GCA) in the West. The objective of our research was to evaluate the relationship between obesity and the risk of GCA in people from North China.

METHODS: A total of 300 patients who had been diagnosed as GCA and had accepted surgical operation at Beijing Cancer Hospital from 1995 to 2002 were enrolled. Data were collected from pathology materials and hospital records. Two hundred and fifty-eight healthy people who had accepted health examination at the same hospital during the same period were enrolled as controls. Height, weight and gender of them at the time of examination were also collected. Obesity was estimated by body mass index (BMI), computed as weight in kilograms per square surface area (kg/m²). The degree of obesity was determined by using BMI ≤ 18.5, 24-27.9 and ≥ 28 (kg/m²) as the cut-off points for underweight/normal, overweight and obesity, respectively. Associations with obesity were estimated by odds ratios (ORs) and 95% confidence intervals (CIs). All ORs were adjusted for age and sex.

RESULTS: The mean level of BMI was significantly lower in the patient group than that in the control group. The ORs for obesity in age groups 30-59 and 60-79 were 1.15 (95%CI = 0.37-3.65) and 0.16 (95%CI = 0.05-0.44) for males and 0.78 (95%CI = 0.26-2.36) and 0.28 (95%CI = 0.04-2.05) for females, respectively. The ORs for underweight were 2.42 (95%CI = 0.56-10.53) and 4.68 (95%CI = 1.13-19.40) for males in age subgroups 30-59 and 60-79 and 40.7 (95%CI = 9.32-177.92) for females older than 60 yrs. BMI was significantly associated with GCA (P < 0.01). Underweight people were at high risk for GCA.

CONCLUSION: BMI is an independent risk factor for GCA. Underweight is positively associated with GCA.