Waiting for scheduled surgery: A complex patient experience

The aim of this study was to understand experiences of wait time among patients awaiting scheduled orthopaedic or cardiac surgery. Using a qualitative approach, 32 patients completed two interviews each regarding their wait time experiences, including effects of waiting. Patient experiences of wait time varied regardless of actual wait time and included reports of restriction, uncertainty, resignation, coping and opportunity. Participants' waiting experiences indicate a complex relationship between greater symptom severity and less tolerance for wait time. We suggest healthcare resources focus on alleviating the deleterious effects of waiting for certain patients rather than reducing absolute wait times.

Cigarette smoke mediates epigenetic repression of miR-217 during esophageal adenocarcinogenesis

Although microRNAs (miRs) have been implicated in the pathogenesis of various human malignancies, limited information is available regarding mechanisms by which these noncoding RNAs contribute to initiation and progression of tobacco-induced esophageal cancers. In this study, array and quantitative reverse transcriptase-PCR techniques were used to examine miR expression in immortalized esophageal epithelia (IEE) and esophageal adenocarcinoma (EAC) cells cultured in normal media with or without cigarette smoke condensate (CSC). Under relevant exposure conditions, CSC significantly decreased miR-217 expression in these cells. Endogenous levels of miR-217 expression in cultured EAC cells (EACC)/primary EACs were significantly lower than those observed in IEE/ paired normal esophageal tissues. RNA crosslink immunoprecipitation, quantitative reverse transcriptase-PCR (qRT-PCR) and immunoblot experiments demonstrated direct interaction of miR-217 with kallikrein 7 (KLK7), encoding a putative oncogene not previously implicated in EAC. Repression of miR-217 correlated with increased levels of KLK7 in primary EACs, particularly those from smokers. Chromatin and methylated DNA immunoprecipitation experiments demonstrated that CSC-mediated repression of miR-217 coincided with DNMT3b-dependent hypermethylation and decreased occupancy of nuclear factor 1 within the miR-217 genomic locus. Deoxyazacytidine induced miR-217 expression and downregulated KLK7 in EACC; deoxyazacytidine also attenuated CSC-mediated miR-217 repression and upregulation of KLK7 in IEE and EACC. Overexpression of miR-217 significantly decreased, whereas overexpression of KLK7 increased proliferation, invasion and tumorigenicity of EACC. Collectively, these data demonstrate that epigenetic repression of miR-217 contributes to the pathogenesis of EAC via upregulation of KLK7 and suggest that restoration of miR-217 expression may be a novel treatment strategy for these malignancies.

Polymorphisms in Genes of Relevance for Oestrogen and Oxytocin Pathways and Risk of Barrett's Oesophagus and Oesophageal Adenocarcinoma: A Pooled Analysis from the BEACON Consortium

BACKGROUND

The strong male predominance in oesophageal adenocarcinoma (OAC) and Barrett's oesophagus (BO) continues to puzzle. Hormonal influence, e.g. oestrogen or oxytocin, might contribute.

METHODS

This genetic-epidemiological study pooled 14 studies from three continents, Australia, Europe, and North America. Polymorphisms in 3 key genes coding for the oestrogen pathway (receptor alpha (ESR1), receptor beta (ESR2), and aromatase (CYP19A1)), and 3 key genes of the oxytocin pathway (the oxytocin receptor (OXTR), oxytocin protein (OXT), and cyclic ADP ribose hydrolase glycoprotein (CD38)), were analysed using a gene-based approach, versatile gene-based test association study (VEGAS).

RESULTS

Among 1508 OAC patients, 2383 BO patients, and 2170 controls, genetic variants within ESR1 were associated with BO in males (p = 0.0058) and an increased risk of OAC and BO combined in males (p = 0.0023). Genetic variants within OXTR were associated with an increased risk of BO in both sexes combined (p = 0.0035) and in males (p = 0.0012). We followed up these suggestive findings in a further smaller data set, but found no replication. There were no significant associations between the other 4 genes studied and risk of OAC, BO, separately on in combination, in males and females combined or in males only.

CONCLUSION

Genetic variants in the oestrogen receptor alpha and the oxytocin receptor may be associated with an increased risk of BO or OAC, but replication in other large samples are needed.

MiRNA-Related SNPs and Risk of Esophageal Adenocarcinoma and Barrett's Esophagus: Post Genome-Wide Association Analysis in the BEACON Consortium

Incidence of esophageal adenocarcinoma (EA) has increased substantially in recent decades. Multiple risk factors have been identified for EA and its precursor, Barrett’s esophagus (BE), such as reflux, European ancestry, male sex, obesity, and tobacco smoking, and several germline genetic variants were recently associated with disease risk. Using data from the Barrett’s and Esophageal Adenocarcinoma Consortium (BEACON) genome-wide association study (GWAS) of 2,515 EA cases, 3,295 BE cases, and 3,207 controls, we examined single nucleotide polymorphisms (SNPs) that potentially affect the biogenesis or biological activity of microRNAs (miRNAs), small non-coding RNAs implicated in post-transcriptional gene regulation, and deregulated in many cancers, including EA. Polymorphisms in three classes of genes were examined for association with risk of EA or BE: miRNA biogenesis genes (157 SNPs, 21 genes); miRNA gene loci (234 SNPs, 210 genes); and miRNA-targeted mRNAs (177 SNPs, 158 genes). Nominal associations (P<0.05) of 29 SNPs with EA risk, and 25 SNPs with BE risk, were observed. None remained significant after correction for multiple comparisons (FDR q>0.50), and we did not find evidence for interactions between variants analyzed and two risk factors for EA/BE (smoking and obesity). This analysis provides the most extensive assessment to date of miRNA-related SNPs in relation to risk of EA and BE. While common genetic variants within components of the miRNA biogenesis core pathway appear unlikely to modulate susceptibility to EA or BE, further studies may be warranted to examine potential associations between unassessed variants in miRNA genes and targets with disease risk.

Polymorphisms near TBX5 and GDF7 are associated with increased risk for Barrett's esophagus

BACKGROUND & AIMS

Barrett's esophagus (BE) increases the risk of esophageal adenocarcinoma (EAC). We found the risk to be BE has been associated with single nucleotide polymorphisms (SNPs) on chromosome 6p21 (within the HLA region) and on 16q23, where the closest protein-coding gene is FOXF1. Subsequently, the Barrett's and Esophageal Adenocarcinoma Consortium (BEACON) identified risk loci for BE and esophageal adenocarcinoma near CRTC1 and BARX1, and within 100 kb of FOXP1. We aimed to identify further SNPs that increased BE risk and to validate previously reported associations.

METHODS

We performed a genome-wide association study (GWAS) to identify variants associated with BE and further analyzed promising variants identified by BEACON by genotyping 10,158 patients with BE and 21,062 controls.

RESULTS

We identified 2 SNPs not previously associated with BE: rs3072 (2p24.1; odds ratio [OR] = 1.14; 95% CI: 1.09-1.18; P = 1.8 × 10(-11)) and rs2701108 (12q24.21; OR = 0.90; 95% CI: 0.86-0.93; P = 7.5 × 10(-9)). The closest protein-coding genes were respectively GDF7 (rs3072), which encodes a ligand in the bone morphogenetic protein pathway, and TBX5 (rs2701108), which encodes a transcription factor that regulates esophageal and cardiac development. Our data also supported in BE cases 3 risk SNPs identified by BEACON (rs2687201, rs11789015, and rs10423674). Meta-analysis of all data identified another SNP associated with BE and esophageal adenocarcinoma: rs3784262, within ALDH1A2 (OR = 0.90; 95% CI: 0.87-0.93; P = 3.72 × 10(-9)).

CONCLUSIONS

We identified 2 loci associated with risk of BE and provided data to support a further locus. The genes we found to be associated with risk for BE encode transcription factors involved in thoracic, diaphragmatic, and esophageal development or proteins involved in the inflammatory response.

Time while waiting: patients' experiences of scheduled surgery

Research on patients' experiences of wait time for scheduled surgery has centered predominantly on the relative tolerability of perceived wait time and impacts on quality of life. We explored patients' experiences of time while waiting for three types of surgery with varied wait times--hip or knee replacement, shoulder surgery, and cardiac surgery. Thirty-two patients were recruited by their surgeons. We asked participants about their perceptions of time while waiting in two separate interviews. Using interpretative phenomenological analysis (IPA), we discovered connections between participant suffering, meaningfulness of time, and agency over the waiting period and the lived duration of time experience. Our findings reveal that chronological duration is not necessarily the most relevant consideration in determining the quality of waiting experience. Those findings helped us create a conceptual framework for lived wait time. We suggest that clinicians and policy makers consider the complexity of wait time experience to enhance preoperative patient care.

Integrative post-genome-wide association analysis of CDKN2A and TP53 SNPs and risk of esophageal adenocarcinoma

Incidence of esophageal adenocarcinoma (EA) in Western countries has increased markedly in recent decades. Although several risk factors have been identified for EA and its precursor, Barrett's esophagus (BE), including reflux, Caucasian race, male gender, obesity, and smoking, less is known about the role of inherited genetic variation. Frequent somatic mutations in the tumor suppressor genes CDKN2A and TP53 were recently reported in EA tumors, while somatic alterations at 9p (CDKN2A) and 17p (TP53) have been implicated as predictors of progression from BE to EA. Motivated by these findings, we used data from a genome-wide association study of 2515 EA cases and 3207 controls to analyze 37 germline single nucleotide polymorphisms at the CDKN2A and TP53 loci. Three CDKN2A polymorphisms were nominally associated (P < 0.05) with reduced risk of EA: rs2518720 C>T [intronic, odds ratio 0.90, P = 0.0121, q = 0.3059], rs3088440 G>A (3'UTR, odds ratio 0.84, P = 0.0186, q = 0.3059), and rs4074785 C>T (intronic, odds ratio 0.85, P = 0.0248, q = 0.3059). None of the TP53 single nucleotide polymorphisms reached nominal significance. Two of the CDKN2A variants identified were also associated with reduced risk of progression from BE to EA, when assessed in a prospective cohort of 408 BE patients: rs2518720 (hazard ratio 0.57, P = 0.0095, q = 0.0285) and rs3088440 (hazard ratio 0.34, P = 0.0368, q = 0.0552). In vitro functional studies of rs3088440, a single nucleotide polymorphism located in the seed sequence of a predicted miR-663b binding site, suggested a mechanism whereby the G>A substitution may attenuate miR-663b-mediated repression of the CDKN2A transcript. This study provides the first evidence that germline variation at the CDKN2A locus may influence EA susceptibility.

Risk of esophageal adenocarcinoma decreases with height, based on consortium analysis and confirmed by Mendelian randomization

BACKGROUND & AIMS

Risks for some cancers increase with height. We investigated the relationship between height and risk of esophageal adenocarcinoma (EAC) and its precursor, Barrett's esophagus (BE).

METHODS

We analyzed epidemiologic and genome-wide genomic data from individuals of European ancestry in the Barrett's and Esophageal Adenocarcinoma Consortium, from 999 cases of EAC, 2061 cases of BE, and 2168 population controls. Multivariable logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (95% CI) for associations between height and risks of EAC and BE. We performed a Mendelian randomization analysis to estimate an unconfounded effect of height on EAC and BE using a genetic risk score derived from 243 genetic variants associated with height as an instrumental variable.

RESULTS

Height was associated inversely with EAC (per 10-cm increase in height: OR, 0.70; 95% CI, 0.62-0.79 for men and OR, 0.57; 95% CI 0.40-0.80 for women) and BE (per 10-cm increase in height: OR, 0.69; 95% CI, 0.62-0.77 for men and OR, 0.61; 95% CI, 0.48-0.77 for women). The risk estimates were consistent across strata of age, education level, smoking, gastroesophageal reflux symptoms, body mass index, and weight. Mendelian randomization analysis yielded results quantitatively similar to those from the conventional epidemiologic analysis.

CONCLUSIONS

Height is associated inversely with risks of EAC and BE. Results from the Mendelian randomization study showed that the inverse association observed did not result from confounding factors. Mechanistic studies of the effect of height on EAC and BE are warranted; height could have utility in clinical risk stratification.

Obesity and risk of esophageal adenocarcinoma and Barrett's esophagus: a Mendelian randomization study

BACKGROUND

Data from observational studies suggest that body mass index (BMI) is causally related to esophageal adenocarcinoma (EAC) and its precursor, Barrett's esophagus (BE). However, the relationships may be affected by bias and confounding.

METHODS

We used data from the Barrett's and Esophageal Adenocarcinoma Genetic Susceptibility Study: 999 patients with EAC, 2061 patients with BE, and 2169 population controls. We applied the two-stage control function instrumental variable method of the Mendelian randomization approach to estimate the unbiased, unconfounded effect of BMI on risk of EAC and BE. This was performed using a genetic risk score, derived from 29 genetic variants shown to be associated with BMI, as an instrument for lifetime BMI. A higher score indicates propensity to obesity. All tests were two-sided.

RESULTS

The genetic risk score was not associated with potential confounders, including gastroesophageal reflux symptoms and smoking. In the instrumental variable analyses (IV), EAC risk increased by 16% (IV-odds ratio [OR] = 1.16, 95% confidence interval [CI] = 1.01 to 1.33) and BE risk increased by 12% (IV-OR = 1.12, 95% CI = 1.00 to 1.25) per 1kg/m(2) increase in BMI. BMI was statistically significantly associated with EAC and BE in conventional epidemiologic analyses.

CONCLUSIONS

People with a high genetic propensity to obesity have higher risks of esophageal metaplasia and neoplasia than people with low genetic propensity. These analyses provide the strongest evidence to date that obesity is independently associated with BE and EAC, and is not due to confounding or bias inherent in conventional epidemiologic analyses.

Gastroesophageal reflux in relation to adenocarcinomas of the esophagus: a pooled analysis from the Barrett's and Esophageal Adenocarcinoma Consortium (BEACON)

BACKGROUND

Previous studies have evidenced an association between gastroesophageal reflux and esophageal adenocarcinoma (EA). It is unknown to what extent these associations vary by population, age, sex, body mass index, and cigarette smoking, or whether duration and frequency of symptoms interact in predicting risk. The Barrett's and Esophageal Adenocarcinoma Consortium (BEACON) allowed an in-depth assessment of these issues.

METHODS

Detailed information on heartburn and regurgitation symptoms and covariates were available from five BEACON case-control studies of EA and esophagogastric junction adenocarcinoma (EGJA). We conducted single-study multivariable logistic regressions followed by random-effects meta-analysis. Stratified analyses, meta-regressions, and sensitivity analyses were also conducted.

RESULTS

Five studies provided 1,128 EA cases, 1,229 EGJA cases, and 4,057 controls for analysis. All summary estimates indicated positive, significant associations between heartburn/regurgitation symptoms and EA. Increasing heartburn duration was associated with increasing EA risk; odds ratios were 2.80, 3.85, and 6.24 for symptom durations of <10 years, 10 to <20 years, and ≥20 years. Associations with EGJA were slighter weaker, but still statistically significant for those with the highest exposure. Both frequency and duration of heartburn/regurgitation symptoms were independently associated with higher risk. We observed similar strengths of associations when stratified by age, sex, cigarette smoking, and body mass index.

CONCLUSIONS

This analysis indicates that the association between heartburn/regurgitation symptoms and EA is strong, increases with increased duration and/or frequency, and is consistent across major risk factors. Weaker associations for EGJA suggest that this cancer site has a dissimilar pathogenesis or represents a mixed population of patients.

Telomerase variant A279T induces telomere dysfunction and inhibits non-canonical telomerase activity in esophageal carcinomas

BACKGROUND

Although implicated in the pathogenesis of several chronic inflammatory disorders and hematologic malignancies, telomerase mutations have not been thoroughly characterized in human cancers. The present study was performed to examine the frequency and potential clinical relevance of telomerase mutations in esophageal carcinomas.

METHODS

Sequencing techniques were used to evaluate mutational status of telomerase reverse transcriptase (TERT) and telomerase RNA component (TERC) in neoplastic and adjacent normal mucosa from 143 esophageal cancer (EsC) patients. MTS, flow cytometry, time lapse microscopy, and murine xenograft techniques were used to assess proliferation, apoptosis, chemotaxis, and tumorigenicity of EsC cells expressing either wtTERT or TERT variants. Immunoprecipitation, immunoblot, immunofluorescence, promoter-reporter and qRT-PCR techniques were used to evaluate interactions of TERT and several TERT variants with BRG-1 and β-catenin, and to assess expression of cytoskeletal proteins, and cell signaling. Fluorescence in-situ hybridization and spectral karyotyping techniques were used to examine telomere length and chromosomal stability.

RESULTS

Sequencing analysis revealed one deletion involving TERC (TERC del 341-360), and two non-synonymous TERT variants [A279T (2 homozygous, 9 heterozygous); A1062T (4 heterozygous)]. The minor allele frequency of the A279T variant was five-fold higher in EsC patients compared to healthy blood donors (p<0.01). Relative to wtTERT, A279T decreased telomere length, destabilized TERT-BRG-1-β-catenin complex, markedly depleted β-catenin, and down-regulated canonical Wnt signaling in cancer cells; these phenomena coincided with decreased proliferation, depletion of additional cytoskeletal proteins, impaired chemotaxis, increased chemosensitivity, and significantly decreased tumorigenicity of EsC cells. A279T expression significantly increased chromosomal aberrations in mouse embryonic fibroblasts (MEFs) following Zeocin™ exposure, as well as Li Fraumeni fibroblasts in the absence of pharmacologically-induced DNA damage.

CONCLUSIONS

A279T induces telomere dysfunction and inhibits non-canonical telomerase activity in esophageal cancer cells. These findings warrant further analysis of A279T expression in esophageal cancers and premalignant esophageal lesions.

A genome-wide association study identifies new susceptibility loci for esophageal adenocarcinoma and Barrett's esophagus

Esophageal adenocarcinoma is a cancer with rising incidence and poor survival. Most such cancers arise in a specialized intestinal metaplastic epithelium, which is diagnostic of Barrett's esophagus. In a genome-wide association study, we compared esophageal adenocarcinoma cases (n = 2,390) and individuals with precancerous Barrett's esophagus (n = 3,175) with 10,120 controls in 2 phases. For the combined case group, we identified three new associations. The first is at 19p13 (rs10419226: P = 3.6 × 10(-10)) in CRTC1 (encoding CREB-regulated transcription coactivator), whose aberrant activation has been associated with oncogenic activity. A second is at 9q22 (rs11789015: P = 1.0 × 10(-9)) in BARX1, which encodes a transcription factor important in esophageal specification. A third is at 3p14 (rs2687201: P = 5.5 × 10(-9)) near the transcription factor FOXP1, which regulates esophageal development. We also refine a previously reported association with Barrett's esophagus near the putative tumor suppressor gene FOXF1 at 16q24 and extend our findings to now include esophageal adenocarcinoma.

Germline genetic contributions to risk for esophageal adenocarcinoma, Barrett's esophagus, and gastroesophageal reflux

BACKGROUND

Esophageal adenocarcinoma (EA) is an increasingly common cancer with poor survival. Barrett's esophagus (BE) is the main precursor to EA, and every year 0.12% to 0.5% of BE patients progress to EA. BE typically arises on a background of chronic gastroesophageal reflux (GERD), one of the risk factors for EA.

METHODS

We used genome-wide association data to investigate the genetic architecture underlying GERD, BE, and EA. We applied a method to estimate the variance explained (array heritability, h(2)g) and the genetic correlation (rg) between GERD, BE, and EA by considering all single nucleotide polymorphisms (SNPs) simultaneously. We also estimated the polygenic overlap between GERD, BE, and EA using a prediction approach. All tests were two-sided, except in the case of variance-explained estimation where one-sided tests were used.

RESULTS

We estimated a statistically significant genetic variance explained for BE (h(2)g = 35%; standard error [SE] = 6%; one-sided P = 1 × 10(-9)) and for EA (h(2)g = 25 %; SE = 5%; one-sided P = 2 × 10(-7)). The genetic correlation between BE and EA was found to be high (rg = 1.0; SE = 0.37). We also estimated a statistically significant polygenic overlap between BE and EA (one-sided P = 1 × 10(-6)), which suggests, together with the high genetic correlation, that shared genes underlie the development of BE and EA. Conversely, no statistically significant results were obtained for GERD.

CONCLUSIONS

We have demonstrated that risk to BE and EA is influenced by many germline genetic variants of small effect and that shared polygenic effects contribute to risk of these two diseases.

Body mass index in relation to oesophageal and oesophagogastric junction adenocarcinomas: a pooled analysis from the International BEACON Consortium

BACKGROUND

Previous studies suggest an association between obesity and oesophageal (OA) and oesophagogastric junction adenocarcinomas (OGJA). However, these studies have been limited in their ability to assess whether the effects of obesity vary by gender or by the presence of gastro-oesophageal reflux (GERD) symptoms.

METHODS

Individual participant data from 12 epidemiological studies (8 North American, 3 European and 1 Australian) comprising 1997 OA cases, 1900 OGJA cases and 11 159 control subjects were pooled. Logistic regression was used to estimate study-specific odds ratios (ORs) and 95% confidence intervals (CIs) for the association between body mass index (BMI, kg/m(2)) and the risk of OA and OGJA. Random-effects meta-analysis was used to combine these ORs. We also investigated effect modification and synergistic interaction of BMI with GERD symptoms and gender.

RESULTS

The association of OA and OGJA increased directly with increasing BMI (P for trend <0.001). Compared with individuals with a BMI <25, BMI ≥40 was associated with both OA (OR 4.76, 95% CI 2.96-7.66) and OGJA (OR 3.07, 95% CI 1.89-4.99). These associations were similar when stratified by gender and GERD symptoms. There was evidence for synergistic interaction between BMI and GERD symptoms in relation to OA/OGJA risk.

CONCLUSIONS

These data indicate that BMI is directly associated with OA and OGJA risk in both men and women and in those with and without GERD symptoms. Disentangling the relationship between BMI and GERD will be important for understanding preventive efforts for OA and OGJA.

The importance of exposure rate on odds ratios by cigarette smoking and alcohol consumption for esophageal adenocarcinoma and squamous cell carcinoma in the Barrett's Esophagus and Esophageal Adenocarcinoma Consortium

BACKGROUND

Cigarette smoking is associated with esophageal adenocarcinoma (EAC), esophagogastric junctional adenocarcinoma (EGJA) and esophageal squamous cell carcinoma (ESCC), and alcohol consumption with ESCC. However, no analyses have examined how delivery rate modifies the strength of odds ratio (OR) trends with total exposure, i.e., the impact on the OR for a fixed total exposure of high exposure rate for short duration compared with low exposure rate for long duration.

METHODS

The authors pooled data from 12 case-control studies from the Barrett's Esophagus and Esophageal Adenocarcinoma Consortium (BEACON), including 1242 (EAC), 1263 (EGJA) and 954 (ESCC) cases and 7053 controls, modeled joint ORs for cumulative exposure and exposure rate for cigarette smoking and alcohol consumption, and evaluated effect modification by sex, body mass index (BMI), age and self-reported acid reflux.

RESULTS

For smoking, all sites exhibited inverse delivery rate effects, whereby ORs with pack-years increased, but trends weakened with increasing cigarettes/day. None of the examined factors modified associations, except for ESCC where younger ages at diagnosis enhanced smoking effects (P<0.01). For EAC and EGJA, ORs with drink-years exhibited inverse associations in <5 drinks/day consumers and no association in heavier consumers. For ESCC, ORs with drink-years increased, with trends strengthening with greater drinks/day. There was no significant effect modification, except for EAC and EGJA where acid reflux mitigated the inverse associations (P=0.02). For ESCC, younger ages at diagnosis enhanced drinking-related ORs (P<0.01).

CONCLUSIONS

Patterns of ORs by pack-years and drink-years, delivery rate effects and effect modifiers revealed common as well as distinct etiologic elements for these diseases.

Nonsteroidal anti-inflammatory drug use reduces risk of adenocarcinomas of the esophagus and esophagogastric junction in a pooled analysis

BACKGROUND & AIMS

Regular use of aspirin and other nonsteroidal anti-inflammatory drugs (NSAIDs) has been reported to reduce risks of esophageal adenocarcinoma (EAC) and esophagogastric junctional adenocarcinoma (EGJA). However, individual studies have been too small to accurately assess the effects of medication type, frequency, or duration of use. We performed a pooled analysis to investigate these associations.

METHODS

We performed a pooled analysis of 6 population-based studies within the Barrett's and Esophageal Adenocarcinoma Consortium to evaluate the association between NSAID use and the risk of EAC and EGJA, using uniform exposure definitions. We collected information from 6 studies (5 case-control and 1 cohort), with a total of 1226 EAC and 1140 EGJA cases, on aspirin and/or NSAID use. Study-specific odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using multivariate adjusted logistic regression models and then pooled using a random effects meta-analysis model.

RESULTS

Compared with nonusers, individuals who have used NSAIDs had a statistically significant reduced risk of EAC (OR, 0.68; 95% CI, 0.56-0.83); they also appeared to have a reduced risk of EGJA (OR, 0.83; 95% CI, 0.66-1.03). Similar reductions in risk were observed among individuals who took aspirin or nonaspirin NSAIDs. The highest levels of frequency (daily or more frequently) and duration (≥10 years) of NSAID use were associated with an approximately 40% reduction in risk of EAC, with ORs of 0.56 (95% CI, 0.43-0.73; P(trend) < .001) and 0.63 (95% CI, 0.45-0.90; P(trend) = .04), respectively.

CONCLUSIONS

Although reverse causation could, in part, explain the inverse association observed between NSAID use and EAC risk, our pooled analysis suggests a possible role for NSAIDs in prevention of adenocarcinomas of the esophagus and esophagogastric junction.

Alcohol intake and risk of oesophageal adenocarcinoma: a pooled analysis from the BEACON Consortium

BACKGROUND AND AIMS

Alcohol intake is a strong and well established risk factor for oesophageal squamous cell carcinoma (OSCC), but the association with oesophageal adenocarcinoma (OA) or adjacent tumours of the oesophagogastric junction (OGJA), remains unclear. Therefore, the association of alcohol intake with OSCC, OA, and OGJA was determined in nine case-control studies and two cohort studies of the Barrett's Esophagus and Esophageal Adenocarcinoma Consortium (BEACON).

MATERIALS AND METHODS

Information was collected on alcohol intake, age, sex, education, body mass index, gastro-oesophageal reflux, and tobacco smoking from each study. Along with 10,854 controls, 1821 OA, and 1837 OGJA, seven studies also collected OSCC cases (n=1016). Study specific ORs and 95% CIs were calculated from multivariate adjusted logistic regression models for alcohol intake in categories compared to non-drinkers. Summary risk estimates were obtained by random effects models. Results No increase was observed in the risk of OA or OGJA for increasing levels of any of the alcohol intake measures examined. ORs for the highest frequency category (≥ 7 drinks per day) were 0.97 (95% CI 0.68 to 1.36) for OA and 0.77 (95% CI = 0.54 to 1.10) for OGJA. Suggestive findings linked moderate intake (eg, 0.5 to <1 drink per day) to decreased risk of OA (OR 0.63, 95% CI 0.41 to 0.99) and OGJA (OR 0.78, 95% CI 0.62 to 0.99). In contrast, alcohol intake was strongly associated with increased risk of OSCC (OR for ≥ 7 drinks per day 9.62, 95% CI 4.26 to 21.71).

CONCLUSIONS

In contrast to OSCC, higher alcohol consumption was not associated with increased risk of either OA or OGJA. The apparent inverse association observed with moderate alcohol intake should be evaluated in future prospective studies.

Abstract 1778: Anticancer activities and regulatory effects on apoptotic gene expression of Bufalin in the orthotopic transplantation model of human colorectal cancer in nude mice

Background: Bufalin, a natural small-molecule compound from the Traditional Chinese Medicine “Chansu”, shows inhibitory effects on many human cancer cells. However, whether or not Bufalin has anticancer activity in human colorectal cancer (CRC), and its possible underlying mechanism, remains unclear.

Objectives: 1) To investigate anticancer activities of Bufalin in human CRC using an orthotopic transplantation model in nude mice and 2) to study possible underlying mechanisms related to apoptosis.

Materials and methods: An orthotopic transplantation tumor model was established by implanting human CRC HCT-116 cells into the colon of nude mice. Sixty mice were randomly divided into five treatment groups (12 mice in each group): normal saline group, 5-FU group, and 3 Bufalin groups with low (BL), medium (BM), and high (BH) doses. After cell transplantation, 0.2 ml normal saline, 25 mg/kg 5-Fu, or 0.5 mg/kg, 1 mg/kg, 1.5 mg/kg Bufalin was injected intraperitoneally in mice in each corresponding group, daily for 7 days (days 15 to 21). Six mice in each group were sacrificed on day 24. Tumor size, growth inhibition rate, and morphological changes of tumor cell under microscopy were recorded. Apoptosis was determined by TUNEL staining, mRNA and protein expressions of Bcl-xl and Bax were evaluated with real-time RT-PCR and immunohistochemical staining, respectively. The overall survival (OS) was determined in the remaining 6 mice in each group.

Results: The tumor size in mice treated with 5-Fu, BL, BM, or BH was significantly smaller than that in mice treated with normal saline (p&lt;0.05), with the tumor inhibitor rates of 64.3%, 51.4%, 48.7%, and 36.3%, respectively. Under microscopy, increased tumor necrosis was observed in the 5-Fu, BM and BH groups. The tumor apoptotic rate in each of 3 Bufalin treated groups was significantly higher than that in the normal saline group (p&lt;0.05). Real time RT-PCR and immunohistochemical staining showed both mRNA and protein expressions of Bcl-xl were decreased, whereas the expression of Bax increased, in tumor treated with Bufalin. The OS was prolonged in groups of BL and BM (p&lt;0.05).

Conclusion: Bufalin has significant anticancer activity in a human CRC orthotopic transplantation model in nude mice, and induces tumor cell apoptosis, which may be associated with the down-regulation of Bcl-xl and up-regulation of Bax in tumor cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1778. doi:10.1158/1538-7445.AM2011-1778

Abstract 1092: Insulin-like growth factors modulate chemosensitivity to cisplatin and 5-fluorouracil in human esophageal cell lines

Resistance to chemotherapy remains a major obstacle to survival of patients with esophageal adenocarcinoma (EADC). The aim of this study was to evaluate whether insulin-like growth factors (IGFs), recently implicated in the molecular pathogenesis of EADC, modulate chemosensitivity to Cisplatin (CDDP) and 5-Fluoruracil (5-Fu), two agents widely used in current clinical practice.

Expression of IGF1, its receptor (IGF1R), and IGF2 (mRNA and protein) were studied using quantitative (real-time) PCR and Western blot in human esophageal cell lines: Het1A (derived from immortalized normal esophageal epithelium), OE33 and JHEsoAd1 (each derived from a primary EADC). For each cell line, the effect of various concentrations of IGFs, CDDP and 5-Fu, alone and in combination, on cell proliferation and clonogenicity were evaluated by standard MTT and colony formation assays, respectively. Changes in expression of 84 critical genes downstream from IGF1R were studied by PCR-array.

Relative to Het1A, IGF1 and IGF2 mRNA were significantly (P&lt;0.05) underexpressed by OE33; by contrast, JHEsoAd1 underexpressed IGF1 but overexpressed IGF2. Administration of either IGF1 (250ng/ml) or IGF2 (500ng/ml) to cell cultures resulted in increased cellular proliferation of JHEsoAD1 cells (after IGF1: 1.24+/-0.05 vs. 1.00+/-0.00 untreated, P&lt;0.01; after IGF2: 1.15+/-0.06 vs. 1.00+/-0.06 untreated, P&lt;0.05). As expected, cell proliferation and clonogenicity of all cell lines were inhibited by CDDP and/or 5-FU (at all dosages ranging from 1-4ug/ml). However, these cytotoxic effects were overcome by the administration of either IGF1 or IGF2 with the exception of: 1) JHEsoAd1 cells treated with CDDP, where IGF2 administration further reduced cellular proliferation (0.35+/-0.06 vs. 0.53+/-0.03 for cells treated with CDDP alone; P&lt;0.05), and 2) JHEsoAd1 cells treated with 5-Fu, where IGF1 administration significantly reduced clonogenicity (0.07+/-0.07 vs. 0.49+/-0.06 for cells treated with 5-Fu alone; P&lt;0.05). PCR-array analysis revealed up-regulation (Het1A and JHEsoAd1) and down-regulation (OE33 and JHEsoAd1) of selected PI3K/AKT pathway genes following IGF1 and IGF2 therapy.

These pre-clinical studies confirm a central role for the IGF axis in esophageal tumor biology, with potential for IGFs to enhance the cytotoxic efficacy of standard chemotherapeutic agents in esophageal cell lines. The identification of novel molecular regulatory pathways downstream from IGF1R modulated by IGF therapy may well inform future cytotoxic and targeting strategies.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1092. doi:10.1158/1538-7445.AM2011-1092

Abstract 1098: Interactions between P53 and IGF2 in human esophageal adenocarcinoma tissues and cell lines

To define the role of the insulin-like growth factor (IGF) axis in esophageal adenocarcinoma (EADC), the objective of this study was to evaluate interactions between IGF2 and P53 in a well characterized series of surgically-resected esophageal tissues and the following cell lines: Het1A (derived from immortalized normal esophageal epithelium), OE33 and JH-EsoAd1 (each derived from a primary EADC). Nucleic acids were extracted from 68 primary EADC (and matched histologically normal) tissues. PCR was performed on gDNA and RT-PCR on RNA followed by ApaI digestion to identify informative (heterozygous) cases and imprinting status, respectively. Expression of IGF2 mRNA was determined by quantitative PCR, and of IGF2 and P53 protein by Western analysis and immunohistochemistry. Molecular findings in tissues were correlated with pathologic and clinical characteristics including patient survival. Functional studies utilizing cell lines evaluated IGF2/P53 interactions. Of 44 informative cases, P53 protein overexpression was significantly higher in normally imprinted tumors (12/30) vs. tumors with loss of IGF2 imprinting (1/14; p&lt;0.05). Multivariable logistic regression confirmed IGF2 imprinting status to be independently associated with P53 expression (OR 0.12, 95% CI 0.01-1.00; p=0.05). Tumors overexpressing both IGF2 and P53 were found to be of advanced stage with poor survival. In patients below age 65 years, IGF2 mRNA expression was significantly higher in tumors with wild type P53, and multivariate analysis showed IGF2 mRNA expression to be independently associated with p53 mutation (OR 0.74, 95% CI 0.58-0.94; p&lt;0.05) and P53 protein expression (OR 0.83, 95% CI 0.69-1.00; p&lt;0.05). Whereas treatment of Het1A cells with IGF2 significantly increased P53 expression (1.34+/-0.06 vs. 1.00+/-0.00 untreated cells; p=0.003), IGF2 did not modulate P53 expression in either of the two tumor cell lines (OE33 and JH-EsoAd1). IGF1 Receptor (IGF1R) inhibition with AG1024 reduced P53 expression only in OE33 (0.48+/-0.22 vs. 1.00+/-0.00 untreated cells; p=0.05) and JH-EsoAd1 (0.71 +/- 0.23 vs. 1.00+/- 0.00 untreated; p = 0.15) cells, an effect not reversed by IGF2 treatment. In conclusion: 1) these studies identify novel molecular regulatory interactions between P53 and IGF2 in esophageal malignancy, which are dependent on IGF2 imprinting status and tissue/cell type. 2) Overexpression of both IGF2 and P53 in esophageal tumors is associated with aggressive disease in younger patients (below age 65 years), and may represent clinically useful biomarkers to define a biologically distinct subset of EADC.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 1098. doi:10.1158/1538-7445.AM2011-1098

Inflammatory and microRNA gene expression as prognostic classifier of Barrett's-associated esophageal adenocarcinoma

PURPOSE

Esophageal cancer is one of the most aggressive and deadly forms of cancer; highlighting the need to identify biomarkers for early detection and prognostic classification. Our recent studies have identified inflammatory gene and microRNA signatures derived from tumor and nontumor tissues as prognostic biomarkers of hepatocellular, lung, and colorectal adenocarcinoma. Here, we examine the relationship between expression of these inflammatory genes and micro RNA (miRNA) expression in esophageal adenocarcinoma and patient survival.

EXPERIMENTAL DESIGN

We measured the expression of 23 inflammation-associated genes in tumors and adjacent normal tissues from 93 patients (58 Barrett's and 35 Sporadic adenocarcinomas) by quantitative reverse transcription-polymerase chain reaction. These data were used to build an inflammatory risk model, based on multivariate Cox regression, to predict survival in a training cohort (n = 47). We then determined whether this model could predict survival in a cohort of 46 patients. Expression data for miRNA-375 were available for these patients and was combined with inflammatory gene expression.

RESULTS

IFN-γ, IL-1α, IL-8, IL-21, IL-23, and proteoglycan expression in tumor and nontumor samples were each associated with poor prognosis based on Cox regression [(Z-score)>1.5] and therefore were used to generate an inflammatory risk score (IRS). Patients with a high IRS had poor prognosis compared with those with a low IRS in the training (P = 0.002) and test (P = 0.012) cohorts. This association was stronger in the group with Barrett's history. When combining with miRNA-375, the combined IRS/miR signature was an improved prognostic classifier than either one alone.

CONCLUSION

Transcriptional profiling of inflammation-associated genes and miRNA expression in resected esophageal Barrett's-associated adenocarcinoma tissues may have clinical utility as predictors of prognosis.

Cigarette smoking and adenocarcinomas of the esophagus and esophagogastric junction: a pooled analysis from the international BEACON consortium

BACKGROUND

Previous studies that showed an association between smoking and adenocarcinomas of the esophagus and esophagogastric junction were limited in their ability to assess differences by tumor site, sex, dose-response, and duration of cigarette smoking cessation.

METHODS

We used primary data from 10 population-based case-control studies and two cohort studies from the Barrett's Esophagus and Esophageal Adenocarcinoma Consortium. Analyses were restricted to white non-Hispanic men and women. Patients were classified as having esophageal adenocarcinoma (n = 1540), esophagogastric junctional adenocarcinoma (n = 1450), or a combination of both (all adenocarcinoma; n = 2990). Control subjects (n = 9453) were population based. Associations between pack-years of cigarette smoking and risks of adenocarcinomas were assessed, as well as their potential modification by sex and duration of smoking cessation. Study-specific odds ratios (ORs) estimated using multivariable logistic regression models, adjusted for age, sex, body mass index, education, and gastroesophageal reflux, were pooled using a meta-analytic methodology to generate summary odds ratios. All statistical tests were two-sided.

RESULTS

The summary odds ratios demonstrated strong associations between cigarette smoking and esophageal adenocarcinoma (OR = 1.96, 95% confidence interval [CI] = 1.64 to 2.34), esophagogastric junctional adenocarcinoma (OR = 2.18, 95% CI = 1.84 to 2.58), and all adenocarcinoma (OR = 2.08, 95% CI = 1.83 to 2.37). In addition, there was a strong dose-response association between pack-years of cigarette smoking and each outcome (P < .001). Compared with current smokers, longer smoking cessation was associated with a decreased risk of all adenocarcinoma after adjusting for pack-years (<10 years of smoking cessation: OR = 0.82, 95% CI = 0.60 to 1.13; and > or =10 years of smoking cessation: OR = 0.71, 95% CI = 0.56 to 0.89). Sex-specific summary odds ratios were similar.

CONCLUSIONS

Cigarette smoking is associated with increased risks of adenocarcinomas of the esophagus and esophagogastric junction in white men and women; compared with current smoking, smoking cessation was associated with reduced risks.

Obesity is not associated with adverse outcome following surgical resection of oesophageal adenocarcinoma

OBJECTIVE

To study the impact of obesity on postoperative morbidity and outcome following surgical resection of primary oesophageal adenocarcinoma (EADC).

METHODS

From a prospective database, we compared clinicopathological findings (age, gender, surgical approach, tumour differentiation and stage), postoperative mortality, morbidity, length of hospitalisation, disease-free survival (DFS) and overall survival (OS) between 56 obese (body mass index (BMI)≥30 mgkg(-2)) and 86 non-obese (BMI<30 mgkg(-2)) patients with EADC.

RESULTS

In this consecutive series, there were 118 male and 24 female patients with a median age of 63 years (range, 36-85 years). For all patients, the 5-year OS was 26.9%, with a median survival of 20 months. No significant differences (P>0.05) were found between obese and non-obese patients, with respect to age, gender, surgical approach (transthoracic vs transhiatal), pT-stage, duration of hospital stay, postoperative mortality or morbidity. However, compared with non-obese patients, obese patients had a higher frequency of postoperative respiratory complications (odds ratio (OR), 3.05; 95% confidence intervals (CIs), 1.29-7.17). DFS and OS at 5 years were increased for patients who were obese at the time of oesophageal resection (P=0.008).

CONCLUSIONS

Obesity is not associated with increased postoperative complication rates or adverse outcome following oesophageal resection, and should therefore not be considered a relative contraindication to the surgical management of EADC. The improved survival of obese patients who underwent oesophageal resection for EADC suggests that further investigation of the association between obesity and oesophageal malignancy is now warranted.

Abstract 194: Loss of imprinting and abnormal expression of insulin-like growth factor II in gastric cancer

Introduction: Gastric carcinoma (GC) is a leading cause of cancer mortality worldwide, and is highly prevalent in China. Loss of imprinting (LOI) of insulin-like growth factor II (IGF-2) gene is an important epigenetic phenomenon related to carcinogenesis and tumor progression in many human cancers. To date, however, few studies have evaluated the IGF-2 LOI in GC.

Aims: This study aimed: (1) to examine the prevalence of LOI of IGF-2 in tumor, matched normal gastric mucosa, and peripheral blood lymphocyte (PBL) from a well characterized series of patients with GC, and in PBL from a control group, (2) To examine the association of LOI of IGF-2 with circulating IGF-2 and tissue IGF-2 expression.

Methods: IGF-2 genomic imprinting status was analyzed by PCR and RT-PCR followed by restrictive endonuclease (Apa I) digestion. Prevalence of LOI in PBL from 33 Apa I informative GC patients (21 males, age: 59.91±13.87) was compared with that from 21 informative controls (13 males, age: 56.81±13.28). Findings were also associated with the clinicopathologic parameters in patients with GC. IGF-2 level in peripheral blood (ng/ml) and tumor were determined with ELISA and immunohistochemical staining, respectively.

Results: LOI of IGF-2 was positive in 48.48% (16/33) GC tumor, 21.21% (7/33) adjacent mucosa (AM), 12.12% (4/33) distant mucosa (DM), and 15.15% (5/33) PBL. The prevalence of LOI in PBL was not significantly different between GC patients (5/33, 15.15%) and controls (2/21, 9.52%) (p=0.693). Patients with LOI-positive tumor were more likely to be advanced stage (93.75% vs. 58.82%, p=0.039) or have positive lymph nodes (87.50% vs. 52.94%, p=0.057). Significantly increased blood IGF-2 level was seen in GC patients with LOI-positive tumor (808.07±255.25) when compared with those with LOI-negative tumor (396.21±198.94) (p&lt;0.01). The positive rate of IGF-2 staining was significantly higher in tumor (10 of 16, 62.50%), AM (7 of 7, 100.00%), and DM (3 of 4, 75.00%) with LOI than that in tissues without LOI (tumor: 2 of 17, 11.76%; AM: 2 of 26, 7.69%; DM: 2 of 29, 6.90%) (p&lt;0.01).

Conclusions: The results of this study suggest that IGF-2 is a critical factor in carcinogenesis and progression of GC, with LOI of IGF-2 modulating tissue and circulating expression of IGF-2. IGF-2 LOI may represent a potential epigenetic marker for gastric cancer risk, prognosis and treatment stratification.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 194.

Abstract 3363: Identification and characterization of stem-like cells in human esophageal epithelial and adenocarcinoma cells

The aim of this study was to identify and characterize stem-like cells in human normal esophageal epithelial and adenocarcinoma cell lines.

The immortalized esophageal epithelial cell line, Het-1A, and the primary esophageal adenocarcinoma (EADC) cell line, OE33, were first studied by flow cytometry and immunofluorescence using a panel of antibodies to putative stem cell biomarkers which included CD34, CD44, CD44/CD24, CD117/integrin α6, Musashi I, EpiCam, and Oct 4. Fluorescence activated cell sorting (FACS) was then used to isolate 15% of cells with the highest CD44 staining (CD44high) or reactive oxygen species (ROS) (ROShigh) and 15% of cells with the lowest (including negative) CD44 staining (CD44low) or ROS (ROSlow). Each cell population was further characterized using sphere-forming assays, soft agar clonogenic assays, flow cytometry for ROS, and synchrotron mid-infrared (IR) spectromicroscopy.

CD44 positivity was found in 90% of Het-1A and 75% of OE33 cells overall. For both Het-1A and OE33 cell lines, spheroid formation (mean±SD/5000 cells) was significantly higher in cells expressing high levels of CD44 (Het-1A:138.33±2.08 vs. 97.67±1.53, p&lt;0.01; OE33: 150.00±31.19 vs. 100.67±7.02, p=0.056) and low levels of ROS (Het-1A: 149.33±20.43 vs. 92.00±8.89, p=0.011; OE33: 199.67±31.63 vs. 119.33±14.47, p=0.016). Colony formation (mean±SD/1000 cells) was also found to be significantly higher in CD44high (Het-1A: 15.33±4.51 vs. 8.00±1.00, p=0.051; OE33: 92.67±11.02 vs. 18.00±1.73, p&lt;0.01) and ROSlow (Het-1A: 45.00±1.00 vs. 31.67±3.79, p&lt;0.01; OE33: 33.00±5.29 vs. 14.67±5.03, p=0.012) cell populations. Whereas OE33 CD44high cells were found to express consistently lower levels of ROS compared with OE33 CD44low cells (p&lt;0.01), no differences in ROS expression were found in Het-1A cells sorted by CD44 expression. Spectromicroscopic analysis revealed only small non-significant differences between cell populations sorted by CD44 and ROS expression.

We conclude that the higher rates of spheroid formation and clonogenicity of Het-1A and OE33 cells expressing high levels of CD44 (CD44high) and low levels of ROS (ROSlow) reflect an enrichment of stem-like cell populations in esophageal cell lines. However, the significant differences in ROS levels between CD44high OE33 cells and CD44high Het-1A cells suggests unique and biologically distinct pathways in stem-like cells derived from normal and malignant esophageal epithelia.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3363.

Dietary folate and vitamin B6 are not associated with p53 mutations in esophageal adenocarcinoma

Recent studies have suggested an association between dietary folate, and related B-vitamins, and risk for cancer, potentially mediated by the p53 tumor suppressor gene. The aim of this study was to explore the effect of dietary folate and vitamin B(6) intake on p53 in the molecular pathogenesis of esophageal adenocarcinoma (EADC). For each participant, a structured questionnaire was used to obtain detailed sociodemographic and lifestyle risk factors, including diet, from which folate and vitamin B(6) intake were calculated. Risks for p53 mutations, p53 mutations at CpG sites, and p53 protein overexpression among EADC cases (n = 54) were calculated using logistic regression with dietary folate and vitamin B(6) intake as predictive variables, adjusting for age, gender, smoking, and alcohol consumption. No significant differences were found for patients with EADC who had p53 mutations (n = 21) compared with patients with wild-type p53 (n = 33) with respect to selected clinicopathologic variables (age, gender, tumor grade, stage, alcohol, or tobacco consumption) and dietary intake of folate or vitamin B(6). No statistically significant associations were seen between dietary folate and vitamin B(6) intake (highest vs. lowest quartiles) and p53 mutations, p53 mutations at CpG sites (n = 12), and p53 protein overexpression (n = 17). We conclude that dietary intake of folate and vitamin B(6) do not appear to have an effect on p53, suggesting alternative molecular mechanisms underlying esophageal adenocarcinogenesis.

Prognostic value of p53 mutations in oesophageal adenocarcinoma: final results of a 15-year prospective study

OBJECTIVE

This study evaluates the clinical significance of p53 mutations in oesophageal adenocarcinoma (EADC).

METHODS

Between February 1991 and February 2006, 142 consecutive patients with EADC underwent potentially curative oesophageal resection. No patient received induction therapy. Strict clinicopathologic criteria were used to define primary EADC (Type I), excluding gastric cardia adenocarcinoma (Type II). Genomic DNA was extracted from oesophageal tumours, each with matched histologically normal oesophageal epithelium (internal control) from the resection margin. Polymerase chain reaction was used to amplify p53 exons 4-10, and mutations were characterised by direct DNA sequencing. The p53 mutations were correlated with clinicopathologic findings, p53 protein expression determined using immunohistochemistry, and outcome using Kaplan-Meier and Cox proportional hazards models.

RESULTS

For all patients, 5-year overall survival (OS) was 26.9%. Conventional predictors of reduced OS included advanced pathological tumour-node-metastasis (pTNM) stage (P<0.0001) and number of involved lymph nodes (0, 1-3, >3; P<0.0001). No p53 mutations were found in normal oesophageal epithelia. A total of 47% of tumours (67/142) had p53 mutations, predominantly G:C to A:T transitions at CpG dinucleotides (36/67). The p53 mutations were associated with p53 protein overexpression (P<0.0001) and poor tumour differentiation (P=0.037). Patients whose tumours had p53 mutations had significantly reduced 5-year OS (hazard ratio (HR): 1.54; 95% confidence interval (CI): 1.03-2.3; P=0.03).

CONCLUSIONS

Patterns of p53 mutations in EADC suggest endogenous molecular mechanisms. The p53 mutations are a predictor of significantly reduced postoperative survival following surgical resection of EADC, and would appear to be a clinically useful molecular prognostic biomarker.

Regulation of fibroblast growth factor-2 by an endogenous antisense RNA and by argonaute-2

We have previously reported that elevated fibroblast growth factor-2 (FGF-2) expression is associated with tumor recurrence and reduced survival after surgical resection of esophageal cancer and that these risks are reduced in tumors coexpressing an endogenous antisense (FGF-AS) RNA. In the present study, we examined the role of the endogenous FGF-AS transcript in the regulation of FGF-2 expression in the human lung adenocarcinoma cell line Seg-1. FGF-2 and FGF-AS were temporally and spatially colocalized in the cytoplasm of individual cells, and knockdown of either FGF-2 or FGF-AS by target-specific siRNAs resulted in dose-dependent up-regulation of the complementary transcript and its encoded protein product. Using a luciferase reporter system, we show that these effects are mediated by interaction of the endogenous antisense RNA with the 3'-untranslated region of the FGF-2 mRNA. Deletion mapping identified a 392-nucleotide sequence in the 5823-nucleotide FGF-2 untranslated tail that is targeted by FGF-AS. Small interfering RNA-mediated knockdown of either FGF-AS or FGF-2 significantly increased the stability of the complementary partner mRNA, demonstrating that these mRNAs are mutually regulatory. Knockdown of FGF-AS also resulted in reduced expression of argonaute-2 (AGO-2) and a number of other elements of the endogenous micro-RNA/RNA interference pathways. Conversely, small interfering RNA-mediated knockdown of AGO-2 significantly increased the stability of the FGF-2 mRNA transcript and the steady-state levels of both FGF-2 mRNA and protein, suggesting a role for AGO-2 in the regulation of FGF-2 expression.

Loss of imprinting of the insulin-like growth factor II (IGF2) gene in esophageal normal and adenocarcinoma tissues

To evaluate loss of imprinting (LOI) and expression of the IGF2 gene in matched esophageal normal and adenocarcinoma tissues, we studied a prospective cohort of 77 patients who underwent esophageal resection between 1998 and 2003. IGF2 imprinting status was determined by reverse transcription-polymerase chain reaction (PCR) following ApaI digestion, and quantitative PCR was used to evaluate IGF2 expression, which was correlated with clinicopathologic findings, disease-free and overall survival. In total, 32% (14/44) of informative tissues showed loss of IGF2 imprinting, with a strong correlation between the tumor and normal esophageal epithelia (Kappa = 0.89, P < 0.01). Normal epithelia with LOI had increased expression of IGF2 [median: 2.91, 95% confidence interval (CI): 0.93-5.06] compared with imprinted normal epithelia (median: 1.13, 95% CI: 0.85-1.39) (P = 0.03). In contrast, tumors with LOI had significantly reduced IGF2 expression (median: 1.87, 95% CI: 0.53-5.21) compared with normally imprinted tumors (median: 6.79, 95% CI: 3.39-15.89) (P = 0.016). Patients below the age of 65 years with normally imprinted tumors had significantly reduced 5 year disease-free survival (DFS) (24%) compared with patients whose tumors had LOI for IGF2 (55%) (P = 0.03). Cox regression analysis showed that IGF2 overexpression was associated with significantly reduced disease-free survival (P = 0.04). We conclude that in a subgroup of younger patients, loss of IGF2 imprinting was associated with improved outcome following esophageal resection. Expression of IGF2 in esophageal adenocarcinoma and normal esophageal epithelia depended on imprinting status and tissue type, suggesting novel molecular regulatory mechanisms in esophageal tumorigenesis.

Insulin-like growth factor type I receptor gene expression and obesity in esophageal adenocarcinoma

The objective of this exploratory study was to evaluate the role of the insulin-like growth factor I receptor (IGF-IR) in esophageal adenocarcinoma (EADC). Using quantitative PCR, we studied IGF-IR mRNA expression in 52 well-characterized surgically resected EADC and matched histologically normal esophageal tissues, and examined IGF-IR expression levels in relation to clinicopathologic characteristics, body mass index (BMI), and the common IGF-IR polymorphism (G1013A), recently proposed to modify risk of obesity for EADC. Expression levels of IGF-IR mRNA were not significantly different between EADC and matched histologically normal esophageal epithelia. Although no significant associations were found between IGF-IR expression and BMI, tumor differentiation, stage or survival, when stratified by genotype, patients with the polymorphic A variant had significantly higher IGF-IR expression in EADC tissues compared with matched normal epithelia. These findings suggest that G1013A most likely modulates IGF-IR function, possibly by influencing gene transcription or mRNA stability, and represents a plausible mechanistic link underlying the association between obesity and esophageal malignancy.

Regulation of CDX2 expression in esophageal adenocarcinoma

Reflux of acidic gastric contents and bile acids into the lower esophagus has been identified to have a central role in esophageal malignancy and is reported to upregulate caudal-related homologue 2 (CDX2), a regulatory gene involved in embryonic development and axial patterning of the alimentary tract. The aim of this study was to characterize the expression of CDX2 in a well-defined series of human esophageal tissues, comprising reflux-induced esophagitis, premalignant Barrett esophagus (BE), and primary esophageal adenocarcinoma (EADC). To explore potential molecular regulatory mechanisms, we also studied the expression of beta-catenin, SOX9, and CDX2 promoter methylation in esophageal tissues, in addition to the effect of bile acids and nitric oxide (NO) on CDX2 expression in the normal human esophageal cell line Het1A. Relative to matched normal esophageal epithelia, CDX2 was overexpressed in esophagitis (37% for RNA; cytoplasmic immunoreactivity in 48% of tissues), a high proportion (91%) of BE tissues, and in EADC (57% for RNA; cell nuclear immunopositivity in 80%). An association with beta-catenin expression was seen, but not with SOX9 or CDX2 promoter methylation. In Het1A cells, CDX2 was upregulated following exposure to bile acids and NO, alone and in combination. These results further implicate CDX2 and beta-catenin in the molecular pathogenesis of human EADC. The observed synergistic effect of NO on the efficacy of bile acid-induction of CDX2 suggests a novel role for NO in modulating the development of the Barrett phenotype and esophageal adenocarcinogenesis.

Waiting for surgery from the patient perspective

The aim of this study was to perform a systematic review of the impact of waiting for elective surgery from the patient perspective, with a focus on maximum tolerance, quality of life, and the nature of the waiting experience. Searches were conducted using Medline, PubMed, CINAHL, EMBASE, and HealthSTAR. Twenty-seven original research articles were identified which included each of these three themes. The current literature suggested that first, patients tend to state longer wait times as unacceptable when they experienced severe symptoms or functional impairment. Second, the relationship between length of wait and health-related quality of life depended on the nature and severity of proposed surgical intervention at the time of booking. Third, the waiting experience was consistently described as stressful and anxiety provoking. While many patients expressed anger and frustration at communication within the system, the experience of waiting was not uniformly negative. Some patients experienced waiting as an opportunity to live full lives despite pain and disability. The relatively unexamined relationship between waiting, illness and patient experience of time represents an area for future research.

MicroRNA expression in squamous cell carcinoma and adenocarcinoma of the esophagus: associations with survival

PURPOSE

The dismal outcome of esophageal cancer patients highlights the need for novel prognostic biomarkers, such as microRNAs (miRNA). Although recent studies have established the role of miRNAs in esophageal carcinoma, a comprehensive multicenter study investigating different histologic types, including squamous cell carcinoma (SCC) and adenocarcinoma with or without Barrett's, is still lacking.

EXPERIMENTAL DESIGN

miRNA expression was measured in cancerous and adjacent noncancerous tissue pairs collected from 100 adenocarcinoma and 70 SCC patients enrolled at four clinical centers from the United States, Canada, and Japan. Microarray-based expression was measured in a subset of samples in two cohorts and was validated in all available samples.

RESULTS

In adenocarcinoma patients, miR-21, miR-223, miR-192, and miR-194 expression was elevated, whereas miR-203 expression was reduced in cancerous compared with noncancerous tissue. In SCC patients, we found elevated miR-21 and reduced miR-375 expression levels in cancerous compared with noncancerous tissue. When comparing cancerous tissue expression between adenocarcinoma and SCC patients, miR-194 and miR-375 were elevated in adenocarcinoma patients. Significantly, elevated miR-21 expression in noncancerous tissue of SCC patients and reduced levels of miR-375 in cancerous tissue of adenocarcinoma patients with Barrett's were strongly associated with worse prognosis. Associations with prognosis were independent of tumor stage or nodal status, cohort type, and chemoradiation therapy.

CONCLUSIONS

Our multicenter-based results highlight miRNAs involved in major histologic types of esophageal carcinoma and uncover significant associations with prognosis. Elucidating miRNAs relevant to esophageal carcinogenesis is potentially clinically useful for developing prognostic biomarkers and identifying novel drug targets and therapies.

Physical activity, obesity and risk for esophageal adenocarcinoma

Over the past three decades, an increasing incidence of esophageal adenocarcinoma (EADC) has been reported throughout North America and Europe at a rate exceeding that of any other human solid tumor. Recent studies have clearly implicated chronic gastroesophageal reflux disease and several lifestyle risk factors, including tobacco consumption, diet and obesity, to be associated with increased risk of EADC. Although physical inactivity is now recognized as a risk factor for several chronic diseases including cancer, only a very limited number of studies have specifically evaluated the association between physical activity and esophageal malignancy. Furthermore, the precise biological mechanisms underlying the association between physical activity, obesity and cancer risk remain unclear. Since successful promotion of healthy body weight and exercise may substantially reduce the future incidence of cancer in the population, the purpose of this review is to explore current evidence linking physical activity, obesity and risk of malignancy – specifically EADC.

A polymorphic variant of the insulin-like growth factor type I receptor gene modifies risk of obesity for esophageal adenocarcinoma

BACKGROUND

To investigate potential biologic mechanisms underlying the association between obesity and risk for esophageal adenocarcinoma (EADC), we studied the frequency of a common polymorphism of the insulin-like growth factor I receptor (IGF-IR) gene in patients with either gastroesophageal reflux disease (GERD), premalignant Barrett esophagus (BE) and or invasive EADC.

METHODS

Using a well characterized series of 431 individuals enrolled in a case-control study, we studied the frequency of the IGF-IR gene polymorphism, G1013A.

RESULTS

On multivariate analysis controlling for age and gender, in comparison to asymptomatic controls, obese individuals with the polymorphic A-variant (G/A, A/A) were found to have significantly increased risk for EADC (OR 4.81; 95%CI 1.09-21.15), whereas obese individuals with the G/G variant were not at statistically significant increased risk (OR 2.69; 95%CI 0.41-17.62). Similarly, compared to asymptomatic controls, only obese individuals with the A-variant (G/A, A/A) were at increased risk for BE (OR 3.11; 95%CI 1.12-8.63), while obese individuals with the G/G variant were not at increased risk for BE (OR 2.91; 95%CI 0.69-12.15).

CONCLUSION

We conclude that the common IGF-IR gene polymorphism G1013A modulates the risk of obesity for EADC, an effect most likely mediated by altered the receptor function by influencing gene transcription or mRNA stability. These findings further implicate the insulin-like growth factor axis in the molecular pathogenesis of EADC, and represent a plausible mechanistic link underlying the association between obesity and malignancy.

Inducible nitric oxide synthase, nitrotyrosine and p53 mutations in the molecular pathogenesis of Barrett's esophagus and esophageal adenocarcinoma

Nitric oxide (NO) has been implicated as a potential causative factor for endogenous p53 mutations in gastrointestinal malignancy. To investigate the role of NO in esophageal adenocarcinoma (EADC), we studied patterns of p53 mutations, expression of inducible nitric oxide synthase (iNOS) and the tissue accumulation of nitrotyrosine (NTS), a stable reaction product of NO and a marker for cellular protein damage, in human premalignant and malignant esophageal epithelia. Tissues were obtained from patients with gastroesophageal reflux disease (GERD)-induced esophagitis (n = 76), Barrett's esophagus (BE; n = 119) and primary EADC (n = 54). DNA sequencing was used to characterize p53 mutations, RT-PCR to study iNOS mRNA expression, and immunohistochemistry to study NTS. Relative to self-matched normal epithelia, a progressive increase in iNOS mRNA expression was seen in GERD (30%; 23/76), BE (48%; 57/119), and EADC (63%; 34/54) tissues (P < 0.001). Among patients with EADC, elevated levels of NTS immunoreactivity were more frequent in tumors with p53 mutations (11/21; 52%) compared with tumors with wild-type p53 (9/33; 27%; P = 0.063), and specifically in tumors with p53 mutations at CpG dinucleotides (10/12; 83%) compared with non-CpG p53 mutations (1/9; 11%; P = 0.008). The increasing frequency of iNOS (mRNA) overexpression in GERD, BE and EADC supports the hypothesis that an active inflammatory process, most likely a consequence of GERD, underlies molecular progression to EADC. The highly significant association between NTS, reflecting chronic NO-induced cellular protein damage, and endogenous p53 mutations at CpG dinucleotides, provides further evidence for a molecular link between chronic inflammation and esophageal malignancy.

Alternative splicing and differential subcellular localization of the rat FGF antisense gene product

Background

GFG/NUDT is a nudix hydrolase originally identified as the product of the fibroblast growth factor-2 antisense (FGF-AS) gene. While the FGF-AS RNA has been implicated as an antisense regulator of FGF-2 expression, the expression and function of the encoded GFG protein is largely unknown. Alternative splicing of the primary FGF-AS mRNA transcript predicts multiple GFG isoforms in many species including rat. In the present study we focused on elucidating the expression and subcellular distribution of alternatively spliced rat GFG isoforms.

Results

RT-PCR and immunohistochemistry revealed tissue-specific GFG mRNA isoform expression and subcellular distribution of GFG immunoreactivity in cytoplasm and nuclei of a wide range of normal rat tissues. FGF-2 and GFG immunoreactivity were co-localized in some, but not all, tissues examined. Computational analysis identified a mitochondrial targeting sequence (MTS) in the N-terminus of three previously described rGFG isoforms. Confocal laser scanning microscopy and subcellular fractionation analysis revealed that all rGFG isoforms bearing the MTS were specifically targeted to mitochondria whereas isoforms and deletion mutants lacking the MTS were localized in the cytoplasm and nucleus. Mutation and deletion analysis confirmed that the predicted MTS was necessary and sufficient for mitochondrial compartmentalization.

Conclusion

Previous findings strongly support a role for the FGF antisense RNA as a regulator of FGF2 expression. The present study demonstrates that the antisense RNA itself is translated, and that protein isoforms resulting form alternative RNA splicing are sorted to different subcellular compartments. FGF-2 and its antisense protein are co-expressed in many tissues and in some cases in the same cells. The strong conservation of sequence and genomic organization across animal species suggests important functional significance to the physical association of these transcript pairs.

Selective cyclooxygenase-2 inhibition suppresses basic fibroblast growth factor expression in human esophageal adenocarcinoma

Inhibition of cyclooxygenase (COX)-2 is reported to suppress growth and induce apoptosis in human esophageal adenocarcinoma (EADC) cells, although the precise biologic mechanism is unclear. In this study we tested the hypothesis that the antitumor activity of COX-2 inhibitors may involve modulation of basic fibroblast growth factor (FGF-2), which is overexpressed in EADC. We evaluated the effects of NS-398, a selective COX-2 inhibitor, on FGF-2 expression and proliferation of EADC cell lines that express COX-2 and those that do not. We also correlated COX-2 and FGF-2 expression with clinico-pathologic findings and outcome in a well-characterized series of surgically resected EADC tissues. Seg-1 cells robustly expressed COX-2 and FGF-2, whereas Bic-1 cells expressed neither transcript. FGF-2 was reduced to undetectable levels in Seg-1 cells following NS-398 treatment, but increased within 4 h of drug removal. NS-398 significantly inhibited the growth of Seg-1 cells, and this effect was ameliorated by addition of exogenous FGF-2. In contrast, NS-398 had no effect on Bic-1 cell proliferation and FGF-2 alone had no effect on proliferation of either cell line. NS-398, or a neutralizing anti-FGF-2 antibody, induced apoptosis in Seg-1 cells, and these effects were inhibited by addition of exogenous FGF-2. COX-2 protein was strongly expressed in 46% (10/22) of EADCs, and was associated with a trend towards reduced disease-free survival. These findings indicate that the antitumor effects of COX-2 inhibition in EADC cells may be mediated via suppression of FGF-2, and that COX-2 may be a clinically relevant molecular marker in the management of human EADC.

Alternative splicing of the FGF antisense gene: differential subcellular localization in human tissues and esophageal adenocarcinoma

Overexpression of FGF-2 is associated with tumor recurrence and reduced survival after surgical resection of esophageal cancer, and these risks are reduced in tumors co-expressing the FGF antisense (FGF-AS) RNA. The aim of this study was to characterize the expression of alternatively spliced FGF-AS transcripts and encoded nudix-motif proteins in normal human tissues and in esophageal adenocarcinoma, and to correlate their expression with clinicopathologic findings and outcome. Three alternatively spliced FGF-AS transcripts encoding GFG/NUDT6 isoforms with distinct N termini were detected in various human tissues including esophageal adenocarcinoma. Expression of each isoform as a fusion protein with enhanced green fluorescent protein revealed differential subcellular trafficking: hGFGa is localized to mitochondria by an N-terminal targeting sequence (MTS), whereas hGFGb and hGFGc were localized in the cytoplasm and nucleus. Mutation/deletion analysis confirmed that the predicted MTS was necessary and sufficient for mitochondrial compartmentalization. The predominant FGF-AS mRNA expressed in esophageal tumors was splice variant b. GFG immunoreactivity was detected in the cytoplasm of all esophageal adenocarcinomas and in 88% of tumor cell nuclei. Although we found a trend towards reduced disease-free survival in patients with FGF-2 overexpressing esophageal adenocarcinomas, significantly worse disease-free survival was noted among patients whose tumors did not also overexpress the FGF-AS b isoform (p = 0.03). Tetracycline-inducible FGF-AS b expression in stably transfected human Seg-1 esophageal adenocarcinoma cells resulted in a significant suppression of steady state FGF-2 mRNA content and cell proliferation. Our data implicate the FGF-AS b isoform in modulation of FGF-2 expression and clinical outcome in esophageal adenocarcinoma.

Suppurative mediastinitis secondary to Burkholderia cepacia in a patient with cystic fibrosis

Burkholderia cepacia is an important opportunistic pathogen among patients with cystic fibrosis (CF); it is associated with deterioration of lung function, poor outcome following lung transplantation and increased mortality. Fever, an elevated white blood cell count, weight loss and an often fatal deterioration in pulmonary function characterize a particular clinical course, termed "Cepacia syndrome". The present case report describes a 40-year-old man with CF who developed Cepacia syndrome complicated by suppurative mediastinitis, from which B cepacia was isolated. Despite optimal medical and surgical therapy, this patient succumbed to his illness. Those caring for patients with CF should be aware of this potentially catastrophic complication of B cepacia infection, especially in the setting of Cepacia syndrome.

Genetic polymorphisms of microsomal epoxide hydroxylase and glutathione S-transferases M1, T1 and P1, interactions with smoking, and risk for esophageal (Barrett) adenocarcinoma

BACKGROUND

The aim of this case-control study was to test the hypothesis that polymorphisms of the microsomal epoxide hydroxylase (mEH) and glutathione S-transferase (GST) genes modulate the susceptibility to esophageal adenocarcinoma (EADC) associated with smoking.

METHODS

Cases included patients with gastroesophageal reflux disease (GERD) (n=126), Barrett esophagus (BE) (n=125), and EADC (n=56); controls comprised 95 strictly asymptomatic individuals. Genomic DNA was extracted from blood samples, and PCR-based assays were used to genotype mEH (slow allele, fast allele, predicted activity) and GSTM1, GSTT1 and GSTP1. Logistic regression was used to study associations between smoking and genotype, adjusting for age, gender and alcohol consumption.

RESULTS

Relative to asymptomatic controls, no significant differences were found for the distribution of mEH and GST polymorphic variants in cases with GERD, BE or EADC. Smoking was a risk factor for EADC, especially when cigarette exposure was greater than 30 pack-years (adjusted odds ratio [OR] 6.11, 95% confidence interval [CI] 2.2-17.32; P=0.001). The strong association between smoking and EADC was seen preferentially in patients with the active allele of either GSTM1 (OR 7.9, 95% CI 1.14-54.76; P=0.003) or GSTT1 (OR 3.2, 95% CI 1.23-8.35; P=0.004).

CONCLUSIONS

Cigarette smoking is an independent risk factor for EADC, and in particular for heavy smokers. The strong statistical association between smoking and risk for EADC in individuals with the active allele of either GSTM1 or GSTT1 may have potential clinical application in endoscopic surveillance programs to identify individuals with BE at increased risk for progression to EADC.

Obesity and lifestyle risk factors for gastroesophageal reflux disease, Barrett esophagus and esophageal adenocarcinoma

The aim of this study was to examine the association of obesity with esophageal adenocarcinoma, and with the precursor lesions Barrett esophagus and gastroesophageal reflux disease (GERD). This case-control study included cases with GERD (n = 142), Barrett esophagus (n = 130), and esophageal adenocarcinoma (n = 57). Controls comprised 102 asymptomatic individuals. Using logistic regression methods, we compared obesity rates between cases and controls adjusting for differences in age, gender, and lifestyle risk factors. Relative to normal weight, obese individuals were at increased risk for esophageal adenocarcinoma (Odds Ratio [OR] 4.67, 95% Confidence Interval [CI] 1.27-17.9). Diets high in vitamin C were associated with a lower risk for GERD (OR 0.40, 95% CI 0.19-0.87), Barrett esophagus (OR 0.44, 95% CI 0.20-0.98), and esophageal adenocarcinoma (OR 0.21, 95% CI 0.06-0.77). For the more established risk factors, we confirmed that smoking was a significant risk factor for esophageal adenocarcinoma, and that increased liquor consumption was associated with GERD and Barrett esophagus. In light of the current obesity epidemic, esophageal adenocarcinoma incidence rates are expected to continue to increase. Successful promotion of healthy body weight and diets high in vitamin C may substantially reduce the incidence of this disease.

Epidemiology and molecular biology of Barrett esophagus

Over the past three decades, there has been a marked change in the epidemiology of esophageal malignancy, with an increasing incidence of esophageal adenocarcinoma. The reasons for this are largely unknown and remain controversial, but several lifestyle risk factors have been proposed, including gastroesophageal reflux disease (GERD). It is hypothesized that chronic GERD results in acute mucosal injury, promotes cellular proliferation, and induces specialized columnar metaplasia (Barrett esophagus). Progression of Barrett esophagus to invasive adenocarcinoma is reflected histologically by the metaplasia-dysplasia-carcinoma sequence. Dysplasia is widely regarded as the precursor of invasive cancer, and high-grade dysplasia in Barrett epithelium is frequently associated with esophageal adenocarcinoma. Although several molecular alterations have been described in Barrett esophagus, it is anticipated that relatively few will prove to be clinically useful. To date, biomarkers which currently appear to predict the progression of Barrett esophagus to invasive malignancy include aneuploidy, loss of heterozygosity of 17p (implicating the p53 tumor suppressor gene), and cyclin D1 protein overexpression, and with further validation, will most likely be incorporated into routine clinical practice. It is anticipated that models incorporating objective scores of sociodemographic and lifestyle risk factors (ie, age, gender, body mass index), severity of reflux symptoms, endoscopic and histologic findings, and an assessment of a panel of biomarkers will be developed to further define subsets of patients with Barrett esophagus at increased risk for malignant progression, thereby permitting the development of more rational endoscopic surveillance and screening programs.

Basic fibroblast growth factor (FGF-2) overexpression is a risk factor for esophageal cancer recurrence and reduced survival, which is ameliorated by coexpression of the FGF-2 antisense gene

PURPOSE

The basic fibroblast growth factor (FGF-2) gene is bidirectionally transcribed to generate overlapping sense and antisense (FGF-AS) mRNAs. FGF-AS has been implicated in the post-transcriptional regulation of FGF-2 expression. The aim of this study was to characterize FGF-2 and FGF-AS in esophageal cancer and to correlate their expression with clinicopathologic findings and outcome.

EXPERIMENTAL DESIGN

Reverse transcription-PCR was used to study FGF-2 and FGF-AS mRNA expression (normalized to glyceraldehyde-3-phosphate dehydrogenase) in 48 esophageal cancers relative to matched histologically normal esophageal epithelia (internal control). We used Cox proportional hazards analysis to calculate hazard ratios for recurrence and survival of patients with underexpression relative to the overexpression of FGF-2 and/or FGF-AS.

RESULTS

Overexpression of FGF-2 mRNA, by comparison with tumors underexpressing FGF-2, was associated with significantly increased risk for tumor recurrence (hazard ratio, 3.80; 95% confidence interval, 1.64-8.76) and reduced overall survival (hazard ratio, 2.11; 95% confidence interval, 1.0-4.58). When the effects of FGF-2 and FGF-AS were considered simultaneously, the association of FGF-2 mRNA overexpression with recurrence and mortality was even more pronounced, whereas FGF-AS mRNA overexpression was associated with reduced risk for recurrence and improved survival.

CONCLUSIONS

Overexpression of FGF-2 mRNA is associated with tumor recurrence and reduced survival after surgical resection of esophageal cancer and that these risks are reduced in tumors coexpressing the FGF-AS mRNA. These data support the hypothesis that FGF-AS is a novel tumor suppressor that modulates the effect of FGF-2 expression and may have potential clinical application to the development of novel therapeutic strategies.