A nested case-control study of oesophageal and stomach cancers in the Linxian nutrition intervention trial

Fruit and vegetable intake in relation to gastric cancer risk: A comprehensive and updated systematic review and dose-response meta-analysis of cohort studies

Background

Since the release of previous meta-analyses, some studies on the associations between fruit and vegetable intake with gastric cancer risk have been published. Therefore, we aimed to update the previous meta-analyses on these associations by including recently published studies as well as considering the main limitations of those meta-analyses.

Methods

A comprehensive search was conducted in online databases including PubMed, Scopus, ISI Web of Science, and Google Scholar to detect relevant prospective cohort studies published up to October 2021. Summary relative risks (RRs) were estimated using a random-effects model.

Results

Overall, 17 articles containing 18 prospective studies with a total sample size of 1,527,995 participants, aged between 18 and 90 years, were included in the current meta-analysis. During the follow-up periods ranging between 4.5 and 21 years, 8,477 cases of gastric cancer were diagnosed. A higher intake of total fruit [RR: 0.87, 95% confidence interval (CI): 0.80 to 0.94, I ² = 0%] and total fruit and vegetable (RR: 0.75, 95% CI: 0.61 to 0.93, I ² = 55.2%) were associated with a lower risk of gastric cancer. For total vegetable intake, a significant inverse association was found among the studies that controlled their analysis for energy intake. Based on the linear dose-response analysis, each 100 g/day increase in total fruit intake (Pooled RR: 0.95, 95% CI: 0.90 to 0.99, I ² = 49%) and 200 g/day increase in total fruit and vegetable intake (RR: 0.94, 95% CI: 0.88 to 0.99, I ² = 37.6%) were associated with a 5 and 6% lower risk of gastric cancer, respectively.

Conclusion

Fruit and vegetable consumption has a protective association with gastric cancer risk.

Porphyromonas gingivalis predicts local recurrence after endoscopic submucosal dissection of early esophageal squamous cell carcinoma or precancerous lesion

BACKGROUND

Porphyromonas gingivalis plays an oncogenic role in development and progression of esophageal squamous cell carcinoma (ESCC). However, the impact of P. gingivalis on local recurrence of early ESCC or precancerous lesion after ESD treatment remains unknown. The present study aimed to evaluate the impact of P. gingivalis on local recurrence after ESD treatment of early ESCC or high-grade dysplasia (HGD).

METHODS

The amount of P. gingivalis was assessed by immunohistochemistry in 205 patients with early ESCC or HGD. Univariate and multivariate Cox regression analyses were performed to determine the effect of P. gingivalis on local recurrence. Propensity score matching analysis was performed to reduce the imbalance of baseline characteristics. A nomogram integrating significant prognostic factors was built for local recurrence prediction.

RESULTS

The amount of P. gingivalis increased significantly in neoplasms that invaded up to muscularis mucosa and submucosa compared with lesions confined to epithelium or lamina propria. Overabundance of P. gingivalis was positively associated with invasion depth, post-ESD stricture and local recurrence. Univariate and multivariate Cox regression analyses revealed that P. gingivalis, longitudinal length of lesion and lymphovascular invasion were independent predictors for post-ESD recurrence. A nomogram comprising P. gingivalis, lymphovascular involvement, and lesion length performed well for prediction of post-ESD local recurrence with the concordance indices of 0.72 (95%CI, 0.62 to 0.80), 0.72 (95%CI, 0.63 to 0.80), and 0.74 (95%CI, 0.65 to 0.83) in the validation cohort, the entire cohort, and the subcohort after PSM, respectively.

CONCLUSION

P. gingivalis overabundance is a risk factor and a potential predictor for local recurrence of early ESCC or HGD after ESD treatment. Thus, clearance of P. gingivalis represents an attractive strategy for prognosis improvement and for prevention of ESCC.

Familial Esophageal Cancer in Taihang Mountain, China: An Era of Personalized Medicine Based on Family and Population Perspective

In the Taihang Mountain areas, known as the “esophageal cancer zone” in China, the incidence of esophageal cancer (ESCA) ranks the first in the country and shows a familial and regional clustering trend. Taihang Mountain areas are located in a mountainous area, with inconvenient transportation, limited living conditions, unbalanced diet, and poor nutrition. Ninety percent of the pathological types of ESCA in Taihang Mountain areas are squamous cell carcinoma, among which the risk factors have not been well understood. These areas are usually remote villages and mountains with low population mobility, large family members, similar environmental factors, and a clear and stable genetic background. Therefore, according to the current situation, second-generation sequencing and multigroup analysis technology are used to analyze the familial ESCA patients; disease-related genetic variation are located; and then disease-related susceptibility genes associated with ESCA are screened and analyzed. Health education, tobacco control, endoscopic screening, and other health management projects for suspected and high-risk patients in areas with a high incidence of ESCA can be carried out for screening and early diagnosis, and the incidence of ESCA in Taihang Mountain areas can be reduced. A comprehensive continuous care pattern based on traditional medical nursing to track, monitor, evaluate, and intervene with patients diagnosed with ESCA to facilitate them with medications guidance, dietary guidance, and timely health problem-solving is established. Furthermore, statistical analysis of epidemiology, gene sequencing, and family genetics information can be performed on patients with ESCA in the Taihang Mountains areas to clarify the relationship between genetic phenotype and genotype during the occurrence of ESCA.

Trends in Incidence and Mortality of Esophageal Cancer in Huai'an District, a High-Risk Area in Northern Jiangsu Province, China

Purpose

This study aimed to provide a clear comparable figure of the trends in incidence and mortality rates of esophageal cancer (EC) in Huai’an District, Huai’an City, Jiangsu Province, China, a high-risk area for EC.

Methods

The data for age- and sex-specific incidence rates between 1998 and 2016, the mortality rates in 1990-2016 and the number of EC patients were obtained from Huai’an District Cancer Registry. Crude rates, Age-standardized rates (ASRs) by world standard population and truncated age-standardized rates of EC incidence and mortality were calculated. The joinpoint regression analysis was used to calculate the annual percent changes (APC), average annual percent changes (AAPC), and their 95% confidence intervals (CIs).

Results

Overall, 20,892 new EC cases and 20,806 EC deaths were registered in Huai’an District. ASR of EC incidence from 1998 to 2016 and mortality from 1990 to 2016 were 73.32/100,000 and 60.03/100,000, respectively. The ASR illustrated that the incidence of EC had significant downward trends in total, male and female (AAPC = −4.65, −4.90, and −5.51, respectively, p <.01). The age-specific incidence and mortality rates of EC increased dramatically in people over the age of 40, and peaked in people between the ages 70-74. In the subdivisions of Huai’an District, geographical diversities in the crude incidence and mortality rates of EC were found.

Conclusion

In summary, the incidence and mortality rates of EC showed downward trends in Huai’an District. However, the burden of EC still remained serious in this high-risk area. Cost-effective methods of intervention and health education should be enhanced for improving EC prevention.

Risk factors for esophageal cancer in a high-incidence area of Malawi

PURPOSE

To explore associations of nutritional, infectious, and lifestyle factors with esophageal cancer (EC) occurrence in a high-risk area of Malawi.

METHODS

This case-control study was performed with 227 patients undergoing endoscopy for dysphagia or other upper gastrointestinal complaints. Data on clinicopathological characteristics and risk factors were collected using a questionnaire developed for this study specifically. Ninety-eight blood samples were collected and the prevalence of antibodies against human immunodeficiency virus, herpes simplex virus, cytomegalovirus, Epstein-Barr virus, varicella-zoster virus, and Helicobacter pylori were determined serologically.

RESULTS

The tumor and control groups comprised 157 (69.2%) and 70 (31.8%) patients, respectively. Patients with tumors were significantly older than controls (55.5 vs. 43.5 years, p < 0.001). The male/female ratio did not differ between groups (59% and 54% male, respectively; p = 0.469). EC was associated with smoking (p < 0.001), and alcohol consumption (p = 0.020), but 43% of patients with tumors did not smoke or drink. EC was associated with the consumption of hot food and tea (p = 0.003) and smoked fish (p = 0.011). EC was not associated with any serologically investigated infectious agents. In an age adjusted binary logistic regression analysis of all nutritive factors, only locally made alcohol was significant [odds ratio (OR), 9.252; 95% confidence interval (CI), 1.455-58.822; p = 0.018].

CONCLUSIONS

Apart from alcohol consumption and smoking, the consumption of hot food or tea and smoked fish are associated with EC. Locally distilled alcohol consumption increases the EC risk in Malawi.

Precision screening for esophageal squamous cell carcinoma in China

Esophageal squamous cell carcinoma (ESCC) is the predominant subtype of esophageal cancer in China, and this neoplasm is associated with high morbidity and mortality as well as clear geographical heterogeneity. Since primary prevention for ESCC lacks a clear intervention target, secondary prevention, also known as screening and early diagnosis and early treatment, has become the mainstay of ESCC prevention and control in China. ESCC screening in China has been subject to decades of evaluation and practice. However, the ESCC screening strategy currently adopted in China has encountered a developmental bottleneck. In this review, we have summarized studies and significant findings for ESCC screening and proposed advancement of screening strategies as follows: 1) evidence from randomized controlled trials is needed to support the effectiveness and health economic value of endoscopic screening for ESCC; 2) the current traditional screening and surveillance strategies warrant reform, and a risk-prediction-based precision strategy should be established; and 3) a deeper understanding of the value of opportunistic screening in the prevention and control of ESCC in China is called for. Due to the low absolute prevalence of precancerous lesions, substantial investment of resources and nonnegligible risks of invasive screening techniques, precision and individualization should be the main direction of cancer screening programs for the future. We advocate cooperation on the part of Chinese scientists to solve this major China-specific health problem in the next decades.

A multinational review: Oesophageal cancer in low to middle-income countries

Oesophageal cancer (OC) is an aggressive neoplasm that manifests in the gastrointestinal tract and is the result of numerous factors that can contribute to the development of the disease. These may include old age, nutritional deficiencies, oesophageal obstruction and food ingestion difficulties. Environmental factors serve a large role in increasing the risk of developing OC. Two factors that serve an increasing risk of developing OC are the use of tobacco and the consumption of alcohol. Genetic factors also exhibit a large effect on the risk of developing OC, for example, the causative genes in Black Africans differ from other races. OC is 3–4 times more common among men than women. OC has been previously reported in >450 000 individuals worldwide, and its incidence is increasing. The current review compares OC in low to middle-income countries with developed countries. The incidence of OC, particularly squamous cell carcinoma (SCC) is high in low and middle-income countries. In developed countries, the incidence of SCC is low compared with adenocarcinoma. The majority of OC cases are diagnosed in the late stages of the disease, leading to high mortality rates. The current review aimed to discuss factors that contribute to the development of this disease in different geographical areas and genetic mechanisms governing these findings. The current review also aims to discuss the preventative treatment options for the disease, and also discusses the diagnosis and surveillance in five LMICs, including South Africa, China, Tanzania, India and Brazil.

Egg Consumption and Risk of Upper Aero-Digestive Tract Cancers: A Systematic Review and Meta-Analysis of Observational Studies

Limited data are available that summarize the relation between egg intake and the risk of upper aero-digestive tract (UADT) cancers. This systematic review and meta-analysis was conducted to investigate the association between egg intake and the risk of UADT cancers. Medline/PubMed, ISI web of knowledge, EMBASE, Scopus, and Google Scholar were searched using relevant keywords. Observational studies conducted on humans investigating the association between egg consumption and the risk of UADT cancers were included. Overall, 38 studies with a total of 164,241 subjects (27, 025 cases) were included. Based on 40 effect sizes from 32 case-control studies, we found a 42% increased risk of UADT cancers among those with the highest egg consumption (ranging from ≥1 meal/d to ≥1 time/mo among studies) compared to those with the lowest intake (ranging from 0-20 g/d to never consumed among studies) (overall OR: 1.42; 95% CI: 1.19, 1.68; P < 0.001). However, this association was only evident in hospital-based case-control (HCC) studies (OR = 1.50; 95% CI: 1.34, 1.68; P < 0.001 for 'oropharyngeal and laryngeal cancer' and OR: 1.27; 95% CI: 1.08, 1.50; P = 0.004 for esophageal cancer) and not in population-based case-control (PCC) studies (OR = 1.25; 95% CI: 0.59, 2.67; P = 0.56 for 'oropharyngeal and laryngeal cancer' and OR: 1.29; 95% CI: 0.92, 1.81; P = 0.13 for esophageal cancer). In addition, the association was not significant in prospective cohort studies (overall OR: 0.86; 95% CI: 0.71, 1.04; P = 0.11). Considering individual cancers, a positive association was observed between the highest egg consumption, compared with the lowest, and risk of oropharyngeal (OR: 1.88; 95% CI: 1.61, 2.20; P < 0.001), laryngeal (OR: 1.83; 95% CI: 1.45, 2.32; P < 0.001), oral & pharyngeal & laryngeal (OR: 1.37; 95% CI: 1.12, 1.67; P < 0.001), and esophageal cancers (OR: 1.28; 95% CI: 1.10,1.48; P = 0.001). We also found an inverse association between egg intake and the risk of oral cancer (OR: 0.78; 95% CI: 0.62, 0.99; P = 0.04). In conclusion, high egg consumption (ranging from ≥1 meal/d to ≥1 time/mo among studies) was associated with increased risk of UADT cancers only in HCC studies but not in PCC or prospective cohort studies. PROSPERO registration number: CRD42018102619.

Esophageal cancer genetics in South Africa

Esophageal cancer (EC) is an extremely aggressive cancer with one of the highest mortality rates. The cancer is generally only diagnosed at the later stages and has a poor 5-year survival rate due to the limited treatment options. China and South Africa are two countries with a very high prevalence rate of EC. EC rates in South Africa have been on the increase, and esophageal squamous cell carcinoma is the predominant subtype and a primary cause of cancer-related deaths in the black and male mixed ancestry populations in South Africa. The incidence of EC is highest in the Eastern Cape Province, especially in the rural areas such as the Transkei, where the consumption of foods contaminated with Fusarium verticillioides is thought to play a major contributing role to the incidence of EC. China is responsible for almost half of all new cases of EC globally. In China, the prevalence of EC varies greatly. However, the two main areas of high prevalence are the southern Taihang Mountain area (Linxian, Henan Province) and the north Jiangsu area. In both countries, environmental toxins play a major role in increasing the chance that an individual will develop EC. These associative factors include tobacco use, alcohol consumption, nutritional deficiencies and exposure to environmental toxins. However, genetic polymorphisms also play a role in predisposing individuals to EC. These include single-nucleotide polymorphisms that can be found in both protein-coding genes and in non-coding sequences such as miRNAs. The aim of this review is to summarize the contribution of genetic polymorphisms to EC in South Africa and to compare and contrast this to the genetic polymorphisms observed in EC in the most comprehensively studied population group, the Chinese.

Efficacy of endoscopic screening for esophageal cancer in China (ESECC): design and preliminary results of a population-based randomised controlled trial

OBJECTIVE

Description of the design and preliminary results of baseline recruitment and screening in the endoscopic screening for esophageal cancer in China (ESECC), the first randomised controlled trial (RCT) assessing efficacy and cost-effectiveness of endoscopic screening for esophageal squamous cell carcinoma (ESCC).

DESIGN

ESECC trial is a cluster RCT, and 668 villages in rural Hua County, Henan Province, a high-incidence area of ESCC in China, were randomised into two arms at a ratio of 1:1. Screening arm participants were screened by Lugol chromoendoscopy; no screening was performed in the control arm. ESCC-specific and all-cause mortality, incidence of advanced ESCC and cost-effectiveness of screening will be evaluated in the next 10-year follow-up. Here, we report the performance of baseline recruitment and randomisation, prevalence of upper GI lesions and risk factors for ESCC.

RESULTS

A total of 17 151 and 16 797 participants were enrolled in screening and control arms from January 2012 to September 2016. The truncated prevalence (aged 45-69 years) of oesophageal and overall upper GI high-grade lesions was 744.0/100 000 and 902.0/100 000. 69.9% of the 113 patients with high-grade oesophageal lesions were of early stage. Risk factors for severe oesophageal dysplasia and more severe lesions in this population included higher age, family history of ESCC, lower body mass index, eating rapidly and frequent ingestion of leftovers.

CONCLUSION

This ESECC trial met the predesigned recruitment and randomisation requirements. Age, family history, undernutrition and unhealthy dietary habits increased the risk for high-grade oesophageal lesions in this high-risk population.

TRAIL REGISTRATION NUMBER

NCT01688908; Pre-results.

An update of the WCRF/AICR systematic literature review and meta-analysis on dietary and anthropometric factors and esophageal cancer risk

Background

In the 2007 World Cancer Research Fund/American Institute for Cancer Research Second Expert Report, the expert panel judged that there was strong evidence that alcoholic drinks and body fatness increased esophageal cancer risk, whereas fruits and vegetables probably decreased its risk. The judgments were mainly based on case–control studies. As part of the Continuous Update Project, we updated the scientific evidence accumulated from cohort studies in this topic.

Methods

We updated the Continuous Update Project database up to 10 January 2017 by searching in PubMed and conducted dose–response meta-analyses to estimate summary relative risks (RRs) and 95% confidence intervals (CIs) using random effects model.

Results

A total of 57 cohort studies were included in 13 meta-analyses. Esophageal adenocarcinoma risk was inversely related to vegetable intake (RR per 100 g/day: 0.89, 95% CI: 0.80–0.99, n = 3) and directly associated with body mass index (RR per 5 kg/m²: 1.47, 95% CI: 1.34–1.61, n = 9). For esophageal squamous cell carcinoma, inverse associations were observed with fruit intake (RR for 100 g/day increment: 0.84, 95% CI: 0.75–0.94, n = 3) and body mass index (RR for 5 kg/m² increment: 0.64, 95% CI: 0.56–0.73, n = 8), and direct associations with intakes of processed meats (RR for 50 g/day increment: 1.59, 95% CI: 1.11–2.28, n = 3), processed and red meats (RR for 100 g/day increment: 1.37, 95% CI: 1.04–1.82, n = 3) and alcohol (RR for 10 g/day increment: 1.25, 95% CI: 1.12–1.41, n = 6).

Conclusions

Evidence from cohort studies suggested a protective role of vegetables and body weight control in esophageal adenocarcinomas development. For squamous cell carcinomas, higher intakes of red and processed meats and alcohol may increase the risk, whereas fruits intake may play a protective role.

GWAS follow-up study of esophageal squamous cell carcinoma identifies potential genetic loci associated with family history of upper gastrointestinal cancer

Based on our initial genome-wide association study (GWAS) on esophageal squamous cell carcinoma (ESCC) in Han Chinese, we conducted a follow-up study to examine the single nucleotide polymorphisms (SNPs) associated with family history (FH) of upper gastrointestinal cancer (UGI) cancer in cases with ESCC. We evaluated the association between SNPs and FH of UGI cancer among ESCC cases in a stage-1 case-only analysis of the National Cancer Institute (NCI, 541 cases with FH and 1399 without FH) and Henan GWAS (493 cases with FH and 869 without FH) data (discovery phase). The top SNPs (or their surrogates) from discovery were advanced to a stage-2 evaluation in additional Henan subjects (2801 cases with FH and 3136 without FH, replication phase). A total of 19 SNPs were associated with FH of UGI cancer in ESCC cases with P < 10^-5 in the stage-1 meta-analysis of NCI and Henan GWAS data. In stage-2, the association for rs79747906 (located at 18p11.31, P = 5.79 × 10^-6 in discovery) was replicated (P = 0.006), with a pooled-OR of 1.59 (95%CI: 1.11-2.28). We identified potential genetic variants associated with FH of UGI cancer. Our findings may provide important insights into new low-penetrance susceptibility regions involved in the susceptibility of families with multiple UGI cancer cases.

Esophageal cancer in high-risk areas of China: research progress and challenges

PURPOSE

The extremely high incidence of esophageal cancer in certain rural areas of China has prompted significant intellectual curiosity and research efforts both in China and abroad.

METHODS

We summarize the research progress over the past several decades in high-risk areas (Linxian, Cixian, Shexian, and Yanting) based on literature research and our field trip (2012-2013).

RESULTS

Considerable progress in clarifying the environmental risk factors and pathogenesis of esophageal cancer in high-risk areas has been achieved over the past several decades. Epidemiologic evidence suggests that carcinogen exposure and nutritional deficiency, rather than smoking and drinking, may be the major risk factors for esophageal cancer in the Taihang Mountains region, where the incidence of esophageal cancer is among the highest in the world. Two genome-wide association studies have identified variants in PLCE1 at 10q23 that are significantly associated with esophageal cancer risk. Recent whole-exome studies have revealed a comprehensive mutation pattern, in which the C>T transition is the predominant mutation type.

CONCLUSIONS

Despite extensive research, the main causative factors that contribute to esophageal cancer in high-risk areas have not yet been elucidated. Challenges in this research area include determining the causative role of nitrosamine, identifying other potential carcinogens, and conducting fruitful international collaborative studies based on a multidisciplinary approach. Increased international collaboration will contribute to a better understanding of the etiology of esophageal cancer.

Association of risk of gastric cancer and consumption of tobacco, alcohol and tea in the Chinese population

This study aimed at summarizing epidemiological research findings on associations between tobacco, alcohol and tea consumption and risk of gastric cancer (GC) in the Chinese population. The review searched PubMed, Embase, China National Knowledge Infrastructure (CNKI) and China Biology Medicine (CBM) databases and reference lists of review papers for all studies published in English or Chinese languages. Information extracted, via two independent researchers, from retrieved articles included first author, year of publication, study design, sample size, source of controls and adjusted odds ratio (OR) or relative risk (RR) with the corresponding 95% confidence intervals (CIs) for each category. Statistical analyses used software STATA version 12.0. The systematic search found 89 articles containing 25,821 GC cases and 135,298 non-cases. The overall random effects in terms of pooled OR and 95%CI for tobacco, alcohol and tea consumption were 1.62 (95%CI: 1.50-1.74), 1.57 (95%CI: 1.41-1.76) and 0.67 (95%CI: 0.59-0.76) respectively; while the heterogeneity among included studies ranged from 80.1% to 87.5%. The majority of subgroup analyses revealed consistent results with the overall analyses. All three behavioral factors showed statistically significant dose-dependent effects on GC (P<0.05). The study revealed that tobacco smoking and alcohol drinking were associated with over 1/2 added risk of GC, while tea drinking conferred about 1/3 lower risk of GC in the Chinese population. However, these results should be interpreted with caution given the fact that most of the included studies were based on a retrospective design and heterogeneity among studies was relatively high.

Consumption of hot beverages and foods and the risk of esophageal cancer: a meta-analysis of observational studies

Background

Previous studies have mostly focused on the effects of specific constituents of beverages and foods on the risk of esophageal cancer (EC). An increasing number of studies are now emerging examining the health consequences of the high temperature of beverages and foods. We conducted a meta-analysis to summarize the evidence and clarify the association between hot beverages and foods consumption and EC risk.

Methods

We searched the PubMed, Embase, and Web of Science databases for relevant studies, published before May 1, 2014, with the aim to estimate the association between hot beverage and food consumption and EC risk. A random-effect model was used to pool the results from the included studies. Publication bias was assessed by using the Begg test, the Egger test, and funnel plot.

Results

Thirty-nine studies satisfied the inclusion criteria, giving a total of 42,475 non-overlapping participants and 13,811 EC cases. Hot beverage and food consumption was significantly associated with EC risk, with an odds ratio (OR) of 1.82 (95% confidence interval [CI], 1.53–2.17). The risk was higher for esophageal squamous cell carcinoma, with a pooled OR of 1.60 (95% CI, 1.29–2.00), and was insignificant for esophageal adenocarcinoma (OR: 0.79; 95% CI: 0.53–1.16). Subgroup analyses suggests that the association between hot beverage and food consumption and EC risk were significant in Asian population (OR: 2.06; 95% CI: 1.62-2.61) and South American population (OR: 1.52; 95% CI: 1.25-1.85), but not significant in European population (OR: 0.95; 95% CI: 0.68-1.34).

Conclusions

Hot beverage and food consumption is associated with a significantly increased risk of EC, especially in Asian and South American populations, indicating the importance in changing people’s dietary habits to prevent EC.

Upregulation of the long noncoding RNA TUG1 promotes proliferation and migration of esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the prevalent and deadly cancers worldwide, especially in Eastern Asia. The prognosis of ESCC remains poor; thus, it is still necessary to further dissect the underlying mechanisms and explore therapeutic targets of ESCC. Recent studies show that long noncoding RNAs (lncRNAs) have critical roles in diverse biological processes, including tumorigenesis. Some lncRNAs, such as HOTAIR and POU3F3, were reported to play important roles in ESCC. Here, we characterized the expression profile of taurine-upregulated gene 1 (TUG1), a lncRNA recruiting and binding to polycomb repressive complex 2 (PRC2), in ESCC. In a cohort of 62 patients, TUG1 was significantly overexpressed in ESCC tissues compared with paired adjacent normal tissues, and high expression level of TUG1 was associated with family history and upper segment of esophageal cancer (p < 0.05). Further, in vitro silencing TUG1 via siRNA inhibited the proliferation and migration of ESCC cells and blocked the progression of cell cycle. Therefore, our study indicates that TUG1 promotes proliferation and migration of ESCC cells and is a potential oncogene of ESCC.

Adverse effects of preserved vegetables on squamous cell carcinoma of esophagus and precancer lesions in a high risk area

INTRODUCTION

Squamous cell carcinoma of esophagus (ESCC) is one of the most common cancers in China. Preserved vegetables are processed foods, consumed in high amounts in the high risk areas for ESCC. This study aimed to investigate the relationships of preserved vegetable consumption with SCC and precancer lesions.

METHODS

Cases from Yanting cancer hospital with pathological diagnosis of primary cancer, along with controls and individuals diagnosed with precancer lesions by endoscopy with iodine staining were interviewed. Trained staff collected data on dietary habits 1 year before the interview. An unconditional logistic regression model was used to estimate the risk odds ratios for preserved vegetable consumption with precancer lesions and cancer.

RESULTS

Adjusting for potential confounders, intake of preserved vegetables (OR=2.92, 95%CI 1.32~6.47) and longer intake period (OR=5.78, 95%CI 2.26~14.80) were associated with higher risk of cancer. Compared with lowest intake frequency, the highest was associated with a 3.0-fold risk for precancer lesions and 3.59-fold risk for ESCC (both p<0.05).

CONCLUSION

Consumption of preserved vegetables is a risk factor for esophageal lesions in high risk areas. The carcinogenicity of preserved vegetables needs investigation in further studies and public health strategies for reduction of consumption might be initiated in high risk areas.

Diet and esophageal cancer risk in the Eastern Cape Province of South Africa

A multicenter hospital-based case-control study comprising 670 incident cases of esophageal cancer (EC) and 1188 controls, frequency-matched for age and sex, was conducted to evaluate the role of diet on EC development in the Eastern Cape Province, South Africa. A locally relevant lifestyle and dietary questionnaire was used. Adjusted odds ratios (OR) and 95% confidence intervals (CI) were computed using unconditional multivariable logistic regression. Individually, maize or sorghum consumption vs. never or rare consumption were not associated with EC (P > 0.1). Males and females consuming green leafy vegetables 5-7 days/wk had 38% (P = 0.04) and 50% (P = 0.007) reduced odds of developing EC, respectively, compared with consumption ≤1 day/wk. A similar reduction in odds was observed with fruit consumption. Principal component factor analysis revealed 3 distinct dietary patterns. In females, high vs. low consumption of Pattern 1 (sorghum, green leafy vegetables, green legumes, fruits, meat) was inversely associated with EC development (OR = 0.54; 95% CI: 0.34-0.89), whereas for Pattern 2 (maize, wild greens-imifino, dry beans) the odds were elevated (OR = 1.67; 95% CI: 1.04-2.67). Compared with low adherence, high adherence to Pattern 3 (wheat-based products) reduced the odds by 35% for both sexes. This study provides further evidence on the role of diet in minimizing EC risk in this population.

Body mass index and risk of gastric cancer: a meta-analysis of a population with more than ten million from 24 prospective studies

BACKGROUND

To provide a quantitative assessment of the association between body mass index (BMI) and the risk of gastric cancer, we summarized the evidence from prospective studies.

METHODS

Eligible studies published up to November 30, 2012, were retrieved via computer searches of MEDLINE and EMBASE as well as manual review of references. Summary relative risks (SRR) with their corresponding 95% confidence intervals (CI) were calculated using a random-effects model.

RESULTS

A total of 24 prospective studies of BMI and gastric cancer risk with 41,791 cases were included in our analysis. Overall, both overweight (BMI, 25-30 kg/m(2)) and obesity (BMI, ≥30 kg/m(2)) were not associated with risk of total gastric cancer (overweight: SRR, 1.01; 95% CI, 0.96-1.07; obesity: SRR, 1.06; 95% CI, 0.99-1.12). Furthermore, we found increased BMI was positively associated with the risk of gastric cardia cancer (GCC; SRR = 1.21 for overweight and 1.82 for obesity), but not with gastric non-cardia cancer (GNCC; SRR = 0.93 for overweight and SRR = 1.00 for obesity). Similar results were observed in a linear dose-response analysis.

CONCLUSION

On the basis of meta-analysis of prospective studies, we find high BMI is positively associated with the risk of GCCs but not with GNCCs.

IMPACT

(i) On the basis of more definite and quantitative evidence than previously available, we found that increasing BMI was not a clear risk factor for total gastric cancer. (ii) Increased BMI was positively associated with risk of GCC but not with GNCCs.

Processed food consumption and risk of esophageal squamous cell carcinoma: A case-control study in a high risk area

This study was conducted to investigate the association between consumption of processed foods and esophageal cancer risk. A population-based case-control study was designed. For the present study, 254 patients with esophageal squamous cell carcinoma with pathological diagnoses were selected from Yanting during 2008 and 2010 and 254 community-based controls were selected from the same area, individually matched with cases by age and sex. Data on demographic, lifestyle and dietary factors were collected using food frequency questionnaires. A conditional logistic regression model was used to estimate the odds ratio (OR) with adjustments for potential confounders. Compared to the frequency of <1 time/week, the intake frequency of >3 times/week of preserved vegetables had a significant association with esophageal cancer (OR = 5.01, 95% confidence interval [CI] 2.07, 12.17). In stratified analyses, the OR of increasing intake of preserved vegetables for esophageal cancer were 2.02 in men (95% CI 1.18, 3.48), 3.15 in women (95% CI 1.28, 7.75), 2.41 (95% CI 1.45 4.01) in the persons <65 years old and 1.28 (95% CI 0.35, 4.65) in persons ≥65 years old. Consumption of pickled vegetables was not associated significantly with esophageal cancer risk. Intake of salted meat with a frequency of ≥1 time/week meant that the OR increased to 2.57 (95%CI 1.02, 6.43), but no significant trend or association in subgroup analysis was observed. Preserved vegetable consumption was associated with increased risk of esophageal cancer, while no association was found with pickled vegetables.

Comparison of gastro-oesophageal junction carcinomas in Chinese versus American patients

AIMS

To compare the clinical and pathological features of gastro-oesophageal junction (GEJ) carcinomas in Chinese and American patients.

METHODS AND RESULTS

Eighty consecutive patients with a GEJ carcinoma (43 from mainland China, and 37 from the USA) were evaluated for association with Barrett oesophagus (BO), chronic Helicobacter pylori gastritis, intestinal metaplasia, and outcome. GEJ carcinomas were defined as tumours that were located within 20 mm of, and crossed, the GEJ. Overall, GEJ carcinomas from Chinese patients revealed significantly more frequent location in the proximal stomach, higher pathological stage, larger size, younger patient age, and association with chronic H. pylori gastritis. In contrast, GEJ cancers from American patients showed a strong association with distal oesophageal location, BO, and associated intestinal metaplasia and dysplasia. Pathologically, GEJ carcinomas from American patients were predominantly adenocarcinomas, whereas Chinese patients showed a higher proportion of mucinous, adenosquamous, acinar or neuroendocrine tumours. Overall, 3- and 5-year survival rates were statistically similar between both patient groups, but upon multivariate analysis, Chinese patients showed statistically better survival rates for stage III tumours.

CONCLUSIONS

Most GEJ carcinomas in patients from China represent proximal gastric cancers associated with chronic H. pylori gastritis, and BO-associated carcinomas are rare among this patient population.

Large body size and sedentary lifestyle during childhood and early adulthood and esophageal squamous cell carcinoma in a high-risk population

BACKGROUND

Little is known about the association of obesity and physical activity at young ages with subsequent risk of esophageal squamous cell carcinoma (ESCC).

PATIENTS AND METHODS

Between 2003 and 2007, we conducted a case-control study in a high-risk population in northeastern Iran. Three hundred ESCC cases and 571 matched controls were recruited. Each individual was shown a standard pictogram, to report body size at ages 15 and 30. Demographic and health-related information, including physical activity at these ages was also collected.

RESULTS

In the fully adjusted models, very obese body size (last two pictograms) at age 15 [odds ratio (OR) 3.2, 95% confidence interval (CI) 1.3-7.7] and age 30 (OR 3.1; 95% CI 1.1-8.5) were associated with ESCC in women, but not in men. Sedentary work at age 15 (OR 3.3, 95% CI 1.3-8.3) and 30 (OR 18.2, 95% CI 3.9-86.2) were also associated with ESCC risk in women only. The increased risk in women at age 15 remained high after later reduction in body size, while women who became very obese only at age 30 did not show a significantly increased risk.

CONCLUSION

These results highlight the importance of early lifestyle modifications in the context of cancer prevention, particularly in women.

Vegetables and fruits consumption and risk of esophageal and gastric cancer subtypes in the Netherlands Cohort Study

Prospective epidemiologic data on vegetables and fruits consumption and risk of subtypes of esophageal and gastric cancer are sparse. We studied the association between vegetables and fruits consumption and risk of esophageal squamous cell carcinoma (ESCC), esophageal adenocarcinoma (EAC), gastric cardia adenocarcinoma (GCA) and gastric noncardia adenocarcinoma (GNCA) in the Netherlands Cohort Study. In 1986, 120,852 Dutch men and women aged 55-69 filled out a questionnaire on diet and other cancer risk factors. After 16.3 years of follow-up, 101 ESCC, 144 EAC, 156 GCA, 460 GNCA cases and 4,035 subcohort members were available for case-cohort analysis using Cox proportional hazards models. Multivariable adjusted incidence rate ratios (RRs) were generally below unity. Total vegetable consumption was nonsignificantly inversely associated with EAC and ESCC risk, but not with GCA and GNCA risk. Significant inverse associations were observed for raw vegetables and EAC risk [RR per 25 g/day: 0.81, 95% confidence interval (CI) 0.68-0.98], and Brassica vegetables and GCA risk (RR per 25 g/day: 0.72, 95% CI 0.54-0.95). Total fruit consumption was associated with a nonsignificantly decreased EAC risk. Citrus fruits were inversely associated with EAC and GCA risk (RRs for highest vs. lowest intake: 0.55, 95% CI 0.31-0.98 and 0.38, 95% CI 0.21-0.69, respectively). Specifically for current smokers, vegetables and possibly also fruits intake was inversely associated with ESCC and EAC risk. Consumption of (specific groups of) vegetables and fruits may protect against subtypes of esophageal and gastric cancer.

Risk factors for esophageal and gastric cancers in Shanxi Province, China: a case-control study

OBJECTIVE

Smoking and alcohol consumption explain little of the risk for upper-gastrointestinal (UGI) cancer in China, where over half of all cases in the world occur.

METHODS

We evaluated questionnaire-based risk factors for UGI cancers in a case-control study from Shanxi Province, China, including 600 esophageal squamous cell carcinomas (ESCCs), 599 gastric cardia adenocarcinomas (GCAs), 316 gastric noncardia adenocarcinomas (GNCAs), and 1514 age- and gender-matched controls.

RESULTS

Ever smoking and ever use of any alcohol were not associated with risk of UGI cancer; only modest associations were observed between ESCC risk and highest cumulative smoking exposure, as well as GNCA risk and beer drinking. While several associations were noted for socioeconomic and some dietary variables with one or two UGI cancers, the strongest and most consistent relations for all three individual UGI cancers were observed for consumption of scalding hot foods (risk increased 150-219% for daily vs. never users) and fresh vegetables and fruits (risk decreased 48-70% for vegetables and 46-68% for fruits, respectively, for high vs. low quartiles).

CONCLUSION

This study confirms the minor role of tobacco and alcohol in UGI cancers in this region, and highlights thermal damage as a leading etiologic factor.

Fruits and vegetables consumption and esophageal squamous cell carcinoma: a case-control study

The authors examined the association of food group intakes and the risk of esophageal squamous cell carcinoma (SCC) in a hospital-based case-control study in Iran. In total, 47 patients with esophageal SCC and 96 controls underwent face-to-face private interviews. Usual dietary intake was assessed using a semiquantitative food frequency questionnaire. Multivariate logistic regression was used to estimate odds ratios and 95% confidence intervals. Cases had higher tobacco consumption and symptomatic gastresophageal reflux, whereas controls had higher mean body mass index (25.3 vs. 20.4) and years of education. A protective independent effect was observed for the highest tertile of total fruit consumption (OR: 0.13, CI: 0.04-0.45, P value = 0.001). Within the group of fruits, a significant inverse association was observed for bananas and kiwis (P for trends: 0.03 and 0.02, respectively). The risk of SCC decreased monotonically with increasing intake frequency of oranges (P value for trend = 0.01). The effect of total vegetable consumption on esophageal SCC was not significant, although a reduction in risk was observed in the highest tertile of intake (OR: 0.66, CI: 0.23-1.87, P value = 0.43). The results of the present study suggest a reasonable association between fruit consumption and esophageal SCC in a Middle Eastern high-risk population.

Prevalence and risk factors for esophageal squamous cell cancer and precursor lesions in Anyang, China: a population-based endoscopic survey

Background:

The etiology of esophageal squamous cell cancer (ESCC) in high prevalence regions of China remains unclear.

Methods:

Endoscopic biopsies were conducted among 7381 inhabitants aged from 25 to 65 of Anyang, China.

Results:

In this study, 2.57, 0.20 and 0.16% of the participants had mild, moderate and severe squamous dysplasia, respectively; 0.19 and 0.08% showed squamous carcinoma in situ and invasive ESCC. Using deep well (depth >100 meters) as water source (odds ratio=0.72, 95% confidence interval: 0.54–0.96) was negatively associated with ESCC and its precursors, whereas tobacco and alcohol use were not significantly associated with ESCC.

Conclusions:

Water source and other factors in this region need further evaluation by longitudinal studies.

The changing face of esophageal cancer

The two main histological esophageal cancer types, adenocarcinoma and squamous cell carcinoma, differ in incidence, geographic distribution, ethnic pattern and etiology. This article focuses on epidemiology with particular reference to geographic and temporal variations in incidence, along with a review of the evidence supporting environmental and genetic factors involved in esophageal carcinogenesis. Squamous cell carcinoma of the esophagus remains predominantly a disease of the developing world. In contrast, esophageal adenocarcinoma is mainly a disease of western developed societies, associated with obesity and gastro-esophageal reflux disease. There has been a dramatic increase in the incidence of adenocarcinoma in developed countries in parallel with migration of both esophageal and gastric adenocarcinomas towards the gastro-esophageal junction.

The risk of upper aero digestive tract cancer associated with smoking, with and without concurrent alcohol consumption

BACKGROUND

Smoking and alcohol are major causal factors for upper aerodigestive tract cancer, but reliable quantification of the combined impact of smoking and alcohol on this cancer and its major subtypes has not been performed.

METHODS

A meta-analysis of studies that had published quantitative estimates of smoking and upper aerodigestive tract cancer by January 2007 was performed. Pooled estimates of relative risks were obtained. Publication bias was investigated through funnel plots and corrected if found to be present.

RESULTS

Overall, 85 studies with information on 53,940 individuals with upper aerodigestive tract cancer were included. The pooled estimate for the association between smoking and the risk of this cancer was 3.47 (95% confidence interval, 3.06-3.92). The risk remained elevated for a decade after smoking cessation but declined thereafter. Individuals who both smoked and consumed alcohol had double the risk of upper aerodigestive tract cancer in comparison with those who only smoked: the relative risk was 6.93 (95% confidence interval, 4.99-9.62) for the former and 2.56 (95% confidence interval, 2.20-2.97) for the latter (P < 0.001).

CONCLUSIONS

Public health interventions that simultaneously discourage smoking and heavy drinking would have greater benefits than would be expected from those that target only one of these risk factors.

Detection of HPV DNA in esophageal cancer specimens from different regions and ethnic groups: a descriptive study

Background

HPV has been found repeatedly in esophageal carcinoma tissues. However, reported detection rates of HPV DNA in these tumors have varied markedly. Differences in detection methods, sample types, and geographic regions of sample origin have been suggested as potential causes of this discrepancy.

Methods

HPV L1 DNA and HPV genotypes were evaluated in 435 esophageal carcinoma specimens collected from four geographic regions with different ethnicities including Anyang in north China, Shantou in south China, Xinjiang in west China, and the United States. The HPV L1 fragment was detected using SPF1/GP6+ primers. HPV genotyping was performed using genotype specific PCR.

Results

Two hundred and forty four of 435 samples (56.1%) tested positive for HPV L1. Significant differences in detection rate were observed neither among the three areas of China nor between China and the US. HPV6, 16, 18, 26, 45, 56, 57, and 58 were identified in L1 positive samples. HPV16 and 57 were the most common types in all regions, followed by HPV26 and HPV18.

Conclusions

HPV infection is common in esophageal carcinoma independent of region and ethnic group of origin. Findings in this study raise the possibility that HPV is involved in esophageal carcinogenesis. Further investigation with a larger sample size over broader geographic areas may be warranted.

Pickled vegetables and the risk of oesophageal cancer: a meta-analysis

BACKGROUND

Ecological and experimental studies have suggested a relationship between Asian pickled vegetable consumption and oesophageal squamous cell carcinoma (OSCC), but the results of epidemiological studies investigating the association have been inconsistent. We conducted a meta-analysis of observational studies of this association to evaluate the existing evidence.

METHODS

We searched the PubMed, ISI-Web of Science, J-EAST, IndMed, Vip Chinese Periodical, and China National Knowledge Infrastructure databases for all studies published in English or Chinese languages. Pooled results for all studies combined and for several study subgroups were computed.

RESULTS

A total of 34 studies were included in this analysis. The overall random effects odds ratio (OR) and 95% confidence interval (CI) for pickled vegetable consumption was 2.08 (1.66-2.60), but the results were heterogeneous across studies. After excluding the three most influential studies, the respective numbers were 2.32 (1.92-2.81). Similar to the overall association, the majority of subgroup analyses showed a statistically significant association between consuming pickled vegetables and OSCC risk. There were only three prospective studies.

CONCLUSION

Our results suggest a potential two-fold increased risk of oesophageal cancer associated with the intake of pickled vegetables. However, because the majority of data was from retrospective studies and there was a high heterogeneity in the results, further well-designed prospective studies are warranted.

High-temperature beverages and foods and esophageal cancer risk--a systematic review

Coffee, tea and maté may cause esophageal cancer (EC) by causing thermal injury to the esophageal mucosa. If so, the risk of EC attributable to thermal injury could be large in populations in which these beverages are commonly consumed. In addition, these drinks may cause or prevent EC via their chemical constituents. Therefore, a large number of epidemiologic studies have investigated the association of an indicator of amount or temperature of use of these drinks or other hot foods and beverages with risk of EC. We conducted a systematic review of these studies and report the results for amount and temperature of use separately. By searching PubMed and the ISI, we found 59 eligible studies. For coffee and tea, there was little evidence for an association between amount of use and EC risk; however, the majority of studies showed an increased risk of EC associated with higher drinking temperature which was statistically significant in most of them. For maté drinking, the number of studies was limited, but they consistently showed that EC risk increased with both amount consumed and temperature, and these 2 were independent risk factors. For other hot foods and drinks, over half of the studies showed statistically significant increased risks of EC associated with higher temperature of intake. Overall, the available results strongly suggest that high-temperature beverage drinking increases the risk of EC. Future studies will require standardized strategies that allow for combining data and results should be reported by histological subtypes of EC.

Association of matrix metalloproteinases-9 gene polymorphisms with genetic susceptibility to esophageal squamous cell carcinoma

Matrix metalloproteinases-9 (MMP-9) plays important roles in tumor invasion and metastasis by degrading extracellular matrix components. Variations in the DNA sequence in the MMP-9 gene may lead to altered MMP-9 production and/or activity, and so this may modulate an individual's susceptibility to esophageal squamous cell carcinoma (ESCC). To test this hypothesis, we investigated the association of the MMP-9 polymorphisms and their haplotypes with the risk of ESCC in a Chinese population. There were significant differences in the genotype and allele distribution of P574R polymorphism of the MMP-9 gene among cases and controls. The P574R GG genotypes were associated with a significantly increased risk of ESCC as compared with the CC genotypes (odds ratio [OR] = 4.08; 95% confidence interval [CI]: 1.58-10.52; p = 0.00). Compared with 279R-574P haplotype, 279R-574R (OR = 3.52; 95% CI: 1.99-6.25) and 279Q-574P (OR = 2.16; 95% CI: 1.07-4.35) haplotypes can increase the onset risk of ESCC statistically, but the role of 279R-574R haplotype is more obvious. MMP-9 P574R polymorphisms and P574R-R279Q haplotype are significantly associated with the risk of ESCC. Our study shows for the first time that MMP-9 gene P574R polymorphism may contribute to a genetic risk factor for ESCC in a Chinese population.

Esophageal cancer and body mass index: results from a prospective study of 220,000 men in China and a meta-analysis of published studies

Several epidemiological studies have reported on the association between body mass index (BMI) and risk of esophageal cancer, but these were mostly in Western populations where many are overweight or obese. There is little direct evidence about the relationship in China where the mean BMI is relatively low and the disease rate is high. We examined the data from a population-based prospective study of 220,000 Chinese men aged 40-79 without a previous history of cancer (mean BMI 21.7 kg/m(2)), which included 1,082 esophageal cancer deaths during 10 years of follow-up. Adjusted hazard ratios for death from esophageal cancer by baseline BMI category were calculated using Cox proportional hazards models. Even among men with good self-assessed health and BMI >or= 18.5 kg/m(2), there was a strong inverse association between BMI and death from esophageal cancer, with each 5 kg/m(2) higher BMI associated with 25% (95%CI: 11-36%) lower esophageal cancer mortality. This inverse association persisted when analysis was restricted to men who had never smoked or when the first 5 years of follow-up were excluded. The strength of the relationship was consistent with the pooled estimate for squamous cell carcinoma of the esophagus in a meta-analysis of prospective studies (31% lower relative risk per 5 kg/m(2) higher BMI; 95% CI: 25-37%), but contrasted with that for adenocarcinoma which showed a positive association with BMI. Together, these data provide reliable evidence that in many populations low BMI is associated with an increased risk of squamous cell carcinoma of the esophagus.

Smoking and gastric cancer: systematic review and meta-analysis of cohort studies

OBJECTIVE

We conducted a systematic review of studies addressing the relation between cigarette smoking and gastric cancer to estimate the magnitude of the association for different levels of exposure and cancer locations.

METHODS

Published cohort, case-cohort, and nested case-control studies were identified through PubMed, Scopus, and Web of Science searches, from inception to July 2007. Relative risk (RR) estimates referring to the comparison of two categories of exposure (e.g., current smokers vs. never smokers) were combined using a random effects model. Generalized least squares regression was used for trend estimation. Heterogeneity was quantified using the I (2) statistic.

RESULTS

Forty-two articles were considered for the systematic review. Comparing current smokers with never smokers: the summary RR estimates were 1.62 in males (95% CI: 1.50-1.75; I (2) = 46.0%; 18 studies) and 1.20 in females (95% CI: 1.01-1.43; I (2) = 49.8%; nine studies); the RR increased from 1.3 for the lowest consumptions to 1.7 for the smoking of approximately 30 cigarettes per day in the trend estimation analysis; smoking was significantly associated with both cardia (RR = 1.87; 95% CI: 1.31-2.67; I (2) = 73.2%; nine studies) and non-cardia (RR = 1.60; 95% CI: 1.41-1.80; I (2) = 18.9%; nine studies) cancers.

CONCLUSION

Our study provides solid evidence to classify smoking as the most important behavioral risk factor for gastric cancer.

An investigation on the polymorphisms of two DNA repair genes and susceptibility to ESCC and GCA of high-incidence region in northern China

AIM

To investigate the possible association of three SNPs, XRCC2 C41657T, XRCC2 G4234C and XRCC3 A17893G with susceptibility to esophageal squamous cell carcinoma (ESCC) and gastric cardia adenocarcinoma (GCA) in a population of northern China.

METHODS

XRCC2 C41657T, XRCC2 G4234C and XRCC3 A17893G SNP were genotyped by polymerase-chain reaction (PCR)-restriction fragment length polymorphism (RFLP) analysis in 583 cancer patients (329 ESCC and 254 GCA) and 614 healthy controls.

RESULTS

The genotype distribution of the XRCC2 C41657T in ESCC and GCA patients were significantly different from that in healthy controls (P values = 0.04 and 0.04 respectively). And a significant difference was found in the allele distribution of GCA patients from that in controls (P = 0.01). The XRCC2 C41657T polymorphism was associated with a modest enhancement in ESCC risk and GCA risk: OR for C/T genotype was 1.38 (1.01-1.89) in GCA risk and for T/T genotype was 2.24 (1.10-4.57) in ESCC risk. When stratified for age, smoking status and family history of UGIC, the C/T genotype showed a modest significant trend on the risk of GCA patients in the groups of age < or =50 years and non-smokers, the adjusted OR were 2.84 (1.21-6.66) and 1.62 (1.06-2.49). The T/T genotype significantly increased the susceptibility of GCA patients in negative family history of UGIC (3.04, 1.02-8.32) and to ESCC patients in the group of age >50 years (3.03, 1.31-6.98), Negative family of UGIC (3.03, 1.12-7.07) and smokers (2.64, 1.02-6.83). The genotype and allele distribution of XRCC2 G4234C and XRCC3 A17893G in ESCC and GCA patients were not significantly different from that in healthy controls (all P values were above 0.05).

CONCLUSION

In this study, we found that the C41657T polymorphism of XRCC2 genes might modify the risk of ESCC and GCA development.

Meta-analysis of antioxidant intake and the risk of esophageal and gastric cardia adenocarcinoma

OBJECTIVE

The incidence of esophageal adenocarcinoma has been increasing rapidly among many countries. Antioxidant intake is a potentially modifiable protective factor, although the results from individual studies are inconclusive. We conducted a systematic review and statistical synthesis of studies that evaluated the associations between vitamin C, vitamin E, or beta-carotene/vitamin A and the risk of esophageal adenocarcinoma or the adjacent gastric cardia (gastroesophageal junction) adenocarcinoma.

METHODS

Studies were included if they reported (a) a measure of dietary antioxidant intake; (b) esophageal or cardia adenocarcinoma occurrence; and (c) a relative risk or odds ratio (OR) with confidence intervals (CI), or sufficient data to permit their calculation.

RESULTS

We identified 10 studies (1 cohort, 9 case-control; 1,057 esophageal and 644 cardia cases). Summary estimates stratified by cancer site suggested that higher intakes of vitamin C, beta-carotene/vitamin A, and vitamin E were inversely associated with the risk of esophageal adenocarcinoma (vitamin C, OR 0.49, 95% CI 0.39-0.62, P(heterogeneity)= 0.10; beta-carotene, OR 0.46, 95% CI 0.36-0.59, P(heterogeneity)= 0.82; vitamin E intake, OR 0.80, 95% CI 0.63-1.03, P(heterogeneity)= 0.59). Beta-carotene intake was also inversely associated with the risk of cardia adenocarcinoma (OR 0.57, 95% CI 0.46-0.72, P(heterogeneity)= 0.17). Dose effects were observed for most associations.

CONCLUSIONS

Pooled results from observational studies suggest that antioxidant intake may be protective against esophageal adenocarcinoma; the data do not support a consistent association between antioxidant intake and the risk of cardia carcinoma. These findings suggest possible etiological differences between these two adjacent malignancies.

The p73 polymorphisms are not associated with susceptibility to esophageal squamous cell carcinoma in a high incidence region of China

P73, a p53 homolog, has some p53-like activities and plays an important role in modulating cell cycle, apoptosis and DNA repair. The two linked polymorphisms in the non-coding region of exon2 of p73 gene, named G4C14-A4T14, may alter translation efficiency of the gene. The transcription of p73 gene is initiated by three promoters, termed P1-P3. There is a single nucleotide substitution (-386G/A) in the P3 promoter region with unknown function. To test the hypothesis that the genetic variations in the exon2 and P3 promoter play a role in the etiology of esophageal squamous cell carcinoma (ESCC), we conducted a population-based case-control study in 348 ESCC patients and 583 healthy controls from a high incidence region of Hebei province, China. The p73 polymorphisms were genotyped by polymerase chain reaction-restriction fragment length polymorphism analysis (PCR-RFLP). The results showed that the family history of upper gastrointestinal cancer (UGIC) significantly increased the risk of developing ESCC (the age, sex and smoking status adjusted OR = 2.02, 95% CI = 1.54-2.67). The overall distribution of the p73 genotype, allelotype and haplotype in cancer patients and controls were not significantly different (all P-values are above 0.05). Stratification analysis by smoking status and family history of UGIC also did not show the significant influence of the polymorphisms on the risk of ESCC development. The results suggested that the p73 exon2 G4C14-A4T14 and P3 promoter -386G/A polymorphisms might not be used as potential markers to predicate the risk of ESCC development in northern China.

Carcinogenic food contaminants

A large number of scientific studies and reviews have addressed the potential for dietary components to influence the risk of developing cancer. One topic of particular interest has been the impact of food contaminants. Two complementary programs, among others, have reviewed and synthesized information on the carcinogenic potential of food contaminants and judged the degree of evidence linking different food contaminants to the risk of cancer in humans. These programs, the International Agency for Research on Cancer's IARC Monographs on the Evaluation of Carcinogenic Risks to Humans and the US National Toxicology Program's Report of Carcinogens have reviewed hundreds of chemicals, mixtures, and natural products and then graded the cancer risk posed to humans. Contaminants with the highest level of evidence include aflatoxin, alcoholic beverages, 2,3,7,8-tetracholordibenzo-p-dioxin. Agents with a moderate level of evidence include acetaldehyde, polycyclic aromatic hydrocarbons, some nitrosamines, and yerba mate. Agents with a low level of evidence include bracken fern, fumonsin B(1), ochratoxin, and others. This review presents a summary of the evidence for the carcinogenicity of these and other agents and the ranks provided by two important assessment programs.

Nutrient intake and risk of squamous cell carcinoma of the esophagus: a case-control study in Uruguay

In 1996-2004 a case-control study on nutrient intake, dietary constituents and risk of squamous cell carcinoma of the esophagus was conducted in Montevideo, Uruguay. In fact, Uruguay, and especially its northern provinces, which border Brazil, are high-risk areas. The study included 234 cases and 936 controls. The controls were hospitalized patients with non-neoplastic disease, which was not related to tobacco smoking and alcohol drinking, and without recent changes in their diets. Controls were frequency matched to cases on age (10-yr intervals), sex, and residence (Montevideo and other provinces). Dietary constituents were energy adjusted using the residuals method and then categorized in quartiles according to the distribution of the controls. The final model included linoleic acid, lycopene, alpha-carotene, beta-cryptoxanthin, vitamin A, monounsaturated fat, total carbohydrates, beta-carotene, and folate. The odds ratio (OR) for high intake of linoleic acid was 1.4 (95% confidence interval, CI = 1.2-1.6), whereas lycopene displayed a strong protective effect (OR = 0.7; 95% CI = 0.6-0.9). The possible role of these and other dietary constituents in esophageal carcinogenesis is discussed.

Diet habits, alcohol drinking, tobacco smoking, green tea drinking, and the risk of esophageal squamous cell carcinoma in the Chinese population

OBJECTIVE

This study aims to investigate the risk of esophageal squamous cell carcinoma in relation to exogenous factors in a rural area of China with a high incidence of esophageal squamous cell carcinoma.

METHODS

A population-based case-control study was conducted in Yangzhong County, Jiangsu Province, China, with 355 histologically confirmed esophageal squamous cell carcinoma cases recruited between 1 January 2004 and 28 February 2006 and 408 controls matched by sex and age, randomly selected from the local population.

RESULTS

Stratified logistic regression analysis by sex revealed that hot-temperature food items, pork braised in brown sauce and old stocked rice intake could increase the risk of esophageal squamous cell carcinoma with odds ratio of 2.127 (95% confidence interval: 1.394-3.245), 2.059 (95% confidence interval: 1.417-2.993) and 9.059 (95% confidence interval: 5.930-13.840), respectively, in men and 3.048 (95% confidence interval: 1.733-5.364), 1.914 (95% confidence interval: 1.159-3.162) and 14.532 (95% confidence interval: 7.816-27.019), respectively, in women, whereas diet high in salt and chili, tobacco smoking and alcohol drinking only showed possible risk effects in men with odds ratio 2.338 (95% confidence interval: 1.568-3.485), 3.378 (95% confidence interval: 2.117-5.389), 1.976 (95% confidence interval: 1.337-2.921) and 2.197 (95% confidence interval: 1.510-3.195), respectively. Green tea drinking showed a protective effect in women (odds ratio=0.257; 95% confidence interval: 0.070-0.941).

CONCLUSIONS

Findings from this study provided evidence that dietary habits, tobacco-smoking and alcohol drinking contribute to the etiology of esophageal squamous cell carcinoma. A healthy dietary habit, with smoking cessation and alcohol controlling is of a great importance in the prevention of esophageal cancer.

Carcinogens and endemic squamous cancer of the oesophagus in Transkei, South Africa. Environmental initiation is the dominant factor; tobacco or other carcinogens of low potency or concentration are sufficient for carcinogenesis in the predisposed mucosa

Oesophageal cancer is common in Africa, and is a major cause of death in Transkei, South Africa. The cause of this endemic disease has been debated for many decades. A continuing focus of research has been identification of a single potent carcinogen. I argue that endemic incidence of oesophageal cancer is associated with potent initiation, not with potent carcinogenesis. Tobacco is a known oesophageal carcinogen, and there is very strong evidence that it is causally involved in a significant proportion of victims. Other potential carcinogens present in the environment include fungal mycotoxins, human papillomavirus, Solanum nigrum and nitrosamines. These are all of lower carcinogenic potential for the oesophagus, and do not have strong evidence associating them with the disease. In the presence of potent environmental initiation, any oesophageal carcinogen even if of low potency or of low concentration may cause the disease. Any or all of the substances named above may be involved, any one of them the cause of the final carcinogenic change in the individual. Tobacco exemplifies this point. It is of relatively low concentration/usage in Transkei, yet has an undeniable association with oesophageal cancer. Carcinogenesis for the oesophagus in Transkei is solely or predominantly due to agents which are already known, including tobacco, acting on a predisposed mucosa. The search for further carcinogens is of low importance, and the search for a single potent carcinogen is misguided. What is of importance is the development of methods to reduce the risks associated with predisposing factors and with known carcinogens.

Fruit and vegetables in cancer prevention

Our aim was to review the epidemiological literature on possible cancer-preventive effects of the consumption of fruits and vegetables in humans, to quantify the effect of high versus low consumption of fruits and vegetables, and to give an overall assessment of the existing evidence. We based our work on an expert meeting conducted by the International Agency for Research on Cancer in 2003. A qualitative reading and evaluation of relevant articles on the cancer-preventive effect of the consumption of fruits and vegetables was made followed by the calculation of the mean relative risk and range for cohort and case-control studies separately. The possible population-preventable fraction for modifying diet in relation to fruit and vegetable consumption was calculated as well as an overall statement about the degree of evidence for the cancer-preventive effect of fruit and vegetable consumption for each cancer site. There is limited evidence for a cancer-preventive effect of the consumption of fruits and vegetables for cancer of the mouth and pharynx, esophagus, stomach, colon-rectum, larynx, lung, ovary (vegetables only), bladder (fruit only), and kidney. There is inadequate evidence for a cancer-preventive effect of the consumption of fruits and vegetables for all other sites. Applying this range of risk difference to the range of prevalence of low intake, the preventable fraction for low fruit and vegetable intake would fall into the range of 5-12%. It is important to recognize that this is only a crude range of estimates and that the proportion of cancers that might be preventable by increasing fruit and vegetable intake may vary beyond this range for specific cancer sites and across different regions of the world.

Body mass index and adenocarcinomas of the esophagus or gastric cardia: a systematic review and meta-analysis

BACKGROUND

The incidence of esophageal adenocarcinoma has increased markedly in recent decades in many countries. Obesity is a potential risk factor, although the results of individual studies differ. We did a systematic review and statistical synthesis of studies that evaluated the association between body mass index (BMI) and the risk of esophageal adenocarcinoma or the adjacent gastric cardia adenocarcinoma.

METHODS

We identified potential studies using Medline, the Web of Science database, a manual review of the literature and expert bibliographies. Studies were included if they reported (a) a measure of body mass; (b) the occurrence of esophageal or cardia adenocarcinoma diagnosis; and (c) a relative risk or odds ratio (OR) with confidence intervals (CI) or provided sufficient data to permit their calculation.

RESULTS

We identified 14 studies (2 cohort, 12 case-control; 2,488 esophageal and 2,509 cardia adenocarcinomas). A high BMI (>25) was associated with an increased risk of esophageal adenocarcinoma (males, OR, 2.2; 95% CI, 1.7-2.7; females, OR, 2.0; 95% CI, 1.4-2.9). Higher levels of BMI were associated with increased risk (overweight males, OR, 1.8; 95% CI, 1.5-2.2; obese males, OR, 2.4; 95% CI, 1.9-3.2). The overall associations with cardia cancer were heterogeneous, although stratification by study location provided homogeneous results for populations from the United States or Europe. A high BMI was weakly associated with the risk of cardia adenocarcinoma (OR, 1.5; 95% CI, 1.3-1.8; P(heterogeneity) = 0.38).

CONCLUSIONS

Pooled results from observational studies support a positive association between high BMI and the risk for esophageal and possibly for cardia adenocarcinoma.

Intake of fruits and vegetables and risk of cancer of the upper aero-digestive tract: the prospective EPIC-study

Epidemiologic studies suggest that a high intake of fruits and vegetables is associated with decreased risk of cancers of the upper aero-digestive tract. We studied data from 345,904 subjects of the prospective European Investigation into Cancer and Nutrition (EPIC) recruited in seven European countries, who had completed a dietary questionnaire in 1992-1998. During 2,182,560 person years of observation 352 histologically verified incident squamous cell cancer (SCC) cases (255 males; 97 females) of the oral cavity, pharynx, larynx, and esophagus were identified. Linear and restricted cubic spline Cox regressions were fitted on variables of intake of fruits and vegetables and adjusted for potential confounders. We observed a significant inverse association with combined total fruits and vegetables intake (estimated relative risk (RR) = 0.91; 95% confidence interval (95% CI) 0.83-1.00 per 80 g/d of consumption), and nearly significant inverse associations in separate analyses with total fruits and total vegetables intake (RR: 0.97 (95% CI: 0.92-1.02) and RR = 0.89 (95% CI: 0.78-1.02) per 40 g/d of consumption). Overall, vegetable subgroups were not related to risk with the exception of intake of root vegetables in men. Restricted cubic spline regression did not improve the linear model fits except for total fruits and vegetables and total fruits with a significant decrease in risk at low intake levels (<120 g/d) for fruits. Dietary recommendations should consider the potential benefit of increasing fruits and vegetables consumption for reducing the risk of cancers of the upper aero-digestive tract, particularly at low intake.

Smoking cessation and the risk of oesophageal cancer: An overview of published studies

The epidemiologic studies on oesophageal cancer and smoking cessation published before December 2005 were reviewed here. The results from at least 10 cohort and 10 case-control studies indicated that former smokers had a lower risk of squamous-cell or unspecified oesophageal cancer than current smokers. Most investigations showed that the risk of oesophageal cancer remains elevated many years (at least 10) after cessation of smoking, to decline by about 40% only thereafter. Moreover, after 10 years since cessation of smoking, ex-smokers still have a twofold increased risk as compared to never smokers. A few studies investigated the effect of smoking cessation on adenocarcinoma, and did not report a clear reduction of risk. Data on oesophageal adenocarcinoma are however too limited to provide adequate inference on the relation with time since smoking cessation. In conclusion, cessation of smoking could have an appreciable impact in reducing (squamous-cell) oesophageal cancer, and represents an obvious priority for prevention and public-health purposes.

Fruit and vegetables consumption and gastric cancer: a systematic review and meta-analysis of cohort studies

Fruit and vegetable intake is widely recognized as protective for gastric cancer occurrence but prospective research challenged this belief. To evaluate the influence of design options in such results we did a meta-analysis of relevant published cohort studies identified from inception to 2004 in PubMed, EMBASE, and LILACS. Random-effects meta-analysis, stratification, and meta-regression were used to pool effects and to analyze the association with type of outcome event and length of follow-up independent of other study characteristics. An inverse association was observed between fruit intake and gastric cancer incidence (relative risk, RR = 0.82; 95% confidence interval, CI = 0.73-0.93) and stronger for follow-up periods of > or = 10 yr (RR = 0.66; 95% CI = 0.52-0.83) but not when the study outcome was death (RR = 1.08; 95% CI = 0.86-1.35). For vegetables, the RR was 0.88 (95% CI = 0.69-1.13) using all incidence studies and 0.71 (95% CI = 0.53-0.94) when considering only those with the longer follow-up. The association observed between vegetable intake and gastric cancer mortality was 1.05 (95% CI = 0.89-1.25). Other study characteristics assessed added no significant contribution to explain heterogeneity. This meta-analysis showed that design options might play a key role in the observed magnitude or the direction of the association between fruit and vegetable intake and gastric cancer.

Incidence and mortality of gastric cancer in China

Gastric cancer is one of the most frequent cancers in the world; almost two-thirds of gastric cancer cases and deaths occur in less developed regions. In China, based on two national mortality surveys conducted in 1970s and 1990s, there is an obvious clustering of geographical distribution of gastric cancer in the country, with the high mortality being mostly located in rural areas, especially in Gansu, Henan, Hebei, Shanxi and Shaanxi Provinces in the middle-western part of China. Despite a slight increase from the 1970s to early 1990s, remarkable declines in gastric cancer mortality were noticed in almost the entire population during the last decade in China. These declines were largely due to the dramatic improvements in the social-economic environment, lifestyle, nutrition, education and health care system after economic reforms started two decades ago. Nevertheless, gastric cancer will remain a significant cancer burden currently and be one of the key issues in cancer prevention and control strategy in China. It was predicted that, in 2005, 0.3 million deaths and 0.4 million new cases from gastric cancer would rank the third most common cancer. The essential package of the prevention and control strategy for gastric cancer in China would focus on controlling Helicobacter pylori (H. pylori) infection, improving educational levels, advocating healthy diet and anti-tobacco campaign, searching for cost-effective early detection, diagnosis and treatment programs including approaches for curable management and palliative care.

Incidence and mortality of gastric cancer in China

Gastric cancer is one of the most frequent cancers in the world; almost two-thirds of gastric cancer cases and deaths occur in less developed regions. In China, based on two national mortality surveys conducted in 1970s and 1990s, there is an obvious clustering of geographical distribution of gastric cancer in the country, with the high mortality being mostly located in rural areas, especially in Gansu, Henan, Hebei, Shanxi and Shaanxi Provinces in the middle-western part of China. Despite a slight increase from the 1970s to early 1990s, remarkable declines in gastric cancer mortality were noticed in almost the entire population during the last decade in China. These declines were largely due to the dramatic improvements in the social-economic environment, lifestyle, nutrition, education and health care system after economic reforms started two decades ago. Nevertheless, gastric cancer will remain a significant cancer burden currently and be one of the key issues in cancer prevention and control strategy in China. It was predicted that, in 2005, 0.3 million deaths and 0.4 million new cases from gastric cancer would rank the third most common cancer. The essential package of the prevention and control strategy for gastric cancer in China would focus on controlling Helicobacter pylori (H pylori) infection, improving educational levels, advocating healthy diet and anti-tobacco campaign, searching for cost-effective early detection, diagnosis and treatment programs including approaches for curable management and palliative care.