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Esophageal cancer (EC), mainly consisting of squamous cell carcinoma (ESCC) in the Eastern world and adenocarcinoma (EAC) in the Western world, is strongly associated with dietary factors such as alcohol use. We aimed to clarify the modifying role in EC etiology in Caucasians of functional genotypes in alcohol-metabolizing enzymes. In all, 351 Caucasian patients with EC and 430 matched controls were included and polymorphisms in CYP2E1, ADH and near ALDH2 genes were determined. In contrast to the results on ESCC in mainly Asian studies, we found that functional genotypes of alcohol-metabolizing enzymes were not significantly associated with EAC or ESCC in an European population.

Susceptibility to esophageal carcinoma (EC) is influenced by the interaction between genetic and environmental factors. To clarify the etiology of EC, several genome-wide association studies have identified single nucleotide polymorphisms (SNPs) in PCLE1 and RFT2 genes as esophageal squamous cell carcinoma (ESCC) susceptibility loci in Asian populations. This study aimed to determine whether these SNPs also modify the risk of esophageal adenocarcinoma (EAC) and ESCC in western populations of Caucasian ethnicity. A European case-control study including 349 EC patients and 580 controls matched for age, sex, geographical location, and race was carried out. The SNPs rs2274223 in the PCLE1 gene at chromosome 10q23 and rs13042395 in the RFT2 gene at chromosome 20p13 were determined using PCR. Genotype distributions were compared between patients and controls, and odds ratios with 95% confidence intervals were calculated. The total EC group included 86 patients with ESCC and 258 patients with EAC. The distribution of PLCE1 and RFT2 genotypes did not differ between patients with EAC or ESSC, and the controls. In contrast to the modulation of the risk of ESCC in Asians, it is unlikely that the PLCE1 rs2274223 and RFT2 13042395 SNPs play a role in EAC or ESCC susceptibility in Dutch Caucasians.

Background: Identifying and monitoring high-risk patients can aid the prevention of esophageal cancer (EC). The interaction of environmental risk factor exposure and genetic susceptibility may contribute to the etiology of EC. Biotransformation enzymes such as Glutathione S-Transferases (GSTs ) detoxify mutagenic and genotoxic compounds and therefore control the rate of detoxification of carcinogens. Functional polymorphisms in the genes coding for GSTs alter their enzyme activity in vitro, and were reported to modify EC risk in Asians. We hypothesized that altered enzyme activity GST genotypes influence the susceptibility for esophageal adeno- (EAC) and squamous cell carcinoma (ESCC) in Caucasians., Methods: We performed a case-control study including 440 Caucasian patients with EC and 592 healthy Caucasian controls matched for age and sex. Functional polymorphisms were selected and genotypes were determined in GST classes Alpha, Mu, Theta and Pi by means of polymerase chain reaction. Genotypes were classified into predicted high, intermediate and low enzyme activity categories based on in vitro activity data. The distribution of the activity genotypes were compared between patients with EAC or ESCC, and controls. Odds ratios (OR) with 95% confidence intervals (CI) were calculated by logistic regression analyses. Gene-gene interactions were tested and for comparison purposes, the predicted low and intermediate activity genotypes were combined. Genotypes with similar risks for EAC or ESCC were combined and analyzed for multiplicative effects., Results: Our analyses includes 327 patients with EAC and 106 patients with ESCC. Low or intermediate activity enzyme genotypes for GSTM1, GSTA1, GSTP1 I105V and A114V as well as for GSTT1, did not significantly modify the risk for ESCC or EAC in our Dutch population., Conclusion: Functional genotypes in GST genes are not involved in EAC or ESCC susceptibility in Caucasians, in contrast to results on ESCC from Asia or Africa.

Esophageal cancer (EC) has a globally increasing incidence with poor curative treatment options and survival rates. Environmental and dietary factors have crucial roles in esophageal carcinogenesis. Polymorphisms in the UGT genes, a superfamily of enzymes essential for the detoxification of carcinogens, may alter enzyme activity and subsequently may play a role in EC etiology. Rather than solely establishing differences in genotype distribution, we investigated whether functional polymorphisms in UGT genes that can predict enzyme activity in vivo, may influence EC risk. A case-control study including 351 Caucasian EC patients and 592 Caucasian controls was conducted and polymorphisms in seven UGT genes were determined, using the polymerase chain reaction. On the basis of allelic in vitro enzyme activity measurements, genotypes were categorized according to their predicted in vivo enzyme activity into high, medium and low categories. Predicted enzyme activity groups were combined and compared between patients and controls. The UGT1A1 and UGT1A8 predicted high enzyme activity genotypes were significantly more (OR=1.62; 95% CI, 1.02-2.56) and less frequent (OR=0.36; 95% CI, 0.15-0.84) among patients with esophageal squamous cell carcinoma (ESCC), respectively. High (OR=0.42; 95% CI, 0.22-0.84) and medium (OR=0.25; 95% CI, 0.12-0.52) activity UGT2B4 genotypes were significantly less often present in ESCC patients. No association was detected between UGT genotypes and esophageal adenocarcinoma (EAC) risk. Polymorphisms in UGT genes, resulting in altered enzyme activity genotypes, do not seem modifiers of EAC risk. However, the predicted high activity UGT1A1 genotype, associated with low serum levels of the antioxidant bilirubin, was associated with an increased ESCC risk. The UGT1A8 and UGT2B4 genotypes associated with decreased predicted enzyme activities, were significantly associated with an increased risk of ESCC, probably by a decreased detoxification of carcinogens.

Esophageal cancer (EC) has a globally increasing incidence with poor curative treatment options and survival rates. Crucial risk factors are exposure to toxins or carcinogens. Microsomal epoxide hydrolase (mEH) is a biotransformation enzyme essential for the detoxification of xenobiotics. Polymorphisms in exon 3 and exon 4 of the microsomal epoxide hydrolase gene (EPHX1) modify catalytic activity of this enzyme and subsequently may play a role in EC etiology. This case-control study investigated whether these polymorphisms in the EPHX1 gene influence esophageal cancer susceptibility in a Dutch Caucasian population. A case-control study including 349 Caucasian EC patients and 581 Caucasian healthy controls was conducted and the polymorphisms Tyr113His (exon 3) and His139Arg (exon 4) in the EPHX1 gene were determined, using polymerase chain reaction. The distribution of exon 3 and exon 4 genotypes were compared between cases and controls. Analyses included a stratification according to tumor histology; esophageal adenocarcinoma (EAC) or squamous cell carcinoma (ESCC). Furthermore, on the basis of allelic in vitro enzyme activity assays, exon 3 and 4 genotypes were combined and categorized according to their predicted high, medium or low enzyme activity. Homozygosity and heterozygosity for both exon 3 and 4 polymorphisms were correlated with a decreased esophageal squamous cell carcinoma risk. Heterozygosity and homozygosity for both polymorphisms correlated with an increased and a decreased esophageal adenocarcinoma risk, respectively. Predicted intermediate and high activity genotypes were risk and protective factors for esophageal squamous cell carcinoma and esophageal adenocarcinoma, respectively. However, none of these associations were statistically significant. In conclusion, the polymorphisms in exon 3 and exon 4 of the EPHX1 gene do not seem to be modifiers of esophageal squamous cell carcinoma or esophageal adenocarcinoma risk in Dutch Caucasians.

Aim: To determine whether -1195 A-->G and/or -765 G-->C polymorphisms in Cyclooxygenase-2 (COX-2) may have a risk modifying effect on the development of esophageal carcinoma in a Dutch Caucasian population., Methods: Two study groups were recruited, 252 patients with esophageal carcinoma and 240 healthy controls, matched for race, age, gender and recruiting area. DNA was isolated from whole blood and used for genotyping. PCR products were digested with restriction enzymes and products were analyzed by agarose gel electrophoresis. Odds ratios (OR) and 95% confidence intervals (CI) were estimated., Results: The distribution of the -1195 A-->G polymorphism was significantly different in esophageal cancer patients compared to controls. The -1195 GG genotype resulted in a higher risk of developing esophageal adenocarcinoma (OR = 3.85, 95% CI: 1.45-10.3) compared with the -1195 AA genotype as a reference. The -765 G-->C genotype distribution was not different between the two groups. The GG/GG haplotype was present more often in esophageal adenocarcinoma patients than in controls (OR = 3.45, 95% CI: 1.24-9.58; with AG/AG as a reference). The same trends were observed in patients with squamous cell carcinomas, however, the results did not reach statistical significance., Conclusion: Presence of the COX-2 -1195 GG genotype and of the GG/GG haplotype may result in a higher risk of developing esophageal carcinoma.