Esophageal cancer: epidemiology, pathogenesis and prevention

A meta-analysis of the association between the hOGG1 Ser326Cys polymorphism and the risk of esophageal squamous cell carcinoma

BACKGROUND

Genetic polymorphism of human 8-oxoguanine glycosylase 1 (hOGG1) Ser326Cys (rs1052133) has been implicated in the risk of Esophageal Squamous Cell Carcinoma (ESCC). However, the published findings are inconsistent. We therefore performed a meta-analysis to derive a more precise estimation of the association between the hOGG1 Ser326Cys polymorphism and ESCC risk.

METHODOLOGY/PRINCIPAL FINDINGS

A comprehensive search was conducted to identify eligible studies of hOGG1 Ser326Cys polymorphism and the risk of the ESCC. Three English and two Chinese databases were used, and ten published case-control studies, including 1987 cases and 2926 controls were identified. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the association in the dominant and recessive model. Pearson correlation coefficient (PCC) and standard error (SE) were used to assess the number of Cys allele and ESCC risk in the additive model. Overall, significant associations between the hOGG1 Ser326Cys polymorphism and ESCC risk were found in the recessive model: OR = 1.37 (95% CI: 1.06-1.76, p = 0.02). We also observed significant associations in the Caucasian, Chinese language, population based control and tissue subgroups. In the additive model, positive correlation was found between the number of Cys allele and the risk of ESCC in overall studies (PCC = 0.109, SE = 0.046, p = 0.02), Caucasian subgroup and population subgroup. Funnel plot and Egger's test indicate there was no publication bias in this meta-analysis.

CONCLUSION

Under the published data, the hOGG1 Ser326Cys polymorphism is associated with ESCC risk in the recessive and additive model. Compared with the Ser/Ser and Ser/Cys genotype, Cys/Cys genotype might contribute to increased risk of ESCC. And the risk of ESCC is positively correlated with the number of Cys allele. A better case-control matched study should be designed in order to provide a more precise estimation.

Tumor associated macrophage expressing CD204 is associated with tumor aggressiveness of esophageal squamous cell carcinoma

Tumor associated macrophages (TAMs) are the most abundant cancer stromal cells educated by tumor microenvironment to acquire trophic functions facilitating angiogenesis, matrix breakdown and cancer cell motility. Tumor associated macrophages have anti-inflammatory properties or "alternatively" activated (M2) phenotype expressing CD204 and/or CD163. To know the role of TAMs in the growth and progression of esophageal squamous cell carcinomas (ESCCs), we calculated intratumoral CD204, CD163 or CD68 expressing macrophage count (MϕC) and CD34-positive microvessel density (MVD) by immunohistochemistry in 70 cases of surgically resected ESCCs and compared them with the clinicopathological factors and prognosis of patients. MϕC had positive linear association with MVD. High CD204(+) MϕC were significantly correlated with more malignant phenotypes including depth of tumor invasion, lymph and blood vessel invasion, lymph node metastasis as well as clinical stages. On the other hand, CD163(+) MϕC did not associate with these clinicopathological factors with the exception of depth of tumor invasion and blood vessel invasion. Patients with high CD204(+) MϕC ESCCs showed poor disease-free survival (P = 0.021). Conditioned media of five ESCC cell lines (TE-8, -9, -10, -11 and -15) induced mRNA as well as protein expression of CD204 but not of CD163 with upregulation of vascular endothelial growth factor-A mRNA in TPA treated human acute monocytic leukemia cell line THP-1. These results overall indicate that CD204 is a useful marker for TAMs contributing to the angiogenesis, progression and prognosis of ESCCs whose specific tumor microenvironment may educate macrophages to be CD204(+) M2 TAMs.

Association between XPD Asp312Asn polymorphism and esophageal cancer susceptibility: a meta-analysis

OBJECTIVE

To investigate the association between xeroderma pigmentosum group D (XPD) Asp312Asn polymorphism and esophageal cancer (EC) susceptibility by meta-analysis.

METHODS

We searched PubMed up to April 9th, 2012, to identify relevant papers, and 8 published case-control studies including 2165 EC patients and 3141 healthy controls were yielded. Odds ratios (ORs) with relevant 95% confidence intervals (CIs) were applied to assess the association between XPD Asp312Asn polymorphism and EC susceptibility with the Comprehensive Meta-Analysis software, version 2.2.

RESULTS

Overall, the meta-analysis results suggested the XPD Asp312Asn polymorphism to be significantly associated with EC susceptibility [(Asn/Asn+Asp/Asn) vs. Asp/Asp: OR=1.20, 95%CI=1.05-1.36, p=0.01; and Asp/Asn vs. Asp/Asp: OR=1.15, 95%CI=1.01-1.31, p=0.04]. In the subgroup analysis by ethnicity and cancer type, significantly associations were found for Caucasian populations [(Asn/Asn+Asp/Asn) vs. Asp/Asp: OR=1.26, 95%CI=1.08-1.47, p<0.001; Asp/Asn vs. Asp/Asp: OR=1.19, 95%CI=1.02- 1.40, p=0.03] and esophageal squamous cell carcinoma [(Asn/Asn+Asp/Asn) vs. Asp/Asp: OR=1.19, 95%CI=1.01-1.41, p=0.04]. There was no heterogeneity and no publication bias existed.

CONCLUSIONS

This meta-analysis shows that the XPD Asp312Asn polymorphism may be a risk factor for developing EC, especially for Caucasian populations and esophageal squamous cell carcinoma.

Utility of baseline positron emission tomography with computed tomography for predicting endoscopic resectability and survival outcomes in patients with early esophageal adenocarcinoma

BACKGROUND AND AIMS

Positron emission tomography with computed tomography (PET/CT) has been used to detect metastasis in the diagnosis of esophageal adenocarcinoma (EAC). However, the utility of PET/CT to assess primary tumor for endoscopic resectability and prognosis in early EAC remains unclear. We conducted a retrospective study to determine the association of PET/CT findings with histopathological tumor invasion depth and survival outcomes.

METHODS

EAC patients who underwent PET/CT followed by endoscopic mucosal resection (EMR) were included. Pathology on EMR and survival outcomes from a prospectively maintained database was retrieved. Two radiologists independently reviewed the PET/CT using the following parameters: detection of malignancy, fluorodeoxyglucose (FDG) uptake intensity, FDG focality, FDG eccentricity, esophageal thickness, maximal standard uptake value (SUVmax), and SUVmax ratio (lesion/liver).

RESULTS

There were 72 eligible patients: 42 (58.3%) had T1a lesions, and 30 (41.7%) had ≥ T1b. Only SUVmax ratio was associated with tumor invasion depth (odds ratio=2.77, 95% confidence interval 1.26-7.73, P=0.0075). Using a cut-off of 1.48, the sensitivity and specificity of SUVmax ratio for identification of T1a lesions were 43.3% and 80.9%, respectively. Adjusting the SUVmax ratio to 2.14, 16.7% (5/30) of ≥ T1b patients were identified without any false-positive cases. Multivariate analysis showed SUVmax ratio, Charlson comorbidity index, and esophagectomy were independent predictors for survival.

CONCLUSIONS

SUVmax ratio (lesion/liver) is more accurate in predicting endoscopic resectability and mortality for EAC than other PET/CT parameters and appears promising as a useful adjunct to the current diagnostic work-up.

Meat, fish, and esophageal cancer risk: a systematic review and dose-response meta-analysis

Risk factors for esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) are well defined, while the role of diet in these conditions remains controversial. To help elucidate the role of particular dietary components, major bibliographic databases were searched for published studies (1990-2011) on associations between esophageal cancer risk (EC) and consumption of various types of meat and fish. Random-effects models and dose-response meta-analyses were used to pool study results. Subgroup analyses were conducted by histological subtype, study design, and nationality. Four cohorts and 31 case-control studies were identified. The overall pooled relative risk (RR) of EC and the confidence intervals (CIs) for the groups with the highest versus the lowest levels of intake were as follows: 0.99 (95% CI: 0.85-1.15) for total meat; 1.40 (95%CI: 1.09-1.81) for red meat; 1.41 (95%CI: 1.13-1.76) for processed meat; 0.87 (95%CI: 0.60-1.24) for poultry; and 0.80 (95%CI: 0.64-1.00) for fish. People with the highest levels of red meat intake had a significantly increased risk of ESCC. Processed meat intake was associated with increased risk of EAC. These results suggest that low levels of red and processed meat consumption and higher levels of fish intake might reduce EC risk.

Salivary microRNAs as promising biomarkers for detection of esophageal cancer

Background and Purpose

Tissue microRNAs (miRNAs) can detect cancers and predict prognosis. Several recent studies reported that tissue, plasma, and saliva miRNAs share similar expression profiles. In this study, we investigated the discriminatory power of salivary miRNAs (including whole saliva and saliva supernatant) for detection of esophageal cancer.

Materials and Methods

By Agilent microarray, six deregulated miRNAs from whole saliva samples from seven patients with esophageal cancer and three healthy controls were selected. The six selected miRNAs were subjected to validation of their expression levels by RT-qPCR using both whole saliva and saliva supernatant samples from an independent set of 39 patients with esophageal cancer and 19 healthy controls.

Results

Six miRNAs (miR-10b*, miR-144, miR-21, miR-451, miR-486-5p, and miR-634) were identified as targets by Agilent microarray. After validation by RT-qPCR, miR-10b*, miR-144, and miR-451 in whole saliva and miR-10b*, miR-144, miR-21, and miR-451 in saliva supernatant were significantly upregulated in patients, with sensitivities of 89.7, 92.3, 84.6, 79.5, 43.6, 89.7, and 51.3% and specificities of 57.9, 47.4, 57.9%, 57.9, 89.5, 47.4, and 84.2%, respectively.

Conclusions

We found distinctive miRNAs for esophageal cancer in both whole saliva and saliva supernatant. These miRNAs possess discriminatory power for detection of esophageal cancer. Because saliva collection is noninvasive and convenient, salivary miRNAs show great promise as biomarkers for detection of esophageal cancer in areas at high risk.

Oesophageal carcinoma

Oesophageal carcinoma affects more than 450,000 people worldwide and the incidence is rapidly increasing. Squamous-cell carcinoma is the predominant form of oesophageal carcinoma worldwide, but a shift in epidemiology has been seen in Australia, the UK, the USA, and some western European countries (eg, Finland, France, and the Netherlands), where the incidence of adenocarcinoma now exceeds that of squamous-cell types. The overall 5-year survival of patients with oesophageal carcinoma ranges from 15% to 25%. Diagnoses made at earlier stages are associated with better outcomes than those made at later stages. In this Seminar we discuss the epidemiology, pathophysiology, diagnosis and staging, management, prevention, and advances in the treatment of oesophageal carcinoma.

Effects of EHD2 interference on migration of esophageal squamous cell carcinoma

C-Terminal EH domain-containing protein 2 (EHD2) of the EHD family is associated with plasma membrane. We investigated the expression of EHD2 in human esophageal squamous cell carcinoma (ESCC) and the EHD2 expression to study the therapeutic effect of chemotherapy drugs. Western blot and immunohistochemistry were used to measure the expression of EHD2 protein in ESCC and adjacent normal tissue in 98 patients. EHD2 protein level was reduced in ESCC tissues in comparison with adjacent normal tissues. Under-expression of EHD2 increased the motility property of ESCC cell TE1 in vitro by wound-healing assays and transwell migration assays, and it was concurrent with the decreased expression of epithelial marker E-cadherin. Under-expression of EHD2 in TE1 can cause resistance to cisplatin. Our results suggested that EHD2 low expression is involved in the pathogenesis of ESCC, and it might be a favorable independent poor prognostic parameter for ESCC.

Serum response factor is overexpressed in esophageal squamous cell carcinoma and promotes Eca-109 cell proliferation and invasion

Recent studies indicate that serum response factor (SRF) is highly expressed in tumors such as hepatocellular, thyroid, esophageal and lung carcinoma. However, the expression and roles of SRF in esophageal squamous cell carcinoma (ESCC) are unclear. In this study, immunohistochemistry was used to compare the expression of SRF in ESCC cases (n=73) and normal controls (n=30). The RNA interference (RNAi) technique was used to knock down the expression of SRF in Eca-109 cells. Cell proliferation, cell cycle stage and invasion were measured with cell counting kit (CCK)-8, flow cytometry and Transwell assays, respectively. Western blotting was used to measure SRF, E-cadherin, β-catenin and cyclin D1 expression in Eca-109 cells treated with siRNA. The study demonstrated that human ESCC has increased expression of SRF. In addition, blocking SRF expression inhibited tumor proliferation and invasion. In conclusion, SRF has the potential to be a new marker for ESCC diagnosis and therapy.

LMP gene promoter hypermethylation is a mechanism for its down regulation in Kazak's esophageal squamous cell carcinomas

Abnormal hypermethylation of CpG islands not only associated with tumor suppressor genes can lead to repression of gene expression, but also contribute to escape of the tumor from immune surveillance and contribute significantly to tumorigenesis. In the present study, we studied the hypermethylation of low molecular-weight protein (LMP) gene and its regulation on protein expression in biopsies from resected tissues from Kazak's esophageal squamous cell carcinoma (ESCC) patients and their neighboring normal tissues. LMP2 and LMP7 genes promoter region methylation sequences were maped in esophageal cancer cell line Eca109 by bisulfite-sequencing PCR and quantitative detection of methylated DNA from 30 pairs of Kazak's ESCC and adjacent normal tissues by MassARRAY (Sequenom, San Diego, CA, USA) and LMP2 and LMP7 protein expression were analyzed with immunohistochemistry. In Eca109, we identified 6 CG sites methylated from all of 22 CpG sites of LMP7 gene. However, no methylation was found for LMP2. The analysis of the data resulted from the quantitative analysis of single CpG site methylation by Sequenom MassARRAY platform, has shown that the methylation level between two groups CpG sites (CpG_5, CpG_9, CpG_20, CpG_21 and CpG_20) from CpG_1, CpG_2, CpG_3, CpG_4, CpG_5, CpG_6, CpG_7, CpG_8, CpG_9, CpG_10.11, CpG_12.13.14, CpG_15.16.17.18, CpG_19, CpG_20, CpG_21 and CpG_22 significant differences between ESCC and neighboring normal tissues. The analysis of methylation level of whole target CpG fragment indicated that the methylation level of LMP7 was significant higher in ESCC (0.0517 ± 0.0357) than in neighboring normal tissues (0.0380 ± 0.0214, P < 0.05). there was a tendency of decreasing the LMP7 proteins expression as the increasing the methylation level of LMP7 gene promoter regions (F = 7.69, P = 0.041). The LMP7 gene promoter methylation and protein downregulation were correlated at high extent in Kazakh's ESCC patients, and may explain the epigenetic regulation on gene expression.

The role of tobacco, alcohol, and obesity in neoplastic progression to esophageal adenocarcinoma: a prospective study of Barrett's esophagus

BACKGROUND

Esophageal adenocarcinoma (EA) incidence in many developed countries has increased dramatically over four decades, while survival remains poor. Persons with Barrett's esophagus (BE), who experience substantially elevated EA risk, are typically followed in surveillance involving periodic endoscopy with biopsies, although few progress to EA. No medical, surgical or lifestyle interventions have been proven to safely lower EA risk.

DESIGN

We investigated whether smoking, obesity or alcohol could predict progression to EA in a prospective cohort of 411 BE patients. Data were collected during personal interview. Adjusted hazard ratios (HR) were estimated using Cox regression.

RESULTS

39% had body mass index (BMI) over 30 and 64% had smoked cigarettes. Main analyses focused on those with at least 5 months of follow-up (33,635 person-months), in whom 45 developed EA. Risk increased by 3% per year of age (trend p-value 0.02), with approximate doubling of risk among males. EA risk increased with smoking pack-years (trend p-value 0.04) and duration (p-value 0.05). Compared to never-smokers, the HR for those in the highest pack-year tertile was 2.29 (95%CI 1.04-5.07). No association was found with alcohol or BMI, whereas a suggestion of increased risk was observed in those with higher waist-hip ratio, especially among males.

CONCLUSION

EA risk significantly increased with increasing age and cigarette exposure. Abdominal obesity, but not BMI, was associated with a modest increased risk. Continued follow-up of this and other cohorts is needed to precisely define these relationships so as to inform risk stratification and preventive interventions.

Expression and significance of vascular endothelial growth factor C from multiple specimen sources in esophageal squamous cell carcinoma

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is a common malignancy with a very poor prognosis. Vascular endothelial growth factor C (VEGF-C) plays an important role in angiogenesis and lymphangiogenesis. This study was designed to analyze the correlation of VEGF-C expression with clinicopathological features and survival in multiple specimen sources from patients with ESCC.

MATERIAL AND METHODS

The expression of VEGF-C in tissues (tVEGF-C), serum (sVEGF-C), and lymph fluid (lVEGF-C) from 48 patients with ESCC was detected by different methods.

RESULTS

There were significant correlations between a high level of tVEGF-C expression and tumor differentiation, tumor depth, lymph node metastasis, TNM stage and metastasis. sVEGF-C was only significantly related to lymph node metastasis, TNM stage and metastasis. The results of lVEGF-C expression were similar to those of tVEGG-C expression, but no relationship to tumor depth was found. High expression levels of tVEGF-C, sVEGF-C and lVEGF-C were significantly associated with shorter overall survival times in univariate analysis (log-rank test).

CONCLUSIONS

The expression of VEGF-C in multiple specimen sources from patients with ESCC was associated with certain clinicopathological parameters. High expression of VEGF-C may be an important factor related to a poor prognosis of ESCC.

The severity of duodeno-esophageal reflux influences the development of different histological types of esophageal cancer in a rat model

The mechanism through which each histological type of carcinoma arises from the esophageal mucosa remains unknown. This study was designed to investigate whether there is an association between the severity of duodeno-esophageal reflux and the histological type of esophageal cancer. A series of 120 male Fischer rats, weighing ∼180 g, were randomized to receive one of the following procedures: duodeno-forestomach reflux (DFR) with reduced exposure to duodenal contents, duodeno-esophageal reflux (DER) with increased exposure to duodenal contents and three control operations (DFR, DER control and sham). The reflux of bile was estimated with (99m)Tc-PMT scintigraphy. All animals were fed a standard diet without carcinogen. The esophageal mucosa was assessed 50 weeks after surgery for carcinoma. The median scanned fraction rate of duodeno-esophageal reflux was significantly lower for the rodents in the DFR group than those in the DER group. Five of 28 rodents in the DFR group and 17 of the 22 rodents in the DER group developed esophageal carcinoma. None of the controls developed carcinoma. The five rodents in the DFR group developed SCC. Of 22 esophageal carcinomas for the DER group, nine were SCC, 12 ADC and one was adenosquamous carcinoma. The fraction of esophageal SCC for the DFR group was significantly higher than that for the DER group, while the fraction of esophageal ADC for the DFR group was significantly lower than that for the DER group. These observations suggest that the severity of duodeno-esophageal reflux in rodents is related to the development of different histological types of esophageal carcinoma.

miR-518b is down-regulated, and involved in cell proliferation and invasion by targeting Rap1b in esophageal squamous cell carcinoma

MicroRNAs (miRNAs) represent a class of small non-coding RNAs that regulate gene expression at the post-transcriptional levels. Recent studies show that miRNAs may function as oncogenes or tumor suppressor genes. In this study, we demonstrated that miR-518b was down-regulated in esophageal squamous cell carcinoma (ESCC) tissues and correlated with metastasis and survival. miR-518b suppressed the proliferation by inducing apoptosis and repressed the invasion in ESCC cells, but had no effect on the cell cycle. Furthermore, Rap1b was revealed to be directly regulated by miR-518b. These findings indicate that miR-518b may function as a tumor suppressor by targeting Rap1b in the development of ESCC and has important clinical and prognostic value.

Cytochrome P450 2E1 RsaI/PstI polymorphism and risk of esophageal cancer: A meta-analysis of 17 case-control studies

The aim of this study was to explore the cytochrome P450 2E1 (CYP2E1) RsaI/PstI polymorphism and risk of esophageal cancer (EC) in mainland Chinese populations. A systematic search of PubMed, EMBASE, Web of Science, CBM, CNKI and VIP databases for publications on the CYP2E1 RsaI/PstI polymorphism and risk of EC was performed. and the genotype data were analyzed in a meta-analysis. Odds ratios (ORs) with relevant 95% confidence intervals (CIs) were estimated to assess the association. Sensitivity analysis, test of heterogeneity and assessment of publication bias were performed. The search yielded 17 studies including 18 trails involving 1,663 cases and 2,603 controls. The meta-analyses showed a significant association between the CYP2E1 RsaI/PstI polymorphism and risk of EC in the mainland Chinese population (c2 vs. c1: OR=0.64; 95% CI, 0.50-0.81; P<0.001; c2/c2 vs. c1/c1: OR=0.73; 95% CI, 0.57-0.93; c2/c2 vs. c1/c1+c1/c2: OR=0.76; 95% CI, 0.60-0.96; P=0.02; c1/c2 vs. c1/c1: OR=0.54; 95% CI, 0.38-0.75; P<0.001; c1/c2+c2/c2 vs. c1/c1: OR=0.48; 95% CI, 0.34-0.70; P<0.001). An increased cancer risk in all genetic models was identified following stratification by ethnicity, source of controls and tumor type. In conclusion, in all genetic models, the association between the CYP2E1 RsaI/PstI polymorphism and risk of EC in the mainland Chinese population was significant. This meta-analysis suggests that the CYP2E1 RsaI/PstI polymorphism is a risk factor for EC, and the c2 allele is a factor that lowers the possibility of EC in the mainland Chinese population and this association did not change due to ethnic differences in genetic backgrounds and the environment.

Overexpression of the DEC1 protein induces senescence in vitro and is related to better survival in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a leading cause of cancer-related death in China and has limited effective therapeutic options except for early surgery, since the underlying molecular mechanism driving its precursor lesions towards invasive ESCC is not fully understood. Cellular senescence is the state of the permanent growth arrest of a cell, and is considered as the initial barrier of tumor development. Human differentiated embryo chondrocyte expressed gene 1 (Dec1) is an important transcription factor that related to senescence. In this study, DEC1 immunohistochemical analysis was performed on tissue microarray blocks constructed from ESCC combined with adjacent precursor tissues of 241 patients. Compared with normal epithelia, DEC1 expression was significantly increased in intraepithelial neoplasia and DEC1 expression was significantly decreased in ESCC in comparison with intraepithelial neoplasia. In vitro, DEC1 overexpression induced cellular senescence, and it inhibited cell growth and colony formation in ESCC cell line EC9706. Fresh esophagectomy tissue sections from five ESCC patients were detected by immunohistochemistry of DEC1 and senescence-associated β-galactosidase (SA-β-Gal) activity, and strongly positive expression of DEC1 was correlated to more senescent cells in these fresh tissue sections. Kaplan – Meier method analysis of the 241 patients revealed that DEC1 expression levels were significantly correlated with the survival of ESCC patients after surgery. The expression levels of DEC1 were also correlated with age, tumor embolus, depth of invasion of ESCC, lymph metastasis status and pTNMs. These results suggest that DEC1 overexpression in precursor lesions of ESCC is a protective mechanism by inducing cellular senescence in ESCC initiation, and DEC1 may be a potential prognostic marker of ESCC.

Role of NQO1 609C>T and NQO2 -3423G>A gene polymorphisms in esophageal cancer risk in Kashmir valley and meta analysis

Esophageal cancer (EC) is a complex multifactorial disorder, where environmental and genetic factors play major role. NADPH:quinone oxidoreductase 1 (NQO1) and NRH:quinone oxidoreductase 2 (NQO2) are phase II cytosolic enzymes that catalyze metabolism of quinones, important in the detoxification of environmental carcinogens. A case-control study was performed to investigated the associations of NQO1 609C>T and NQO2 -3423G>A polymorphisms with susceptibility to EC in a high-risk Kashmiri population of India in 135 EC patients and 195 unrelated healthy controls using PCR-RFLP. We also performed a meta analysis of nine published studies (1,224 cases and 1,740 controls) on NQO1 609C>T and evaluated the association between the NQO1 609C>T polymorphisms and esophageal cancer risk. A significant difference in NQO1 609C>T and NQO2 -3423G>A genotype distribution between EC cases and corresponding controls groups was observed (OR = 2.65; 95 % CI = 1.29-5.42 and OR = 1.88; 95 % CI = 1.02-3.49 respectively). Further, gene-gene interaction showed significantly increased risk for esophageal adenocarcinoma with variant genotypes of NQO1 609C>T and NQO2 -3423G>A polymorphisms and interaction with environmental risk factors revealed pronounced risk of EC with NQO1 609C>T TT genotype in high salted tea users of Kashmir valley (OR = 3.72, 95 % CI = 0.98-14.19). Meta analysis of NQO 609C>T polymorphism also suggested association of the polymorphism with EC in Asians as well as Europeans. In conclusion, NQO1 609C>T and NQO2 -3423G>A genetic variations modulate risk of EC in high-risk Kashmir population.

Locally advanced cancer of the esophagus, current treatment strategies, and future directions

For patients with locally advanced esophageal cancer no clear standard of care exists. Notwithstanding several negative phase III studies the data provide support for so-called trimodality treatment and this is probably the most common approach. Even the role of surgery has been questioned. These alternative approaches are set against a changing epidemiological background whereby adenocarcinoma has become the predominant tumor type, at least in the western world. In recent times an emphasis has been placed on the better selection of patients, predominantly based on data that shows a markedly improved survival in those who exhibit a response to neo-adjuvant therapy. In this article we review the major studies and discuss new approaches to the management of patients with locally advanced cancer of the esophagus.

Promoter methylation of tumor suppressor genes in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is a prevalent and fatal cancer in China and other Asian countries. Epigenetic silencing of key tumor suppressor genes (TSGs) is critical to ESCC initiation and progression. Recently, many novel TSGs silenced by promoter methylation have been identified in ESCC, and these genes further serve as potential tumor markers for high-risk group stratification, early detection, and prognosis prediction. This review summarizes recent discoveries on aberrant promoter methylation of TSGs in ESCC, providing better understanding of the role of disrupted epigenetic regulation in tumorigenesis and insight into diagnostic and prognostic biomarkers for this malignancy.

Reelin is involved in transforming growth factor-β1-induced cell migration in esophageal carcinoma cells

Reelin (RELN), which is a glycoprotein secreted by Cajal-Retzius cells of the developing cerebral cortex, plays an important role in neuronal migration, but its role in cell migration and cancer metastasis is largely unclear. Here, we showed that cell motility was significantly increased in KYSE-510 cells by TGF-β1 treatment. Moreover, TGF-β1 decreased RELN mRNA expression and overexpression of Reelin at least partly reversed TGF-β1-induced cell migration in KYSE-30 cells. Furthermore, this negative regulation of Reelin expression by TGF-β1 was through Snail, one transcription factor which was induced by TGF-β1 in KYSE-510 cells. RELN promoter activity was reduced in parallel with the induction of Snail after TGF-β1 treatment and Snail suppressed both RELN promoter activity and expression through binding to E-box sequences in the RELN promoter region in ESCC cells. Knockdown of RELN induced cell migration in KYSE-510 cells, together with the increase of mesenchymal markers expression. Taken together, Reelin is an essential negative regulator in the TGF-β1-induced cell migration process, and is suppressed by TGF-β pathway at the transcriptional level through Snail regulation. Therefore, the correlation of Reelin and TGF-β pathway was critical in cancer metastasis, and Reelin could be one potential anti-metastasis target in future clinical practice.

The Anyang Esophageal Cancer Cohort Study: study design, implementation of fieldwork, and use of computer-aided survey system

Background

Human papillomavirus (HPV) has been observed repeatedly in esophageal squamous cell carcinoma (ESCC) tissues. However, the causal relationship between HPV infection and the onset of ESCC remains unknown. A large cohort study focusing on this topic is being carried out in rural Anyang, China.

Methodology/Principal Findings

The Anyang Esophageal Cancer Cohort Study (AECCS) is a population-based prospective endoscopic cohort study designed to investigate the association of HPV infection and ESCC. This paper provides information regarding the design and implementation of this study. In particular we describe the recruitment strategies and quality control procedures which have been put into place, and the custom designed computer-aided survey system (CASS) used for this project. This system integrates barcode technology and unique identification numbers, and has been developed to facilitate real-time data management throughout the workflow using a wireless local area network. A total of 8,112 (75.3%) of invited subjects participated in the baseline endoscopic examination; of those invited two years later to take part in the first cycle of follow-up, 91.9% have complied.

Conclusions/Significance

The AECCS study has high potential for evaluating the causal relationship between HPV infection and the occurrence of ESCC. The experience in setting up the AECCS may be beneficial for others planning to initiate similar epidemiological studies in developing countries.

Areca users in combination with tobacco and alcohol use are associated with younger age of diagnosed esophageal cancer in Taiwanese men

BACKGROUND

Whether the habitual use of substances (tobacco, alcohol, or areca nut (seed of the Areca palm)) can affect the age of esophageal squamous cell carcinoma (ESCC) presentation has rarely been examined.

METHODS

The study subjects were those who were males and the first time to be diagnosed as ESCC (ICD-9 150) and who visited any of three medical centers in Taiwan between 2000 and 2009. A standardized questionnaire was used to collect substance uses and other variables.

RESULTS

Mean age (±SD) at presentation of ESCC was 59.2 (±11.3) years in a total of 668 cases. After adjusting for other covariates, alcohol drinkers were 3.58 years younger to have ESCC than non-drinkers (p = 0.002). A similar result was found among areca chewers, who were 6.34 years younger to have ESCC than non-chewers (p<0.0001), but not among cigarette smokers (p = 0.10). When compared to the group using 0-1 substances, subjects using both cigarettes and alcohol were nearly 3 years younger to contract ESCC. Furthermore, those who use areca plus another substance were 7-8 years younger. Subjects using all three substances had the greatest age difference, 9.20 years younger (p<0.0001), compared to the comparison group.

CONCLUSION

Our findings suggest that habitually consuming tobacco, alcohol, and areca nut can influence the age-onset of ESCC. Since the development of ESCC is insidious and life-threatening, our observation is worthy to be reconfirmed in the large-scale and long-term follow-up prospective cohort studies to recommend the screening strategy of this disease.

Role of Smac in determining the chemotherapeutic response of esophageal squamous cell carcinoma

PURPOSE

Second mitochondria-derived activator of caspase (Smac) regulates chemotherapy-induced apoptosis. Smac mimetics have been tested in clinical trials as chemosensitizers. We determined the role of Smac in modulating the chemosensitivity of esophageal squamous cell carcinoma (ESCC).

EXPERIMENTAL DESIGN

Smac expression was evaluated in tissues from ESCC patients with differential chemotherapeutic responses. The effects of Smac knockdown and Smac mimetics on the chemosensitivity of ESCC cells and the molecular mechanisms by which Smac and Smac mimetics modulate chemosensitivity were determined. The therapeutic responses of ESCC cells with different Smac statuses were compared using xenograft models.

RESULTS

We found that Smac was significantly downregulated in most ESCC samples (36.8%, 25/68, P = 0.001), and Smac expression differed significantly (P < 0.05) between chemosensitive and chemoresistant tumors. The associations of tested factors and their responses were examined using logistic regression analysis. In ESCC cells treated with cisplatin, a common chemotherapeutic drug, Smac and cytochrome c were released from mitochondria, and caspase-3 and caspase-9 were activated. Knockdown of Smac abrogated cisplatin-induced apoptosis, mitochondrial dysfunction, cytochrome c release, and caspase activation. Smac deficiency also reduced the effect of cisplatin on long-term cell viability, and led to cisplatin resistance in xenograft tumors in vivo. LBW242, a small molecule Smac mimetic, enhanced cisplatin-induced apoptosis and caspase activation and restored cisplatin sensitivity in Smac-deficient cells.

CONCLUSION

Our data suggested that downregulation of Smac may be a chemoresistance mechanism in ESCC. Combinations of Smac mimetics with chemotherapeutic agents may have therapeutic benefits for the treatment of esophageal cancer.

Clinicopathological pattern and Annexin A2 and Cdc42 status in patients presenting with differentiation and lymphnode metastasis of esophageal squamous cell carcinomas

Annexin A2 and Cdc42 were identified by 2-dimensional electrophoresis (2-DE) and MALDI-TOF-MS between esophageal squamous cell carcinomas (ESCC) and corresponding normal esophagus mucosa in our previous study. To assess clinico-pathological pattern and Annexin A2 and Cdc42 status with respect to cell differentiation and lymphnode metastasis in patients with ESCC. The expression of Annexin A2 and Cdc42 in 22 pairs of fresh ESCC and matched tissues were detected by qRT-PCR and western blot, respectively. And it was further confirmed by immunohistochemistry with 175 pairs of formalin-fixed, paraffin-embedded ESCC. Results showed that Annexin A2 expression was significantly down-regulated, and Cdc42 was up-regulated in ESCC compared to matched control on both mRNA and protein level (P < 0.05), which was in accordance with our previous results on proteomics data. Additionally, Annexin A2 and Cdc42 expression was significantly correlated with lymphoid node metastasis (P < 0.05) and pathological differentiation (P < 0.05). Taken together, we proposed that the aberrant expression of Annexin A2 and Cdc42 played a role in carcinogenesis, differentiation and metastasis of ESCC, which implied its potential target for clinical biomarkers in differentiation and lymph node metastasis.

Chemotherapy followed by surgery versus surgery alone in patients with resectable oesophageal squamous cell carcinoma: long-term results of a randomized controlled trial

Background

This is a randomized, controlled trial of preoperative chemotherapy in patients undergoing surgery for oesophageal squamous cell carcinoma (OSCC). Patients were allocated to chemotherapy, consisting of 2-4 cycles of cisplatin and etoposide, followed by surgery (CS group) or surgery alone (S group). Initial results reported only in abstract form in 1997, demonstrated an advantage for overall survival in the CS group. The results of this trial have been updated and discussed in the timeframe in which this study was performed.

Methods

This trial recruited 169 patients with OSCC, 85 patients assigned to preoperative chemotherapy and 84 patients underwent immediate surgery. The primary study endpoint was overall survival (OS), secondary endpoints were disease free survival (DFS) and pattern of failure. Survival has been determined from Kaplan-Meier curves and treatment comparisons made with the log-rank test.

Results

There were 148 deaths, 71 in the CS and 77 in the S group. Median OS time was 16 months in the CS group compared with 12 months in the S group; 2-year survival rates were 42% and 30%; and 5-year survival rates were 26% and 17%, respectively. Intention to treat analysis showed a significant overall survival benefit for patients in the CS group (P = 0.03, by the log-rank test; hazard ratio [HR] 0.71; 95%CI 0.51-0.98). DFS (from landmark time of 6 months after date of randomisation) was also better in the CS-group than in the S group (P = 0.02, by the log-rank test; HR 0.72; 95%CI 0.52-1.0). No difference in failure pattern was observed between both treatment arms.

Conclusions

Preoperative chemotherapy with a combination of etoposide and cisplatin significantly improved overall survival in patients with OSCC.

Overcoming challenges in implementing a minimally invasive esophagectomy program at a Veterans Administration medical center

BACKGROUND

Minimally invasive esophagectomy (MIE) is a technically demanding procedure that requires expertise in laparoscopy and esophageal surgery. The authors hypothesized that the safe and effective development of such a program could be performed at a Veterans Administration health care system using existing faculty members.

METHODS

Length of stay, operative factors, and morbidity and mortality of patients undergoing MIE from December 2007 to August 2009 were reviewed.

RESULTS

Eighteen consecutive patients underwent planned MIE. They were all men, with a median age of 60 years (range, 43-69 years) and a median American Society of Anesthesiologists score of 3. Eighty-three percent were able to undergo MIE resection. Eighty-nine percent of patients received neoadjuvant therapy. The median operative duration was 420 minutes (range, 300-480 minutes). There was 1 death within 30 days because of a pulmonary embolus and 1 anastomotic leak. Three patients had postoperative pneumonias. The median and mean length of stay were 10 and 13 days, respectively (range, 6-50 days). Negative margins were achieved in all patients. The mean number of lymph nodes resected was 15 (range, 6-30).

CONCLUSIONS

The development of an MIE program is feasible at a Veterans Administration hospital when combining the expertise of minimally invasive and esophageal surgeons.

Targeting the cell cycle in esophageal adenocarcinoma: An adjunct to anticancer treatment

Esophageal adenocarcinoma is a major cause of cancer death in men in the developed world. Continuing poor outcomes with conventional therapies that predominantly target apoptosis pathways have lead to increasing interest in treatments that target the cell cycle. A large international effort has led to the development of a large number of inhibitors, which target cell cycle kinases, including cyclin-dependent kinases, Aurora kinases and polo-like kinase. Initial phase I/II trials in solid tumors have often demonstrated only modest clinical benefits of monotherapy. This may relate in part to a failure to identify the patient populations that will gain the most clinical benefit. Newer compounds lacking the side effect profile of first-generation compounds may show utility as adjunctive treatments targeted to an individual’s predicted response to treatment.

Infection and integration of human papillomavirus in esophageal carcinoma

Infection with human papillomavirus (HPV) could be a suspected or potential modifiable risk factor in esophageal carcinoma (EC) but findings have not been consistent. We therefore investigated the epidemiology of HPV infection and integration in the pathogenesis of esophageal carcinoma (EC) in the Shantou region, China. This was a retrospective study involving nested PCR to evaluate HPV presence, HPV genotyping, and analyzing HPV-16 integration status in esophageal tumor tissues (n=106) and paired tumor-adjacent normal tissues, as well as normal esophagus tissue from control subjects (n=100). The detection rates of HPV DNA in EC and tumor-adjacent tissue were significantly higher than that in normal controls (77.4% and 80.2% vs. 33.0%). HPV infection was mainly found in adults, ages 35-47 years old, and the infection rate was negatively associated with the age of EC patients (P-trend<0.05). In addition, the HPV infection rates in patients who smoked was 3.27 times higher than in non-smoking patients (84.9% vs. 67.4%, P<0.05) but was not associated with gender, alcohol consumption, tumor grade or lymph-node metastasis of EC patients. The distribution of HPV genotypes in patients from high to low proportion was HPV-16, -58, -18, -33, -31 and -11. Infection with multiple HPV genotypes mainly included HPV-16/-18 and HPV-16/-33. The integration rate of HPV-16 in EC tissue was higher than that in tumor-adjacent and control tissues (93.4% vs. 50.9% and 45.5%). Our findings indicate that infection with HPV, especially the high-risk HPV, and their integration suggest an association in malignant transformation of EC in the high-incidence EC region in Shantou, China.

Cigarette smoking, cyclooxygenase-2 pathway and cancer

Cigarette smoking is a major cause of mortality and morbidity worldwide. Cyclooxygenase (COX) and its derived prostanoids, mainly including prostaglandin E2 (PGE2), thromboxane A2 (TxA2) and prostacyclin (PGI2), have well-known roles in cardiovascular disease and cancer, both of which are associated with cigarette smoking. This article is focused on the role of COX-2 pathway in smoke-related pathologies and cancer. Cigarette smoke exposure can induce COX-2 expression and activity, increase PGE2 and TxA2 release, and lead to an imbalance in PGI2 and TxA2 production in favor of the latter. It exerts pro-inflammatory effects in a PGE2-dependent manner, which contributes to carcinogenesis and tumor progression. TxA2 mediates other diverse biologic effects of cigarette smoking, such as platelet activation, cell contraction and angiogenesis, which may facilitate tumor growth and metastasis in smokers. Among cigarette smoke components, nicotine and its derived nitrosamines 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) are the most potent carcinogens. COX-2 and PGE2 have been shown to play a pivotal role in many cancers associated with cigarette smoking, including cancers of lung, gastric and bladder, while the information for the role of TxA2 and PGI2 in smoke-associated cancers is limited. Recent findings from our group have revealed how NNK influences the TxA2 to promote the tumor growth. Better understanding in the above areas may help to generate new therapeutic protocols or to optimize the existing treatment strategy.

Role of survivin gene promoter polymorphism (-31G>C) in susceptibility and survival of esophageal cancer in northern India

BACKGROUND AND AIM

Survivin is an upregulated inhibitor of apoptosis protein in esophageal cancer (EC), and a promoter region polymorphism (-31G>C) in the survivin gene has been reported as a modulator of gene expression. We aim to explore the role of survivin -31G>C polymorphism in susceptibility and survival of EC patients in northern Indian population.

MATERIALS AND METHODS

A case-control study was performed in 500 subjects (250 EC patients and 250 controls), and genotyping was done by polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) method.

RESULTS

Survivin CC genotype was found to be significantly associated with EC susceptibility [odds ratio (OR) = 2.29; 95% confidence interval (CI) = 1.27-4.14; P = 0.006], particularly in males (OR = 4.91; 95% CI = 2.19-11.02; P = 0.0001) having squamous cell carcinoma (SCC) histopathology (OR = 2.4; 95% CI = 1.36-4.21; P = 0.002) at middle third esophagus location (OR = 2.60; 95% CI = 1.40-4.82; P = 0.002). Patients carrying CC genotype were found to have higher susceptibility to lymph node metastasis (OR = 2.82; 95% CI = 1.46-5.48; P = 0.002). However, on survival analysis, no prognostic role of survivin -31G>C polymorphism was detected. In case-only analysis, no gene-environment interaction was observed.

CONCLUSION

Survivin promoter region polymorphism (-31G>C) is associated with susceptibility and clinical characteristics but not prognosis of esophageal cancer in northern Indian population.

Northwestern China: a place to learn more on oesophageal cancer. Part one: behavioural and environmental risk factors

Oesophageal squamous cell carcinoma (OSCC) remains a public health problem in many countries, especially in emerging and developing countries. Epidemiology of OSCC is characterized by marked differences in prevalence between countries/regions/ethnical groups. The highest incidence in the world is reached by populations living in specific areas of northwestern Xinjiang, China where age-adjusted mortality may reach 150 of 100 000. In fact, there are also marked differences among the various geographical areas and the various ethnic groups within the region, which suggests specific risk factors. Behavioural factors include those factors which are common to all 'high-risk populations', such as tobacco smoking and alcohol drinking. However, the very unusual sex ratio (1.2 : 1.0) and young age range of OSCC occurrence suggests the involvement of additional early risk factors shared by males and females, and which are different from those studied in other 'high-risk' areas of the world, including China, such as LinXian area. These include drinking very hot and salted tea, boiled with milk; a diet rich in meat, especially salted, dry and/or smoked meat, and dairy products; and a diet poor in fresh fruit and vegetables. The combination of hot drinks (such as milk, tea and soups) and high-degree spirit drinks, and hard food (bread, meat and cheese), together with poor oral hygiene and tooth loss, is likely to add mechanical injury of the oesophagus to other factors linked to climate characteristics of the area (drought) and dietary habits, which promote a sodium and nitrosamine-rich diet. Association of early and severe hypertension in the same populations at high risk of OSCC might likely raise more attention. Human papilloma virus (HPV) infection, and especially HPV 16/18 E6/E7, with gene mutations and association with p53 overexpression, may contribute to the extremely high incidence of OSCC observed in Xinjiang, and could be accessible to prevention. Infection may especially be a crucial additional factor in the Uygur population in which not only HPV infection but also infection with other oncogenic viruses, such as HHV8, are highly prevalent. Genetic polymorphism might interact with viruses and/or viral products to promote carcinogenesis. These observations in northwestern China suggest that usually neglected factors, such as sodium excess and viral infection, could be taken into more account when studying OSCC risk factors in other parts of the world, especially Europe.

DNA polymorphism and risk of esophageal squamous cell carcinoma in a population of North Xinjiang, China

AIM: To investigate the role of metabolic enzyme and DNA repair genes in susceptibility of esophageal squamous cell carcinoma (ESCC).

METHODS: A case-control study was designed with 454 samples from 128 ESCC patients and 326 gender, age and ethnicity-matched control subjects. Genotypes of 69 single nucleotide polymorphisms (SNPs) of metabolic enzyme (aldehyde dehydrogenase-2, ALDH2; alcohol dehydrogenase-1 B, ADHB1; Cytochrome P450 2A6, CYP2A6) and DNA repair capacity genes (excision repair cross complementing group 1, ERCC1; O⁶-methylguanine DNA methyltransferase, MGMT; xeroderma pigmentosum group A, XPA; xeroderma pigmentosum group A, XPD) were determined by the Sequenom MassARRAY system, and results were analyzed using unconditional logistic regression adjusted for age, gender.

RESULTS: There was no association between the variation in the ERCC1, XPA, ADHB1 genes and ESCC risk. Increased risk of ESCC was suggested in ALDH2 for frequency of presence C allele of SNP [Rs886205: 1.626 (1.158-2.284)], XPD for C allele [Rs50872: 1.482 (1.058-2.074)], and MGMT for A allele [Rs11016897: 1.666 (1.245-2.228)]. Five variants of MGMT were associated with a protective effect on ESCC carcinogenesis, including C allele [Rs7069143: 0.698 (0.518-0.939)], C allele [Rs3793909: 0.653 (0.429-0.995)], A allele [Rs12771882: 0.719 (0.524-0.986)], C allele [Rs551491: 0.707 (0.529-0.945)], and A allele [Rs7071825: 0.618 (0.506-0.910)]. At the genotype level, increased risk of ESCC carcinogenesis was found in homozygous carriers of the ALDH2 Rs886205 [CC vs TT, odds ratios (OR): 3.116, 95% CI: 1.179-8.234], MGMT Rs11016879 (AA vs GG, OR: 3.112, 95% CI: 1.565-6.181), Rs12771882 (AA vs GG, OR: 2.442, 95% CI: 1.204-4.595), and heterozygotes carriers of the ALDH2 Rs886205 (CT vs TT, OR: 3.930, 95% CI: 1.470-10.504), MGMT Rs11016879 (AG vs GG, OR: 3.933, 95% CI: 2.216-6.982) and Rs7075748 (CT vs CC, OR: 1.949, 95% CI: 1.134-3.350), respectively. Three variants were associated with a protective effect on ESCC carcinogenesis, carriers of the MGMT Rs11016878 (AG vs AA, OR: 0.388, 95% CI: 0.180-0.836), Rs7069143(CT vs CC, OR: 0.478, 95% CI: 0.303-0.754) and Rs7071825 (GG vs AA, OR: 0.493, 95% CI: 0.266-0.915). Increased risk of ESCC metastasis was indicated in MGMT for frequency of presence C allele [Rs7068306: 2.204 (1.244-3.906)], A allele [Rs10734088: 1.968 (1.111-3.484)] and C allele [Rs4751115: 2.178 (1.251-3.791)]. Two variants in frequency of presence C allele of CYP2A6 [Rs8192720: 0.290 (0.099-0.855)] and A allele of MGMT [Rs2053139: 0.511 (0.289-0.903)] were associated with a protective effect on ESCC progression. Increased risk of ESCC metastasis was found in heterozygote carriers of the MGMT Rs7068306 (CG vs CC, OR: 4.706, 95% CI: 1.872-11.833).

CONCLUSION: Polymorphic variation in ALDH2, XPD and MGMT genes may be of importance for ESCC susceptibility. Polymorphic variation in CYP2A6 and MGMT are associated with ESCC metastasis.

Minimally invasive surgery and cancer: controversies part 1

Perhaps there is no more important issue in the care of surgical patients than the appropriate use of minimally invasive surgery (MIS) for patients with cancer. Important advances in surgical technique have an impact on early perioperative morbidity, length of hospital stay, pain management, and quality of life issues, as clearly proved with MIS. However, for oncology patients, historically, the most important clinical questions have been answered in the context of prospective randomized trials. Important considerations for MIS and cancer have been addressed, such as what are the important immunologic consequences of MIS versus open surgery and what is the role of laparoscopy in the staging of gastrointestinal cancers? This review article discusses many of the key controversies in the minimally invasive treatment of cancer using the pro-con debate format.

Pharmacokinetics and pharmacogenomics in esophageal cancer chemoradiotherapy

Esophageal cancer is one of the most lethal malignancies. Surgical resection of the tumor from the primary site has been the standard treatment, especially for localized squamous cell carcinoma, but considerable clinical efforts during the last decade have resulted in novel courses of treatment. These options include chemoradiotherapy, consisting of a continuous infusion of 5-fluorouracil (5-FU), cisplatin (CDDP), and concurrent radiation. Given the substantial inter- and/or intra-individual variation in clinical outcome, future improvements will likely require the incorporation of a novel anticancer drug, pharmacokinetically guided administration of CDDP or 5-FU, and identification of potential responders by patient genetic profiling prior to treatment. In this review, the latest information on incidence, risk factors, biomarkers, therapeutic strategies, and the pharmacokinetically guided or genotype-guided administration of CDDP and 5-FU is summarized for future individualization of esophageal cancer treatment.

[Risk factors for esophageal cancer, and possible genetic background]

Esophageal cancer is the sixth most common cancer mortality, with increasing incidence. 95% of the esophageal cancer is squamous cell carcinoma or adenocarcinoma. Although they differ in histology and epidemiology, some of their risk factors (smoking, dietary factors) and their pathogenesis are the same. More than 90% of esophageal cancer is diagnosed in late stage. Despite the development of diagnostic and therapeutic techniques, esophageal cancer has poor prognosis, with 5-year survival rates between 10-13%. Understanding the exact pathogenesis can help the prevention of this highly aggressive cancer, with the use of natural substances and nonsteroid inflammatory drugs.

The alcohol flushing response: an unrecognized risk factor for esophageal cancer from alcohol consumption

Philip Brooks and colleagues discuss evidence linking the alcohol flushing response (predominantly due to ALDH2 deficiency) with a much higher risk of esophageal cancer from alcohol consumption.