Population attributable risks of esophageal and gastric cancers

Adenosine diphosphate ribosyl transferase and x-ray repair cross-complementing 1 polymorphisms in gastric cardia cancer

BACKGROUND & AIMS

Adenosine diphosphate ribosyl transferase (ADPRT) and x-ray repair cross-complementing 1 (XRCC1) are major DNA base excision repair proteins acting interactively in repair processes. This study examined the effects of ADPRT Val762Ala and XRCC1 Arg399Gln polymorphisms on ADPRT-XRCC1 interaction in vitro in cells and their contributions to gastric cardia adenocarcinoma (GCA) risk.

METHODS

The ADPRT-XRCC1 interaction in cells transfected with ADPRT and XRCC1 variant complementary DNA (cDNA) constructs were examined by immunoprecipitation and immunoblotting analysis. Genotypes were analyzed in 500 patients and 1000 controls, and odds ratios (ORs) were estimated by logistic regression.

RESULTS

Interactions between ADPRT-762Val and XRCC1-399Arg or XRCC1-399Gln were robust, but interactions between ADPRT-762Ala and either XRCC1-399Arg or XRCC1-399Gln were very weak. A case-control analysis showed ORs of 2.17 (95% CI, 1.55-3.04) and 1.61 (95% CI, 1.06-2.44) for GCA in the ADPRT Ala/Ala or XRCC1 Gln/Gln genotype carriers, respectively, compared with noncarriers. Gene-gene interaction of ADPRT and XRCC1 polymorphisms increased the OR of GCA in a multiplicative manner (OR for the presence of both ADPRT Ala/Ala and XRCC1 Gln/Gln genotypes, 6.43; 95% CI, 1.80-22.97). A supermultiplicative joint effect between the ADPRT polymorphism and smoking was observed. The ORs (95% CIs) of the Ala/Ala genotype for nonsmokers and smokers who smoked < or = 24 or > 24 pack-years were 1.44 (0.89-2.32), 2.00 (1.09-3.67), or 3.19 (1.59-6.42), respectively (Ptrend test = .008).

CONCLUSIONS

The ADPRT and XRCC1 polymorphisms confer host susceptibility to GCA, which might result from reduced ADPRT-XRCC1 interaction and attenuated base excision repair capacity.

Dietary selenium intake, aldehyde dehydrogenase-2 and X-ray repair cross-complementing 1 genetic polymorphisms, and the risk of esophageal squamous cell carcinoma

BACKGROUND

To the authors' knowledge, few studies have been conducted to date regarding dietary selenium and the potential gene-nutrient interactions with single-nucleotide polymorphisms (SNPs) in different pathways on the risk of esophageal cancer.

METHODS

The authors investigated the role of dietary selenium intake and its interplay with SNPs of the ALDH2 (glutamic acid [Glu] 487 lysine [Lys]) and the X-ray repair cross-complementing 1 (XRCC1) (arginine [Arg] 399 glutamine [Gln]) genes on the risk of esophageal squamous cell carcinoma (ESCC) in a population-based, case-control study in China. In total, 218 patients with ESCC and 415 healthy population control participants were interviewed. Dietary selenium intake was estimated from a food frequency questionnaire with 97 food items. ALDH2 and XRCC1 polymorphisms were detected with a polymerase chain reaction-restriction fragment length polymorphism assay.

RESULTS

The adjusted odds ratio (OR) for the highest quintile of dietary selenium intake, compared with the lowest quintile of intake, was 0.48 (95% confidence interval [95% CI], 0.25-0.89), with a strong dose-response relation (P for trend, <.01). The ALDH2 Lys and XRCC1 Gln variant alleles were associated with an increased risk of ESCC with adjusted ORs of 1.91 (95% CI, 0.96-3.80) and 1.67 (95% CI, 1.08-2.59), respectively. An elevation of the risk for ESCC was pronounced most among carriers of ALDH2 Lys/Lys and XRCC1 399Gln/Gln or Gln/Arg who consumed a low level of dietary selenium (adjusted OR, 4.16; 95% CI, 1.14-15.12).

CONCLUSIONS

To the authors' knowledge, this is the first in-depth study to suggest that genetic susceptibility may modify the association between selenium intake and the risk of ESCC. The findings indicated that individuals with low dietary selenium intake and ALDH2 Lys/Lys and XRCC1 399Gln/Gln or Gln/Arg genotypes were associated with an increased ESCC risk, especially in the presence of exposure to tobacco and alcohol carcinogens.

Polymorphisms in inflammation-related genes and risk of gastric cancer (Finland)

Helicobacter pylori infection is an important risk factor for gastric cancer, but <3% of carriers of this organism will ever develop gastric cancer. Since inflammation plays a significant role in gastric carcinogenesis, it has been suggested that polymorphisms in genes involved in inflammatory response may partly explain why only a subgroup of patients infected with H. pylori develop gastric cancer. We compared relative frequencies of 17 single nucleotide polymorphisms (SNPs) in eight inflammation-related genes between 112 gastric cancer patients and 208 controls. Cases and controls were selected from a large cohort of Finnish male smokers who were recruited into the Alpha-Tocopherol, Beta-Carotene Cancer Prevention (ATBC) Study. The studied SNPs were IL-1A (-889 C/T), IL-1B (-511 C/T and -31 T/C), IL-6 (-174 G/C and -597 G/A), IL-8 (-251 T/A, +396 T/G and +781 C/T), IL-8RA (Ex2 +860 G/C), IL-8RB (Exon 3 +1235 T/C, Exon 3 +811 C/T, and Exon 3 +1010 G/A), IL-10 (-819 C/T, -592 C/A, -1082 A/G), and TNF A (-308 G/A, -238 G/A). We found no statistically significant association between any of these SNPs, or the number of pro-inflammatory polymorphisms, with risk of gastric cancer. Our results do not support the hypothesis that polymorphisms in genes involved in the inflammatory response confer differences in gastric cancer risk among different individuals.

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.

Higher urine 1-hydroxy pyrene glucuronide (1-OHPG) is associated with tobacco smoke exposure and drinking maté in healthy subjects from Rio Grande do Sul, Brazil

BACKGROUND

The highest rates of esophageal squamous cell carcinoma (ESCC) in Brazil occur in Rio Grande do Sul, the most southern state, which has incidence rates of 20.4/100,000/year for men and 6.5/100,000/year for women. Exposure to carcinogenic polycyclic aromatic hydrocarbons (PAHs) through tobacco smoke and other sources may increase the risk of ESCC. The aims of the current study were to investigate the degree and sources of PAH exposure of the inhabitants of this region of southern Brazil.

METHODS

Two hundred healthy adults (half smokers, half non smokers, half male and half female) were recruited, given a standardized questionnaire, and asked to provide a urine sample for measurement of 1-hydroxypyrene glucuronide (1-OHPG), a PAH metabolite). Urine 1-OHPG concentrations were measured using immunoaffinity chromatography and synchronous fluorescence spectroscopy and urine cotinine was measured using a dipstick test. We examined factors associated with 1-OHPG concentration using Wilcoxon tests and multiple linear regression.

RESULTS

Urine 1-hydroxypyrene glucuronide (1-OHPG) was successfully measured on 199 subjects. The median (interquartile range) of urine 1-OHPG in the 199 participants was 2.09 pmol/mL (0.51, 5.84). Tobacco smoke exposure and maté drinking were statistically significantly associated with higher urine 1-OHPG concentrations in the multivariate linear regression model.

CONCLUSION

Tobacco smoke and maté both contribute to high levels of benzo[a]pyrene exposure in the people of southern Brazil. This high PAH exposure may contribute to the high rates of ESCC observed in this population. The increased urine 1-OHPG concentrations associated with maté suggest that contaminants, not just thermal injury, may help explain the increased risk of ESCC previously reported for maté consumption.

Fruit and vegetable intake and the risk of stomach and oesophagus adenocarcinoma in the European Prospective Investigation into Cancer and Nutrition (EPIC-EURGAST)

It is considered that fruit and vegetable (F&V) protect against oesophagus and gastric cancer (GC). However, 2 recent meta-analyses suggest that the strength of association on GC seems to be weaker for vegetables than for fruit and weaker in cohort than in case-control studies. No evidence exists from cohort studies about adenocarcinoma of oesophagus (ACO). In 521,457 men and women participating in the EPIC cohort in 10 European countries, information of diet and lifestyle was collected at baseline. After an average of 6.5 years of follow-up, a total of 330 GC and 65 ACO, confirmed and classified by a panel of pathologists, was used for the analysis. We examined the relation between F&V intake and GC and ACO. A calibration study in a sub-sample was used to control diet measurement errors. In a sub-sample of cases and a random sample of controls, antibodies against Helicobacter pylori (Hp) were measured and interactions with F&V were examined in a nested case-control study. We observed no association with total vegetable intake or specific groups of vegetables and GC risk, except for the intestinal type, where a negative association is possible regarding total vegetable (calibrated HR 0.66; 95% CI 0.35-1.22 per 100 g increase) and onion and garlic intake (calibrated HR 0.70; 95% CI 0.38-1.29 per 10 g increase). No evidence of association between fresh fruit intake and GC risk was observed. We found a negative but non significant association between citrus fruit intake and the cardia site (calibrated HR 0.77; 95% CI 0.47-1.22 per 100 g increase) while no association was observed with the non-cardia site. Regarding ACO, we found a non significant negative association for vegetable intake and for citrus intake (calibrated HRs 0.72; 95% CI 0.32-1.64 and 0.77; 95% CI 0.46-1.28 per 100 and 50 g increase, respectively). It seems that Hp infection does not modify the effect of F&V intake. Our study supports a possible protective role of vegetable intake in the intestinal type of GC and the ACO. Citrus fruit consumption may have a role in the protection against cardia GC and ACO.

Multistage carcinogenesis in Barrett's esophagus

The multistage carcinogenesis of esophageal adenocarcinoma is a process of clonal evolution within Barrett's esophagus neoplasms. The initiating event for Barrett's esophagus is unknown, but is associated with chronic gastric reflux which probably also promotes progression. Inactivation of both alleles of CDKN2A appear to be early events causing clonal expansion. Clones with TP53 inactivated expand if they have already inactivated CDKN2A. After TP53 has been inactivated, tetraploid and aneuploid clones tend to develop. The final events that lead to invasion and metastasis are unknown. Evolutionary biology provides important tools to understand clonal evolution in progression and cancer prevention.

Patterns of cancer incidence, mortality, and prevalence across five continents: defining priorities to reduce cancer disparities in different geographic regions of the world

Efforts to reduce global cancer disparities begin with an understanding of geographic patterns in cancer incidence, mortality, and prevalence. Using the GLOBOCAN (2002) and Cancer Incidence in Five Continents databases, we describe overall cancer incidence, mortality, and prevalence, age-adjusted temporal trends, and age-specific incidence patterns in selected geographic regions of the world. For the eight most common malignancies-cancers of lung, breast, colon and rectum, stomach, prostate, liver, cervix, and esophagus-the most important risk factors, cancer prevention and control measures are briefly reviewed. In 2002, an estimated 11 million new cancer cases and 7 million cancer deaths were reported worldwide; nearly 25 million persons were living with cancer. Among the eight most common cancers, global disparities in cancer incidence, mortality, and prevalence are evident, likely due to complex interactions of nonmodifiable (ie, genetic susceptibility and aging) and modifiable risk factors (ie, tobacco, infectious agents, diet, and physical activity). Indeed, when risk factors among populations are intertwined with differences in individual behaviors, cultural beliefs and practices, socioeconomic conditions, and health care systems, global cancer disparities are inevitable. For the eight most common cancers, priorities for reducing cancer disparities are discussed.

Adenocarcinoma of the oesophagus and gastric cardia: Male preponderance in association with obesity

Recent evidence links obesity with the rising incidence of oesophageal adenocarcinoma. In Ireland between 1995 and 2004 the incidence of oesophageal adenocarcinoma increased by 38%, and this coincided with a 67% increase in the prevalence of obesity. In this study, a prospective case-control study was undertaken in 760 patients presenting to a tertiary centre between 1994 and 2004 diagnosed with cancer of the oesophagus, gastric cardia or stomach. Data were compared with 893 healthy controls. Multivariate logistic regression models were used to calculate the odds ratio (OR) of developing either cancer type according to quartiles of body mass index (BMI). Based on pre-illness BMI, 82% of patients who developed adenocarcinoma of the oesophagus were either overweight or obese compared with 59% of the healthy control population (P<0.001). A dose-dependent relationship existed between BMI and oesophageal adenocarcinoma in males. The adjusted odds ratio was 4.3 (95% CI: 2.3-7.9) among males in the highest BMI quartile compared with males in the lowest quartile (P<0.001 for trend). Using common cut-off points for BMI, the OR of adenocarcinoma of the lower oesophagus was 11.3 times higher (95% CI: 3.5-36.4) for individuals with a BMI >30 kg/m2 versus individuals with a BMI <22 kg/m2 (P<0.001 for trend). For adenocarcinoma of the gastric cardia, males in the top quartile of BMI had an OR of 3.5 (95% CI: 1.3-9.4) compared with the lowest quartile (P=0.03 for trend). A significant (P<0.001) inverse relationship between BMI and oesophageal SCC was observed. The odds ratio for adenocarcinoma of the oesophagus, the oesophago-gastric junction and gastric cardia rose significantly with increasing BMI. For tumours of the lower oesophagus, obesity increased the risk 10.9-fold. The increased risk is significant in males only.

Association of esophageal adenocarcinoma with other subsequent primary cancers

PURPOSE

Esophageal adenocarcinoma shares risk factors such as obesity and smoking with other common cancers. The association of esophageal adenocarcinoma with other primary cancers has not been systematically evaluated. The authors used the Surveillance, Epidemiology and End-Results database of the National Cancer Institute to explore the association of esophageal adenocarcinoma with other primary cancers.

PATIENTS AND METHODS

All adult patients with esophageal cancers, both adenocarcinoma and squamous cell carcinoma diagnosed between 1973 and 2001, were identified from the Surveillance, Epidemiology, and End-Results database, and standardized incidence rates were calculated for all subsequent primary cancers in these patients. The analysis was reversed to estimate the standardized incidence rate for subsequent primary esophageal cancer after a first primary cancer.

RESULTS

In comparison with a standard population, patients with esophageal adenocarcinoma were at higher risk for the development of another subsequent cancer, specifically, cancers of the oral cavity and pharynx, lung and bronchus, and kidney and renal pelvis, and adenocarcinoma of the colon/rectum and pancreas. With squamous cell esophageal cancer, there was an association with tobacco-related cancers such as those of the oral cavity and pharynx, the lung and bronchus, and the breast. There was either no association or even a negative association of esophageal adenocarcinoma with other obesity-related cancers such as breast, uterine, and prostate cancers.

CONCLUSIONS

Patients with esophageal adenocarcinoma and squamous cell carcinoma are at increased risk for the development of specific second primary cancers that share smoking as a common risk factor. Esophageal adenocarcinoma does not have a strong association with obesity-related cancers with respect to the relative risk for the development of subsequent primary cancers.

Difference in the incidence trend of nasopharyngeal and oropharyngeal carcinomas in Taiwan: implication from age-period-cohort analysis

Lifestyle factors are considered important for the pathogenesis of both nasopharyngeal and oropharyngeal carcinomas. In Taiwan, the incidence of nasopharyngeal carcinoma gradually decreased over the past 20 years, whereas that of oropharyngeal carcinoma increased rapidly. To compare the incidence trends of nasopharyngeal and oropharyngeal carcinomas in Taiwan, the age-period-cohort model was used to analyze epidemiologic data from 1981 to 2000 obtained from the Taiwan Cancer Registry. The calendar time period of 1986 to 1990 and the 1931 to 1940 birth cohort were used as reference groups for estimates of relative risk. For nasopharyngeal carcinoma, the incidence seemed to decrease in most age groups and was more prominent in women (30%) than in men (23%). For oropharyngeal carcinoma, the incidence increased in all age groups and was more prominent in men (391.4%) than in women (59.2%). Cohort effect was found for both nasopharyngeal and oropharyngeal carcinomas. The relative risk of nasopharyngeal carcinoma for the 1971 to 1980 birth cohort was 0.38 for women and 0.68 for men. The relative risk of oropharyngeal carcinoma for the 1971 to 1980 cohort was 45.67 for men and 2.69 for women. Change in lifestyle seemed to be an important factor for the difference in the incidence trend between nasopharyngeal and oropharyngeal carcinomas and between men and women.

Controversies surrounding body mass, reflux, and risk of oesophageal adenocarcinoma

At first the association between body mass, reflux, and oesophageal adenocarcinoma might seem easily interpreted, but a more thorough assessment of the published work shows that several factors are missing. Reflux and obesity are established risk factors for oesophageal adenocarcinoma, particularly when they occur in combination. However, the interplay between these and other factors with regard to oesophageal adenocarcinoma is uncertain. Moreover, the contribution of these risk factors in explaining the increasing incidence of oesophageal adenocarcinoma is unclear, because the trends in prevalence of reflux and obesity do not match those of incidence of oesophageal adenocarcinoma. Moreover, none of these factors contribute strongly to the striking predominance of oesophageal adenocarcinoma in men. Thus, several factors that can explain the development of oesophageal adenocarcinoma need to be addressed.

Esophageal Squamous Cell Carcinoma and Aldehyde Dehydrogenase-2 Genotypes in Japanese Females

BACKGROUND

Aldehyde dehydrogenase-2 (ALDH2) is the key enzyme for elimination of acetaldehyde, an established animal carcinogen produced after drinking. In persons with inactive ALDH2, the body fails to metabolize acetaldehyde rapidly, leading to excessive accumulation of acetaldehyde. Inactive heterozygous ALDH2 enhances the risk of esophageal squamous cell carcinoma (SCC) in Japanese male drinkers.

METHODS

We studied whether this is the case for women. The risk factors of esophageal SCC were examined in 52 Japanese women with esophageal SCC and 412 cancer-free Japanese women.

RESULTS

The increasing trend in cancer risk according to the quantity of alcohol consumption was significantly steeper in women with inactive heterozygous ALDH2 than in those with active ALDH2 [adjusted odds ratios (ORs) (95% confidence intervals (CIs)) per +7 U/wk increment of alcohol drinking were 3.91 (2.09-7.31) and 1.39 (0.92-2.09), respectively; p = 0.006 for difference in OR; 1 Ut = 22 g of ethanol]. The results obtained using an alcohol-flushing questionnaire were essentially comparable with those obtained by ALDH2 genotyping [adjusted ORs (95% CIs) per +7 U/wk increment of alcohol drinking were 3.94 (1.87-8.31) and 1.46 (0.96-2.23) in those with and without flushing, respectively; p = 0.021 for difference in OR]. The risk of esophageal cancer was markedly higher in heavy drinkers with ALDH2*1/*2 than in never/rare drinkers with ALDH2*1/*1 [adjusted OR (95% CI) = 59.1 (4.65-750)]. Other independent significant risk factors of esophageal SCC were smoking, a preference for hot food or drinks, and lower intake of green and yellow vegetables.

CONCLUSIONS

Japanese men and women shared several common risk factors of esophageal SCC, including drinking with inactive heterozygous ALDH2.

A clinically practicable diagnostic score for metabolic syndrome improves its predictivity of diabetes mellitus: the Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto miocardico (GISSI)-Prevenzione scoring

BACKGROUND

Metabolic syndrome (MS) is associated with late-onset diabetes. However, diagnostic criteria for individual components of MS are based on categorical/arbitrary cut points and, therefore, do not exploit the information yield of each factor. We aimed to generate a diagnostic score for MS (MS-Score), aimed at predicting diabetes by giving appropriate weight to the individual components of MS.

METHODS

Of 11,323 patients with prior myocardial infarction and followed up for 3.5 years in the GISSI-Prevenzione study, 3855 subjects with diabetes at baseline or missing information for relevant variables were excluded. A Cox proportional hazards model including age, sex, glycemia, high-density lipoprotein cholesterol, triglycerides, hypertension, and body mass index was fitted to create a diagnostic score. A cutoff point of 28 of the score was the best compromise between sensitivity and specificity for MS diagnosis (MS-Score). The prognostic performance of the MS-Score was compared with that of the diagnostic criteria of MS, as defined by National Cholesterol Education Program Adult Treatment Panel III (MS-ATP).

RESULTS

Of 7468 patients, 940 developed diabetes. The risk of getting diabetes significantly and progressively increased in the quintiles of the score reaching > 6-fold higher risk in the last one. The predictive capability of MS-Score was significantly higher than that of the MS-ATP (AUC = 0.650 vs 0.587, sensitivity 67% vs 52%, specificity 63% vs 66%, P = .0002). The MS-Score, but not the MS-ATP, was significantly associated with mortality.

CONCLUSION

MS-Score improves the prediction of diabetes development by using the full informative content of individual components for diagnosis of MS.

Risk factors associated with myocardial infarction in Africa: the INTERHEART Africa study

BACKGROUND

Cardiovascular disease (CVD) is rising in low-income countries. However, the impact of modifiable CVD risk factors on myocardial infarction (MI) has not been studied in sub-Saharan Africa (SSA). Therefore, we conducted a case-control study among patients with acute MI (AMI) in SSA to explore its association with known CVD risk factors.

METHODS AND RESULTS

First-time AMI patients (n=578) were matched to 785 controls by age and sex in 9 SSA countries, with South Africa contributing approximately 80% of the participants. The relationships between risk factors and AMI were investigated in the African population and in 3 ethnic subgroups (black, colored, and European/other Africans) and compared with those found in the overall INTERHEART study. Relationships between common CVD risk factors and AMI were found to be similar to those in the overall INTERHEART study. Modeling of 5 risk factors (smoking history, diabetes history, hypertension history, abdominal obesity, and ratio of apolipoprotein B to apolipoprotein A-1) provided a population attributable risk of 89.2% for AMI. The risk for AMI increased with higher income and education in the black African group in contrast to findings in the other African groups. A history of hypertension revealed higher MI risk in the black African group than in the overall INTERHEART group.

CONCLUSIONS

Known CVD risk factors account for approximately 90% of MI observed in African populations, which is consistent with the overall INTERHEART study. Contrasting gradients found in socioeconomic class, risk factor patterns, and AMI risk in the ethnic groups suggest that they are at different stages of the epidemiological transition.

Incidence of esophageal and gastric carcinomas among American Asians/Pacific Islanders, whites, and blacks

BACKGROUND

The authors examined subsite-specific and histology-specific esophageal and gastric carcinoma incidence patterns among the Asians/Pacific Islander (API) population in the United States and compared them with those among whites and blacks.

METHODS

Data on newly diagnosed esophageal and gastric carcinomas during 1996-2000 were obtained from 24 population-based central cancer registries, representing approximately 80% of the API population in the United States. Age-adjusted rates, using the 2000 United States standard population, and age-specific rates were computed by anatomic subsite, histology, race, and gender. The difference in the age-adjusted rates between APIs and other races were examined using the two-tailed z statistic.

RESULTS

Greater than 75% of esophageal carcinomas among APIs, both males and females, were squamous cell carcinoma. Adenocarcinoma accounted for <20% of all esophageal carcinomas. This pattern was similar to that among blacks but was completely opposite to that among whites. The rate of esophageal squamous cell carcinoma was 81% higher among API males compared with white males, but it was 64% less compared with black males. The rates of esophageal adenocarcinoma were significantly lower among APIs than among both whites and blacks both males and females. The majority of gastric carcinomas among APIs were noncardia adenocarcinoma, whereas cardia adenocarcinoma accounted for only 11% of gastric carcinomas among API males and 6% of gastric carcinomas among API females. The age-adjusted incidence rate of cardia adenocarcinoma was 23% lower among API males compared with white males, but it was 26% higher compared with black males. In contrast, the rates of noncardia adenocarcinoma among APIs were approximately 3.7 times the rate among whites for both males and females and 33% higher than the rate among blacks.

CONCLUSIONS

Subsite-specific and histology-specific incidence patterns of esophagogastric carcinoma among APIs differ from those among whites and blacks. The reasons for significantly higher rates of noncardia adenocarcinoma among APIs compared with whites and blacks need further investigation.

Carbonated soft drink consumption and risk of esophageal adenocarcinoma

Carbonated soft drinks (CSDs) have been associated with gastroesophageal reflux, an established risk factor for esophageal adenocarcinoma. As both CSD consumption and esophageal adenocarcinoma incidence have sharply increased in recent decades, we examined CSD as a risk factor for esophageal and gastric cancers in a U.S. multicenter, population-based case-control study. Associations between CSD intake and risk were estimated by adjusted odds ratios (ORs), comparing the highest versus lowest quartiles of intake. All statistical tests were two-sided. Contrary to the proposed hypothesis, CSD consumption was inversely associated with esophageal adenocarcinoma risk (highest versus lowest quartiles, OR = 0.47, 95% confidence interval = 0.29 to 0.76; Ptrend = .005), due primarily to intake of diet CSD. High CSD consumption did not increase risk of any esophageal or gastric cancer subtype in men or women or when analyses were restricted to nonproxy interviews. These findings indicate that CSD consumption (especially diet CSD) is inversely associated with risk of esophageal adenocarcinoma, and thus it is not likely to have contributed to the rising incidence rates.

Nutrition in the prevention of gastrointestinal cancer

Diet has been hypothesized to play a role in the etiology of gastrointestinal cancer for a long time. Initially, strong evidence of such effects was found in retrospective epidemiological studies. Dietary habits, in particular those from the distant past, are difficult to measure, however. Results from recent, prospective and larger studies of better quality did not always confirm these associations. Consumption of fruits and vegetables appear to have a modest role in the prevention of gastrointestinal cancers. In contrast, the roles of alcohol consumption and overweight on risk of gastrointestinal cancer have become much clearer. Overweight and obesity are important risk factors for adenocarcinoma (but not squamous carcinoma) of the esophagus, gastric cardia carcinoma (but not noncardia carcinoma), and colorectal cancer, the latter in particular among men. Alcohol consumption is a risk factor for squamous carcinoma (but not adenocarcinoma) of the esophagus, gastric cancer and colorectal cancer. Selenium may be inversely related to esophageal and gastric cancer.

Management and prognosis of esophageal cancers: Has progress been made?

The aim of this study was to investigate time trends in treatment and prognosis of esophageal cancer in a well-defined French population. Data was obtained from the Burgundy Cancer Registry (France) and three time periods were defined: 1976-90, 1991-96 and 1997-2002. A logistic regression was used to identify factors associated with an R0 resection. A multivariate survival analysis was performed using a Cox model. From 1976 to 2002, 2267 patients were included. The R0 resection rate slightly increased from 20.9% to 25.8% (P=0.019) then remained stable. Operative mortality decreased from 11.7% to 6.7% (NS). Age and subsite significantly influenced the rate of resection for cure whereas period had no effect. Chemotherapy alone was seldom used and radiotherapy alone dramatically dropped over time. Chemoradiation used as adjuvant treatment increased from 16.3% (1976-90) to 30.6% (1997-02) (P<0.001) and as sole treatment from 16.0% to 48.5% (P<0.001). The 3-year survival rates were respectively 10.1% and 9.7% (NS). Age and stage at diagnosis influenced the prognosis of esophageal cancer whereas time period and histology had no influence. This study claims that esophageal cancer remains a serious cancer problem and no improvement has been seen in the study population in France in its management over time.

Regular aspirin use and esophageal cancer risk

Given the high mortality rate and the rapidly increasing incidence rate of esophageal carcinoma, chemopreventive agents are highly desirable. Aspirin has been shown to be associated with reduced risk of developing colorectal carcinoma and other cancers. Even though previous studies have shown reduced risk of esophageal cancer associated with aspirin use, results were inconsistent with respect to frequency and duration of use. In this hospital-based case-control study, 163 esophageal cancer cases were compared to 482 age- and sex-matched hospital controls with nonneoplastic conditions. Participants were classified as regular aspirin users if they had taken the drug at least once a week for 6 months. Results suggest that esophageal cancer risk is significantly lower for regular aspirin users compared to nonusers [adjusted odds ratio (aOR) 0.54; 95% confidence interval (CI) 0.36-0.86]. Individuals who used an equivalent of at least 1 aspirin a day (> or =7 tablets/week) were half as likely to have been diagnosed with esophageal carcinoma (aOR 0.47; 95% CI 0.26-0.85), and a linear trend was noted with increasing frequency of use (p(trend) 0.007). Similar protective effects were noted with < or =20 years of use, whereas no risk reduction was noted with >20 years of use. Consistent reduction in risk associated with aspirin use was noted among both the major histological subtypes, but the protective effect appears to be more pronounced in adenocarcinoma compared to squamous cell carcinoma. Overall, results from the current study suggest that regular aspirin use may be associated with reduced risk of esophageal cancer.

Smoking--a trigger for chronic inflammation and cancer development in the pancreas

Tobacco smoke, with its complexity of constituents, damages the pancreatic organ in multiple ways. Smoke not only affects pancreatic secretion patterns via its nicotine content but induces inflammatory reactions and exerts carcinogenic effects by several other constituents. Smoke enhances ethanol-induced pancreatic injury and accelerates the development and progression of chronic pancreatitis independent of etiology. Through the process of inflammation, smoking contributes to pancreatic carcinogenesis. The experiment of Wittel and colleagues published in this issue of the American Journal of Gastroenterology sheds further light on this topic by reporting in great detail two different kinds of pancreatic damage in rats exposed to high doses of smoke.

Low-fat, high fruit and vegetable diets and weight loss do not affect biomarkers of cellular proliferation in Barrett esophagus

Risk factors for esophageal adenocarcinoma include obesity, high fat intake, and low consumption of fruits and vegetables. This trial tested whether an intervention to reduce these risk factors in patients with Barrett esophagus, a preneoplastic condition for esophageal adenocarcinoma, could reduce biomarkers of cellular proliferation and, by inference, the risk of neoplastic progression. Eighty-seven men and women with Barrett esophagus were randomized to an intensive dietary intervention or control group. At baseline, 18 and 36 months after intervention, biopsies were obtained at 2-cm intervals throughout the length of the Barrett segment. Ki67/DNA content flow cytometry was used to assess (a) % Ki67-positive proliferating diploid G(1) cells, (b) % total Ki67-positive proliferating cells, (c) presence of aneuploidy, and (d) presence of >6% of cells in the 4N (G(2)/tetraploid) fraction of the cell cycle. We also assessed re-epithelialization and length of the Barrett segment, reflux symptoms, and medication use. The intervention effects for energy, fat, fruits and vegetables, and weight were, respectively, -314 kcal, -12.2% energy, 1.8 servings/d, and -4.0 kg at 18 months (all P < 0.005) and were smaller but remained significant at 36 months. There were no significant effects of the intervention on any biomarker of cellular proliferation. The intervention effects +/- SE for mean %G(1) Ki67+ cells were 0.98 +/- 1.58 at 18 months and 1.79 +/- 1.31 at 36 months; the relative risks (95% confidence interval) for developing >6% of cells in 4N were 0.5 (0.1-2.6) at 18 months and 0.75 (0.2-3.1) at 36 months. A single control participant developed aneuploidy. There were no significant effects on re-epithelialization, segment length, or reflux medication use. We conclude that substantial dietary change has no short-term effects on biomarkers of cellular proliferation in Barrett esophagus or on clinical observations of the Barrrett segment.

Non-steroidal anti-inflammatory drugs and risk of neoplastic progression in Barrett's oesophagus: a prospective study

BACKGROUND

Aspirin and other non-steroidal anti-inflammatory drugs (NSAID) probably decrease the risk of colorectal neoplasia; however their effect on development of oesophageal adenocarcinoma is less clear. We aimed to assess the role of NSAID in the development of oesophageal adenocarcinoma and precursor lesions in people with Barrett's oesophagus--a metaplastic disorder that confers a high risk of oesophageal adenocarcinoma.

METHODS

We did a prospective study of the relation between duration, frequency, and recency of NSAID use and the risk of oesophageal adenocarcinoma, aneuploidy, and tetraploidy in a cohort of 350 people with Barrett's oesophagus followed for 20,770 person-months. We used proportional-hazards regression to calculate hazard ratios (HR) adjusted for age, sex, cigarette use, and anthropometric measurements.

FINDINGS

Median follow-up was 65.5 months (range 3.1-106.9). Compared with never users, HR for oesophageal adenocarcinoma (n=37 cases) in current NSAID users was 0.32 (95% CI 0.14-0.76), and in former users was 0.70 (0.31-1.58). 5-year cumulative incidence of oesophageal adenocarcinoma was 14.3% (95% CI 9.3-21.6) for never users, 9.7% (4.5-20.5) for former users, and 6.6% (3.1-13.6) for current NSAID users. When changes in NSAID use during follow up were taken into account, the associations were strengthened: HR for oesophageal adenocarcinoma for current users at baseline or afterwards was 0.20 (95% CI 0.10-0.41) compared with never users. Compared with never users, current NSAID users (at baseline and follow-up) had less aneuploidy (n=35 cases; 0.25 [0.12-0.54]) and tetraploidy (n=45 cases; 0.44 [0.22-0.87]).

INTERPRETATION

NSAID use might be an effective chemopreventive strategy, reducing the risk of neoplastic progression in Barrett's oesophagus.

Epidemiology of esophageal adenocarcinoma

The incidence of esophageal adenocarcinoma has risen rapidly over the past 25 years in the United States as well as in several Western European countries. This increase had been most dramatic among white males. The majority of these cancers arise from a background of premalignant Barrett esophagus. However, less than 10% of the patients with esophageal adenocarcinoma were known to have Barrett esophagus previously. It is uncertain which risk factors contribute to the increasing incidence of esophageal adenocarcinoma, although gastroesophageal reflux disease, cigarette smoking, and obesity have been implicated. Whereas infection with Helicobacter pylori and use of non-steroidal anti-inflammatory drugs are associated with reduced risk, low intakes of fruit, vegetables, and cereal fibers seem to increase the risk of esophageal adenocarcinoma. Presently there is no evidence that strongly supports any specific strategy to screen a subgroup of the population at risk for Barrett esophagus and adenocarcinoma of the esophagus.

The role of P53 and MDM2 polymorphisms in the risk of esophageal squamous cell carcinoma

The tumor suppressor P53 pathway plays a crucial role in preventing carcinogenesis and genetic variations of this pathway may be associated with cancer susceptibility. We tested this hypothesis by examining the contribution of functional polymorphisms in P53 and MDM2 to risk of esophageal squamous cell carcinoma (ESCC). DNA from 758 ESCC patients and 1,420 controls were genotyped for P53 codon 72Arg>Pro and MDM2 309T>G polymorphisms. Odds ratios (OR) and 95% confidence intervals (CI) of ESCC were estimated by logistic regression. We observed an increased risk of ESCC associated with the P53 Pro/Pro (OR, 1.83; 95% CI, 1.43-2.35; P < 0.001) or MDM2 GG (OR, 1.49; 95% CI, 1.16-1.91; P = 0.002) genotype, compared with the P53 Arg/Arg or MDM2 TT genotype, respectively. Interaction between these P53 and MDM2 polymorphisms increased risk of ESCC in a multiplicative manner, with the OR being 3.10 (95% CI, 2.07-4.69) for subjects carrying both P53 Pro/Pro and MDM2 GG genotypes. Significant interactions were observed between these polymorphisms and smoking, with risk being the highest (OR, 5.29; 95% CI, 2.91-9.61) in smokers having both P53 Pro/Pro and MDM2 GG genotypes. The MDM2 GG genotype was also associated with risk of developing poorly differentiated and advanced ESCC compared with the GT or TT genotype (OR for high-grade and stages III-IV versus low-grade and stages I-II = 1.60; 95% CI, 1.00-2.64; P = 0.049). The P53 and MDM2 polymorphisms may be genetic determinants for the development of ESCC.

Predictors of esophageal cancer risk: assessment of susceptibility to DNA damage using comet assay

Individuals' susceptibility to DNA damage could be identified by mutagen-challenged assays. We tested the hypothesis that susceptibility to DNA damage, measured by comet assay, may be associated with increased esophageal cancer (EC) risk. We recruited 102 subjects with previously untreated EC and 112 healthy controls. Baseline (untreated), benzo[a]pyrene diol epoxide (BPDE)-induced, and gamma-radiation-induced DNA damage were quantified by the Olive tail moment parameter. The mean tail moment was significantly higher in cases than in controls at baseline (case vs. control: 2.6 vs. 1.9, P < 0.01), after BPDE induction (case vs. control: 3.8 vs. 2.7, P < 0.01), and after gamma-radiation-induction (case vs. control: 5.0 vs. 3.8, P < 0.01). When data were dichotomized with the median values in the controls, a significantly increased risk for EC was observed for high baseline tail moment [odds ratio (OR) = 5.7, 95% confidence interval (CI) = 2.9-11.4], high BPDE-induced tail moment (OR = 5.8, 95% CI = 2.9-11.8), and high gamma-radiation-induced tail moment (OR = 4.6, 95% CI = 2.4-8.8). Further, the association between DNA damage and EC was stronger in never smokers than in ever smokers. Compared with subjects not sensitive to both mutagens, individuals sensitive to only one mutagen showed a 3.4-fold risk for EC and those sensitive to both mutagens showed an 8.7-fold risk for EC. Thus, we conclude that susceptibility to DNA damage as assessed by comet assay might help identify individuals with high EC risk.

Communicating the ocular and systemic complications of obesity to patients

BACKGROUND

Obesity has become a growing worldwide epidemic that is associated with serious medical complications. Many clinicians and patients are aware of the systemic complications of obesity, but there are few providers and patients who are aware of the ocular manifestations of obesity.

METHODS

A review of the current medical literature was performed. Ocular and systemic manifestations associated with obesity are described, and a methodology for educating the optometric patient is presented.

RESULTS

There is significant morbidity and mortality associated with obesity, which is causing serious consequences to patients and an enormous economic strain on the health care system. Optometrists have a tremendous opportunity and obligation to educate their patients on the potential sight-threatening complications of obesity and encourage them to decrease their caloric intake and increase their physical activity to help alleviate this individual and collective burden.

CONCLUSIONS

Optometrists have a duty to educate and counsel their overweight and obese patients on the devastating ocular complications that could manifest as a result of obesity.

Trends in incidence and management of esophageal adenocarcinoma in a well-defined population

OBJECTIVES

Little epidemiological data is available concerning esophageal adenocarcinomas in France. The aim of this study was to study epidemiological characteristics and management of esophageal adenocarcinoma in a well-defined population.

METHODS

Data were collected by the Burgundy Digestive Cancer Registry covering a population of 1 052 000, over a 28-year period (1976-2001). Incidence, treatment and stage at diagnosis were noted. Univariate and multivariate analysis of survival was performed.

RESULTS

Age standardized incidence rates were 1.60/100,000 in men and 0.15/100,000 in women. The mean increase in incidence rates by 5-year periods were respectively + 68.1% (P<0.001) and + 97.4% (P<0.001). Overall, 69.9% of the cancers were located in the lower third of the esophagus. Surgical resection was performed in 32.1% of patients. Among the surgical patients, the tumor was limited to the esophageal wall in 11.4%, lymph node metastases were present in 18.1% and non-resectable distant metastases in 70.5%. There was no improvement of stage at diagnosis over time. Survival rates were 14.4% at 3 years and 9.2% at 5 years. Five-year survival rates varied from 38.4% for cases limited to the esophageal wall to 1.8% for metastatic and non resectable cases. Stage at diagnosis was the only significant prognostic factor in the multivariate analysis.

CONCLUSION

Esophageal adenocarcinomas are rare cancers characterized by a sharp rise in incidence over the past years in France. Stage at diagnosis and prognosis are worse than reported in hospital statistics.

Fruits, vegetables, and antioxidants and risk of gastric cancer among male smokers

The effect of consumption of fruits, vegetables, and antioxidants on the incidence of gastric cancer is inconclusive. In this prospective cohort study, we report the association of dietary intake of fruits, vegetables, antioxidants, and baseline serum levels of antioxidants with subsequent incidence of gastric cardia cancer (GCC) and gastric noncardia cancer (GNCC). Participants of this study were 29,133 male smokers recruited into the alpha-Tocopherol, beta-Carotene Cancer Prevention study between 1985 and 1988. At baseline, a self-administered food use questionnaire with 276 food items was used to assess dietary intake. Baseline serum samples were stored at -70 degrees C. During a median follow-up of 12 years, 243 incident gastric adenocarcinomas (64 GCC and 179 GNCC) were diagnosed in this cohort, of whom 220 (57 GCC and 163 GNCC) had complete dietary information. For GCC, high dietary intake of retinol was protective [hazard ratio (HR), 0.46; 95% confidence interval (95% CI), 0.27-0.78], but high intake of alpha-tocopherol (HR, 2.06; 95% CI, 1.20-3.54) and gamma-tocopherol (HR, 1.94; 95% CI, 1.13-3.34) increased risk. For GNCC, higher intakes of fruits (HR, 0.51; 95% CI, 0.37-0.71), vitamin C (HR, 0.60; 95% CI, 0.41-0.86), alpha-tocopherol (HR, 0.78; 95% CI, 0.55-1.10), gamma-tocopherol (HR, 0.69; 95% CI, 0.49-0.96), and lycopene (HR, 0.67; 95% CI, 0.47-0.95) were protective. Our results suggest a difference in the effect of some of these exposures on GCC and GNCC. Tocopherols were associated with higher risk of GCC, whereas dietary intake of fruits, vitamin C, tocopherols, and lycopene seemed protective for GNCC.

Mechanisms of disease: Carcinogenesis in Barrett's esophagus

The pathogenesis of cancer in Barrett's esophagus is multifactorial. Gastroesophageal reflux seems to be important in the initiation of Barrett's esophagus, but its role in promoting carcinogenesis has yet to be established. Diet, lifestyle and carcinogens, especially the nitrates, may be important in the development of carcinogenesis, and require further investigation. Inhibition of reflux-stimulated inflammatory changes, for example by inhibiting cyclooxygenase, holds promise for decreasing cancer progression. Similarly, dietary and lifestyle modification used in the management of reflux may also help to prevent the development of esophageal cancer. The molecular changes that are associated with the development of cancer in Barrett's esophagus offer several potential areas of intervention to prevent and manage esophageal cancer. Limiting cell growth, increasing apoptosis of damaged cells, limiting cell invasion and angiogenesis factors could be useful to accomplish this goal. Having a greater understanding of the pathogenesis of this condition can only help to develop more management options in the future.

Causes of cancer in the world: comparative risk assessment of nine behavioural and environmental risk factors

INTRODUCTION

With respect to reducing mortality, advances in cancer treatment have not been as effective as those for other chronic diseases; effective screening methods are available for only a few cancers. Primary prevention through lifestyle and environmental interventions remains the main way to reduce the burden of cancers. In this report, we estimate mortality from 12 types of cancer attributable to nine risk factors in seven World Bank regions for 2001.

METHODS

We analysed data from the Comparative Risk Assessment project and from new sources to assess exposure to risk factors and relative risk by age, sex, and region. We applied population attributable fractions for individual and multiple risk factors to site-specific cancer mortality from WHO.

FINDINGS

Of the 7 million deaths from cancer worldwide in 2001, an estimated 2.43 million (35%) were attributable to nine potentially modifiable risk factors. Of these, 0.76 million deaths were in high-income countries and 1.67 million in low-and-middle-income nations. Among low-and-middle-income regions, Europe and Central Asia had the highest proportion (39%) of deaths from cancer attributable to the risk factors studied. 1.6 million of the deaths attributable to these risk factors were in men and 0.83 million in women. Smoking, alcohol use, and low fruit and vegetable intake were the leading risk factors for death from cancer worldwide and in low-and-middle-income countries. In high-income countries, smoking, alcohol use, and overweight and obesity were the most important causes of cancer. Sexual transmission of human papilloma virus is a leading risk factor for cervical cancer in women in low-and-middle-income countries.

INTERPRETATION

Reduction of exposure to key behavioural and environmental risk factors would prevent a substantial proportion of deaths from cancer.

The association of body mass index with Barrett's oesophagus

BACKGROUND

Obesity has been linked to gastro-oesophageal reflux disease symptoms and oesophageal adenocarcinoma; however, there is no published evidence for an association with Barrett's oesophagus.

AIM

To investigate the association between obesity and Barrett's oesophagus.

METHODS

We conducted a retrospective cross-sectional study of patients who underwent upper endoscopy at the Southern Arizona Veteran's Affairs Healthcare System between 1998 and 2004. We examined male patients without malignancy, with available information on weight and height. Based on endoscopic and histological findings, patients were classified as cases with Barrett's oesophagus or non-cases without Barrett's oesophagus. Multivariable logistic regression analysis was conducted to examine the association of body mass index and obesity with Barrett's oesophagus and Barrett's oesophagus length while adjusting for age and race.

RESULTS

There were 65 cases with Barrett's oesophagus and 385 non-cases without Barrett's oesophagus. The mean body mass index was significantly higher in cases than in non-cases (29.8 vs. 28.0, P = 0.03). Cases had significantly greater mean weight than controls (206 lb vs. 190,P = 0.005). The proportions of cases with body mass index 25-30 and body mass index > or =30 were greater than those in non-cases (44.6% vs. 37.7%) and (40.0% vs. 33.5%), respectively (P = 0.08). In the multivariable logistic regression model adjusting for race and age, when compared with body mass index < 25, the odds ratio was 2.43 (95% confidence interval: 1.12-5.31) for body mass index 25-30 and 2.46 (1.11-5.44) for body mass index > or =30. When examined as a continuous variable the adjusted odd ratio for each five-point increase in body mass index was 1.35 (95% confidence interval: 1.06-1.71, P = 0.01). The association between weight and Barrett's oesophagus was also statistically significant (adjusted odd ratio for each 10 pound increase = 1.10, 1.03-1.17, P =0.002). Among the 65 cases of Barrett's oesophagus, there was no correlation between the length of Barrett's oesophagus at the time of diagnosis and the body mass index (correlation coefficient = 0.03, P = 0.79).

CONCLUSION

This retrospective cross-sectional study in male veterans shows that overweight is associated with a two-and-half-fold increased risk of Barrett's oesophagus. Larger studies of the underlying mechanism are warranted to better understand how and why obese patients are at greater risk for Barrett's oesophagus.

Prevalence of Helicobacter pylori infection and associated factors among adults in Southern Brazil: a population-based cross-sectional study

BACKGROUND

Helicobacter pylori (Hp) infection is associated with several upper gastrointestinal disorders. Local data on the epidemiology of the infection are scarce in Brazil. The purpose of this study is to measure the prevalence rate and to explore the associated factors among the adult population living in Pelotas, a southern Brazilian city.

METHODS

This was a population-based cross-sectional study. Through a multi-stage sampling method all individuals 20 years and over living at the selected households at the urban area of the city were interviewed regarding past and current socio-economic indicators; demographic characteristics; nutritional and behavioural habits; and history of upper gastrointestinal symptoms.Hp infection was ascertained through the 13C-UBT. Due to the high prevalence, data were analysed through robust Poisson regression. All analyses took into account the family clustering of the data.

RESULTS

Among 563 eligible individuals, 363 agreed to perform the 13C-UBT (refusal rate of 35.5%). Refusals were associated with female sex, consumption of mate drinking, and presence of upper gastrointestinal symptoms. The prevalence rate of H. pylori infection was 63.4% (95%CI 59.3%-69.3%). In crude analyses, prevalence was associated with increasing age, non-white skin colour, lower current family income, lower education level, higher size of the family, low socio-economic conditions in childhood, higher number of siblings and attendance to day-care centres in childhood, and presence of dyspeptic symptoms. In adjusted analysis the level of education of the father was inversely associated with the infection, whereas number of siblings and attendance to day-care centre in childhood were directly associated with it. Non-white skin colour remained significantly associated with increased prevalence even after allowing for past and current socio-economic characteristics, age and sex. Compared to non-symptomatic individuals, those reporting dyspeptic symptoms presented a higher prevalence of the infection even after allowing for current and past socio-economic conditions, ethnicity, age, and sex.

CONCLUSION

Hp infection is as common among adults in southern Brazil as it is in other developing countries. Socio-economic conditions in childhood besides ethnicity and presence of dyspeptic symptoms were the factors significantly associated with the infection.

Obesity and the risk of myocardial infarction in 27,000 participants from 52 countries: a case-control study

BACKGROUND

Obesity is a major risk factor for cardiovascular disease, but the most predictive measure for different ethnic populations is not clear. We aimed to assess whether markers of obesity, especially waist-to-hip ratio, would be stronger indicators of myocardial infarction than body-mass index (BMI), the conventional measure.

METHODS

We did a standardised case-control study of acute myocardial infarction with 27 098 participants in 52 countries (12,461 cases and 14,637 controls) representing several major ethnic groups. We assessed the relation between BMI, waist and hip circumferences, and waist-to-hip ratio to myocardial infarction overall and for each group.

FINDINGS

BMI showed a modest and graded association with myocardial infarction (OR 1.44, 95% CI 1.32-1.57 top quintile vs bottom quintile before adjustment), which was substantially reduced after adjustment for waist-to-hip ratio (1.12, 1.03-1.22), and non-significant after adjustment for other risk factors (0.98, 0.88-1.09). For waist-to-hip ratio, the odds ratios for every successive quintile were significantly greater than that of the previous one (2nd quintile: 1.15, 1.05-1.26; 3rd quintile: 1.39; 1.28-1.52; 4th quintile: 1.90, 1.74-2.07; and 5th quintiles: 2.52, 2.31-2.74 [adjusted for age, sex, region, and smoking]). Waist (adjusted OR 1.77; 1.59-1.97) and hip (0.73; 0.66-0.80) circumferences were both highly significant after adjustment for BMI (p<0.0001 top vs bottom quintiles). Waist-to-hip ratio and waist and hip circumferences were closely (p<0.0001) associated with risk of myocardial infarction even after adjustment for other risk factors (ORs for top quintile vs lowest quintiles were 1.75, 1.33, and 0.76, respectively). The population-attributable risks of myocardial infarction for increased waist-to-hip ratio in the top two quintiles was 24.3% (95% CI 22.5-26.2) compared with only 7.7% (6.0-10.0) for the top two quintiles of BMI.

INTERPRETATION

Waist-to-hip ratio shows a graded and highly significant association with myocardial infarction risk worldwide. Redefinition of obesity based on waist-to-hip ratio instead of BMI increases the estimate of myocardial infarction attributable to obesity in most ethnic groups.

Identification of a novel polymorphism Arg290Gln of esophageal cancer related gene 1 (ECRG1) and its related risk to esophageal squamous cell carcinoma

We previously cloned and identified the esophageal cancer related gene 1 (ECRG1), a novel candidate tumor suppressor gene, from human esophageal cells. A single nucleotide polymorphism (Arg290Gln) was identified in the coding region of ECRG1 and might play a role in susceptibility to esophageal squamous cell carcinoma (ESCC). To examine this hypothesis, we analyzed 998 ESCC patients and 1252 controls in a hospital-based, case-control study in a Chinese population for this polymorphism. We observed a statistically significantly increased risk of ESCC associated with the ECRG1 290Arg/Gln and 290Gln/Gln genotypes compared with the 290Arg/Arg [odds ratio (OR)=1.23, 95% confidence interval (CI)=1.03-1.46; P<0.05]. A greater than multiplicative joint effect between the ECRG1 polymorphism and tobacco smoking exposure was also observed (OR=1.95, 95% CI=1.48-2.56; P<0.001). Furthermore, the elevated risk of ESCC associated with the ECRG1 polymorphism was increased consistently with cumulative smoking dose. ORs (95% CI) for 290Arg/Gln and 290Gln/Gln genotypes among non-smokers and smokers who smoked<or=27 and >27 pack-years were 1.03 (0.78-1.35), 1.91 (1.36-2.67) and 2.08 (1.48-2.92), respectively (P trend test<0.001). Taken together, our results indicate that the ECRG1 290Gln variant allele might be a genetic susceptibility factor for developing ESCC, especially in the smoking population.

Etiologic clues from the similarity of histology-specific trends in esophageal and lung cancers

OBJECTIVE

We tested whether descriptive evidence exists for differing roles of specific tobacco constituents on different histologic subtypes of esophageal cancer. Esophageal adenocarcinoma incidence rates are increasing while squamous cell esophageal cancer rates are declining in Westernized countries as are the histology-specific lung counterparts. Squamous cell lung cancers, while caused by smoking, are believed to be caused by different constituents of tobacco smoke than lung adenocarcinomas. Smoking is also a risk factor for esophageal cancers.

METHODS

We compared patterns of incidence of squamous cell cancers of the lung with those of squamous cell esophageal cancers, and incidence trends in lung adenocarcinomas with those of esophageal adenocarcinomas during the time period from 1976 to 2000 using data from the population-based Los Angeles Cancer Surveillance Program.

RESULTS

Rates of squamous cell esophageal cancer declined in a similar fashion to those of squamous cell lung cancer, while esophageal adenocarcinoma incidence increased at a rate similar to that of lung adenocarcinoma, in both men and women, and blacks and whites. Histology-specific socio-economic gradients in lung and esophageal cancers were also strikingly similar. Increases in esophageal adenocarcinoma were confined to the lower third of the esophagus.

CONCLUSIONS

While increases in obesity over time might explain these trends, they are also consistent with a specific effect of some constituent of tobacco smoke working through reflux disease to cause esophageal adenocarcinoma.

Review article: Helicobacter pylori and gastro-oesophageal reflux disease

Epidemiological studies demonstrate a negative association between Helicobacter pylori infection and gastro-oesophageal reflux disease and its complications. This might represent a protective effect because of the tendency for H. pylori infection to lower gastric acid secretion with advancing age. However, studies of the effect of H. pylori eradication on gastro-oesophageal reflux disease have failed to show any worsening of gastro-oesophageal reflux disease symptoms. Several interactions between H. pylori and proton-pump inhibitor therapy used to treat gastro-oesophageal reflux disease need to be considered. Helicobacter pylori infection improves the control of gastric acidity by proton-pump inhibitors and this produces a small advantage in clinical control of reflux disease. The infection prevents rebound acid hypersecretion occurring when proton-pump inhibitor therapy is discontinued. However, concerns have been expressed that the body gastritis induced by proton-pump inhibitor therapy in H. pylori-infected subjects might increase the risk of gastric cancer. At present, it is unclear whether H. pylori should be eradicated in gastro-oesophageal reflux disease patients.

Relationship between diabetes mellitus and adenocarcinoma of the oesophagus and gastric cardia

BACKGROUND

Obesity is a risk factor for adenocarcinomas of the oesophagus and gastric cardia. Diabetes mellitus might mediate that association.

AIM

To estimate the risk of diabetes mellitus on the development of adenocarcinoma of distal oesophagus and gastric cardia beyond that of gastro-oesophageal reflux disease.

METHODS

A case-control study was performed using a national administrative database of the Veterans Administration.

RESULTS

A total of 311 cases of cancer and 10,154 controls were identified. Gender, age, and race were risks for cancer. Diabetes was diagnosed in 36% of cases, and 32% of controls (P = 0.15). Diabetic complications were diagnosed in 14% of cases and 13% of controls (P = 0.60). Multiple logistic regression confirmed the absence of an association between cancer and diabetes (odds ratio 1.1, 95% confidence interval 0.8-1.5) or diabetic complications (odds ratio 0.8, 95% confidence interval 0.6-1.3), adjusting for age, gender, and race.

CONCLUSIONS

Within the limitations of this case-control study, there is no evidence of an association between diabetes and adenocarcinoma of the oesophagus or gastric cardia among US veterans with gastro-oesophageal reflux disease.

Nutritional factors and gastric cancer in Zhoushan Islands, China

AIM: To investigate the association between nutrient intakes and high incidence rate of gastric cancer among residents in Zhoushan Islands.

METHODS: A frequency-matched design of case-control study was used during the survey on dietary factors and gastric cancer in Zhoushan Islands, China. A total of 103 cases of gastric cancer diagnosed in 2001 were included in the study and 133 controls were randomly selected from the residents in Zhoushan Islands. A food frequency questionnaire was specifically designed for the Chinese dietary pattern to collect information on dietary intake. A computerized database of the dietary and other relative information of each participant was completed. Total calories and 15 nutrients were calculated according to the food composition table and their adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated by gender using unconditional logistic regression models.

RESULTS: High intakes of protein, saturated fat, and cholesterol were observed with the increased risk of gastric cancer particularly among males (ORQ4 vs Q1 were 10.3, 3.24, 2.76 respectively). While carbohydrate was a significant high-risk nutrient (ORQ4 vs Q1 = 14.8; P for linear trend = 0.024) among females. Regardless of their gender, the cases reported significantly higher daily intake of sodium mainly from salts. As to the nutrients of vitamins A and C, an inversed association with the risk of GC was found. Baseline characteristics of participants were briefly described.

CONCLUSION: The findings from this study confirm the role of diet-related exposure in the etiology of gastric cancer from the point of view of epidemiology. An increased risk of gastric cancer is associated with high intakes of protein, saturated fat, cholesterol and sodium, while consumption of polyunsaturated fat, vitamin A and ascorbic acid may have a protective effect against gastric cancer.

The association between microsomal epoxide hydrolase genotypes and esophageal squamous-cell-carcinoma in Taiwan: interaction between areca chewing and smoking

One hundred and forty-five ESCC patients and 352 controls were recruited from three hospitals in Taiwan to determine the association between esophageal squamous-cell-carcinoma (ESCC) and microsomal epoxide hydrolase (mEH) genotypes at Thy113His and His139Arg. Stratified by their exposures, the His113His genotype was a significant protective factor for ESCC in areca chewers and tobacco smokers. Stratified by His113 polymorphisms, the risk of contracting ESCC for participants with His113His who chewed areca and smoked was >50% less than for those with Thy113Thy. We suggest that the mEH His113His genotype can differentiate the association between smoking, areca chewing, and ESCC.

Rates of endoscopy and endoscopic findings among people with frequent symptoms of gastroesophageal reflux in the community

BACKGROUND

Epidemiological studies have confirmed that gastroesophageal symptoms are highly prevalent. However, studies linking epidemiology with clinical or chart data are scarce. We aimed to determine the frequency of endoscopy and endoscopic findings, as well as predictors of health-care utilization, among people with reflux symptoms in the community.

METHODS

A previous survey of 2,118 Olmsted County, MN, residents in 1993 identified 242 subjects with frequent reflux symptoms (at least weekly) who received care at a medical center in the county. Data were abstracted from Mayo Clinic records between 1988 and 1998.

RESULTS

Overall, 130 of the 242 (54%, 95% CI 47-60%) had sought care for reflux. Twenty-five patients (10%) had visited a gastroenterologist; 47 (19%) had an upper endoscopy (EGD), 64 (26%) had an upper GI X-ray, and one had an ambulatory 24-h esophageal pH study. Long segment Barrett's esophagus was detected in 4 (9%) of those having an EGD and adenocarcinoma was found in one patient with Barrett's. Three patients had surgery for gastroesophageal reflux disease. Thirteen patients (5%) died, but no deaths were due to esophageal reflux or adenocarcinoma. Age, higher education, frequent heartburn, and dysphagia were all significant, independent predictors of consulting.

CONCLUSIONS

Although many people in the community have frequent reflux symptoms, few have investigations, and deaths were unrelated to reflux disease or its complications. Data from referral clinic or endoscopy series should not be extrapolated to the large numbers of people in the community with symptoms of reflux.

Tooth loss is associated with increased risk of gastric non-cardia adenocarcinoma in a cohort of Finnish smokers

OBJECTIVE

Tooth loss has been associated with upper gastrointestinal cancer in several studies, but only one previous study used prospectively collected data. The importance of confounding by Helicobacter pylori has not previously been addressed. The objective was to determine the association between tooth loss and upper gastrointestinal cancer in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study cohort and to determine the importance of potentially confounding dietary factors or H. pylori seropositivity.

MATERIAL AND METHODS

A prospective cohort study with 29,124 subjects included 49 esophageal squamous cell carcinomas, 66 esophageal/gastric cardia adenocarcinomas, and 179 gastric non-cardia adenocarcinomas occurring between 1985 and 1999. Cox proportional hazards models adjusted for age and education were used to estimate hazard ratios (HRs) and 95% CIs. Odds ratios and 95% CIs were calculated with and without adjustment for H. pylori seropositivity in a nested case-control group to determine whether H. pylori confounded the association between tooth loss and gastric cancer.

RESULTS

Tooth loss significantly increased the hazard ratio for gastric non-cardia cancer, the HR (95% CI) for edentulous subjects versus those with < 10 teeth lost was 1.65 (1.09, 2.49, respectively). No statistically significant associations were found between tooth loss and esophageal squamous cell carcinoma or esophageal/gastric cardia adenocarcinoma. Confounding by dietary factors, tobacco smoking, or H. pylori did not explain these results.

CONCLUSIONS

Tooth loss was associated with increased risk of gastric non-cardia cancer, but not esophageal squamous cell carcinoma or esophageal/gastric cardia adenocarcinoma in this Finnish cohort.

The effect of eradicating helicobacter pylori on the development of gastric cancer in patients with peptic ulcer disease

OBJECTIVES

Infection with Helicobacter pylori is a risk factor for the development of gastric cancer. However, it is not known whether eradication therapy can prevent the development of gastric cancer in persons in whom the cancer is not yet established. In the present study, we investigated whether the eradication of H. pylori in patients with peptic ulcer disease reduces the likelihood of their developing gastric cancer.

METHODS

Prospective posteradication evaluations were conducted in 1,342 consecutive patients (1,191 men and 151 women; mean age: 50 yr) with peptic ulcer diseases who had received H. pylori eradication therapy. After confirmation of eradication, endoscopy and a urea breath test were performed yearly.

RESULTS

A total of 1,120 patients completed more than 1-yr follow-up and were followed for up to 8.6 yr (a mean of 3.4 yr). Gastric cancer developed in 8 of 944 patients cured of infection and 4 of 176 who had persistent infection (p= 0.04; log-rank test). All the gastric cancer developed in patients with gastric ulcer, but none in patients with duodenal ulcer (p= 0.005; Fisher's exact test). In patients with gastric ulcer, persistent infection was identified as a significant factor for the risk of developing gastric cancer (hazard ratio: 3.35; 95% confidence interval: 1.00-11.22; p= 0.04; Cox's proportional-hazards model).

CONCLUSION

H. pylori eradication may reduce their risk of developing gastric cancer in patients with gastric ulcer. Large-scale studies in additional populations of this important international public-health issue are warranted.

Advances in Barrett's esophagus and esophageal adenocarcinoma

Despite advances in diagnosis and therapy, esophageal adenocarcinoma remains an aggressive and usually lethal tumor. This review focuses on the epidemiology of esophageal adenocarcinoma and its presumed precursor lesion, Barrett's esophagus; the pathogenesis of the cancer; advances in treatment of adenocarcinoma and Barrett's esophagus; and strategies for cancer prevention. Emphasis is placed on recent literature. Although the absolute number of cases of adenocarcinoma in the United States is still small, the incidence of this cancer has increased dramatically in the last 40 years, and adenocarcinoma is now the predominant form of esophageal cancer in this country. Recent evidence suggests that Barrett's esophagus is more prevalent in asymptomatic individuals than previously appreciated. The pathogenesis of Barrett's esophagus is poorly understood. Given that some subjects will have repeated bouts of severe erosive esophagitis and never develop Barrett's esophagus, host factors must play an important role. The utility of neoadjuvant radiation and chemotherapy in those with adenocarcinoma, although they are widely practiced, is not of clear benefit, and some authorities recommend against it. Ablative therapies, as well as endoscopic mucosal resection, hold promise for those with superficial cancer or high-grade dysplasia. Most series using these modalities feature relatively short follow-up, and longer-term data will be necessary to better describe the effects of these therapies. The value of chemoprevention in subjects with dysplastic Barrett's esophagus by use of cyclooxygenase 2 inhibitors, nonsteroidal anti-inflammatory drugs, or proton pump inhibitors is unknown. Similarly, although endoscopic screening is widely practiced, its value in patients with chronic gastroesophageal reflux disease symptoms is of unproven value, and recommending bodies are divided as to its practice.

Significant increase in risk of gastroesophageal cancer is associated with interaction between promoter polymorphisms in thymidylate synthase and serum folate status

Thymidylate synthase (TS) catalyzes the 5,10-methylene-tetrahydrofolate-mediated conversion of deoxyuridine monophosphate to deoxythymydine monophosphate, a nucleotide required for DNA synthesis and repair. The impaired TS expression has been shown to be related to 28 bp tandem repeats and a G-->C SNP in the 5'-UTR of TS. Folate deficiency has been demonstrated to play a role in gastroesophageal carcinogenesis. This case-control study was to examine the hypothesis that the TS polymorphisms, alone or in combination with serum folate status, may confer susceptibility of the hosts to gastroesophageal cancer. We analyzed TS genotype and serum folate concentration in 324 patients with esophageal squamous cell carcinoma (ESCC), 231 patients with gastric cardia adenocarcinoma (GCA) and 492 controls. It was found that compared with the normal expression TS genotype, the low expression TS genotype alone was significantly associated with increased risk of ESCC [adjusted odds ratio (OR) 1.47; 95% confidence interval (CI) 1.03-2.10] but not GCA (OR=0.98, 95% CI=0.68-1.40). More importantly, a significant interaction between the TS polymorphisms and serum folate status in risk of ESCC and GCA was observed. Among subjects with low serum folate concentration (<3 ng/ml), the ORs of ESCC and GCA for the low expression genotype were 22.63 (95% CI=10.44-49.05) and 4.08 (95% CI=1.94-8.59), which were greater than respective 9.97 (95% CI=5.67-17.53) and 1.88 (95% CI=1.18-3.24) for the normal expression genotype (P=0.002 and 0.029). These results suggest an important role for folate deficiency and impaired TS activity in the etiology of ESCC and GCA.

RECENT TRENDS IN INCIDENCE RATES FOR SELECTED ALCOHOL-RELATED CANCERS IN THE UNITED STATES

AIMS

To examine recent trends in incidence rates for cancer types most strongly associated with alcohol use, using data from US cancer registries.

METHODS

Age-standardized annual incidence rates (ASIRs) for squamous cell carcinomas of the oral cavity and pharynx, esophagus and larynx diagnosed in the most recent 10-year period (1992-2001) were examined for geographic areas included in the US National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) program of high-quality cancer registries.

RESULTS

For all geographic areas combined, ASIRs for these cancers declined over time, with no evidence for a recent plateau or upturn. This also held true for ASIRs in younger adults (age 20-54 years at diagnosis). For white males, declines in ASIRs occurred in each of the 11 geographic areas, and were statistically significant in nine areas. The declines in ASIRs were consistent with temporal declines in apparent alcohol consumption by state, although the prevalence of binge and heavy drinking in adults increased in some states.

CONCLUSIONS

Although there was no evidence for a recent plateau in ASIRs, continued surveillance is needed, in view of recent increases in the prevalence of binge and heavy drinking among US adults.

Cytochrome p450 2E1 polymorphisms and the risk of gastric cardia cancer

AIM: Genetic polymorphisms of drug-metabolizing enzymes have recently been shown to affect susceptibility to chemical carcinogenesis. Cytochrome P450 2E1 (CYP2E1) enzyme catalyzes the metabolism of many procarcinogens, such as N-nitrosamines and related compounds. The gene coding for this enzyme is polymorphic and thus may play a role in gastric cardia cancer (GCC) etiology. In this hospital-based case-control study, we evaluate the relationship between genetic polymorphisms of CYP2E1 and the risk of GCC.

METHODS: The study subjects comprised 159 histologically confirmed GCC cases identified via hospital cancer registry and surgical records at five hospitals in Fuzhou, Fujian Province, China, between April and November 2001. Controls were 192 patients admitted to the same hospitals for nonmalignant conditions. The genotypes of CYP2E1 were detected by a PCR-based RFLP assay. The odds ratios were estimated by logistic regression analyses and were adjusted for potential confounding factors.

RESULTS: The distribution of three genotypes of CYP2E1 in GCC cases and controls was significantly different (χ² = 16.04, P<0.01). The frequency of the CYP2E1 (c1/c1) genotype in GCC cases and controls was 60.4% and 40.1%, respectively. The CYP2E1 (c1/c1) genotype was associated with an increased risk for GCC (the adjusted (OR) was 2.37, 95% confidence interval (CI): 1.52-3.70). Subjects who carried the CYP2E1 (c1/c1) genotype and were habitual smokers were at a significantly higher risk of developing GCC (OR = 4.68, 95%CI: 2.19-10.04) compared with those who had the CYP2E1 (c1/c2 or c2/c2) genotype and did not smoke.

CONCLUSION: These results suggest that the CYP2E1 genotype may influence individual susceptibility to development of GCC, and that the risk increases significantly in smokers.