This study represents a multiplex cytokine analysis of serum from a 10-month randomized, controlled trial of 238 subjects that investigated the effects of selenomethionine and/or celecoxib in subjects with mild or moderate esophageal squamous dysplasia. The original chemoprevention study found that among those with mild dysplasia, selenomethionine treatment favorably altered dysplasia grade. The current analysis found that selenomethionine down-regulated IL-2 by 9% (p=0.04), while celecoxib down-regulated IL-7 by 11% (p=0.006) and up-regulated IL-13 by 17% (p=0.008). In addition, an increase in IL-7 tertile from baseline to t10 was significantly associated with an increase in dysplasia grade, both overall (OR=1.47, p=0.03) and among those with mild dysplasia at t0 (OR=2.53 p=0.001). An increase in IL-2 tertile from baseline to t10 was also non-significantly associated with worsening dysplasia for all participants (OR=1.32 p=0.098), and significantly associated with worsening dysplasia among those with mild dysplasia at baseline (OR=2.0 p=0.01). The association of increased IL-2 with worsening dysplasia remained significant in those on selenomethionine treatment who began the trial with mild dysplasia (OR=2.52 p=0.03). The current study shows that selenomethionine supplementation decreased serum IL-2 levels, while celecoxib treatment decreased IL-7 levels and increased IL-13 levels during a 10 month randomized chemoprevention trial. An increase in IL-2 or IL-7 was associated with increased severity of dysplasia over the course of the trial, especially in those who began the trial with mild dysplasia. The favorable effect of selenomethionine on esophageal dysplasia in the original trial may have been mediated in part by its effect on reducing levels of IL-2.

Background

Polycyclic aromatic hydrocarbon (PAH) exposure is a risk factor for esophageal squamous cell carcinoma (ESCC), and PAHs are ligands of the aryl hydrocarbon receptor (AhR). This study measured the expression of AhR and related genes in frozen esophageal cell samples from patients exposed to different levels of indoor air pollution, who did or did not have high-grade squamous dysplasia (HGD), and who did or did not have a family history (FH) of upper gastrointestinal cancer (UGI Ca).

Methods

147 samples were evaluated, including 23 (16%) from patients with HGD and 48 (33%) from patients without DYS who heated their homes with coal, without a chimney (a “high” indoor air pollution group), and 27 (18%) from patients with HGD and 49 (33%) from patients without DYS who did not heat their homes at all (a “low” indoor air pollution group). Nearly half (64 (44%)) had a FH of UGI Ca. RNA was extracted and Quantitative-PCR analysis was performed.

Results

AhR gene expression was detectable in 85 (58%) of the samples, and was more than 9-fold higher in those with a FH of UGI Ca (median expression (IQR) -1964 (-18000, -610) versus -18000 (-18000, -1036) Wilcoxon P = 0.02). Heating status, dysplasia category, age, gender, and smoking were not associated with AhR expression (linear regression, all P-values ≥0.1).

Conclusion

AhR expression was higher in patients with a FH of UGI Ca. Such individuals may be more susceptible to the deleterious effects of PAH exposure, including PAH-induced cancer.

Background

Squamous dysplasia is the precursor lesion for esophageal squamous cell carcinoma (ESCC), and nutritional factors play an important role in the etiology of this cancer. Previous studies using a variety of measures of vitamin D exposure have reached different conclusions about the association between vitamin D and risk of developing esophageal cancer.

Methods

We measured serum 25-hydroxyvitamin D (25(OH)D) concentrations in a cross-sectional analysis of 720 subjects from Linxian, China, a population at high risk for developing ESCC. All subjects underwent endoscopy and biopsy and were categorized by presence or absence of histologic squamous dysplasia. We used crude and multivariate adjusted generalized linear models to estimate the relative risk (RR) and 95% confidence intervals (CI) for the association between squamous dysplasia and sex-specific quartiles of serum 25(OH)D concentration.

Results

Two hundred and thirty (32%) of 720 subjects had squamous dysplasia. Subjects with dysplasia had significantly higher median serum 25(OH)D concentrations then subjects without dysplasia, 36.5 and 31.5 nmol/L respectively (Wilcoxon two-sample test p = 0.0004). In multivariate adjusted models, subjects in the highest compared to the lowest quartile were at significantly increased risk of squamous dysplasia, RR (95% CI) = 1.86 (1.35–2.62). Increased risks were similar when examined in men and women separately: Men RR (95% CI) = 1.74 (1.08–2.93); Women RR (95% CI) = 1.96 (1.28–3.18).

Conclusions

Higher serum 25(OH)D concentration was associated with significantly increased risk of squamous dysplasia. No obvious source of measured or unmeasured confounding explains this finding.

Pepsinogens are a class of endopeptidases that are secreted by the gastric epithelium and released into the circulation. Low serum pepsinogen I (PGI) and low serum pepsinogen I / pepsinogen II ratio (PGI/II ratio) are markers of gastric fundic atrophy, and have recently been shown to be associated with increased risk of esophageal squamous cell carcinoma (ESCC). We conducted the current study to test whether these markers are also associated with esophageal squamous dysplasia (ESD), the precursor lesion of ESCC.

We measured serum PGI and PGII, using enzyme-linked immunosorbent (ELISA) assays, in 125 case subjects (patients with moderate or severe ESD) and 250 sex-matched control subjects (no ESD) selected from an endoscopic screening study in Linxian, China. We used conditional logistic regression models adjusted for age, smoking, and place of residence to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs).

Serum PGI showed no statistically significant association with ESD, whether analyzed as a dichotomous, ordinal (quartiles), or continuous variable. Lower serum PGI/II ratio, however, showed a dose-response association with increased risk of ESD, with an adjusted OR (95% CI) of 2.12 (1.08 − 4.18), comparing the lowest versus the highest quartile. The association between lower serum PGI/II ratio and log OR of ESD was nearly linear, and the p-value for the continuous association was 0.03.

Lower serum PGI/II ratio was linearly associated with higher risk of ESD. This result is consistent with recent findings that gastric atrophy may increase the risk of ESCC.

The incidence of esophageal squamous cell carcinoma (ESCC) is very high in northern China. This cancer has a very poor prognosis, mostly because it is usually diagnosed at a late stage. Detection an earlier stage can dramatically improve prognosis. Microscopic evaluation of esophageal balloon cytology (EBC) specimens has been the most common method for early detection of ESCC, but this technique is limited by low sensitivity and specificity. The use of molecular markers may improve these screening characteristics. This study evaluates whether measurement of gene methylation in EBC specimens may have utility for the detection of esophageal squamous dysplasia and early ESCC. We evaluated the presence of methylation in eight genes shown to be methylated in ESCC in previous studies in EBC specimens from 147 patients with endoscopic biopsy diagnoses ranging from normal mucosa through severe squamous dysplasia. Methylation status was determined using quantitative methylation-specific PCR techniques. The sensitivity and specificity of methylation of each individual gene and combinations of these genes to detect biopsy-proven high-grade (moderate or severe) squamous dysplasia was determined. For individual genes, the sensitivities ranged from 9–34% and the specificities ranged from 77–99%. Using a panel of four genes (AHRR, p16INK4a, MT1G, and CLDN3) resulted in sensitivity and specificity of 50% and 68%, respectively. This study suggests that evaluation of gene methylation in EBC samples may have utility for early detection of esophageal squamous dysplasia and early ESCC, however, identification of more sensitive methylation markers will be required for development of a clinically useful screening test.

Background

To estimate the contribution of tobacco smoking, alcohol drinking, low vegetable intake and low fruit intake to esophageal cancer mortality and incidence in China.

Methodology/Principal Findings

We calculated the proportion of esophageal cancer attributable to four known modifiable risk factors [population attributable fraction (PAF)]. Exposure data was taken from meta-analyses and large-scale national surveys of representative samples of the Chinese population. Data on relative risks were also from meta-analyses and large-scale prospective studies. Esophageal cancer mortality and incidence came from the 3rd national death cause survey and population-based cancer registries in China. We estimated that 87,065 esophageal cancer deaths (men 67,686; women: 19,379) and 108,206 cases (men: 83,968, women: 24,238) were attributable to tobacco smoking, alcohol drinking, low vegetable intake and low fruit intake in China in 2005. About 17.9% of esophageal cancer deaths among men and 1.9% among women were attributable to tobacco smoking. About 15.2% of esophageal cancer deaths in men and 1.3% in women were caused by alcohol drinking. Low vegetable intake was responsible for 4.3% esophageal cancer deaths in men and 4.1% in women. The fraction of esophageal cancer deaths attributable to low fruit intake was 27.1% in men and 28.0% in women. Overall, 46% of esophageal cancers (51% in men and 33% in women) were attributable to these four modifiable risk factors.

Conclusions/Significance

Tobacco smoking, alcohol drinking, low vegetable intake and low fruit intake were responsible for 46% of esophageal cancer mortality and incidence in China in 2005. These findings provide useful data for developing guidelines for esophageal cancer prevention and control in China.

Certain regions of China have high rates of esophageal squamous cell carcinoma (ESCC). Previous studies of human papillomavirus (HPV), a proposed causal factor, have produced highly variable results. We attempted to evaluate HPV and ESCC more definitively using extreme care to prevent DNA contamination. We collected tissue and serum in China from 272 histopathologically-confirmed ESCC cases with rigorous attention to good molecular biology technique. We tested for HPV DNA in fresh-frozen tumor tissue using PCR with PGMY L1 consensus primers and HPV16 and 18 type-specific E6 and E7 primers, and in formalin-fixed paraffin-embedded tumor tissue using SPF10 L1 primers. In HPV-positive cases, we evaluated p16INK4a overexpression and HPV E6/E7 seropositivity as evidence of carcinogenic HPV activity. β-globin, and thus DNA, was adequate in 98.2% of the frozen tumor tissues (267/272). Of these, 99.6% (95% confidence interval (CI) = 97.9–100.0%) were negative for HPV DNA by PGMY, and 100% (95% CI = 98.6–100%) were negative by HPV16/18 E6/E7 PCR. In the corresponding formalin-fixed paraffin-embedded tumor specimens, 99.3% (95% CI = 97.3–99.9%) were HPV negative by SPF10. By PGMY, 1 case tested weakly positive for HPV89, a noncancer causing HPV type. By SPF10, 2 cases tested weakly positive: 1 for HPV16 and 1 for HPV31. No HPV DNA-positive case had evidence of HPV oncogene activity as measured by p16INK4a overexpression or E6/E7 seropositivity. This study provides the most definitive evidence to date that HPV is not involved in ESCC carcinogenesis in China. HPV DNA contamination cannot be ruled out as an explanation for high HPV prevalence in ESCC tissue studies with less stringent tissue procurement and processing protocols.