Etiology and risk factors for oesophageal adenocarcinoma: possibilities for chemoprophylaxis?

In vitro development and validation of a non-invasive (13)C-stable isotope assay for ornithine decarboxylase

Oesophageal cancer is a significant cause of cancer related mortality, with increasing incidence worldwide. Ornithine decarboxylase (ODC) is an enzyme involved in polyamine synthesis and cellular proliferation, and ODC expression and activity has been implicated as a prognostic marker of oesophageal cancer. This study aimed to develop and optimise an in vitro (13)C-stable isotope assay for ODC activity as a non-invasive marker of oesophageal cancer. Experiments were performed in triplicate (n  =  3/group/cell line) using Caco2, HeLa, Flo-1, OE33, TE7 and OE21 cell lines (colorectal, cervical, oesophageal adenocarcinoma and oesophageal squamous carcinoma respectively). Following addition of 2mM (13)C-ornithine to cells, 10 ml gas samples were collected from the headspace every 20 min for a total of five hours. Gas samples were analysed using isotope ratio mass spectrometry to quantify (13)CO2. Assay specificity was determined using the selective ODC inhibitor, N-(4'-Pyridoxil)-Ornithine(BOC)-OMe (POB). All data is expressed as δ (13)CO2 from baseline. High ODC activity was detected by (13)C-ornithine assay in Caco2 (32.00  ±  1.12 δ (13)CO2) in contrast to HeLa cells (5.44  ±  0.14 δ (13)CO2) cells. POB inhibited activity in Caco2 cells to 12.87  ±  1.10 δ (13)CO2. Differential ODC activity was detected in all oesophageal cancer cells, and 53 h incubation of cell lines with POB reduced activity by 72%, 56%, 64% and 69% in the Flo-1, OE33, OE21 and TE7 cell lines respectively. We have shown that ODC activity can be selectively detected by a non-invasive, stable-isotope (13)C-ornithine assay. ODC activity was detected in all oesophageal cancer cell lines in vitro. Further studies are indicated to quantify ODC activity in oesophageal cancer patients.

Incidence of esophageal cancer in Sri Lanka: Analysis of cancer registry data and comparison with other South Asian populations

INTRODUCTION

The objectives of this study were to report the incidence of Carcinoma of Esophagus (CaE) in Sri Lanka and to compare these values with other cancer registry data of the region and with migrant populations.

MATERIALS AND METHODS

We compared the data published by the National Cancer Control Program over the last two decades with data from the National Cancer Registry Programme of the Indian Council of Medical Research and Karachi Cancer Registry. SEERstat was used to analyze the surveillance, epidemiology and end results database to analyze data on Indian migrant population.

RESULTS

CaE was the fourth most common cancer overall and among females and third most common cancer among males. The incidence of CaE rises with age in both sexes, with a peak in the 70-74 year age group. There was a disproportionately higher number of CaE in the Tamil population (chi-square test, P < 0.00001). The commonest type of CaE in Sri Lanka was squamous cell carcinoma, Not otherwise specified (NOS) (n = 750, 70.5%), followed by adenocarcinoma, NOS (n = 83, 7.8%). India, Pakistan and Sri Lanka have comparable age-adjusted incidence and age distribution of CaE. All migrant populations had lower incidence of CaE than original population or population in their present country. Both cigarette smoking and alcohol consumption are more prevalent in Sri Lankan males than females.

DISCUSSION AND CONCLUSIONS

The incidence of CaE and its distribution among age groups in Sri Lanka was comparable to other countries of the region. Persons of Tamil ethnicity have a higher risk of developing CaE.

Lifestyle measures in the management of gastro-oesophageal reflux disease: clinical and pathophysiological considerations

Several lifestyle and dietary factors are commonly cited as risk factors for gastro-oesophageal reflux disease (GORD) and modification of these factors has been advocated as first-line measures for the management of GORD. We performed a systematic review of the literature from 2005 to the present relating to the effect of these factors and their modification on GORD symptoms, physiological parameters of reflux as well as endoscopic appearances. Conflicting results existed for the association between smoking, alcohol and various dietary factors in the development of GORD. These equivocal findings are partly due to methodology problems. There is recent good evidence that weight reduction and smoking cessation are beneficial in reducing GORD symptoms. Clinical and physiological studies also suggest that some physical measures as well as modification of meal size and timing can also be beneficial. However, there is limited evidence for the role of avoiding alcohol and certain dietary ingredients including carbonated drinks, caffeine, fat, spicy foods, chocolate and mint.

Meta-analysis of Barrett’s esophagus in China

AIM: To investigate the epidemiology and characteristics of Barrett’s esophagus (BE) in China and compare with cases in the west.

METHODS: Studies were retrieved from the China National Knowledge Infrastructure and PubMed databases using the terms “Barrett” and “Barrett AND China”, respectively, as well as published studies about BE in China from 2000 to 2011. The researchers reviewed the titles and abstracts of all search results to determine whether or not the literature was relevant to the current topic of this research. The references listed in the studies were also searched. Inclusion and exclusion criteria for the literature were appropriately established, and the data reported in the selected studies were analyzed. Finally, a meta-analysis was performed.

RESULTS: The current research included 3873 cases of BE from 69 studies. The endoscopic detection rate of BE in China was 1%. The ratio of male to female cases was 1.781 to 1, and the average age of BE patients was 49.07 ± 5.09 years. Island-type and short-segment BE were the most common endoscopic manifestations, accounting for 4.48% and 80.3%, respectively, of all cases studied. Cardiac-type BE was observed in 40.0% of the cases, representing the most common histological characteristic of the condition. Cancer incidence was 1.418 per 1000 person-years.

CONCLUSION: Average age of BE patients in China is lower than in Western countries. Endoscopic detection and cancer incidence were also lower in China.

Dietary fiber and the risk of precancerous lesions and cancer of the esophagus: a systematic review and meta-analysis

Dietary fiber has several anticarcinogenic effects and is thought to be protective against esophageal cancer. The aim of this systematic review was to quantify the association between dietary fiber and the risk of esophageal cancer by investigating histological subtypes of esophageal cancer and the stage at which fiber may influence the carcinogenic pathway. Systematic search strategies were used to identify relevant studies, and adjusted odds ratios (ORs) were combined using random-effects meta-analyses to assess the risk of cancer when comparing extreme categories of fiber intake. Ten relevant case-control studies were identified within the timeframe searched. Pooled estimates from eight studies of esophageal adenocarcinoma revealed a significant inverse association with the highest fiber intakes (OR 0.66; 95% confidence interval [CI] 0.44-0.98). Two studies also identified protective effects of dietary fiber against Barrett's esophagus. Similar, though nonsignificant, associations were observed when results from five studies of fiber intake and risk of squamous cell carcinoma were combined (OR 0.61; 95%CI 0.31-1.20). Dietary fiber is associated with protective effects against esophageal carcinogenesis, most notably esophageal adenocarcinoma. Potential methods of action include modification of gastroesophageal reflux and/or weight control.

The risk of Barrett's esophagus associated with abdominal obesity in males and females

Esophageal adenocarcinoma arises from Barrett's esophagus (BE). Both occur predominantly in males. The role of abdominal obesity in this sex distribution is uncertain. Our study aimed to determine whether there is an association between abdominal obesity and risk of BE and if present was it modified by sex. A structured interview and anthropometric measures were conducted within a population-based case-control study. We recruited 237 BE cases (70% male) and 247 population controls, frequency matched by age and sex. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using multivariable logistic regression analysis. In the overall group and males, all measures of abdominal obesity [waist circumference (WC), waist-hip ratio (WHR), sagittal abdominal diameter (SAD) and waist-height ratio (WHtR)] were strongly associated with risk of BE (Overall: WC OR 2.2 95% CI 1.4-3.5, WHR 1.8 95% CI 1.2-2.9, SAD 2.3 95% CI 1.4-3.7, WHtR 1.9 95% CI 1.2-3.0, males WC 2.5 95% CI 1.4-4.3, WHR 2.4 95% CI 1.3-4.2, SAD 2.5 95% CI 1.4-4.3, WHtR 1.9 95% CI 1.1-3.4). These associations were minimally attenuated by adjusting for ever-symptoms of gastroesophageal reflux (GER). These findings suggest in males, non-GER factors related to abdominal obesity may be important in the development of BE. In females, there was modest association between measures of abdominal obesity and risk of BE but these were all abolished after adjusting for ever-symptoms of GER. The power to detect differences between sexes in the risk of BE associated with abdominal obesity was limited by the number of females in the study.

Trends in incidence of gastrointestinal tract cancers in Western iran, 1993-2007

BACKGROUND

Few studies have addressed the secular trend of malignancies in developing countries such as Iran. This study aimed to determine the trend in the incidence of gastrointestinal cancers during a period of 15 years in Kermanshah, Iran.

METHODS

All of the confirmed positive pathologic reports for esophageal, gastric and colorectal cancers from 1993 to 2007 were collected and compared with the data compiled in the provincial health center. The incidence rate was standardized for world population using a direct method. The Fay and Feuer method was used to calculate the 95% confidence intervals for each cancer in each year. Trends were investigated using linear regression.

RESULTS

Over the period, 2951 cases of gastrointestinal cancer were reported in Kermanshah Province. The age-standardized incidence rates for gastric, esophageal and colorectal cancers were 9.2, 8.1 and 4.5 per 100,000 respectively over 15 years. In all types, the incidence increased with age. The study showed that the incidence of gastric and esophageal cancers decreased annually by 0.28 (-0.67-0.11) and 0.36 (-0.70 - (-0.02)), respectively. Colorectal cancer demonstrated an increase in the incidence [0.14 (95% CI: -0.01-0.29) annually].

CONCLUSION

A decrease in the incidence of gastric and esophageal cancers and an increase in the incidence of colorectal cancer are in line with reports from other developing countries in epidemiologic transition. Such trends warrant in depth investigation for the exact reasons.

From GERD to Barrett's esophagus: is the pattern in Asia mirroring that in the West?

Gastroesophageal reflux disease (GERD) is a known predisposing factor for Barrett's esophagus. Amongst individuals with symptomatic GERD, the prevalence of Barrett esophagus is estimated to be more than 10%, and an individual with Barrett's esophagus is more likely than the general population to develop esophageal adenocarcinoma. In Western Europe and North America, incidence of esophageal adenocarcinoma had been on the upward trend for many decades. In comparison, although the prevalence of GERD and reflux esophagitis has increased several fold in some parts of Asia, the prevalence of esophageal adenocarcinoma and Barrett's esophagus remains generally low in the region. Rising incidence of esophageal adenocarcinoma has been observed in regions witnessing increasing prevalence of GERD. If the recent increase in prevalence of GERD in parts of urbanized Asia is any indication of the beginning of an upsurge in the incidence of Barrett's esophagus and associated adenocarcinoma, would we be witnessing a pattern of epidemiological shift mirroring that in the West? Given that more than 90% of Barrett's esophagus in Asian patients is of the short-segment type, which is reported to have lesser propensity to develop to adenocarcinoma, could the ongoing epidemiologic transition take Asia on the same trail as that which the West has taken? This article will draw on relevant findings from various parts of Asia and take an in-depth look at prevailing disease trends to see where Asia stands now in the changing epidemiology of GERD, Barrett's esophagus and associated adenocarcinoma.

A population-based study of IGF axis polymorphisms and the esophageal inflammation, metaplasia, adenocarcinoma sequence

BACKGROUND & AIMS

Insulin-like growth factor (IGF) axis plays a key role in cell development, proliferation, and survival and is implicated in the etiology of several cancers. Few studies have examined the relationship between genetic variation of this axis and esophageal adenocarcinoma (EAC) or its precursors.

METHODS

In a population-based case-control study, we investigated the association of common polymorphisms of IGF-1, IGF-2, IGF-1 receptor, IGF binding protein-3, growth hormones (GH) 1 and GH2, and GH receptor with reflux esophagitis (RE), Barrett esophagus (BE), and EAC. Two hundred and thirty RE, 224 BE, 227 EAC cases, and 260 controls were studied. Gene polymorphisms were identified using publicly available online resources; 102 IGF axis tag and putatively functional single-nucleotide polymorphisms (SNPs) were analyzed using MassARRAY iPLEX and Taqman assays. Results were analyzed using Haploview.

RESULTS

Three polymorphisms were disease-associated. IGF1 SNP rs6214 was associated with BE (adjusted P = .039). Using GG genotype as reference, odds ratio for BE in AA (wild-type) was 0.43 (95% confidence interval [CI], 0.24-0.75). GH receptor SNP rs6898743 was associated with EAC (adjusted P = .0112). With GG as reference, odds ratio for EAC in CC (wild-type) genotype was 0.42 (95% CI, 0.23-0.76). IGF1 (CA)(17) 185-bp allele was associated with RE (adjusted P = .0116). Using IGF1(non17) as reference, odds ratio for RE in IGF1(17) carriers was 7.29 (95% CI, 1.57-46.7).

CONCLUSIONS

In this study, 3 polymorphisms of IGF genes were associated with EAC or its precursors. These polymorphisms may be markers of disease risk; independent validation of our findings is required. These results suggest the IGF pathway is involved in EAC development.

MicroRNAs in Barrett's esophagus and esophageal adenocarcinoma

The molecular genetics of Barrett's esophagus (BE) and its evolution to esophageal adenocarcinoma (EAC) have been widely studied; however, the molecular mechanism of BE-EAC carcinogenesis has not been completely understood. MicroRNA (miRNA) is now essential to understand the molecular mechanism of cancer progression. Recent findings include the following: firstly, miRNA expression profiles can distinguish between BE and EAC; secondly, miR-196a is upregulated in EAC tissues targeting annexin A1, thereby exerting antiapoptotic effects and contributing to EAC cell survival; miR-196a may also constitute a good biomarker of progression during BE-EAC carcinogenesis; and thirdly, The miR-106b-25 polycistron is activated by genomic amplification and is involved in esophageal neoplastic progression and proliferation via the suppression of two target genes, p21 and Bim.

Aspirin is not chemoprotective for Barrett's adenocarcinoma of the oesophagus in multicentre cohort

Barrett's columnar-lined oesophagus is the precursor lesion for oesophageal adenocarcinoma. The overall rate of progression to adenocarcinoma is 0.59% per annum. A large prospective multicentre trial is recruiting to assess the role of aspirin as a chemoprotective agent in prevention of development of cancer as well as cardiovascular protection in patients with Barrett's oesophagus. This retrospective analysis of the large UK National Barrett's Oesophagus Registry database seeks to analyse this question from within its large natural history study cohort. Multicentre UK retrospective cohort compared patients known to have been taking aspirin with those who did not take aspirin during the course of surveillance for columnar-lined oesophagus. End point was development of dysplasia or oesophageal adenocarcinoma. Analysis was undertaken using Cox's proportional hazard ratio. Total follow-up was 3683 patient-years. Eighty-six patients were taking aspirin, 650 were not taking aspirin (reference group). Numbers of patients developing all grades of dysplasia and adenocarcinoma were: 13 aspirin (15.1%) and 97 no aspirin (14.9%) (hazard ratio 0.723, 95% confidence interval 0.410-1.310, P = 0.294), high-grade dysplasia and adenocarcinoma: five aspirin (5.8%) and 25 no aspirin (3.8%) (hazard ratio 0.898, 95% confidence interval 0.340-2.368, P = 0.827) and adenocarcinoma: four aspirin (4.7%) and 16 no aspirin (2.5%) (hazard ratio 1.092, 95% confidence interval 0.358-3.335, P = 0.877). No significant difference was observed in hazard of developing dysplasia or adenocarcinoma between patients taking aspirin and those not taking aspirin during the course of follow-up of surveillance for columnar-lined oesophagus. In conclusion, no difference in risk of development of dysplasia or adenocarcinoma was observed between patients taking aspirin and those not taking aspirin in this large cohort.

Statins in esophageal cancer cell lines: promising lead?

Barrett's-associated esophageal adenocarcinoma (BEAC) is an important health concern in many western populations owing to its increasing incidence and the paucity of effective treatments. Statins have recently been suggested to induce anticancer effects against a variety of cancers in several, but not all, in vitro, in vivo, and epidemiologic studies. In the accompanying article by Ogunwobi and Beales, three statins were shown to inhibit proliferation and stimulate apoptosis in two EAC cell lines. These effects were achieved by reducing Ras, extracellular signal-regulated kinase (ERK), and protein kinase B (Akt)-related cellular signaling. Although these results are promising, they are clearly preliminary, and much additional work is needed to confirm or refute the potential anticancer effects of statins in human BEAC. In addition, the work of Ogunwobi and Beales highlights the importance of developing better, more predictive in vitro and in vivo models of BEAC, and of taking promising, low-risk agents, such as statins, into early-phase therapeutic and preventive clinical trials involving cancer patients and patients with Barrett's metaplasia/dysplasia, respectively.