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

Global burden of esophageal cancer attributable to high BMI in 204 countries and territories: 1990-2019

BACKGROUND

Esophageal cancer (EC), a common and fatal disease, includes two histological subtypes; esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (ECA). To aid policymakers in the allocation of resources for the prevention and treatment of EC, updated data on EC deaths and disability-adjusted life years (DALYs) attributable to high body mass index (BMI) are necessary. The objective of this study was to identify trends in EC associated with high BMI between 1990 and 2019 using 2019 Global Burden of Disease data.

METHODS

In this observational population-based study, epidemiological data on the association between high BMI and EC were obtained from GBD 2019. The age-standardized mortality rate (ASMRs) and disability-adjusted life year rate (ASDRs) attributable to high BMI-related EC were stratified by year, age, country, and sociodemographic index (SDI). The estimated annual percentage change (EAPC) was calculated to evaluate the temporal trends of the ASMRs and ASDRs between 1990 and 2019.

RESULTS

In 2019, the proportion of EC deaths and DALYs attributed to high BMI was 18.1% and 18.9%, respectively, resulting in 89 904 (95% confidence interval [CI]: 27 879-171 255) deaths and 2 202 314 (95% CI: 681 901-4 173 080) DALYs. High BMI-related deaths and DALYs showed a strong upward trend, increasing by more than two-fold since 1990. East Asia and Western Europe showed the highest risk of EC mortality and DALYs attributable to high BMI; China and the USA bear the greatest burden. The ASMR and ASDR increased in five SDI regions.

CONCLUSIONS

The incidence of EC is increasing, particularly in developing nations, which may be attributed to the prevalence of high BMI. To mitigate the impact of high BMI on the incidence of EC, it is important to increase awareness of its deleterious effects, which may alleviate the burden of this disease.

Aberrations in ion channels interacting with lipid metabolism and epithelial-mesenchymal transition in esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) is the most prevalent malignant gastrointestinal tumor. Ion channels contribute to tumor growth and progression through interactions with their neighboring molecules including lipids. The dysregulation of membrane ion channels and lipid metabolism may contribute to the epithelial-mesenchymal transition (EMT), leading to metastatic progression. Herein, transcriptome profiles of patients with ESCC were analyzed by performing differential gene expression and weighted gene co-expression network analysis to identify the altered ion channels, lipid metabolism- and EMT-related genes in ESCC. A total of 1,081 differentially expressed genes, including 113 ion channels, 487 lipid metabolism-related, and 537 EMT-related genes, were identified in patients with ESCC. Thereafter, EMT scores were correlated with altered co-expressed genes. The altered co-expressed genes indicated a correlation with EMT signatures. Interactions among 22 ion channels with 3 hub lipid metabolism- and 13 hub EMT-related proteins were determined using protein-protein interaction networks. A pathway map was generated to depict deregulated signaling pathways including insulin resistance and the estrogen receptor-Ca²⁺ signaling pathway in ESCC. The relationship between potential ion channels and 5-year survival rates in ESCC was determined using Kaplan-Meier plots and Cox proportional hazard regression analysis. Inositol 1,4,5-trisphosphate receptor type 3 (ITPR3) was found to be associated with poor prognosis of patients with ESCC. Additionally, drugs interacting with potential ion channels, including GJA1 and ITPR3, were identified. Understanding alterations in ion channels with lipid metabolism and EMT in ESCC pathophysiology would most likely provide potential targets for the better treatment of patients with ESCC.

Updated epidemiology of gastrointestinal cancers in East Asia

Globally, gastrointestinal cancers represent more than one-fourth of all cancer incidence and one-third of cancer-related mortality. Although there has been much progress in screening colorectal cancer, the prognosis of other gastrointestinal cancers tends to be poor. The highest burden of gastrointestinal cancers, including stomach, liver, oesophageal and gallbladder cancers, was observed in regions in East Asia. The increasing burden of gastrointestinal cancers in East Asian regions is related to population growth, ageing and the westernization of lifestyle habits in this region. Furthermore, the rising incidence of young-onset colorectal cancer is an emerging trend in East Asia. This Review provides a comprehensive and updated summary of the epidemiology of gastrointestinal cancers in East Asia, with emphasis on comparing their epidemiology in East Asia with that in Western regions, and highlights the major risk factors and implications for prevention. Overall, to optimally reduce the disease burden incurred by gastrointestinal cancers in East Asian regions, a concerted effort will be needed to modify unhealthy lifestyles, promote vaccination against the hepatitis virus, control Helicobacter pylori, liver fluke and hepatitis virus infections, increase the uptake rate of colorectal cancer screening, enhance detection of early cancers and their precursors, and improve cancer survivorship through an organized rehabilitation programme.

Epidemiological Review: Esophagus Squamous Cell Carcinoma in India

Worldwide the incidence of esophagus squamous cell carcinoma (ESCC), remains one of the most common causes of cancer death. ESCC is one of the leading types of cancer in the North and Northeast regions of India among both genders. Risk factors of ESCC include tobacco, alcohol, areca nut, hot beverages, low fruit diet, poor oral hygiene, unpiped water, and human papillomavirus infection. This review tries to elaborate on various modifiable risk factors for ESCC, which have been studied worldwide and need to be studied in India. PubMed was used as a search platform using keywords, such as “esophagus cancer,” “esophagus squamous cell carcinoma,” “epidemiology,” “India,” “incidence,” “mortality,” “risk factors,” “treatment,” “survival,” “prevention” and their corresponding Medical Subject Heading terms, were used in combination with Boolean operators “OR” and “AND.” Studies from India are mostly hospital-based case-control studies from the North region. Further research is required in India to understand the etiology, to design large-scale screening and prevention strategies.

Pictogram Is a Valid Instrument to Classify At-Risk Adult Population Based on Abdominal Obesity: Results from Pars Cohort Study

BACKGROUND

Abdominal obesity is associated with increased risk of myocardial infarction and death events. Thus, obtaining data on the status of abdominal obesity is important in risk factor assessment and prevention of non-communicable diseases. This study aimed to evaluate the validity of using pictograms to classify abdominal obesity indices (waist circumference [WC], waist-hip ratio [WHR], and waist-height ratio [WHtR]) into normal and at-risk categories and determine the effects of demographic characteristics on this validity.

METHODS

This cross-sectional study used data from Pars Cohort Study (PCS). Participants chose the most similar pictogram scores to their body size at 15, 30 years, and current age. Optimal normal/at-risk cut-off values for pictograms were calculated using sensitivity/specificity plots. Receiver operating characteristic curves were used to evaluate the validity of pictograms. Validity measures were analyzed across different subgroups of demographic characteristics.

RESULTS

A total of 9263 participants (46% males) were included in the study. The estimated area under the curves were 84% for WC, 77% for WHR, and 89% for WHtR in males, and 84% for WC, 73% for WHR, and 90% for WHtR in females. Optimal pictogram cutoffs to classify central obesity for WC, WHR, and WHtR were 4, 4, and 5 in males and 4, 4, and 6 in females, respectively. The majority of demographic characteristics were not associated with the validity of pictograms.

CONCLUSION

Using pictograms to determine normal and at-risk categories of abdominal obesity indices is valid among adult population with a wide range of demographic characteristics. However, the results need to be interpreted with caution in those with a positive history of weight fluctuation.

Association between physical activity and digestive-system cancer: An updated systematic review and meta-analysis

BACKGROUND

Physical activity (PA) may have an impact on digestive-system cancer (DSC) by improving insulin sensitivity and anticancer immune function and by reducing the exposure of the digestive tract to carcinogens by stimulating gastrointestinal motility, thus reducing transit time. The current study aimed to determine the effect of PA on different types of DSC via a systematic review and meta-analysis.

METHODS

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched for relevant studies in PubMed, Embase, Web of Science, Cochrane Library, and China National Knowledge Infrastructure. Using a random effects model, the relationship between PA and different types of DSC was analyzed.

RESULTS

The data used for meta-analysis were derived from 161 risk estimates in 47 studies involving 5,797,768 participants and 55,162 cases. We assessed the pooled associations between high vs. low PA levels and the risk of DSC (risk ratio (RR)  = 0.82, 95% confidence interval (95%CI): 0.79-0.85), colon cancer (RR = 0.81, 95%CI: 0.76-0.87), rectal cancer (RR = 0.88, 95%CI: 0.80-0.98), colorectal cancer (RR = 0.77, 95%CI: 0.69-0.85), gallbladder cancer (RR = 0.79, 95%CI: 0.64-0.98), gastric cancer (RR = 0.83, 95%CI: 0.76-0.91), liver cancer (RR = 0.73, 0.60-0.89), oropharyngeal cancer (RR = 0.79, 95%CI: 0.72-0.87), and pancreatic cancer (RR = 0.85, 95%CI: 0.78-0.93). The findings were comparable between case-control studies (RR = 0.73, 95%CI: 0.68-0.78) and prospective cohort studies (RR = 0.88, 95%CI: 0.80-0.91). The meta-analysis of 9 studies reporting low, moderate, and high PA levels, with 17 risk estimates, showed that compared to low PA, moderate PA may also reduce the risk of DSC (RR = 0.89, 95%CI: 0.80-1.00), while compared to moderate PA, high PA seemed to slightly increase the risk of DSC, although the results were not statistically significant (RR = 1.11, 95%CI: 0.94-1.32). In addition, limited evidence from 5 studies suggested that meeting the international PA guidelines might not significantly reduce the risk of DSC (RR = 0.96, 95%CI: 0.91-1.02).

CONCLUSION

Compared to previous research, this systematic review has provided more comprehensive information about the inverse relationship between PA and DSC risk. The updated evidence from the current meta-analysis indicates that a moderate-to-high PA level is a common protective factor that can significantly lower the overall risk of DSC. However, the reduction rate for specific cancers may vary. In addition, limited evidence suggests that meeting the international PA guidelines might not significantly reduce the risk of DSC. Thus, future studies must be conducted to determine the optimal dosage, frequency, intensity, and duration of PA required to reduce DSC risk effectively.

Strenuous occupational physical activity: Potential association with esophageal squamous cell carcinoma risk

Objective:

The impact of recreational physical activity (RPA) on cancer risk has been extensively studied. However, the association of occupational physical activity (OPA), which differs in dose and intensity from RPA, with different cancers including esophageal squamous cell carcinoma (ESCC), has received less attention.

Materials and methods:

We conducted a hospital-based case–control study in Kashmir, India, majorly a rural population, to evaluate the association of OPA with ESCC risk. Histopathologically confirmed 703 ESCC cases and 1664 controls, individually matched to the respective cases for age, sex and district of residence, were recruited.

Main outcome measures:

Information on type, duration and intensity of physical activity was obtained in face-to-face interviews with participants using a structured questionnaire. Conditional logistic regression models were used to calculate odds ratios (ORs) and 95% confidence intervals (95% CIs). Body mass index was unable to be accounted for in the analysis.

Results:

A high level of OPA was associated with increased ESCC risk (OR = 2.17, 95% CI; 1.41–3.32), compared to subjects with moderate OPA. The association with ESCC risk was stronger in strenuous workers (OR = 3.64, 95% CI; 2.13–6.20). The association of strenuous OPA with ESCC risk persisted only in subjects that were involved in strenuous activities for equal to or greater than five days/week.

Conclusions:

Our study suggests a possible association of strenuous OPA with ESCC risk. Although our results were adjusted for multiple factors, including indicators of socioeconomic status, more replicative occupational epidemiological studies are needed to rule out any residual confounding.

Adult height, body mass index change, and body shape change in relation to esophageal squamous cell carcinoma risk: A population-based case-control study in China

The relationship between risk of esophageal squamous cell carcinoma (ESCC) and adult height, changes in individual body mass index (BMI) and body shape is not established. We performed a large population‐based case‐control study, which enrolled a total of 1414 ESCC cases and 1989 controls in a high‐incidence area in China. Using face‐to‐face interview with a structured questionnaire, information on participants' heights, weights, and perceived body shapes at 20 years of age was collected. Additionally, data on weight and perceived body shape among the same participants 10 years prior to ascertainment were collected using the same method. Odd ratios (ORs) of ESCC risk in relation to BMI and body shape were estimated using unconditional logistic regression models. The adjusted results indicated that ESCC risk in adults rapidly rose as height increased, plateauing at 170 cm among men and 157 cm among women. Among participants who were underweight, normal weight, or thinner than body shape 4, body weight loss was associated with increased risk of ESCC, and body weight gain was associated with decreased incidence of ESCC (ORs ranging from 0.40 to 0.76). Notably, however, changes in body weight did not significantly affect ESCC risk among participants who were overweight, obese, or larger than body shape 3. Maintaining a fit body shape and a reasonable BMI is advisable and of vital importance to reduce the risk of ESCC, especially in high‐risk areas.

Physical Activity and Gastrointestinal Cancer Risk: A Review

Introduction: Western lifestyle characterized by increased consumption of red meat, fat, processed food, smoking, alcohol drinking, lower consumption of vegetables and physical inactivity has been associated with a higher gastrointestinal cancer risk. Digestive system cancers are diagnosed at late stages when they show poor response to treatment and are associated with a high mortality rate. Colorectal, gastric, esophageal and pancreatic cancers are among the most common cancers worldwide. Studies show that more than 50% of gastrointestinal cancers develop as a result of inappropriate lifestyle. An inverse association between physical activity and many chronic diseases has been proved so far. However, the association between physical activity and some gastrointestinal cancers is still controversial. This study was aimed to determine the association between physical activity and gastrointestinal cancers risk.

Methods: We conducted a comprehensive search of English and Persian databases from February 2007 till December 2017, for studies investigating the association of physical activity and risk of gastrointestinal cancers. Finally, after reading full text of articles, 123 studies were included.

Results: Physical activity can be helpful in reducing the risk of gastrointestinal cancer, especially colon and pancreatic cancers. The risk reduction is not similar for different types of gastrointestinal cancers and also among males and females.

Conclusion: Different types of physical activity are associated with a lower risk of gastrointestinal cancer. However, it is unknown which type and intensity of physical activity are associated with a protective effect against gastro-intestinal cancer.

Global patterns in excess body weight and the associated cancer burden

The prevalence of excess body weight and the associated cancer burden have been rising over the past several decades globally. Between 1975 and 2016, the prevalence of excess body weight in adults-defined as a body mass index (BMI) ≥ 25 kg/m² -increased from nearly 21% in men and 24% in women to approximately 40% in both sexes. Notably, the prevalence of obesity (BMI ≥ 30 kg/m² ) quadrupled in men, from 3% to 12%, and more than doubled in women, from 7% to 16%. This change, combined with population growth, resulted in a more than 6-fold increase in the number of obese adults, from 100 to 671 million. The largest absolute increase in obesity occurred among men and boys in high-income Western countries and among women and girls in Central Asia, the Middle East, and North Africa. The simultaneous rise in excess body weight in almost all countries is thought to be driven largely by changes in the global food system, which promotes energy-dense, nutrient-poor foods, alongside reduced opportunities for physical activity. In 2012, excess body weight accounted for approximately 3.9% of all cancers (544,300 cases) with proportion varying from less than 1% in low-income countries to 7% or 8% in some high-income Western countries and in Middle Eastern and Northern African countries. The attributable burden by sex was higher for women (368,500 cases) than for men (175,800 cases). Given the pandemic proportion of excess body weight in high-income countries and the increasing prevalence in low- and middle-income countries, the global cancer burden attributable to this condition is likely to increase in the future. There is emerging consensus on opportunities for obesity control through the multisectoral coordinated implementation of core policy actions to promote an environment conducive to a healthy diet and active living. The rapid increase in both the prevalence of excess body weight and the associated cancer burden highlights the need for a rejuvenated focus on identifying, implementing, and evaluating interventions to prevent and control excess body weight.

Physical activity, sedentary behaviour and risk of oesophago-gastric cancer: A prospective cohort study within UK Biobank

BACKGROUND

Few observational studies have assessed the role of physical activity in oesophago-gastric cancer risk.

OBJECTIVE

This prospective cohort study aimed to assess the association between physical activity and risk of oesophageal or gastric cancer.

METHODS

A cohort of 359,033 adults aged 40-69 years were identified from the UK Biobank, which recruited participants between 2006 and 2010. Adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) for the associations between self-reported levels of physical activity and screen-based sedentary behaviour and risk of oesophageal and gastric cancer were calculated using Cox proportional hazards models.

RESULTS

During eight years of follow-up (mean = 5.5), 294 oesophageal cancer and 217 gastric cancer cases were identified. Physical activity and screen-based sedentary behaviour levels were not associated with overall oesophago-gastric cancer risk. However, when compared with low levels, high physical activity levels were associated with a significantly reduced risk of gastric non-cardia cancer (HR 0.58, 95% CI 0.37-0.95). Moderate physical activity levels were associated with a 38% reduced risk of oesophageal adenocarcinoma (HR 0.62, 95% CI 0.43-0.89), although no dose-response association was apparent.

CONCLUSION

Moderate, rather than high, physical activity levels were associated with the strongest reductions in oesophageal adenocarcinoma risk in this large UK prospective cohort.

Building cancer registries in a lower resource setting: The 10-year experience of Golestan, Northern Iran

INTRODUCTION

The Golestan population-based cancer registry (GPCR) was established in Golestan province, Northern Iran, within the Asian belt with predominance of upper-gastrointestinal cancers. We aimed to present the experiences of the registry in a resource-limited setting over the 10 years since its inception (2004-2013).

METHODS

The GPCR was established as a research project to enable sustainable funding. A clear plan was developed for use of the GPCR data. New primary cancers were registered based on international standards, indices of data quality were routinely assessed and age-standardized incidence rates (ASR) per 100,000 person-years calculated using IARC's CanReg-5 software.

RESULTS

Overall, 19807 new cancer cases were registered during the study period, an average of 1981 cases per annum, with overall ASR of 175.0 and 142.4 in males and females, respectively. The GPCR data suggested gastrointestinal and breast cancers as the most common malignancies in Golestan province. We observed increasing incidence rates of breast and colorectal cancers but declining trends of esophageal cancer. Overall, indices of data quality were within acceptable ranges.

CONCLUSIONS

The GPCR data have been included in IARC's Cancer Incidence in Five Continents series, were used in 21 research projects, and published as 30 research papers. The key ingredients for the successful establishment and maintenance of the GPCR included sustainable sources of funding, a clear action plan for the use of data as well as stakeholder cooperation across all areas of the registration. The GPCR may be considered as a model for planning population-based cancer registries in lesser-resourced settings.

Epidemiology of Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) accounts for about 90% of the 456,000 incident esophageal cancers each year. Regions of high incidence include Eastern to Central Asia, along the Rift Valley in East Africa, and into South Africa. There are many causes of ESCC, which vary among regions. Early studies in France associated smoking cigarettes and heavy alcohol consumption with high rates of ESCC, but these factors cannot explain the high incidence in other regions. We discuss other risk factors for ESCC, including polycyclic aromatic hydrocarbons from a variety of sources, high-temperature foods, diet, and oral health and the microbiome-all require further research. A growing list of defined genomic regions affects susceptibility, but large genome-wide association studies have been conducted with ethnic Chinese subjects only; more studies are called for in the rest of Asia and Africa. ESCC has been understudied, but growing infrastructure in more high-incidence countries will allow rapid progress in our understanding.

Sitting time and occupational and recreational physical activity in relation to the risk of esophageal squamous cell carcinoma

Backgrounds

Sitting time and physical activity are associated with cancer risk; however, their roles in the development of esophageal squamous cell carcinoma (ESCC) are inconclusive. This study aimed to investigate the effects of total sitting time, occupational activity time (OAT), and recreational activity time (RAT) on ESCC risk.

Methods

Five hundred fifty-seven ESCC patients and 543 healthy controls matched by sex and age were recruited for this study. Conditional logistic regression was performed to obtain odds ratios (ORs) and 95% confidence intervals (CIs).

Results

Longer total sitting time (adjusted OR [AOR] 2.54, 95% CI 1.58–4.09) and longer OAT (AOR 2.90, 95% CI 2.11–3.99) were associated with higher ESCC risk, while longer RAT (AOR 0.27, 95% CI 0.19–0.38) could reduce ESCC risk. When the body mass index was incorporated into the multivariable models, the results changed slightly. In risk estimation according to sex, the same trends were observed in both men and women. Furthermore, longer RAT could completely or partially diminish the impacts of longer sitting time and OAT on increasing ESCC risk.

Conclusion

Long sitting time and long OAT can increase the risk of ESCC, while long RAT is significantly associated with decreased ESCC risk.

Cancers of the Esophagus and Stomach: Potential Mechanisms Behind the Beneficial Influence of Physical Activity

OBJECTIVE

To compare findings from several recent meta-analyses showing a reduced risk of gastric and esophageal cancers in physically active individuals, to assess the magnitude of this benefit, and to seek information on potential underlying mechanisms.

DATA SOURCES

A comprehensive search of Ovid/Medline from 1996 to February 2016, using the terms physical activity or exercise or training and esophageal or gastric cancer, and supplementing the articles identified by material from references lists and personal files.

MAIN RESULTS

Moderate-to-vigorous physical activity is associated with a 20% to 30% reduction in the risk of gastroesophageal adenocarcinomas, with a significant dose/response relationship. Benefit is greater in women than in men, and greater for noncardia than for cardia or esophageal tumors. Mechanisms could include a reduction of visceral fat (with a lesser production of cancer promoting hormones and reduced gastroesophageal reflux) and/or a lesser likelihood of smoking and excessive alcohol consumption. Physical activity does not protect against Helicobacter pylori infections or gastric ulceration, but mechanisms related to the impact of exercise on immune function, antioxidant mechanisms, and gastroesophageal reflux remain to be explored.

CONCLUSIONS

Regular, moderate-to-vigorous physical activity is associated with a clinically significant reduction in the risk of gastroesophageal adenocarcinomas, but mechanisms are as yet unclear, and a causal relationship remains to be proven.

A prospective cohort study of body size and risk of head and neck cancers in the NIH-AARP diet and health study

BACKGROUND

The association between body size and head and neck cancers (HNCA) is unclear, partly because of the biases in case-control studies.

METHODS

In the prospective NIH-AARP cohort study, 218,854 participants (132,288 men and 86,566 women), aged 50 to 71 years, were cancer free at baseline (1995 and 1996), and had valid anthropometric data. Cox proportional hazards regression was used to examine the associations between body size and HNCA, adjusted for current and past smoking habits, alcohol intake, education, race, and fruit and vegetable consumption, and reported as HR and 95% confidence intervals (CI).

RESULTS

Until December 31, 2006, 779 incident HNCAs occurred: 342 in the oral cavity, 120 in the oro- and hypopharynx, 265 in the larynx, 12 in the nasopharynx, and 40 at overlapping sites. There was an inverse association between HNCA and body mass index, which was almost exclusively among current smokers (HR = 0.76 per each 5 U increase; 95% CI, 0.63-0.93), and diminished as initial years of follow-up were excluded. We observed a direct association with waist-to-hip ratio (HR = 1.16 per 0.1 U increase; 95% CI, 1.03-1.31), particularly for cancers of the oral cavity (HR, 1.40; 95% CI, 1.17-1.67). Height was also directly associated with total HNCAs (P = 0.02), and oro- and hypopharyngeal cancers (P < 0.01).

CONCLUSIONS

The risk of HNCAs was associated inversely with leanness among current smokers, and directly with abdominal obesity and height.

IMPACT

Our study provides evidence that the association between leanness and risk of HNCAs may be due to effect modification by smoking.

Physical activity is associated with reduced risk of esophageal cancer, particularly esophageal adenocarcinoma: a systematic review and meta-analysis

Background

Physical activity has been inversely associated with risk of several cancers. We performed a systematic review and meta-analysis to evaluate the association between physical activity and risk of esophageal cancer (esophageal adenocarcinoma [EAC] and/or esophageal squamous cell carcinoma [ESCC]).

Methods

We conducted a comprehensive search of bibliographic databases and conference proceedings from inception through February 2013 for observational studies that examined associations between recreational and/or occupational physical activity and esophageal cancer risk. Summary adjusted odds ratio (OR) estimates with 95% confidence intervals (CI) were estimated using the random-effects model.

Results

The analysis included 9 studies (4 cohort, 5 case–control) reporting 1,871 cases of esophageal cancer among 1,381,844 patients. Meta-analysis demonstrated that the risk of esophageal cancer was 29% lower among the most physically active compared to the least physically active subjects (OR, 0.71; 95% CI, 0.57-0.89), with moderate heterogeneity (I² = 47%). On histology-specific analysis, physical activity was associated with a 32% decreased risk of EAC (4 studies, 503 cases of EAC; OR, 0.68; 95% CI, 0.55-0.85) with minimal heterogeneity (I² = 0%). There were only 3 studies reporting the association between physical activity and risk of ESCC with conflicting results, and the meta-analysis demonstrated a null association (OR, 1.10; 95% CI, 0.21-5.64). The results were consistent across study design, geographic location and study quality, with a non-significant trend towards a dose–response relationship.

Conclusions

Meta-analysis of published observational studies indicates that physical activity may be associated with reduced risk of esophageal adenocarcinoma. Lifestyle interventions focusing on increasing physical activity may decrease the global burden of EAC.

The association between physical activity and gastroesophageal cancer: systematic review and meta-analysis

Physical activity may decrease gastroesophageal cancer risk through a reduction of oxidative stress and decreased chronic inflammation, yet few epidemiologic studies have been able to report a clear inverse association between physical activity and gastroesophageal cancer. Because no meta-analysis has investigated the relation of physical activity to gastroesophageal cancer, we conducted a comprehensive systematic review and meta-analysis according to the PRISMA guidelines based on 24 studies with a total of 15,745 cases. When we compared high versus low physical activity levels and summarized associations according to anatomic site and tumor histology, risk reductions were evident for esophageal adenocarcinoma [relative risk (RR) = 0.79, 95% confidence interval (CI) = 0.66-0.94], gastric cardia adenocarcinoma (RR = 0.83, 95% CI = 0.69-0.99) and gastric non-cardia adenocarcinoma (RR = 0.72, 95% CI = 0.62-0.84). The risk reduction for esophageal squamous cell carcinoma (RR = 0.94, 95% CI = 0.41-2.16) became statistically significant (RR = 0.66, 95% CI = 0.46-0.96) after excluding an influential study. The test for heterogeneity by gastroesophageal cancer subtype was statistically non-significant (p-difference = 0.71). The RR of total gastroesophageal cancer for high versus low physical activity was 0.82 (95% CI = 0.74-0.90). A dose-response analysis of frequency of physical activity and total gastroesophageal cancer risk revealed that the greatest risk reduction was achieved among those engaging in moderate to vigorous physical activity five times per week (RR = 0.67, 95% CI = 0.58-0.79). Our results provide support for an inverse relation of physical activity, in particular exercise frequency, to gastroesophageal cancer risk.

Impact of body size and physical activity during adolescence and adult life on overall and cause-specific mortality in a large cohort study from Iran

We conducted this study to examine life-course body size and physical activity in relation to total and cause-specific mortality, which has not previously been studied in the low and middle-income countries in Asia. The Golestan Cohort Study is a population-based cohort in northeastern Iran in which 50,045 people above the age of 40 have been followed since 2004. Participants were shown a validated pictogram to assess body size at ages 15, 30, and the time of recruitment. Information on occupational physical activity at these ages was also collected. Subjects were followed up annually, and cause of death was determined. Cox regression models were adjusted for age at cohort start, smoking, socioeconomic status, ethnicity, place of residence, education, and opium use. Models for body size were also adjusted for physical activity at the same age, and vice versa. During a total of 252,740 person-years of follow-up (mean follow-up duration 5.1 ± 1.3 years) through December 2011, 2,529 of the cohort participants died. Larger body sizes at ages 15 or 30 in both sexes were associated with increased overall mortality. Cancer mortality was more strongly associated with adolescent obesity, and cardiovascular mortality with early adulthood body size. Weight gain between these ages was associated with cardiovascular mortality. Obese adolescents who lost weight still had increased mortality from all medical causes in both sexes. Physical activity during adolescence and early adulthood had no association with mortality, but at cohort baseline higher levels of activity were associated with reduced mortality. Mortality in this Middle-Eastern population was associated with obesity both during adolescence and early adult life.

Physical activity and risks of esophageal and gastric cancers: a meta-analysis

BACKGROUND

The incidence of esophageal and gastric cancer has been increasing rapidly worldwide in recent years, although the reason for this increase is unclear. Here, a statistical synthesis of studies that evaluated the association between physical activity, a well-known protecting factor against death and other chronic diseases, and the risk of esophageal and gastric cancer was performed.

METHODS

Potentially suitable studies were identified using Medline and Embase. The reference lists of all included articles and those of several recent reviews were searched manually. Studies were included if they (1) were published as case-control or cohort studies evaluating the association between physical activity and risk of esophageal or gastric cancer; and (2) reported point estimates (i.e., risk ratios, odds ratios) and measures of variability (i.e., 95% confidence intervals [CIs]) for physical activity and risk of esophageal or gastric cancer.

RESULTS

Fifteen studies were identified (7 cohorts, 8 case-controls; 984 esophageal and 7,087 gastric cancers). Collectively, they indicated that the risk of gastric cancer was 13% lower among the most physically active people than among the least active people (RR = 0.87, 95% confidence interval [CI] = 0.78 to 0.97) and that of esophageal cancer was 27% lower (RR = 0.73, 95% CI = 0.56 to 0.97).

CONCLUSIONS

Pooled results from observational studies support a protective effect of physical activity against both esophageal and gastric cancer.

Physical activity and sedentary behavior in relation to esophageal and gastric cancers in the NIH-AARP cohort

Introduction

Body mass index is known to be positively associated with an increased risk of adenocarcinomas of the esophagus, yet there is there limited evidence on whether physical activity or sedentary behavior affects risk of histology- and site-specific upper gastrointestinal cancers. We used the NIH-AARP Diet and Health Study to assess these exposures in relation to esophageal adenocarcinoma (EA), esophageal squamous cell carcinoma (ESCC), gastric cardia adenocarcinoma (GCA), and gastric non-cardia adenocarcinoma (GNCA).

Methods

Self-administered questionnaires were used to elicit physical activity and sedentary behavior exposures at various age periods. Cohort members were followed via linkage to the US Postal Service National Change of Address database, the Social Security Administration Death Master File, and the National Death Index. Cox proportional hazards regression models were used to estimate hazard ratios (HR) and 95 percent confidence intervals (95%CI)

Results

During 4.8 million person years, there were a total of 215 incident ESCCs, 631 EAs, 453 GCAs, and 501 GNCAs for analysis. Strenuous physical activity in the last 12 months (HR_{>5 times/week vs. never}=0.58, 95%CI: 0.39, 0.88) and typical physical activity and sports during ages 15–18 years (p for trend=0.01) were each inversely associated with GNCA risk. Increased sedentary behavior was inversely associated with EA (HR_{5–6 hrs/day vs. <1 hr}=0.57, 95%CI: 0.36, 0.92). There was no evidence that BMI was a confounder or effect modifier of any relationship. After adjustment for multiple testing, none of these results were deemed to be statistically significant at p<0.05.

Conclusions

We find evidence for an inverse association between physical activity and GNCA risk. Associations between body mass index and adenocarcinomas of the esophagus do not appear to be related to physical activity and sedentary behavior.

Cooking methods and esophageal squamous cell carcinoma in high-risk areas of Iran

Cooking methods have been implicated in the etiology of gastrointestinal cancers, reflecting exposure to potential carcinogens as results of cooking. We used a validated food frequency questionnaire and a pretested cooking method questionnaire in 3 groups: 40 esophageal squamous cell carcinoma (ESCC) cases from a high-risk area in northeast of Iran, 40 healthy subjects from the same high-risk area, and 40 healthy subjects from a low-risk area in Southern Iran. We compared the frequency of boiling, grilling, and frying, and the frying score among these 3 groups. We also calculated "frying index" by multiplying the frequency of each fried food item by its frying score. Mean frying to boiling ratios were 18.2:1, 12.8:1, and 2.6:1 for cases, high-risk controls, and low-risk controls, respectively (P < 0.01). Reuse of cooking oil for frying was reported in 37.5% of the ESCC cases, 25% of high-risk controls, and 7.5% of low-risk controls (P < 0.001). Frying index was higher in the high-risk than in the low-risk controls (P < 0.001) and in cases than in the high-risk controls (P < 0.05) after adjusting for smoking, opium use, rural residence, education, and ethnicity. High-temperature cooking and frying may be associated with increased risk of ESCC in high-risk areas.

Socioeconomic status and esophageal squamous cell carcinoma risk in Kashmir, India

Studies have persistently associated esophageal squamous cell carcinoma (ESCC) risk with low socioeconomic status (SES), but this association is unexplored in Kashmir, an area with a high incidence of ESCC in the northernmost part of India. We carried out a case-control study to assess the association of multiple indicators of SES and ESCC risk in the Kashmir valley. A total number of 703 histologically confirmed ESCC cases and 1664 controls matched to the cases for age, sex, and district of residence were recruited from October 2008 to January 2012. Conditional logistic regression models were used to calculate unadjusted and adjusted odds ratios and 95% confidence intervals. Composite wealth scores were constructed based on the ownership of several appliances using multiple correspondence analyses. Higher education, living in a kiln brick or concrete house, use of liquefied petroleum gas and electricity for cooking, and higher wealth scores all showed an inverse association with ESCC risk. Compared to farmers, individuals who had government jobs or worked in the business sector were at lower risk of ESCC, but this association disappeared in fully adjusted models. Occupational strenuous physical activity was strongly associated with ESCC risk. In summary, we found a strong relationship of low SES and ESCC in Kashmir. The findings need to be studied further to understand the mechanisms through which such SES parameters increase ESCC risk.

The severity of duodeno-esophageal reflux influences the development of different histological types of esophageal cancer in a rat model

The mechanism through which each histological type of carcinoma arises from the esophageal mucosa remains unknown. This study was designed to investigate whether there is an association between the severity of duodeno-esophageal reflux and the histological type of esophageal cancer. A series of 120 male Fischer rats, weighing ∼180 g, were randomized to receive one of the following procedures: duodeno-forestomach reflux (DFR) with reduced exposure to duodenal contents, duodeno-esophageal reflux (DER) with increased exposure to duodenal contents and three control operations (DFR, DER control and sham). The reflux of bile was estimated with (99m)Tc-PMT scintigraphy. All animals were fed a standard diet without carcinogen. The esophageal mucosa was assessed 50 weeks after surgery for carcinoma. The median scanned fraction rate of duodeno-esophageal reflux was significantly lower for the rodents in the DFR group than those in the DER group. Five of 28 rodents in the DFR group and 17 of the 22 rodents in the DER group developed esophageal carcinoma. None of the controls developed carcinoma. The five rodents in the DFR group developed SCC. Of 22 esophageal carcinomas for the DER group, nine were SCC, 12 ADC and one was adenosquamous carcinoma. The fraction of esophageal SCC for the DFR group was significantly higher than that for the DER group, while the fraction of esophageal ADC for the DFR group was significantly lower than that for the DER group. These observations suggest that the severity of duodeno-esophageal reflux in rodents is related to the development of different histological types of esophageal carcinoma.