Expression of Wnt11 and Rock2 protein with clinical characteristics of esophageal squamous cell carcinoma in Kazakh and Han patients

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is one of the most malignancies with a very poor outcome in China. Wnt11 and Rock2, new identified proteins highly associated with metastasis of many cancers, which were never reported in esophageal squamous cell carcinoma (ESCC). Here we measured the expression levels of Wnt11 and Rock2 in tissues from 265 patients with ESCC. Immunohistochemical staining was employed to detect the correlation of Wnt11 and Rock2 expression with clinicopathological features.

METHODS

The expression of Wnt11 and Rock2 was detected by immunohistochemistry in esophageal squamous cell carcinomas and normal esophageal tissues. A chi-square test was used to assess the statistical significance of the correlations between Wnt11, Rock2 expression and different clinicopathological parameters, respectively.

RESULTS

The high-expression of Wnt11 and Rock2 was observed in ESCCs. Seventy-five cases of ESCC (51.7%) showed a positive expression of Wnt11, which indicated a significant association with the AJCC stage (P=0.007). Ninety-eight cases of ESCC (65.5%) showed a positive expression of Rock2, which indicated a significant association with ethnic background. There were no close correlations between Rock2 expression and gender, tumor location, AJCC stage, lymph node metastasis. Specifically, the expression of Rock2 was significantly different between Hans and Kazaks ethnicities (P=0.000). In Kaplan-Meier curve analysis, no significant correlation was observed between the expression of Wnt11, Rock-2 and the poor prognosis of ESCCs.

CONCLUSION

Our finding suggests that the over-expression of Rock2 may play an important role in the carcinogenesis and progression, and may become a new underlying molecular marker in the diagnosis and treatment in ESCC.

Is tumor length a prognostic indicator for esophageal squamous cell carcinoma? A single larger study among Chinese patients

OBJECTIVE

In esophageal cancer, depth of wall penetration, reflected by T classification, represents the most important prognostic variable. Our study aimed to investigate the impact of tumor length, measured as the longitudinal length, on the outcome of esophageal squamous cell carcinoma (ESCC) patients.

METHODS

The survival data of 362 ESCC patients who underwent surgical resection as the primary treatment between 1999 and 2007 were collected retrospectively. Receiver-operator characteristic analysis was applied to identify the optimal cut-off values.

RESULTS

4.0 cm was identified as the optimal cut-off value within the whole group. Tumor length greater than 4.0 cm was associated with increasing T stage (P=0.001), N stage (P=0.046), and tumor differentiation (P=0.033). Univariate analysis and multivariate analysis both found that tumor length greater than 4.0 cm was associated with worse overall survival compared with shorter tumors (P<0.001). It appeared to have a greater impact on N0-N1 (P<0.001, P=0.026, respectively) than N2-N3 and appeared to have a higher impact on the lower-stage patients than the higher-stage patients.

CONCLUSIONS

Tumor length proved to be an independent prognostic parameter for ESCC patients, especially for node-negative and lower-stage patients. More attention should be paid to its role in the management of ESCC.

Association between PLCE1 rs2274223 A > G polymorphism and cancer risk: proof from a meta-analysis

Phospholipase C epsilon 1 (PLCE1) plays an important role in cell growth, differentiation and oncogenesis. An increasing number of individual studies have investigated the association between PLCE1 rs2274223 polymorphism and cancer risk, but the conclusions are inconclusive. To obtain a comprehensive conclusion, we performed a meta-analysis of 22 studies with 13188 cases and 14666 controls. The pooled results indicated that PLCE1 rs2274223 A > G polymorphism was associated with an increased risk of overall cancer (G vs. A: OR = 1.15, 95% CI = 1.06-1.25; GG vs. AA: OR = 1.30, 95% CI = 1.10-1.55; GA vs. AA: OR = 1.18, 95% CI = 1.08-1.30; GG/GA vs. AA: OR = 1.20, 95% CI = 1.08-1.32; GG vs.

GA/AA

OR = 1.22, 95% CI = 1.04-1.42). The stratification analysis showed the polymorphism was significantly associated with an increased risk of esophageal squamous cell carcinoma (ESCC) other than gastric cancer (GC), especially among the subgroups of Asian, high quality score, sample size > 1000 and the studies consistent with Hardy-Weinberg equilibrium (HWE). This meta-analysis demonstrated that PLCE1 rs2274223 A > G polymorphism may be associated with increased susceptibility to cancer, especially for ESCC. However, due to the substantial heterogeneities across the studies, the conclusion might be not conclusive that need more studies to confirm.

TGF-β1/Smad signaling pathway regulates epithelial-to-mesenchymal transition in esophageal squamous cell carcinoma: in vitro and clinical analyses of cell lines and nomadic Kazakh patients from northwest Xinjiang, China

Invasion and metastasis are the major causes of death in patients with esophageal squamous cell carcinoma (ESCC). Epithelial-mesenchymal transition (EMT) is a critical step in tumor progression and transforming growth factor-β1 (TGF-β1) signaling has been shown to play an important role in EMT. In this study, we investigated how TGF-β1 signaling pathways contributed to EMT in three ESCC cell lines as well as 100 patients of nomadic ethnic Kazakhs residing in northwest Xinjiang Province of China. In vitro analyses included Western blotting to detect the expression of TGF-β1/Smad and EMT-associated proteins in Eca109, EC9706 and KYSE150 cell lines following stimulation with recombinant TGF-β1 and SB431542, a potent inhibitor of ALK5 that also inhibits TGF-β type II receptor. TGF-β-activated Smad2/3 signaling in EMT was significantly upregulated as indicated by mesenchymal markers of N-cadherin and Vimentin, and in the meantime, epithelial marker, E-cadherin, was markedly downregulated. In contrast, SB431542 addition downregulated the expression of N-cadherin and Vimentin, but upregulated the expression of E-cadherin. Moreover, the TGF-β1-induced EMT promoted invasion capability of Eca109 cells. Tumor cells undergoing EMT acquire fibroblastoid-like phenotype. Expressed levels of TGF-β1/Smad signaling molecules and EMT-associated proteins were examined using immunohistochemical analyses in 100 ESCC tissues of Kazakh patients and 58 matched noncancerous adjacent tissues. The results showed that ESCC tissues exhibited upregulated expression of TGF-β1/Smad. We also analyzed the relationship between the above proteins and the patients' clinicopathological characteristics. The TGF-β1/Smad signaling pathway in human Eca109 ESCC cells may carry similar features as in Kazakh ESCC patients, suggesting that TGF-β1/Smad signaling pathway may be involved in the regulation of EMT in ethnic Kazakh patients with ESCC from Xinjiang, China.

Xeroderma pigmentosum group D polymorphisms and esophageal cancer susceptibility: A meta-analysis based on case-control studies

AIM: To clarify the effects of the xeroderma pigmentosum group D (XPD) Asp312Asn and Lys751Gln gene polymorphisms on the risk of esophageal cancer (EC).

METHODS: A computerised literature search was conducted to identify the relevant studies from the PUBMED and EMBASE databases, reviews, and reference lists of relevant articles. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the associations between the XPD Asp312Asn and/or Lys751Gln polymorphisms and EC susceptibility. Statistical analyses were performed using the software Stata 12.0. A fixed or random effects model was selected based on a heterogeneity test. Publication bias was estimated using funnel plots and Egger’s linear regression method. Subgroup analyses were performed based on histological type and ethnicity.

RESULTS: Thirteen case-control studies with a total of 10 comparisons for the Asp312Asn polymorphism, including 2373 cases and 3175 controls, and 15 comparisons for the Lys751Gln polymorphism, including 3226 cases and 5237 controls, were recruited for the meta-analysis. In terms of the XPD Asp312Asn polymorphism, significantly increased EC risks were identified in the Asp/Asn vs Asp/Asp comparison (OR = 1.17, 95%CI: 1.02-1.33, P = 0.03) and in the dominant-model comparison (Asn/Asn+Asp/Asn vs Asp/Asp: OR = 1.18, 95%CI: 1.04-1.34, P = 0.01). However, no significant associations were found in the Asn/Asn vs Asp/Asp comparison (OR = 1.30, 95%CI: 1.00-1.70, P = 0.05) or in the recessive-model comparison (Asn/Asn vs Asp/Asn + Asp/Asp: OR = 1.17, 95%CI: 0.91-1.50, P = 0.22). In terms of the XPD Lys751Gln polymorphism, a significant association with EC susceptibility was found under the recessive model (Gln/Gln vs Lys/Gln+Lys/Lys: OR = 1.21, 95%CI: 1.02-1.43, P = 0.03). However, no associations were identified in the other comparisons (co-dominant model: Lys/Gln vs Lys/Lys: OR = 1.11, 95%CI: 0.94-1.31, P = 0.20; Gln/Gln vs Lys/Lys: OR = 1.31, 95%CI: 0.98-1.75, P = 0.07; dominant model: OR = 1.14, 95%CI: 0.96-1.35, P = 0.14).

CONCLUSION: The results of this meta-analysis suggest that the XPD Asp312Asn and Lys751Gln gene polymorphisms are associated with a significantly increased risk for EC.

Polymorphisms of MTHFR and susceptibility to oesophageal adenocarcinoma in a Caucasian United Kingdom population

AIM: To identify if methylene tetra-hydrofolatereductase (MTHFR) C677T polymorphisms are associated with oesophageal adenocarcnomas in a Caucasian population and to test whether folic acid and homocysteine levels are linked with cancer risk.

METHODS: A case control study comprising of 58 non cancer and 48 cancer patients, MTHFR C667T genotyping was made and serum folate, homocysteine and vitamin B12 levels were made. Tumour stage, differentiation and survival was recorded. A P value of less than 0.05 was taken to be significant. The χ² used to compare discrete variables and the Mantel-Cox was used to compare survival. A P value less than 0.05 was deemed to be significant.

RESULTS: MTHFR polymorphisms is associated with an increased risk of several cancers. A link between MTHFR C677T polymorphisms and oesophageal squamous cell carcinoma and gastric cardia adenocarcinoma has been demonstrated in at risk Chinese populations. In a Western European population the role of the MTHFR gene has not previously been investigated in the setting of oesophageal adenocarcinoma. No association between folic acid levels and cancer patients was found. The unstable MTHFR 667 TT genotype occurred in 11% cancers and 7% controls, but statistical significance was not reached, homocysteine levels and folic acid levels were not affected, cancer patients with TT genotype displayed a trend for a shorter survival 7 mo vs 20 mo. Serum vitamin B12 levels were higher in the cancer group. The MTHFR 667 TT genotype is much lower than previous population studies.

CONCLUSION: We conclude that serum folic acid and MTHFR polymorphisms are not associated with an increased risk of oesophageal adenocarcinoma, although cancers with unstable TT genotype may indicate a more aggressive disease course.

Identification of microRNAs as novel biomarkers for detecting esophageal squamous cell carcinoma in Asians: a meta-analysis

Accumulating evidence has suggested that microRNAs (miRNAs) may play potential role as ideal diagnostic indicators of esophageal squamous cell carcinoma (ESCC). However, previous studies have met discrepant results. Thus, we conducted this meta-analysis to assess the potential diagnostic value of miRNAs for ESCC. A systematic literature search was conducted in PubMed and other databases. The pooled sensitivity (SEN), specificity (SPE), positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and area under the curve (AUC) were calculated to evaluate the overall test performance. The Q statistic and the I(2) test were used to assess between-study heterogeneity. The potential sources of heterogeneity were further analyzed by subgroup analyses and meta-regression. Seventeen studies from eight articles, including 995 ESCC patients and 733 healthy controls, were included in this meta-analysis. The pooled SEN and SPE were 0.81 (95% confidence interval (CI) 0.76-0.85) and 0.83 (95 % CI 0.76-0.88), respectively. The pooled PLR was 4.6 (95% CI 3.3-6.5), NLR was 0.23 (95% CI 0.19-0.29), and DOR was 20 (95% CI 13-31). The pooled AUC was 0.91 (95% CI 0.88-0.93). Subgroup analyses indicated that blood-based miRNA assay displays better diagnostic accuracy than saliva-based miRNA assay. In summary, miRNA analysis may serve as novel noninvasive biomarkers for ESCC with excellent diagnostic characteristic. In addition, subgroup analysis suggested that blood-based assay yields better diagnostic characteristics than saliva-based assay. However, many issues should be managed before these findings can be translated into a clinically useful detection method for ESCC.

The impact of pri-miR-218 rs11134527 on the risk and prognosis of patients with esophageal squamous cell carcinoma

MicroRNA-218 (miR-218) acts as a tumor suppressor in numerous types of cancer by regulation of the expression of target genes. The aim of this study was to investigate whether polymorphisms in miR-218 LAMB3 pathway were associated with the risk and prognosis of esophageal squamous cell carcinoma (ESCC). Pri-mir-218 rs11134527 and LAMB3 rs2566 were genotyped in ESCC patients and 745 controls to assess their associations with cancer risk and overall survival. Pri-mir-218 rs11134527 was significantly associated with a decreased risk of ESCC under codominant, recessive and additive models. Although there was a significant association between rs11134527 and better survival of ESCC patients under codominant, recessive and additive models, the association disappeared after adjustment for TNM and LNM. However, further stratified analysis revealed that the association remained significant in patients with TNM stages I and II or non-LNM. Our data suggest that pri-miR-218 rs11134527 may contribute to the genetic susceptibility and prognosis for ESCC in Chinese Han population.

Significance of elevated ERK expression and its positive correlation with EGFR in Kazakh patients with esophageal squamous cell carcinoma

Extracellular signal-regulated kinases (ERKs) are activated by the MAPK pathway. ERKs are downstream effectors of the epidermal growth factor receptor (EGFR), which belongs to the receptor tyrosine kinases family. Studies on the activation of the EGFR-ERK pathway in Kazakh patients with esophageal squamous cell carcinoma (ESCC) have not been reported. Using immunohistochemical staining on tissue microarrays, we investigated the protein expression of EGFR and ERK in 90 ethnic Kazakh patients with ESCC and 48 adjacent normal esophageal tissues (NETs). EGFR and ERK1 expression was localized in the cytoplasm, whereas ERK2 expression was localized in the nucleus. Both were more highly expression in the ESCC tissues than in the NETs, and the difference was considered significant (P=0.003, 0.002, and 0.005, respectively). ERK1 and EGFR expression was positively correlated with lymph nodes metastasis (P=0.011 and 0.013, respectively). ERK1 staining was also significantly associated with tumor-node-metastases stage of ESCC (P=0.044). ERK2 staining was significantly associated with Histological grade (P=0.012). Furthermore, ERK1 and EGFR expression in the ESCC tissues were positively correlated (r=0.413, P<0.001); EGFR was more highly expressed in the ESCC tissues with high ERK1 expression than in the ESCC tissues with low ERK1 expression (4.95±0.57 vs. 3.21±0.35, P=0.01). This study is thus far the first to demonstrate the correlation between EGFR overexpression and ERK overexpression in Kazakh patients with ESCC. This correlation suggests that the EGFR-ERK signaling pathway participates in ESCC progression and can thus be used as a prognostic marker.

[Relationship between rs2274223 and rs3765524 polymorphisms of PLCE1 and risk of esophageal squamous cell carcinoma in a Kazakh Chinese population]

OBJECTIVE

To investigate the association between the rs2274223 and rs3765524 polymorphism of phospholipase C epsilon 1 (PLCE1) gene and the susceptibility to develop esophageal squamous cell carcinoma (ESCC) in a pure Kazakh Chinese population.

METHODS

Matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF MS) was utilized to genotype the potentially functional single nucleotide polymorphism rs2274223 A>G and rs3765524 C>T of PLCE1 in an ongoing hospital-based and case-control study of 200 ESCC cases with 300 cancer-free age ( ± 5 years) and sex matched controls. Statistical analyses were performed with Statistical Products and Services Solutions software (version 13.0). Adjusted odds ratios (OR) and 95% confidence evaluation intervals (95%CI) measured by multivariate logistic regression analysis were adopted to study the correlation of the gene polymorphism with the susceptibility to ESCC.

RESULTS

The genotype frequencies observed for rs2274223 was consistent with Hardy-Weinberg equilibrium in controls. Univariate analysis revealed significant differences between cases and controls with respect to genotype distribution for rs2274223 (P = 0.006). The variants of rs2274223 were found to confer significantly increased risk of ESCC (GG vs AA: OR = 3.17, 95%CI = 1.45-6.93; AG/GG vs AA: OR = 1.55, 95%CI = 1.08-2.22) in the Kazakh Chinese population. Moreover, AG/GG genotype of rs2274223 was found to be significantly associated with poorly-differentiated ESCC (OR = 2.48, 95%CI = 1.10-5.60). When the ESCC patients were divided into two subgroups, stage I/II and stage III/IV according to the AJCC TNM classification, the GT/GG genotype of rs2274223 was significantly associated with stage III/IV ESCC (OR = 1.85, 95%CI = 1.05-3.25). No significant association was found between rs3765524 and Kazakh ESCC.

CONCLUSIONS

These results indicate that rs2274223 site polymorphism of the PLCE1 gene is strongly associated with risk of ESCC in a Kazakh Chinese population, especially the poorly-differentiated and stage III/IV ESCC.

Association of CHRNA5-A3-B4 variation with esophageal squamous cell carcinoma risk and smoking behaviors in a Chinese population

BACKGROUND

CHRNA5-A3-B4, the gene cluster encoding nicotinic acetylcholine receptor subunits, is associated with lung cancer risk and smoking behaviors in people of European descent. Because cigarette smoking is also a major risk factor for esophageal squamous cell carcinoma (ESCC), we investigated the associations between variants in CHRNA5-A3-B4 and ESCC risk, as well as smoking behaviors, in a Chinese population.

METHODS

A case-control study of 866 ESCC patients and 952 healthy controls was performed to study the association of polymorphisms (rs667282 and rs3743073) in CHRNA5-A3-B4 with cancer risk using logistic regression models. The relationships between CHRNA5-A3-B4 polymorphisms and smoking behaviors that can be quantified by cigarettes smoked per day (CPD) and pack-years of smoking were separately estimated with Kruskal-Wallis tests among all 840 smokers.

RESULTS

CHRNA5-A3-B4 rs667282 TT/TG genotypes were associated with significantly increased risk of ESCC [adjusted odds ratio (OR) = 1.32, 95% confidence interval (CI) = 1.03 - 1.69, P = 0.029]. The increased ESCC risk was even higher among younger subjects (≤60 years) (OR = 1.44, 95% CI = 1.04 - 1.98, P = 0.024). These effects were not found in another polymorphism rs3743073. No evident association between the two polymorphisms and smoking behaviors was observed.

CONCLUSIONS

These results support the hypothesis that CHRNA5-A3-B4 is a susceptibility gene cluster for ESCC. The relationship between CHRNA5-A3-B4 and smoking behaviors in a Chinese population needs further investigation.

XRCC1 Arg399Gln, Arg194Trp, and Arg280His polymorphisms in esophageal cancer risk: a meta-analysis

BACKGROUND

The X-ray repair cross-complementation group 1 (XRCC1) protein plays an important role in base excision repair.

AIM

To elucidate the role of XRCC1 Arg399Gln, Arg194Trp and Arg280His genotypes in esophageal cancer risk, all available studies were considered in the present meta-analysis.

METHODS

Eligible studies were identified by searching several electronic databases for relevant reports published before June 2012.

RESULTS

According to the inclusion criteria and exclusion criteria, a total of 21 eligible studies were included in the pooled analyses. Among the 21 studies, 18 focused on Arg399Gln polymorphism, 11 described the Arg194Trp, and 4 articles investigated on Arg280His. Our analysis suggested that there was no evidence of significant association between XRCC1 Arg399Gln polymorphism and esophageal cancer risk in any genetic model. In the stratified analysis by ethnicity for Arg399Gln polymorphism and esophageal cancer, the results showed that Arg399Gln polymorphism was not associated with esophageal cancer risk. Only 4 studies analyzed the relationship between XRCC1 Arg280His polymorphism and the risk of esophageal cancer. The Arg/His and His/His genotypes were not significantly associated with increased risk of EC. A similar negative association was maintained in dominant and recessive models. However, for XRCC1 Arg194Trp polymorphism, our study showed individuals carrying the variant genotype Trp/Trp had a significant increased risk of esophageal cancer (OR = 1.295, 95 % CI 1.053-1.591, P = 0.014). In addition, increased associations were found in recessive model (OR = 1.332, 95 % CI 1.093-1.624, P = 0.005).

CONCLUSIONS

Our meta-analysis suggested that Arg194Trp Trp allele might act as a risk allele in its association with esophageal cancer.

Interleukin 1B rs16944 G>A polymorphism was associated with a decreased risk of esophageal cancer in a Chinese population

OBJECTIVE

Esophageal cancer is the sixth leading cause of cancer-associated deaths worldwide and represents a particularly aggressive type of cancer. Genetic polymorphisms may partly explain individual differences in esophageal cancer susceptibility.

DESIGNS AND METHODS

We conducted a hospital-based case-control study to evaluate the genetic effects of functional single nucleotide polymorphisms (SNPs) in the interleukin 1 (IL1A and IL1B), IL1f7, IL3 and IL7Ra genes on the development of esophageal cancer. A total of 380 esophageal squamous cell carcinoma (ESCC) cases and 380 controls were recruited for this study. The genotypes were determined using a custom-by-design 48-Plex SNPscan™ Kit.

RESULTS

When the IL1B rs16944 GG homozygote genotype was used as the reference group, the GA genotype was associated with a significantly decreased risk of ESCC (GA vs. GG: adjusted OR=0.69, 95% CI=0.49-0.99, p=0.041). However, there were no significant associations between the other five SNPs and ESCC risk. Stratified analyses indicated no significantly different risks of ESCC associated with the IL1B rs16944 G>A polymorphism according to sex, age, smoking status or alcohol consumption. IL3 rs2073506 G>A polymorphism was associated with an increased risk for ESCC higher tumor, nodal, and metastatic (TNM) stages.

CONCLUSIONS

These findings indicated that the functional IL1B rs16944 G>A polymorphism might contribute to ESCC susceptibility. IL3 rs2073506 G>A polymorphism was associated with an increased risk for ESCC higher TNM stages. However, the results were based on a limited sample size and larger well-designed studies are warranted to confirm these initial findings.

Prognostic significance of vascular endothelial growth factor expression in esophageal carcinoma: a meta-analysis

PURPOSE

The purpose of this study was to comprehensively and quantitatively review eligible published studies to explore the prognostic significance of vascular endothelial growth factor (VEGF) expression in patients with esophageal carcinoma (EC).

METHODS

PubMed and Embase databases were searched until September 11, 2011. A meta-analysis was performed to demonstrate any relationship between VEGF and 5-year overall survival (OS) in EC patients.

RESULTS

The final analysis included 1453 patients from 19 studies. The studies were grouped by patient source, histology, VEGF isoform and cutoff value. The estimated risk of death suggested that VEGF positivity had negative impact on prognosis of patients with EC, esophageal squamous cell carcinoma (ESCC) and Asian patients. The risk ratios (RR) and 95% confidence interval (95% CI) were 1.26 (1.16-1.37) in EC patients, 1.28 (1.16-1.40) in ESCC patients and 1.35 (1.24-1.48) in Asian patients. Furthermore, when the cutoff value was set at 10% in 6 studies, the RR (95% CI) was 1.48 in the VEGF positive group (1.27-1.73). In addition, VEGFC was also correlated with patient poor prognosis with a RR (95% CI) of 1.30 (1.15-1.48). However, EC patients from non-Asian countries and cutoff value at 30% showed no significant correlation with survival. Data were not sufficient to determine the prognostic value of VEGF expression in esophageal adenocarcinoma (EA) patients and VEGFD expression.

CONCLUSIONS

VEGF positivity indicated poor prognosis in patients with EC, ESCC and of Asian origin. Cutoff value at 10% may be a more appropriate standard to define VEGF positivity. VEGFC also correlated with poor prognosis in EC patients.

Human papillomavirus type 16 infection may be involved in esophageal squamous cell carcinoma carcinogenesis in Chinese Kazakh patients

The aim of this study was to investigate human papillomavirus type 16 (HPV16) prevalence in esophageal squamous cell carcinoma (ESCC) in Xinjiang Kazakh patients and its role in ESCC carcinogenesis. One hundred and fifty cases of ESCC and 150 cases of corresponding normal esophageal mucosa (CNGM) samples were collected from north Xinjiang where the Kazakh ethnic group has lived since ancient times. HPV16 infection in ESCC and CNGM was detected by genotype-specific polymerase chain reaction. HPV16 DNA was detected in 55 of 150 ESCC samples (36.7%) and 24 of 150 corresponding normal esophageal mucosa samples (16%) with significant differences (P < 0.001, odds ratio = 3.039, 95% confidence interval: 1.756-5.260). No statistically significant correlations were found between HPV16 infection and the age or gender of patients, tumor site, tumor cell differentiation, or lymph node metastasis (P > 0.05). HPV16 infection is common in cases of ESCC in the Kazakh ethnic group in Xinjiang and may be involved in ESCC carcinogenesis.

Carcinoma of the gastroesophageal junction in Chinese patients

Carcinoma of the gastroesophageal junction (GEJ) is defined as carcinoma that crosses the GEJ line, irrespective of where the tumor epicenter is located. This group of cancer is rare but controversial. Based on study results from the majority of epidemiologic and clinicopathologic investigations carried out in Western countries, this cancer is believed to arise from Barrett’s esophagus (BE) and includes both distal esophageal and proximal gastric carcinomas because of similar characteristics in epidemiology, clinicopathology, and molecular pathobiology in relation to BE. As such, the most recent American Joint Committee on Cancer staging manual requires staging all GEJ carcinomas with the rule for esophageal adenocarcinoma (EA). This mandate has been challenged recently by the data from several studies carried out mainly in Chinese patients. The emerging evidence derived from those studies suggests: (1) both BE and EA are uncommon in the Chinese population; (2) almost all GEJ cancers in Chinese arise in the proximal stomach and show the features of proximal gastric cancer, not those of EA; (3) application of the new cancer staging rule to GEJ cancer of Chinese patients cannot stratify patients’ prognosis effectively; and (4) prognostic factors of GEJ cancer in Chinese are similar, but not identical, to those of EA. In conclusion, the recent evidence suggests that GEJ cancer in Chinese shows distinct clinicopathologic characteristics that are different from EA. Further investigations in molecular pathology may help illustrate the underlying pathogenesis mechanisms of this cancer in Chinese patients and better manage patients with this fatal disease.

Ethnicity in relation to incidence of oesophageal and gastric cancer in England

BACKGROUND

This study investigated the variation in incidence of all, and six subgroups of, oesophageal and gastric cancer between ethnic groups.

METHODS

Data on all oesophageal and gastric cancer patients diagnosed between 2001 and 2007 in England were analysed. Self-assigned ethnicity from the Hospital Episode Statistics dataset was used. Male and female age-standardised incidence rate ratios (IRRs) were calculated for each ethnic group, using White groups as the references.

RESULTS

Ethnicity information was available for 83% of patients (76 130/92 205). White men had a higher incidence of oesophageal cancer, with IRR for the other ethnic groups ranging from 0.17 95% confidence interval (CI) (0.15-0.20) (Pakistani men) to 0.58 95% CI (0.50-0.67) (Black Caribbean men). Compared with White women, Bangladeshi women (IRR 2.02 (1.24-3.29)) had a higher incidence of oesophageal cancer. For gastric cancer, Black Caribbean men (1.39 (1.22-1.60)) and women (1.57 (1.28-1.92)) had a higher incidence compared with their White counterparts. In the subgroup analysis, White men had a higher incidence of lower oesophageal and gastric cardia cancer compared with the other ethnic groups studied. Bangladeshi women (3.10 (1.60-6.00)) had a higher incidence of upper and middle oesophageal cancer compared with White women.

CONCLUSION

Substantial ethnic differences in the incidence of oesophageal and gastric cancer were found. Further research into differences in exposures to risk factors between ethnic groups could elucidate why the observed variation in incidence exists.

Circulating miR-155 expression in plasma: a potential biomarker for early diagnosis of esophageal cancer in humans

MicroRNAs (miRNAs) are postulated to play important roles in oncogenesis. Recently, extracellular miRNAs were detected in plasma or serum of diseased subjects. However, the role of circulating miRNAs in plasma/serum remains to be elucidated. In this study, the relative expressions of miR-155, miR-183, and miR-20a in esophageal tissue were found to be significantly associated with increased risk for esophageal cancer. The relative expressions of circulating miR-155 and miR-183 were significantly reduced in cancer patients. Circulating miR-155 showed significantly higher risk for esophageal cancer when adjusted by smoking status and alcohol use. Circulating miR-155 was found to have significant diagnostic value for esophageal cancer as evidenced by a receiver operating characteristic curve area of 66%. However, Pearson analysis showed no statistical correlation in the relative miRNAs expression between plasma and esophageal tissues, which suggested different origins of circulating miRNAs distinct from tumor cell miRNAs. In conclusion, results suggest that circulating miR-155 in plasma may serve as a reliable, novel, noninvasive biomarker for early diagnosis and detection of esophageal cancer.

Association of a deletion of GSTT2B with an altered risk of oesophageal squamous cell carcinoma in a South African population: a case-control study

Background

Polymorphisms in the Glutathione S-transferase genes are associated with altered risks in many cancers, but their role in oesophageal cancer is unclear. Recently a 37-kb deletion polymorphism of GSTT2B that reduces expression of GSTT2 has been described. We evaluated the influence of the GSTT1 and GSTT2B deletion polymorphisms, and the GSTP1 Ile105Val polymorphism (rs1695) on susceptibility to oesophageal squamous cell carcinoma (OSCC) in the Black and Mixed Ancestry populations of South Africa.

Methods and Results

The GSTT1, GSTT2B and GSTP1 variants were genotyped in 562 OSCC cases and 907 controls, and tested for association with OSCC and for interaction with smoking and alcohol consumption. Linkage disequilibrium (LD) between the deletions at GSTT1 and GSTT2B was determined, and the haplotypes tested for association with OSCC. Neither the GSTT1 deletion nor the GSTP1 Ile105Val polymorphism was associated with OSCC risk in the Black or Mixed Ancestry populations. The GSTT2B deletion was not associated with OSCC risk in the Black population, but was associated with reduced risk of OSCC in the Mixed Ancestry population (OR = 0.71; 95% CI 0.57–0.90, p = 0.004). Case-only analysis showed no interaction between the GST polymorphisms and smoking or alcohol consumption. LD between the neighboring GSTT1 and GSTT2B deletions was low in both populations (r²_Black = 0.04; r²_MxA = 0.07), thus these deletions should be assessed independently for effects on disease risk.

Conclusions

Although there was no association between the GSTT1 deletion polymorphism or the GSTP1 Ile105Val polymorphism with OSCC, our results suggest that the presence of the recently described GSTT2B deletion may have a protective effect on the risk of OSCC in the Mixed Ancestry South African population. This is the first report of the contribution of the GSTT2B deletion to cancer risk.

Association of mitochondrial haplogroup D and risk of esophageal cancer in Taihang Mountain and Chaoshan areas in China

Both the Taihang Mountain area in north-central China and Chaoshan area in the southeastern littoral of China are areas with high risk of esophageal cancer (EC). Our previous study confirmed that populations from the two areas might share similar matrilineal backgrounds and found that mitochondrial DNA (mtDNA) haplogroup D, especially subhaplogroups D4a and D5a, might be genetic background markers of EC in Chaoshan area. Here, to further determine whether D4a, D5a, and D might be susceptibility markers for EC in the two high-risk areas, we performed a case-control study with larger samples and analyzed the distributions of these three haplogroups in subjects (controls [n = 898] and patients [n = 768]) from the two areas. D4a haplogroup was significantly associated with increased risk of EC in Taihang Mountain subjects, especially women. D5 haplogroup was associated with EC at the general population level in the Taihang Mountain area and in subjects ≤ 60 years, especially women ≤ 60 years, in the Chaoshan area. D haplogroup was associated with EC only in subjects ≤ 60 years, especially men ≤ 60 years, in the Chaoshan area. D4a and D5 showing positive association with EC in the Taihang Mountain area became the predominant subhaplogroups of D in Chaoshan controls. In conclusion, D, D4a, and D5 haplogroups might be susceptibility markers for EC in the two high-risk areas in China, particularly D4a and D5 for the Taihang Mountain area and D and D5 for the Chaoshan area.

Systematic review on the relationship between genetic polymorphisms of methylenetetrahydrofolate reductase and esophageal squamous cell carcinoma

BACKGROUND

Both genetic and environmental factors play roles in pathogenesis of esophageal squamous cell carcinoma (ESCC) and susceptibility may be modified by functional polymorphisms in folate metabolic genes, such as methylenetetrahydrofolate reductase (MTHFR). We here aimed to evaluate associations of MTHFR C677T and A1298C polymorphisms with ESCC.

METHODS

We searched MEDLINE, EMBASE and the Chinese Biomedical Database and 2 evaluators independently reviewed all the articles identified according to predetermined criteria.

RESULTS

A total of 15 case-control studies published between 2001 and 2010 were included. When all the studies were pooled, the crude odds ratio (95% CI) of ESCC for individuals carrying MTHFR 677 CT and TT genotypes, as compared to CC, were 1.39 (1.11-1.75) and 1.79 (1.31-2.43), respectively. Individuals with MTHFR 1298CC showed non-significantly increased risk of ESCC, with an OR (95%CI) of 3.31 (0.90-12.17). In smokers, a significantly increased risk of ESCC was observed for those with the MTHFR 677T allele (OR (95% CI)=2.2 (1.31-2.41)). Chinese carrying MTHFR 677T and MTHFR 1298C alleles had a greater increase in ESCC risk than other ethnicities.

CONCLUSIONS

The present meta-analysis provided evidence that MTHFR 677CT/TT plays a carcinogenic role in ESCC, and its effect is modified by tobacco and ethnicity. The small number of subjects with the MTHFR 1299C allele genotype in published studies limits conclusions regarding this polymorphism.

Frequent germline mutation in the BRCA2 gene in esophageal squamous cell carcinoma patients from a low-risk Chinese population

BACKGROUND

The incidence of esophageal squamous cell cancer (ESCC) is strikingly variable by geographic area, which reflect different exposures to risk factors, including genetic predisposition. Previous studies of ESCC patients from several high-risk populations suggested that BRCA2 might play a role in the etiology. This study was conducted to screen for mutations of BRCA2 gene in ESCC cases from a low-risk population.

METHODS

Forty-seven ESCC patients from a low-risk area of Southeast China were screened for mutations in the entire coding region of the BRCA2 gene by direct sequencing.

RESULTS

No somatic mutations were observed in tumors. In total, 9 germline missense point mutations, each in one patient, were identified in male sporadic patients, with a mutation frequency of 19%. Of the 9 mutations, 7 were of heterozygous, while the remaining 2 were homozygous. Screening of an additional 94 healthy controls for the 9 mutations identified in ESCC cases showed that there was only 2 (2%) positive individuals, each carrying one of the mutations. Thus the mutation frequency in ESCC cases (19%) was significantly higher than that in healthy controls (OR = 10.9, 95% CI = 2.2-52.8, P = 0.003). No significant associations were observed for germline BRCA2 mutations with age, sex, cigarette smoking, alcohol drinking and family history of cancer.

CONCLUSION

This series of cases from a low-risk Chinese population presented the highest frequency of germline BRCA2 mutations in ESCC reported to date, highlighting possible etiology roles in this population.

Correlates of circulating 25-hydroxyvitamin D: Cohort Consortium Vitamin D Pooling Project of Rarer Cancers

Low vitamin D status is common globally and is associated with multiple disease outcomes. Understanding the correlates of vitamin D status will help guide clinical practice, research, and interpretation of studies. Correlates of circulating 25-hydroxyvitamin D (25(OH)D) concentrations measured in a single laboratory were examined in 4,723 cancer-free men and women from 10 cohorts participating in the Cohort Consortium Vitamin D Pooling Project of Rarer Cancers, which covers a worldwide geographic area. Demographic and lifestyle characteristics were examined in relation to 25(OH)D using stepwise linear regression and polytomous logistic regression. The prevalence of 25(OH)D concentrations less than 25 nmol/L ranged from 3% to 36% across cohorts, and the prevalence of 25(OH)D concentrations less than 50 nmol/L ranged from 29% to 82%. Seasonal differences in circulating 25(OH)D were most marked among whites from northern latitudes. Statistically significant positive correlates of 25(OH)D included male sex, summer blood draw, vigorous physical activity, vitamin D intake, fish intake, multivitamin use, and calcium supplement use. Significant inverse correlates were body mass index, winter and spring blood draw, history of diabetes, sedentary behavior, smoking, and black race/ethnicity. Correlates varied somewhat within season, race/ethnicity, and sex. These findings help identify persons at risk for low vitamin D status for both clinical and research purposes.

Y-chromosome evidence for common ancestry of three Chinese populations with a high risk of esophageal cancer

High rates of esophageal cancer (EC) are found in people of the Henan Taihang Mountain, Fujian Minnan, and Chaoshan regions of China. Historical records describe great waves of populations migrating from north-central China (the Henan and Shanxi Hans) through coastal Fujian Province to the Chaoshan plain. Although these regions are geographically distant, we hypothesized that EC high-risk populations in these three areas could share a common ancestry. Accordingly, we used 16 East Asian-specific Y-chromosome biallelic markers (single nucleotide polymorphisms; Y-SNPs) and six Y-chromosome short tandem repeat (Y-STR) loci to infer the origin of the EC high-risk Chaoshan population (CSP) and the genetic relationship between the CSP and the EC high-risk Henan Taihang Mountain population (HTMP) and Fujian population (FJP). The predominant haplogroups in these three populations are O3*, O3e*, and O3e1, with no significant difference between the populations in the frequency of these genotypes. Frequency distribution and principal component analysis revealed that the CSP is closely related to the HTMP and FJP, even though the former is geographically nearer to other populations (Guangfu and Hakka clans). The FJP is between the CSP and HTMP in the principal component plot. The CSP, FJP and HTMP are more closely related to Chinese Hans than to minorities, except Manchu Chinese, and are descendants of Sino-Tibetans, not Baiyues. Correlation analysis, hierarchical clustering analysis, and phylogenetic analysis (neighbor-joining tree) all support close genetic relatedness among the CSP, FJP and HTMP. The network for haplogroup O3 (including O3*, O3e* and O3e1) showed that the HTMP have highest STR haplotype diversity, suggesting that the HTMP may be a progenitor population for the CSP and FJP. These findings support the potentially important role of shared ancestry in understanding more about the genetic susceptibility in EC etiology in high-risk populations and have implications for determining the molecular basis of this disease.