Environmental causes of esophageal cancer

Expression and clinical implications of estrogen receptors in thoracic malignancies: a narrative review

Thoracic malignancies represent a significant global health burden with incidence and mortality increasing year by year. Thoracic cancer prognosis and treatment options depend on several factors, including the type and size of the tumor, its location, and the overall health status of patients. Gender represents an important prognostic variable in thoracic malignancies. One of the greatest biological differences between women and men is the presence of female sex hormones, and an increasing number of studies suggest that estrogens may play either a causative or a protective role in thoracic malignancies. Over the past 60 years since the discovery of the first nuclear estrogen receptor (ER) isoform α and the almost 20 years since the discovery of the second estrogen receptor, ERβ, different mechanisms governing estrogen action have been identified and characterized. This literature review reports the published data regarding the expression and function of ERs in different thoracic malignancies and discuss sex disparity in clinical outcomes. From this analysis emerges that further efforts are warranted to better elucidate the role of sex hormones in thoracic malignancies, and to reduce disparities in care between genders. Understanding the mechanisms by which gender-related differences can affect and interfere with the onset and evolution of thoracic malignancies and impact on response to therapies could help to improve the knowledge needed to develop increasingly personalized and targeted treatments.

Tackling the cancer burden: the economic impact of primary prevention policies

Cancer is a noncommunicable disease (NCD) with increasing incidence and therefore constitutes a major public health issue. To reduce the health and economic burden of cancer, policy-makers across the world have implemented a range of preventative interventions targeting risk factors with a known link to the disease. In this article, we examine the impact of six primary prevention interventions - related to physical inactivity, unhealthy diet or harmful alcohol use - on cancer-related health outcomes and healthcare expenditure. Here, we used the OECD Strategic Public Health Planning for NCDs (SPHeP-NCDs) model to quantify outcomes and costs for each intervention for years 2020-2050 across 37 countries. Results from the model indicate that all interventions could lead to a reduction in the number of new cancer cases, in particular those targeting harmful alcohol consumption. Introducing an alcohol tax, for instance, is estimated to reduce related cancer cases by 5619 a year or 174 193 by 2050. A breakdown of results by type of cancer revealed interventions had the largest impact on colorectal cancer with, on average, 41 140 cases avoided per intervention by 2050. In proportional terms, interventions had the greatest impact on new oesophageal and liver cancers. Findings from this article are designed to assist decision-makers efficiently allocate limited resources to meet public health objectives.

Dietary and Environmental Determinants of Oesophageal Cancer in Arsi Zone, Oromia, Central Ethiopia: A Case-Control Study

PURPOSE

Oesophageal cancer is ranked 5th of all types of malignancies in Ethiopia and highly prevalent in the Arsi Zone. However, no study was conducted to elucidate the dietary and environmental determinants of oesophageal cancer in the Arsi Zone.

METHODS

A matched case-control study was conducted from June 1, 2019, to June 30, 2020. A total of 104 cases and 208 controls were interviewed. Data were collected using food frequency questionnaires (structured questionnaires). Binary and multiple logistic regression analyses were conducted to check the association between independent and dependent variables. Adjusted odds ratios and the corresponding 95% confidence intervals were estimated for the strength of association. Statistical significance was declared at a P-value of <0.05.

RESULTS

In multivariable logistic regression, drinking very hot coffee (AOR=5.1,[95% CI: (1.95, 13.71), drinking large volume of coffee (AOR=4.9, [95% CI: (2.03, 12.17), very hot porridge (AOR= 3.1,[95% CI: (1.38,7.03) and eating porridge fast (AOR=7.0, [95% CI: (2.48, 20.14), low intake of dairy products (AOR=6.0, [95% CI: (2.29, 15.95), cooking food in sleeping room (AOR=3.7, [95% CI: (1.22, 11.39), exposure to x-ray (AOR=9.4,[95% CI: (3.94, 22.82), nonalcohol homemade drinks (AOR=5.4,[95% CI: (1.97, 15.14), use of chemical containers (AOR=3.4, [95% CI: (1.48, 8.23) were determinants of oesophageal cancer.

CONCLUSION

Coffee temperature, coffee drinking volume, porridge consumption temperature, porridge consumption speed, dairy products intake patterns, food cooking place, x-ray exposure, nonalcohol homemade drink, and use of chemical containers were independent determinants of the increased risk of oesophageal cancer in the study community.

NRF2/ACSS2 axis mediates the metabolic effect of alcohol drinking on esophageal squamous cell carcinoma

Alcohol drinking is a leading risk factor for the development of esophageal squamous cell carcinoma (ESCC). However, the molecular mechanisms of alcohol-associated ESCC remain poorly understood. One of the most commonly mutated genes in ESCC is nuclear factor erythroid 2 like 2 (NFE2L2 or NRF2), which is a critical transcription factor regulating oxidative stress response and drug detoxification. When NRF2 is hyperactive in cancer cells, however, it leads to metabolic reprogramming, cell proliferation, chemoradioresistance, and poor prognosis. In this study, hyperactive NRF2 was found to up-regulate acetyl-CoA synthetase short-chain family members 2 (ACSS2), an enzyme that converts acetate to acetyl-CoA, in ESCC cells and mouse esophagus. We also showed that knockdown of NRF2 or ACSS2 led to decreased ACSS2 expression, which in turn reduced the levels of acetyl-CoA and ATP with or without ethanol exposure. In addition, ethanol exposure enhanced lipid synthesis in ESCC cells. Moreover, we observed a change in the metabolic profile of ESCC cells exposed to ethanol as a result of their NRF2 or ACSS2 status. We further showed that ACSS2 contributed to the invasive capability of NRF2high ESCC cells exposed to ethanol. In conclusion, the NRF2/ACSS2 axis mediates the metabolic effect of alcohol drinking on ESCC.

Comprehensive assessment of nutritional status and nutritional-related complications in newly diagnosed esophageal cancer patients: A cross-sectional study

BACKGROUND & AIMS

Malnutrition is prevalent in upper gastrointestinal cancer patients. The purpose of this study was a comprehensive assessment of nutritional status in newly diagnosed patients with esophageal cancer.

METHODS

Newly diagnosed esophageal cancer patients were referred to a chemo-radiation referral center in Mashhad, Iran, between February 2017 to February 2019. Anthropometric indices, a Patient-Generated Subjective Global Assessment (PG-SGA) tool, body composition, dietary intake, nutritional-related complications, and laboratory tests were assessed.

RESULTS

One hundred and eighty-nine patients with a mean age of 67.1 ± 12 and a male to female ratio of 98 to 91 were included. Ninety-seven (51.3%) of patients had experienced significant weight loss and 56 (29.6%) were underweight at diagnosis. According to PG-SGA, 179 (94.7%) needed nutritional interventions. Reduced muscle mass and low handgrip strength were observed in 70 (39.4%) and 26 (14.4%) of patients, respectively. Inadequate intakes of energy (less than 24 kcal/kg/day) and protein (less than 1.2 g/kg/day) were found in 146 (77.8%) and 171 (91%) patients, respectively. The mean total daily energy and protein intakes of subjects were 943.8 ± 540 kcal/day, and 30.6 ± 21 g/day, respectively. The most common nutritional-related complications were as follows: dysphagia (84.8%), anorexia (31.6%), constipation (62.1%), esophageal pain (48.4%), and dyspepsia (41.1%).

CONCLUSION

Our study demonstrated a high prevalence of malnutrition in newly diagnosed esophageal cancer patients. This fact demonstrates the importance of early screening of nutritional status via PG-SGA tool, clinical evaluation, dietary intake evaluations, and laboratory tests, based on which effective nutritional interventions and Symptoms management may be introduced in these patients.

Different Genotype Distribution of Human Papillomavirus between Cervical and Esophageal Cancers: A Study in Both High-Incidence Areas, Xinjiang, China

The aim of this study is to reveal the certain human papillomavirus (HPV) genotype distribution between cervical cancer and esophageal cancer in the both high-incidence geographic regions. For this study, we collected and detected the infection of HPV in 120 paraffin-embedded esophageal tissues and 152 paraffin-embedded cervical tissues, respectively. The esophageal tissues include 40 normal epithelium (ENOR), 26 dysplasia (DYS), and 54 invasive squamous cell carcinoma (ESCC). The cervical tissues consisted of 40 normal epithelium (CNOR), 53 intraepithelial neoplasia (CIN), and 59 invasive squamous cell carcinoma (CSCC). Both esophageal and cervical tissues collected in this study came from the same area, in which both the ESCC and CSCC were in high incidence, Xinjiang province, China. HPV GenoArray test kits were served to analyze the HPV infection. The result shows that among the 59 CSCC tissues, the total infection rate of HPV was 98.3% (58/59). The positive rate of HPV-16 infection was 63.8% (37/58). It indicated that HPV-16 is the most common infection among all of the high-risk HPV. The multiple infection rate was 19.0% (11/58). Among the 54 ESCC, a total of 7 genotypes were detected. The total infection rate of HPV was 61.1% (33/54). The positive rate of HPV-16 infection was 63.6% (21/33). The multiple infection rate was 6.1% (2/33). Our result shows that high-risk-type HPV-16 was associated with both cervical cancer and esophageal cancer, which play a role in the high-incidence area in Xinjiang. We hope that our results could point out the direction for the treatment strategy of HPV-associated cancer, cervical cancer, and esophageal cancer and for the application of HPV vaccines in the future.

Gender Differences in Oesophageal Squamous Cell Carcinoma in a South African Tertiary Hospital

(1) Oesophageal squamous cell carcinoma is common in Africa and has a male preponderance. The gender-based differences in clinical presentation and risk factor exposure are poorly studied in the African context. Our aim was to compare males and females with this disease. We analyzed the differences in clinical features and risk factor exposure between males and females with oesophageal cancer. (2) Data from patients presenting to a tertiary hospital in South Africa with oesophageal squamous cell carcinoma were analyzed. Data collected included patient demographics, clinical presentation, pathology and risk factor exposure. (3) Three hundred and sixty three patients were included in the study. The male to female ratio was 1.4:1. The mean age was 66 years for females and 61 years for males (p < 0.0001). A significantly larger percentage of males were underweight compared to females (60% vs. 32%, p < 0.001). There were no differences between the genders with regards to performance status, dysphagia grade and duration and tumor length, location and degree of differentiation. There were significant differences between risk factor exposure between the two genders. Smoking and alcohol consumption was an association in more than 70% of males but in less than 10% of females There was no difference survival. (4) Female patients with oesophageal squamous cell carcinoma (OSCC) are older and have a higher body mass index (BMI) than their male counterparts. Traditionally purported risk factors of smoking and alcohol consumption are infrequent associations with OSCC in female patients and other environmental risk factors may be more relevant in this gender.

The Relationship Between Single Nucleotide Polymorphisms of SMAD3/SMAD6 and Risk of Esophageal Squamous Cell Carcinoma in Chinese Population

Background

The TGF-β signal pathways play a key role in the development and promotion of squamous cell carcinoma (SCC). The pathway is mediated by the SMAD family proteins that include SMAD3 and SMAD6. Our study aimed to evaluate the relationship between single nucleotide polymorphism (SNP) of SMAD3/SMAD6 and susceptibility to esophageal squamous cell carcinoma (ESCC) in the Chinese population.

Patients and Methods

This was a hospital-based case-control study compromised of 1043 ESCC patients and 1315 non-cancer patients. Seven SMAD3/SMAD6 (rs8028147, rs3743343, rs3743342, rs8025774, rs8031440, rs803167, and rs34643453) SNPs were selected and used to evaluate their correlation with ESCC susceptibility. Genetic model tests, stratified analyses, linkage disequilibrium analyses, and haplotype analyses were performed in our study.

Results

Participants with SMAD3 rs3743342 C>T, rs8025774 C>T, rs8031440 G>A or rs8031627 G>A had a significantly higher risk of ESCC. This was more evident in males, older patients (>63 years), smokers, and non-alcohol drinking participants. Linkage disequilibrium analyses further revealed that there were strong correlations between SMAD3 rs3743342 C>T, rs8025774 C>T, rs8031440 G>A, and rs8031627 G>A. In the same line, haplotype analyses revealed that SMAD3 ACCCGGSMAD6A and SMAD3AGCCGGSMAD6A were associated with less susceptibility to ESCC while SMAD3ATTTAASMAD6A was associated with a higher risk of ESCC.

Conclusion

SNPs of SMAD3 were related to higher susceptibility to ESCC. As such, they may contribute to the development of viable strategies for early diagnosis and treatment of ESCC. However, more detailed association mechanisms between SMAD3/SMAD6 SNPs and ESCC need further experiments to prove.

Understanding Esophageal Cancer: The Challenges and Opportunities for the Next Decade

Esophageal cancer (EC) is the seventh most common cancer worldwide with over 570,000 new cases annually. In China, the incidence of EC is particularly high where approximately 90% of cases are defined as esophageal squamous cell carcinoma (ESCC). Although various risk factors have been identified, the knowledge of genetic drivers for ESCC is still limited due to high mutational loading of the cancer and lack of appropriate EC models, resulting in inadequate treatment choices for EC patients. Currently, surgery, chemotherapy, radiation, and limited targeted therapy options can only bring dismal survival advantages; thus, the prognosis for ESCC is very poor. However, cancer immunotherapy has unleashed a new era of cancer treatment with extraordinary therapeutic benefits for cancer patients, including EC patients. This review discusses the latest understanding of the risk factors and clinical rational for EC treatment and provides accumulated information, which describes the ongoing development of immunotherapy for EC with a specific emphasis on ESCC, the most prevalent EC subtype in the Chinese population.

Associations Between Gastric Atrophy and Its Interaction With Poor Oral Health and the Risk for Esophageal Squamous Cell Carcinoma in a High-Risk Region of China: A Population-Based Case-Control Study

Previous findings concerning gastric atrophy as a potential risk factor for esophageal squamous cell carcinoma (ESCC) have been inconsistent. We aimed to test whether gastric atrophy and, further, its interaction with poor oral health elevated the risk of ESCC in a high-risk region of China. Our population-based case-control study in Taixing, China (2010–2014), recruited cases from local hospitals and the local cancer registry. Controls were selected randomly from the local population registry. Ultimately, 1,210 cases and 1,978 controls answered questionnaires and provided blood samples for assay of pepsinogens. Unconditional logistic regression models were used to estimate odds ratios and 95% confidence intervals. Gastric atrophy (defined as a serum level of pepsinogen I of <55 μg/L) was associated with an increased risk for ESCC (odds ratio = 1.61; 95% confidence interval: 1.33, 1.96), even after full adjustment for potential confounding factors. In addition, suggestion of an additive interaction between gastric atrophy and poor oral health was observed (relative excess risk due to interaction = 1.28, 95% confidence interval: 0.39, 2.18). We conclude that gastric atrophy appears to be a risk factor for ESCC in a high-risk region of China, and there is a suggested additive interaction with poor oral health that increases this risk even further.

Is opium use associated with an increased risk of lung cancer? A case-control study

Background

In recent years, lung cancer (LC) incidence has increased in Iran. The use of opium and its derivatives (O&D) has increased as well. This study aimed to investigate the association between the use of O&D and LC incidence.

Methods

In this case-control study conducted in Kerman, Iran; 140 patients with lung cancer and 280 healthy controls matched by age, sex, and place of residence were included. Data, including O&D use, cigarette smoking, alcohol use, and diet, were collected using a structured questionnaire. The relation between the use of O&D and LC was evaluated using conditional logistic regression adjusted for tobacco smoking, education, daily intake of fruit, vegetables, red meat, and hydrogenated fats.

Results

Opium ever-use was associated with an increased risk of LC (Adjusted Odds Ratio (AOR) =5.95, 95% CI: 1.87–18.92). Participants were divided into low and high use groups based on the median of opium use in the control group. A significant dose-response relation was observed between the amount of daily O&D use and LC; and the relation was stronger in high users (AOR _{low users} = 3.81% CI: 1.13–12.77 and OR _{high users} = 9.36, 95% CI: 2.05–42.72). Also, LC was higher among participants starting the use of O&D at younger ages (≤ 41 years old vs never users AOR = 8.64, 95% CI: 1.90–39.18) compared to those who started at an older age (> 41 years old vs never users, AOR = 4.71, 95% CI: 1.38–16.08). The association between opium, and lung cancer among non-smokers was OR: 6.50 (95% CI: 2.89 to 14.64).

Conclusion

The results of this study show that opium use is probably a dose related risk factor for lung cancer.

Polycyclic aromatic hydrocarbons (PAHs) and esophageal carcinoma in Handan-Xingtai district, North China: a preliminary study based on cancer risk assessment

Extremely high risk of esophageal carcinoma (EC) occurs in Handan-Xingtai district of North China. In spite of various preventive measures and epidemiological investigations that have been conducted for years, incidence and mortality of EC are still in the highest level of China. The etiology of EC remains unclear in the region. Previous studies of our research group proposed that polycyclic aromatic hydrocarbons (PAHs) that derived from numerous coal gangue dumps and atmospheric particulates were major contaminants in these regions. In consideration of mutagenic, teratogenic, and carcinogenic characteristics of PAHs, the authors hypothesized that severe exposure to PAHs could preform as a causative factor for EC. Therefore, four data sets documented in our previous studies were employed in this paper. To quantitatively evaluate the carcinogenic risk imposed by sixteen priority PAHs, incremental lifetime cancer risks (ILCRs) via three exposure pathways were calculated. The results showed that total ILCRs for adult group ranged from 2.08E-05 to 8.63E-02, with an average of 2.00E-02. Total ILCRs for childhood group ranged from 1.09E-05 to 4.48E-02, with an average of 1.04E-02. Total ILCR value of 94% samples exceeded 10^-4, indicating a particularly high carcinogenic risk to local residents. Furthermore, ingestion and dermal contact conducted as principal pathways of exposing to PAHs for each population group, rather than inhalation. It can be speculated that severely exposing to PAHs may be a pathogenesis of EC in Handan-Xingtai district. The rigorous supervise and governance are imperative to avoid severe exposure to PAHs that derived from coal gangue dumps.

FvatfA regulates growth, stress tolerance as well as mycotoxin and pigment productions in Fusarium verticillioides

FvatfA from the maize pathogen Fusarium verticillioides putatively encodes the Aspergillus nidulans AtfA and Schizasaccharomyces pombe Atf1 orthologous bZIP-type transcription factor, FvAtfA. In this study, a ΔFvatfA deletion mutant was constructed and then genetically complemented with the fully functional FvatfA gene. Comparing phenotypic features of the wild-type parental, the deletion mutant and the restored strains shed light on the versatile regulatory functions played by FvAtfA in (i) the maintenance of vegetative growth on Czapek-Dox and Potato Dextrose agars and invasive growth on unwounded tomato fruits, (ii) the preservation of conidiospore yield and size, (iii) the orchestration of oxidative (H₂O₂, menadione sodium bisulphite) and cell wall integrity (Congo Red) stress defences and (iv) the regulation of mycotoxin (fumonisins) and pigment (bikaverin, carotenoid) productions. Expression of selected biosynthetic genes both in the fumonisin (fum1, fum8) and the carotenoid (carRA, carB) pathways were down-regulated in the ΔFvatfA strain resulting in defected fumonisin production and considerably decreased carotenoid yields. The expression of bik1, encoding the polyketide synthase needed in bikaverin biosynthesis, was not up-regulated by the deletion of FvatfA meanwhile the ΔFvatfA strain produced approximately ten times more bikaverin than the wild-type or the genetically complemented strains. The abolishment of fumonisin production of the ΔFvatfA strain may lead to the development of new-type, biology-based mycotoxin control strategies. The novel information gained on the regulation of pigment production by this fungus can be interesting for experts working on new, Fusarium-based biomass and pigment production technologies.

Key points • FvatfA regulates vegetative and invasive growths of F. verticillioides. • FvatfA also orchestrates oxidative and cell wall integrity stress defenses. • The ΔFvatfA mutant was deficient in fumonisin production. • FvatfA deletion resulted in decreased carotenoid and increased bikaverin yields.

Upper Gastrointestinal Cancer in China: Spatial Epidemiologic Evidence from Screening Areas

Upper gastrointestinal cancer (UGIC) including esophageal cancer and gastric cancer, which has been a significant burden in China. Few studies have explored the spatial pattern and association of incidence and mortality using nationwide data. This study aims to explore the spatial pattern and association of incidence and mortality between esophageal cancer and gastric cancer, and identify high-risk areas of the cancers to provide scientific evidence for tailoring endoscopic screening programs. We collected UGIC data in 2014 from a National Cancer Report, and then adopted methods of correlation analysis and spatial statistics to identify high-risk areas on the cancers and to explore the pattern. The results show a spatial autocorrelation on the spatial distribution of incidence and mortality of esophageal and gastric cancers, and the relative risks were from 2.52 (95% CI (confidence interval), 2.37-2.67; P < 0.001) to 3.80 (95% CI, 3.46-4.18; P < 0.001) in primary risk areas, respectively. Moreover, esophageal cancer shows an upward and then downward trend from west to east, and from south to north, yet gastric cancer exhibits an upward and then downward trend only from south to north. This study indicates habitants in overlapping risk areas have heavier cancer burdens, and suggests esophageal cancer and gastric cancer have a significant correlation. Therefore, more endoscopic screening attention should focus on overlapping risk areas.

The global, regional, and national burden of oesophageal cancer and its attributable risk factors in 195 countries and territories, 1990-2017: a systematic analysis for the Global Burden of Disease Study 2017

BACKGROUND

Oesophageal cancer is a common and often fatal cancer that has two main histological subtypes: oesophageal squamous cell carcinoma and oesophageal adenocarcinoma. Updated statistics on the incidence and mortality of oesophageal cancer, and on the disability-adjusted life-years (DALYs) caused by the disease, can assist policy makers in allocating resources for prevention, treatment, and care of oesophageal cancer. We report the latest estimates of these statistics for 195 countries and territories between 1990 and 2017, by age, sex, and Socio-demographic Index (SDI), using data from the Global Burden of Diseases, Injuries, and Risk Factors Study 2017 (GBD).

METHODS

We used data from vital registration systems, vital registration-samples, verbal autopsy records, and cancer registries, combined with relevant modelling, to estimate the mortality, incidence, and burden of oesophageal cancer from 1990 to 2017. Mortality-to-incidence ratios (MIRs) were estimated and fed into a Cause of Death Ensemble model (CODEm) including risk factors. MIRs were used for mortality and non-fatal modelling. Estimates of DALYs attributable to the main risk factors of oesophageal cancer available in GBD were also calculated. The proportion of oesophageal squamous cell carcinoma to all oesophageal cancers was extracted by use of publicly available data, and its variation was examined against SDI, the Healthcare Access and Quality (HAQ) Index, and available risk factors in GBD that are specific for oesophageal squamous cell carcinoma (eg, unimproved water source and indoor air pollution) and for oesophageal adenocarcinoma (gastro-oesophageal reflux disease).

FINDINGS

There were 473 000 (95% uncertainty interval [95% UI] 459 000-485 000) new cases of oesophageal cancer and 436 000 (425 000-448 000) deaths due to oesophageal cancer in 2017. Age-standardised incidence was 5·9 (5·7-6·1) per 100 000 population and age-standardised mortality was 5·5 (5·3-5·6) per 100 000. Oesophageal cancer caused 9·78 million (9·53-10·03) DALYs, with an age-standardised rate of 120 (117-123) per 100 000 population. Between 1990 and 2017, age-standardised incidence decreased by 22·0% (18·6-25·2), mortality decreased by 29·0% (25·8-32·0), and DALYs decreased by 33·4% (30·4-36·1) globally. However, as a result of population growth and ageing, the total number of new cases increased by 52·3% (45·9-58·9), from 310 000 (300 000-322 000) to 473 000 (459 000-485 000); the number of deaths increased by 40·0% (34·1-46·3), from 311 000 (301 000-323 000) to 436 000 (425 000-448 000); and total DALYs increased by 27·4% (22·1-33·1), from 7·68 million (7·42-7·97) to 9·78 million (9·53-10·03). At the national level, China had the highest number of incident cases (235 000 [223 000-246 000]), deaths (213 000 [203 000-223 000]), and DALYs (4·46 million [4·25-4·69]) in 2017. The highest national-level age-standardised incidence rates in 2017 were observed in Malawi (23·0 [19·4-26·5] per 100 000 population) and Mongolia (18·5 [16·4-20·8] per 100 000). In 2017, age-standardised incidence was 2·7 times higher, mortality 2·9 times higher, and DALYs 3·0 times higher in males than in females. In 2017, a substantial proportion of oesophageal cancer DALYs were attributable to known risk factors: tobacco smoking (39·0% [35·5-42·2]), alcohol consumption (33·8% [27·3-39·9]), high BMI (19·5% [6·3-36·0]), a diet low in fruits (19·1% [4·2-34·6]), and use of chewing tobacco (7·5% [5·2-9·6]). Countries with a low SDI and HAQ Index and high levels of indoor air pollution had a higher proportion of oesophageal squamous cell carcinoma to all oesophageal cancer cases than did countries with a high SDI and HAQ Index and with low levels of indoor air pollution.

INTERPRETATION

Despite reductions in age-standardised incidence and mortality rates, oesophageal cancer remains a major cause of cancer mortality and burden across the world. Oesophageal cancer is a highly fatal disease, requiring increased primary prevention efforts and, possibly, screening in some high-risk areas. Substantial variation exists in age-standardised incidence rates across regions and countries, for reasons that are unclear.

FUNDING

Bill & Melinda Gates Foundation.

Environmental geochemistry and cancer: a pertinent global health problem requiring interdisciplinary collaboration

Primary prevention is a key strategy to reducing the global burden of cancer, a disease responsible for ~ 9.6 million deaths per year and predicted to top 13 million by 2030. The role of environmental geochemistry in the aetiology of many cancers-as well as other non-communicable diseases-should not be understated, particularly in low- and middle-income countries where 70% of global cancer deaths occur and reliance on local geochemistry for drinking water and subsistence crops is still widespread. This article is an expansion of a series of presentations and discussions held at the 34th International Conference of the Society for Environmental Geochemistry and Health in Livingstone, Zambia, on the value of effective collaborations between environmental geochemists and cancer epidemiologists. Key technical aspects of each field are presented, in addition to a case study of the extraordinarily high incidence rates of oesophageal cancer in the East African Rift Valley, which may have a geochemical contribution. The potential merit of veterinary studies for investigating common geochemical risk factors between human and animal disease is also highlighted.

Trends in the incidence and survival of patients with esophageal cancer: A SEER database analysis

BACKGROUND

Recent studies have indicated that the incidence of esophageal cancer has declined in the past decade in the U.S. However, trends in the incidence and survival have not been thoroughly examined.

METHODS

Data from 46 063 patients with esophageal cancer between 1973 and 2015 were collected from the Surveillance, Epidemiology, and End Results database. The trends in the age-adjusted incidence and survival were analyzed using joinpoint regression models.

RESULTS

The age-adjusted incidence of esophageal cancer increased from 5.55 to 7.44 per 100 000 person-years between 1973 and 2004. Later, it decreased at an annual percentage change of 1.23%. In the last 40 years, the strong male predominance increased slightly. Importantly, the percentage of patients with localized stage of squamous cell cancer decreased. It was observed that the incidence of esophageal squamous cell carcinoma declined since 1986, while the incidence of esophageal adenocarcinoma sharply increased since 1973 and surpassed the rate of squamous cell cancer, mainly due to the increase in the incidence among men. Consistently, the estimated 40-year limited-duration prevalence of esophageal adenocarcinoma was higher than that of esophageal squamous cell carcinoma. Additionally, we observed a modest but significant improvement in survival during the study period.

CONCLUSION

The incidence of esophageal squamous cell carcinoma has decreased significantly over the past four decades in the U.S., while the incidence of adenocarcinoma has increased, particularly among men. Overall, the long-term survival of patients with esophageal cancer is poor but it has improved over the past decades, especially for the localized disease.

KEY POINTS

Significant findings of the study The incidence of esophageal cancer has decreased at an annual percentage change of 1.23% since 2004. The incidence of esophageal adenocarcinoma has sharply increased since 1973 and surpassed the rate of squamous cell cancer, mainly due to the increase in the incidence among men. What this study adds There has been a shift in the prevalence of esophageal cancer histological subtypes over the past decades in the U.S. We found that the incidence of esophageal squamous cell carcinoma has continued to decrease, while the esophageal adenocarcinoma rate has continued to increase.

Critical review of the evidence for a causal association between exposure to asbestos and esophageal cancer

Esophageal cancers comprise about 1% of all cancers diagnosed in the US but are more prevalent in other regions of the world. Several regulatory agencies have classified asbestos as a known human carcinogen, and it is linked to multiple diseases and malignancies, including lung cancer and mesothelioma. In a 2006 review of the epidemiological literature, the Institute of Medicine (IOM) did not find sufficient evidence to demonstrate a causal relationship between asbestos exposure and esophageal cancer. To reevaluate this conclusion, we performed a critical review of the animal toxicological, epidemiological, and mechanism of action literature on esophageal cancer and asbestos, incorporating studies published since 2006. Although there is some evidence in the epidemiological literature for an increased risk of esophageal cancer in asbestos-exposed occupational cohorts, these studies generally did not control for critical esophageal cancer risk factors (e.g. smoking, alcohol consumption). Furthermore, data from animal toxicological studies do not indicate that asbestos exposure increases esophageal cancer risk. Based on our evaluation of the literature, and reaffirming the IOM's findings, we conclude that there is insufficient evidence to demonstrate a causal link between asbestos exposure and esophageal cancer.

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.

RNA sequence analysis reveals macroscopic somatic clonal expansion across normal tissues

How somatic mutations accumulate in normal cells is poorly understood. A comprehensive analysis of RNA sequencing data from ~6700 samples across 29 normal tissues revealed multiple somatic variants, demonstrating that macroscopic clones can be found in many normal tissues. We found that sun-exposed skin, esophagus, and lung have a higher mutation burden than other tested tissues, which suggests that environmental factors can promote somatic mosaicism. Mutation burden was associated with both age and tissue-specific cell proliferation rate, highlighting that mutations accumulate over both time and number of cell divisions. Finally, normal tissues were found to harbor mutations in known cancer genes and hotspots. This study provides a broad view of macroscopic clonal expansion in human tissues, thus serving as a foundation for associating clonal expansion with environmental factors, aging, and risk of disease.

Association of wheat chaff derived silica fiber and esophageal cancer in north China

BACKGROUND

Despite decades of research and intervention programs, the epidemic of esophageal squamous cell carcinoma (ESCC) in the Taihang Mountain area of north China has not seen convincing explanation by any risk factor yet and the incidence has not seen a substantial decrease. Based on recently disclosed association of aridity and wheat consumption with esophageal cancer, we revisited the hypothesis of biogenic silica in esophageal cancer development.

METHODS

From the archives of the Pathology Department of Heping Hospital, Changzhi Medical College, we selected three pairs of formalin-fixed samples, tumor tissues and distant normal tissues, of three patients operated for ESCC who had no history of workplace exposure to silica dust. Two pairs of dried tissue samples were used for phytolith (silica body) analysis and another pair for microanalysis with Transmission Electron Microscope (TEM).

RESULTS

One of the phytoliths in ESCC tumor tissue was similar to the prickle hair on the surface of wheat bract. In the mineral particles detected in the tumor tissue the predominant elements were Si, Ca, and P, whereas Si signals were not obvious in the distant normal tissue.

CONCLUSIONS

The preliminary findings on the detection of phytoliths and the higher than normal Si concentration in ESCC tumor tissue warrants further testing the role of biogenic silica in esophageal cancer.

Esophageal cancer in Mozambique: should mycotoxins be a concern?

Fumonisin B1 (FB1) is a mycotoxin frequently found in agricultural commodities. The toxin poses a considerable risk for human and animal health. FB1 is among several mycotoxins produced by Fusarium spp. contaminating virtually any cereal and other Poaceae. Their intracellular action includes the promotion of oxidative stress through the generation of reactive oxygen species (ROS) that damage biomolecules such as DNA. These toxic effects were observed in vivo and in vitro. However, the association between esophageal lesions and oxidative stress induced by FB1. Studies in China, Iran and South Africa showed higher exposure to fumonisins in areas with higher risk of esophageal cancer (EC). Exposure to mycotoxins may be inevitable in Mozambique. How mycotoxins, particularly fumonisins from the contaminated food, can be associated with the emergence of EC in Mozambique? Herein, we revise the literature and present some pieces of evidence in order to highlight the burden of mycotoxins and to provide evidence-based considerations for the stakeholders involved in the management of the EC agenda in Mozambique. The information presented herein supports the need to implement novel and/or to revisit the existent detoxification methods to reduce the global burden of mycotoxins and its outcomes in health management.

Biomass fuel as a risk factor for esophageal squamous cell carcinoma: a systematic review and meta-analysis

BACKGROUND

The link between use of solid biomass fuel (wood, charcoal, coal, dung, and crop residues) for cooking and/or heating and esophageal squamous cell carcinoma (ESCC) is inconclusive.

OBJECTIVE

We systematically reviewed the literature and performed a meta-analysis to determine whether cooking fuel type influences esophageal squamous cell carcinoma.

METHODS

We searched MEDLINE, EMBASE, Web of Knowledge and Cochrane Database of Systematic Reviews for studies investigating cooking fuel and ESCC from 2000 until March 2019. We performed random effects meta-analysis stratified by the continent, World Bank's country income classifications and fuel type and calculated pooled odds ratios and 95% CIs for the risk of esophageal squamous cell carcinoma in biomass fuel users compared with non-users.

RESULTS

Our analysis included 16 studies (all case-control) with 16,189 participants (5233 cases and 10,956 controls) that compared risk of ESCC among those using nonsolid fuels and biomass fuels. We found use of biomass fuel was associated with Esophageal squamous cell carcinoma with a pooled odds ratio (OR) 3.02 (95% CI 2.22, 4.11, heterogeneity (I2) = 79%). In sub-group analyses by continent, Africa (OR 3.35, 95%CI 2.34, 4.80, I2 = 73.4%) and Asia (OR 3.08, 95%CI 1.27, 7.43, I2 = 81.7%) had the highest odds of ESCC. Use of wood as fuel had the highest odds of 3.90, 95% CI 2.25, 6.77, I2 = 63.5%). No significant publication bias was detected.

CONCLUSIONS

Biomass fuel is associated with increased risk of Esophageal squamous cell carcinoma. Biomass fuel status should be considered in the risk assessment for Esophageal squamous cell carcinoma.

Etiology, cancer stem cells and potential diagnostic biomarkers for esophageal cancer

Esophageal cancer (EC) has been a leading cause of cancer death worldwide in part due to late detection and lack of precision treatment. EC includes two major malignancies, esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC). Recent studies reveal that ESCC and EAC have distinct cell of origin and contain cancer stem cells (also known as tumor initiating cells) expressing different cell surface markers. These biomarkers have potentially important values for both early detection and finding effective therapy. In this review we summarize the updated findings for cell of origin and provide an overview of cancer cell biomarkers that have been tested for ESCC and EAC. In addition, we also discuss recent progress in the study of molecular mechanisms leading to these malignancies.

What have we learned from Linxian esophageal cancer etiological studies?

Esophageal cancer is the sixth leading cause of cancer death in the world. Esophageal squamous cell carcinoma (ESCC) accounts for 90% of esophageal cancer cases, over half of which occur in China. Linxian, a county located in the North Central Taihang Mountain range, has the highest ESCC mortality rate, which may be the leading cause of death in this area. In a decades-long research program in Linxian, Chinese and international scientists have exerted great efforts to describe the epidemiological characteristics and elucidate the etiology of ESCC. A systematic review and summary of the current knowledge gained from previous research is informative for future ESCC prevention and control in similar populations, and may be translated to other high-incidence countries, such as Brazil, Iran, Malawi, and South Africa. As ESCC is a major cause of cancer death, more research is required in China and in other high-incidence countries to deepen our understanding of the etiology of ESCC and develop preventative strategies.

A Distinct Epidemiologic Pattern of Precancerous Lesions of Esophageal Squamous Cell Carcinoma in a High-risk Area of Huai'an, Jiangsu Province, China

Better understanding of esophageal precancerous lesions (EPL) can inform prevention strategies for esophageal squamous cell carcinoma (ESCC). Here, a cross-sectional epidemiologic study based on the Early Diagnosis and Early Treatment Project of Esophageal Cancer database from 2011 to 2017 was performed to fully investigate and characterize the epidemiology of EPL in rural Huai'an District. Data of 11,518 participants ages 35-75 years were collected through face-to-face interviews by questionnaire. Participants underwent a routine endoscopy examination, tissues were biopsied, and diagnosed according to the histologic criteria of dysplasia. Unconditional univariate and multivariate logistic regression analyses were performed to obtain crude and adjusted odds ratios and corresponding 95% confidence intervals, respectively. A total of 667 subjects were diagnosed with EPL. Factors associated with an increased risk of EPL included: drinking shallow well water and surface water, irregular diet, excessive smoking, exposure to secondhand smoke, consumption of corn, corn flour, pickled food, fried food, and hot food, and having a history of digestive system diseases. In addition, liquor use, but not other alcohol types, contributed to risk of EPL. Consumption of deep well water and vegetables, fruits, and animal livers were associated with lower EPL risk. This study suggested a completely distinct pattern that alcohol use plays only a minor role in EPL and excessive tobacco use shows a significant association in rural Huai'an District, while eating habits and environmental exposure may be the dominant factors. This work may be promising to provide scientific evidence to support primary prevention of ESCC in this region.

Intra-household agreement of urinary elemental concentrations in Tanzania and Kenya: potential surrogates in case-control studies

Element deficiencies and excesses play important roles in non-communicable disease aetiology. When investigating their roles in epidemiologic studies without prospective designs, reverse-causality limits the utility of transient biomarkers in cases. This study aimed to investigate whether surrogate participants may provide viable proxies by assessing concentration correlations within households. We obtained spot urine samples from 245 Tanzanian and Kenyan adults (including 101 household pairs) to investigate intra-household correlations of urinary elements (As, Ba, Ca, Cd, Co, Cs, Cu, Fe, Li, Mn, Mo, Ni, Pb, Rb, S, Se, Sr, Tl, V and Zn) and concentrations (also available for: Bi, Ce, Sb, Sn and U) relative to external population-levels and health-based values. Moderate-strong correlations were observed for As (r = 0.65), Cs (r = 0.67), Li (r = 0.56), Mo (r = 0.57), Se (r = 0.68) and Tl (r = 0.67). Remaining correlations were <0.41. Median Se concentrations in Tanzania (29 µg/L) and Kenya (24 µg/L) were low relative to 5738 Canadians (59 µg/L). Exceedances (of reference 95th percentiles) were observed for: Co, Mn, Mo, Ni and U. Compared to health-based values, exceedances were present for As, Co, Mo and Se but deficiencies were also present for Mo and Se. For well correlated elements, household members in East African settings provide feasible surrogate cases to investigate element deficiencies/excesses in relation to non-communicable diseases.

Comparison of tumor regression grading system in locally advanced esophageal squamous cell carcinoma after preoperative radio-chemotherapy to determine the most accurate system predicting prognosis

Background

Nowadays, preoperative radio-chemotherapy is a standard treatment for locally advanced esophageal squamous cell carcinoma (ESCC). Tumor regression grade (TRG), referring to a classification of cancer response to preoperative treatment, can predict a prognosis of survival. Many TRG systems are proposed for use in esophageal cancer, but none of them has become standard grading system. This research compared five TRG systems, including Mandard system, Chirieac system, Schneider system, Hermann system, and Japan Esophageal Society (JES) system, to find the most accurately predictive system.

Methods

We recruited 37 participants with locally advanced ESCC from 2006 to 2014. All of them were treated with radio-chemotherapy followed by esophagectomy. The resection specimens were evaluated microscopically for percentage of viable residual tumor comparing with tumor bed, number of positive lymph nodes and, consequently, assigned TRG grade according to each TRG system. Kaplan-Meier (KM) graphs were used to describe the median survival time. Log-rank tests and cox proportional hazard regression models were used in assessing associations between TRG systems and survival. Proportional hazard assumptions were evaluated on the basis of Schoenfeld and log-log plot. Akaike information criterion (AIC) values and pseudo R-squared values assessed model fit. All statistical tests were two-sided.

Results

The KM graphs displayed overlapped curves in all TRG systems. The log-rank tests revealed that Schneider, JES and Mandard systems were statistically associated with overall-survival (P<0.05). Only the multivariate cox regression analysis of Schneider system showed the statistically significant hazard ratio (P=0.037). Schneider system also had the best AIC and pseudo R-squared values.

Conclusions

Schneider system might be the best predictive system. However, the overlapped KM curve opposed. This study had limitation due to small number of participants. More participants were needed to confirm our findings.

Investigating tea temperature and content as risk factors for esophageal cancer in an endemic region of Western Kenya: Validation of a questionnaire and analysis of polycyclic aromatic hydrocarbon content

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is common in certain areas worldwide. One area, western Kenya, has a high risk of ESCC, including many young cases (<30 years old), but has limited prior study of potential risk factors. Thermal injury from hot food and beverages and exposure to polycyclic aromatic hydrocarbons (PAHs) have been proposed as important risk factors for ESCC in other settings. The beverage of choice in western Kenya is milky tea (chai).

METHODS

Healthy individuals >18 years of age who were accompanying relatives to an endoscopy unit were recruited to participate. The preferred initial temperature of chai consumption in these adults was measured by questionnaire and digital thermometer. Comparisons of these results were assessed by kappa statistics. Concentrations of 26 selected PAHs were determined by gas chromatography/mass spectrometry in samples of 11 brands of commercial tea leaves commonly consumed in Kenya.

RESULTS

Kappa values demonstrated moderate agreement between questionnaire responses and measured temperatures. The mean preferred chai temperatures were 72.1 °C overall, 72.6 °C in men (n = 78), and 70.2 °C in women (n = 22; p < 0.05). Chai temperature did not significantly differ by age or ethnic group. The PAH levels in the commercial Kenyan tea leaves were uniformly low (total PAH < 300 ng/g of leaves).

CONCLUSIONS

Study participants drink chai at higher temperatures than previously reported in other high-risk ESCC regions. Chai is not, however, a source of significant PAH exposure. Very hot chai consumption should be further evaluated as a risk factor for ESCC in Kenya with the proposed questionnaire.

A possible role of biogenic silica in esophageal cancer in North China?

Certain areas in North China have the highest incidence of esophageal squamous cell carcinoma (ESCC) in the world, which has not seen convincing explanation by any risk factor yet. Biogenic silica in millet bran was linked to ESCC in the early 1980s but the hypothesis was largely dismissed because of the lack of geographic correlation between millet consumption and ESCC. Later epidemiological studies disclosed the linkage of wheat consumption in North China to ESCC instead. Now, we hypothesize silica phytoliths (silicified bodies that have definite shapes) from wheat chaff are a major etiologic factor of ESCC in this region. This hypothesis is supported by the potentially high abundance of silica phytoliths on the bracts of wheat (Triticum aestivum) in North China due to favorable Si-accumulation genotype, arid climate, and siallitic soil with bioavailable Si. These silica phytoliths can contaminate wheat flour and cause repeated local injuries in the esophagus and stimulate proliferation by providing anchorage.

Identification of Adenosquamous Carcinoma as a Rare Aggressive HER2-negative Subgroup of Esophageal/Gastroesophageal Junction Adenocarcinoma

BACKGROUND

Our purpose was to evaluate the prognostic impact of pathologically confirmed esophageal adenosquamous carcinoma (ASC) and its association with HER2 status and clinicopathologic characteristics.

METHODS

Among 796 patients with esophageal or gastroesophageal junction adenocarcinoma who underwent curative resection, surgical pathology reports were reviewed, and suspected ASC was confirmed utilizing p63 and CK5/6 immunostaining. HER2 status was determined using immunohistochemistry and fluorescence in situ hybridization. Cox models were used to assess the impact of ASC on disease-specific survival and overall survival.

RESULTS

Overall, 2.0% (16/796) of patients had esophageal ASC, mostly demonstrating a close intermingling of squamous and adenocarcinoma cells within the same tumor. The percentage of squamous versus adenocarcinoma cells in the primary was generally recapitulated in nodal metastases, and intrapatient internodal heterogeneity was uncommon. Patients with esophageal ASC were statistically significantly more likely to be female (vs. male), have normal (vs. excess) body mass index, and harbor HER2-negative (vs. positive) tumors, as compared with patients with adenocarcinoma only. No ASC tumor was HER2-positive as compared with 16% of adenocarcinoma only tumors (P=0.018). Compared with patients with adenocarcinoma only, those with ASC demonstrated profoundly worse disease-specific survival (5-year event-free rate, 34% vs. 6%; multivariate hazard ratio, 2.87 [95% confidence interval, 1.59-4.76]; P=0.0010) and overall survival (P=0.0027) that was independent of known prognostic factors and HER2 status.

CONCLUSION

ASC identifies a rare aggressive HER2-negative subgroup of esophageal/gastroesophageal junction adenocarcinoma.

Mediterranean diet adherence and risk of esophageal and gastric cancer subtypes in the Netherlands Cohort Study

BACKGROUND

Mediterranean diet (MD) adherence has been associated with reduced risks of esophageal and gastric cancer (subtypes) in a limited number of studies. We prospectively investigated associations between MD adherence and risks of esophageal squamous cell carcinoma (ESCC), esophageal adenocarcinoma (EAC), gastric cardia adenocarcinoma (GCA), and gastric non-cardia adenocarcinoma (GNCA) in a Dutch cohort.

METHODS

Analyses were conducted using data from the 120852 participants of the Netherlands Cohort Study (NLCS), who were aged between 55 and 69 years at enrollment. Various MD scores, with and without alcohol, were calculated to estimate MD adherence. Using 20.3 years of follow-up, 133 ESCC, 200 EAC, 191 GCA, and 586 GNCA cases could be included in multivariable Cox regression analyses.

RESULTS

Of the investigated scores, the alternate Mediterranean diet score without alcohol (aMEDr) performed best. aMEDr was inversely associated with risks of GCA and GNCA in men and women. However, statistical significance was only reached in men [p_trend: 0.019 (GCA), 0.016 (GNCA)]. Furthermore, higher aMEDr values were significantly associated with a reduced ESCC risk in men [HR_{per two-point increment} (95% CI) = 0.57 (0.41-0.80), p_trend = 0.013], but not in women (p_{heterogeneity} = 0.008). There was no evidence of an association between aMEDr and EAC risk. Educational level was a significant effect modifier for the association between aMEDr and GNCA risk (p_{heterogeneity} = 0.0073).

CONCLUSIONS

Higher MD adherence was associated with reduced risks of ESCC, GCA, and GNCA in the NLCS. However, the decreased ESCC risk might be limited to men.

Systematic review: the etiology of esophageal squamous cell carcinoma in low-income settings

Esophageal carcinoma causes over 380 000 deaths per year, ranking sixth worldwide in mortality amongst all malignancies. Globally, the squamous cell subtype is most common and accounts for 80% of esophageal cancers. Nonetheless, esophageal squamous cell carcinoma is much more poorly understood than esophageal adenocarcinoma, including what is driving such high prevalences, why it often presents in young patients, and shows such marked geographical delineations Areas covered: The current literature was searched for articles focusing on aetiopathogenesis of squamous cell esophageal carcinoma via a systematic review, particularly in low-resource settings. This was supplemented by papers of interest known to the authors. Expert commentary: Current putative mechanisms include polycyclic aromatic hydrocarbons, nitrosamines, acetaldehyde, cyclo-oxygenase-2 pathways, androgen and their receptor levels, as well as smoking & alcohol, micronutrient deficiencies and diet, mycotoxins, thermal damage, oral hygiene and microbiotal factors, inhaled smoke, viral infections such as HPV, and chronic irritative states. Etiology is likely multifactorial and varies geographically. Though smoking and alcohol play a predominant role in high-income settings, there is strong evidence that mycotoxins, diet and temperature effects may play an under-recognized role in low and middle-income settings.

WWOX, the FRA16D gene: A target of and a contributor to genomic instability

WWOX is one of the largest human genes spanning over 1.11 Mbp in length at chr16q23.1-q23.2 and containing FRA16D, the second most common chromosomal fragile site. FRA16D is a hot spot of genomic instability, prone to breakage and for causing germline and somatic copy number variations (CNVs). Consequentially WWOX is frequent target for deletions in cancer. Esophageal, stomach, colon, bladder, ovarian, and uterine cancers are those most commonly affected by WWOX deep focal deletions. WWOX deletions significantly correlate with various clinicopathological features in esophageal carcinoma. WWOX is also a common target for translocations in multiple myeloma. By mapping R-loop (RNA:DNA hybrid) forming sequences (RFLS) we observe this to be a consistent feature aligning with germline and somatic CNV break points at the edges and core of FRA16D spanning from introns 5 to 8 of WWOX. Germline CNV polymorphisms affecting WWOX are extremely common in humans across different ethnic groups. Importantly, structural variants datasets allowed us to identify a specific hot spot for germline duplications and deletions within intron 5 of WWOX coinciding with the 5' edge of the FRA16D core and various RFLS. Recently, multiple pathogenic CNVs spanning WWOX have been identified associated with neurological conditions such as autism spectrum disorder, infantile epileptic encephalopathies, and other developmental anomalies. Loss of WWOX function has recently been associated with DNA damage repair abnormalities, increased genomic instability, and resistance to chemoradiotherapy. The described observations place WWOX both as a target of and a contributor to genomic instability. Both of these aspects will be discussed in this review.

Novel risk factors for primary prevention of oesophageal carcinoma: a case-control study from Sri Lanka

BACKGROUND

Oesophageal carcinoma (OC) is one of the leading cancers in Sri Lanka. Its increasing incidence despite the implementation of various preventive activities addressing the conventional risk factors indicates the possibility of the existence of novel, country-specific risk factors. Thus, the identification of novel risk factors of OC specific to Sri Lanka is crucial for implementation of primary prevention activities.

METHODS

A case-control study was conducted among 49 incident cases of OC recruited from the National Cancer Institute, Maharagama using a non-probability sampling method, and unmatched hospital controls (n = 196) excluded of having OC recruited from the endoscopy unit of the National Hospital of Sri Lanka. Data were collected using an interviewer administered questionnaire. Risk factors for OC were assessed by odds ratio (OR) with 95% confidence interval (CI). The risk factors were adjusted for possible confounding by logistic regression analysis.

RESULTS

Of the study population, OC was common among males (69%) and the majority presented with squamous cell carcinoma (65%) at late stages (Stage IV: 45%; Stage III: 37%). Following adjusting for confounders, the risk factor profile for OC included; age > 65 years (OR = 4.0; 95% CI: 1.2-14.2); family history of cancer (OR = 5.04; 95% CI: 1.3-19.0); sub-optimal consumption of dietary fibre (OR = 3.58; 95% CI: 1.1-12.3); sub-optimal consumption of anti-oxidants (OR = 7.0; 95% CI: 2.2-22.5); over-consumption of deep fried food (OR = 6.68; 95% CI:2.0-22.6); 'high risk' alcohol drinking (OR = 11.7; 95% CI: 2.8-49.4); betel quid chewing (OR = 6.1; 95% CI: 2.0, 20.0); 'low' lifetime total sports and exercise activities (MET hours/week/year) (OR = 5.83; 95% CI: 1.5-23.0); agrochemicals exposure (OR = 6.57; 95% CI: 1.4-30.3); pipe-borne drinking water (OR = 5.62; 95% CI:1.7-18.9) and radiation exposure (OR = 4.64; 95% CI: 1.4-15.5). Significant effect modifications were seen between betel quid chewing and male sex (p = 0.01) and between ever exposure to radiation and age over 65 years (p = 0.04).

CONCLUSIONS

Risk profile for OC includes novel yet modifiable risk factors in relation to diet, occupation, environment and health. Primary prevention should target these to combat OC in Sri Lanka.

Very hot tea drinking increases esophageal squamous cell carcinoma risk in a high-risk area of China: a population-based case-control study

Background

Previous studies on the association between green tea drinking and esophageal squamous cell carcinoma (ESCC) risk show inconsistent results.

Materials and methods

We conducted a large population-based case–control study from 2010 to 2013 in a high-risk area of China, in which 1,355 ESCC cases and 1,962 controls were recruited. Information on lifelong tea drinking was collected via face-to-face interviews using an electronic structured questionnaire. ORs with 95% CIs were estimated using unconditional logistic regression models.

Results

Most tea drinkers were males and consumed exclusively green tea. After adjustment for potential confounders, among men the OR of ever green tea drinking for ESCC risk was 1.52 (95% CI: 1.24–1.85), compared with never tea drinking. The excess risk increased monotonically with earlier age at starting, longer duration, more intensity, and accumulation of tea drinking. The OR of drinking very hot green tea for ESCC risk was 2.15 (95% CI: 1.52–3.05), compared with never drinking tea. For accumulation of tea drinking and the risk of ESCC, a non-linear relationship was observed. Before the accumulation of tea drinking reached 5 L/day*years, drinking tea showed a mild protective effect; then the ORs sharply increased to around 2.0 from 5 L/day*years to 25 L/day*years, and leveled off thereafter. The non-linear relationship was further modified by tea temperature. The joint effect of tea drinking and alcohol consumption on ESCC risk was also significant (P=0.019).

Conclusion

Very hot tea drinking significantly increases the risk of ESCC among Chinese men, which is particularly evident among alcohol drinkers.

Evaluating intrinsic and non-intrinsic cancer risk factors

Discriminating the contribution of unmodifiable random intrinsic DNA replication errors ('bad luck') to cancer development from those of other factors is critical for understanding cancer in humans and for directing public resources aimed at reducing the burden of cancer. Here, we review and highlight the evidence that demonstrates cancer causation is multifactorial, and provide several important examples where modification of risk factors has achieved cancer prevention. Furthermore, we stress the need and opportunities to advance understanding of cancer aetiology through integration of interaction effects between risk factors when estimating the contribution of individual and joint factors to cancer burden in a population. We posit that non-intrinsic factors drive most cancer risk, and stress the need for cancer prevention.

Hydroxylated-Graphene Quantum Dots Induce DNA Damage and Disrupt Microtubule Structure in Human Esophageal Epithelial Cells

Graphene quantum dots (GQDs) have attracted significant interests due to their unique chemical and physical properties. In this study, we investigated the potential effects of hydroxyl-modified GQDs (OH-GQDs) on the human esophageal epithelial cell line HET-1A. Our data revealed significant cytotoxicity of OH-GQDs which decreased the viability of HET-1A in a dose and time-dependent manner. The moderate concentration (25 or 50 µg/ml) of OH-GQDs significantly blocked HET-1A cells in G0/G1 cell cycle phase. An increased percentage of γH2AX-positive and genomically unstable cells were also detected in cells treated with different doses of OH-GQDs (25, 50, and 100 µg/ml). Microarray data revealed that OH-GQDs treatment down-regulated genes related to DNA damage repair, cell cycle regulation and cytoskeleton signal pathways indicating a novel role of OH-GQDs. Consistent with the microarray data, OH-GQDs disrupted microtubule structure and inhibited microtubule regrowth around centrosomes in HET-1A cells. In conclusion, our findings provide important evidence for considering the application of OH-GQDs in biomedical fields.

Natural Borneol Enhances Paclitaxel-Induced Apoptosis of ESCC Cells by Inactivation of the PI3K/AKT

Paclitaxel (PTX) has been used in a variety of malignancies for inhibiting tumor development and improving survival. However, its clinical application is limited due to poor solubility, drug resistance, and gastrointestinal reactions. Natural borneol (NB), as a promoter, could help to improve drug absorption. Therefore, the aims of the present study were to investigate the ability of NB to synergize with PTX to induce human esophageal squamous cell carcinoma (ESCC) cells apoptosis and the underlying mechanism of synergistic effects. In this study, our findings showed that NB could effectively synergize with PTX to inhibit the survival of ESCC cells by inducing apoptosis. The molecular mechanism by western blotting elucidated that combination treatment with PTX and NB significantly activated apoptotic pathway by triggering upregulation of cleaved caspase-3 expression and downregulation of survivin and P-AKT expression. These results demonstrated that NB could strongly potentiate PTX-induced apoptosis in ESCC cells through suppressing PI3K/AKT pathway. Thus, the combination therapy with NB and PTX might be a promising treatment strategy for human esophageal cancer.

PRACTICAL APPLICATION

Esophageal cancer is one of the most common cancers in the world. It has brought about a major public health problem. Many natural agents have been employed in the synergized treatments of esophageal cancer. This study provides a comprehensive way to investigate the ability of borneol to synergize with paclitaxel to induce human esophageal squamous cell carcinoma cells apoptosis and the underlying mechanism of synergistic effects. The research showed that the combination treatment with some natural agents might be a promising treatment strategy for human esophageal cancer.

Esophageal cancer male to female incidence ratios in Africa: A systematic review and meta-analysis of geographic, time and age trends

Esophageal squamous cell carcinoma (ESCC) remains the predominant histological subtype of esophageal cancer (EC) in many transitioning countries, with an enigmatic and geographically distinct etiology, and consistently elevated incidence rates in many Eastern and Southern African countries. To gain epidemiological insights into ESCC patterns across the continent, we conducted a systematic review and meta-analysis of male-to-female (M:F) sex ratios of EC age-standardised (world) incidence rates in Africa according to geography, time and age at diagnosis. Data from 197 populations in 36 countries were included in the analysis, based on data from cancer registries included in IARC's Cancer Incidence in Five Continents, Cancer in Africa and Cancer in Sub-Saharan Africa reports, alongside a systematic search of peer-reviewed literature. A consistent male excess in incidence rates overall (1.7; 95% CI: 1.4, 2.0), and in the high-risk Eastern (1.6; 95% CI: 1.4, 1.8) and Southern (1.8; 95% CI: 1.5, 2.0) African regions was observed. Within the latter two regions, there was a male excess evident in 30-39 year olds that was not observed in low-risk regions. Despite possible referral biases affecting the interpretability of the M:F ratios in place and time, the high degree of heterogeneity in ESCC incidence implies a large fraction of the disease is preventable, and directs research enquiries to elucidate early-age exposures among young men in Africa.

High Prevalence of Barrett's Esophagus and Esophageal Squamous Cell Carcinoma After Repair of Esophageal Atresia

BACKGROUND & AIMS

Esophageal atresia is rare, but improved surgical and intensive care techniques have increased rates of survival in children, so there are now many adults with this disorder. Many patients with esophageal atresia develop gastroesophageal reflux (GER), raising concerns about increased risk of Barrett's esophagus (BE; prevalence of 1.3%-1.6% in general population) and esophageal carcinoma. We assessed the prevalence of BE and esophageal carcinoma in this population.

METHODS

We performed a prospective study of 289 patients with esophageal atresia at the Department of Gastroenterology and Hepatology at Erasmus MC University Medical Center in The Netherlands, from May 2012 through March 2017. A total of 151 (median age, 25.4 y; age range, 16.8-68.6 y) underwent upper endoscopies as part of a surveillance program for (pre)malignant esophageal lesions. Biopsies were collected and analyzed by histology. We collected data on patients' use of medications, tobacco, and alcohol; gastrointestinal symptoms; ability to swallow; complaints of GER; and type of atresia and surgeries. Prevalence of esophageal squamous cell carcinoma (ESCC) was determined using data from The Netherlands Cancer Registry. The number of persons alive on January 1, 2016, in the esophageal atresia cohort and in the general Dutch population were used to calculate the 10-year prevalence of ESCC per 100,000 persons in both populations.

RESULTS

Forty-seven percent of patients with esophageal atresia had a history of GER and 20.5% had undergone fundoplication surgery. Endoscopy revealed normal esophagus in 68.2% of patients, esophagitis in 7.3%, and columnar-lined esophagus in 24.5%. Histology revealed normal mucosa in 50.3% of patients, esophagitis in 23.2%, gastric metaplasia in 17.2%, and BE in 6.6% (at a median age of 31.6 years). A history of fundoplication surgery was associated with BE (P = .03). Three ESCCs developed, in 2 men, at ages 42, 44, and 60 years. This corresponded to a prevalence of 0.7% in patients with esophageal atresia-a value 108-fold higher than in the same age group in the general population.

CONCLUSIONS

The prevalence of BE is 4-fold higher in young adults with esophageal atresia, and the prevalence of ESCC is 108-fold higher than in the general population. This finding could have important implications for transition of young adults from pediatric care to adult gastroenterology departments to receive life-long endoscopic follow-up evaluation to facilitate early diagnosis of relevant lesions.

Clinical values of Ku80 upregulation in superficial esophageal squamous cell carcinoma

Ku80 is an important DNA repair protein. Here, this study sought to investigate clinical impacts of Ku80 expression for patients with superficial esophageal squamous cell carcinoma (ESCC). Immunohistochemical analysis of Ku80 expression was carried out in normal esophageal mucosa, squamous epithelial dysplasia, carcinoma in situ, and superficial ESCC. Its relationships with clinicopathological features and survival of superficial ESCC patients were further clarified. Lentivirus-mediated RNA interference was used to silence Ku80 gene in ECA109 and KYSE150 cells. Both quantitative real-time PCR and Western blot were employed to evaluate Ku80 levels. CCK-8 assay, clone formation assay, flow cytometry, and tumorigenesis experiment were performed to evaluate the malignant phenotype of ECA109 and KYSE150 cells. Increased Ku80 expression was observed in dysplastic esophageal mucosa and carcinoma in situ compared to normal esophageal mucosa (P < 0.001, P < 0.001). Ku80 expression was further increased in superficial ESCC in comparison with dysplastic esophageal mucosa and carcinoma in situ (P < 0.001, P = 0.034). In superficial ESCC, Ku80 overexpression was related to tumor differentiation (P = 0.017), T status (P = 0.011), nodal involvement (P = 0.005), TNM stage (P = 0.004), and postoperative recurrence (P = 0.008). Cox proportional hazards regression showed tumor differentiation, T status, nodal involvement, TNM stage, and Ku80 expression were both independent predictors of patients' overall survival and disease-free survival. Ku80 shRNA effectively reduced Ku80 expression, which significantly inhibited proliferation, clone formation, and induced apoptosis in ECA109 and KYSE150 cells. The tumor growth of xenografts was significantly reduced by Ku80 silencing in ECA109 and KYSE150 cells. Ku80 overexpression associates with unfavorable prognosis of superficial ESCC patients, and silencing of Ku80 could inhibit the malignant behavior of ESCC cells. We provide evidence that Ku80 has unrecognized roles in carcinogenesis and development of ESCC.

Four cancer cases after esophageal atresia repair: Time to start screening the upper gastrointestinal tract

Esophageal atresia (EA) is one of the most common congenital digestive malformations and requires surgical correction early in life. Dedicated centers have reported survival rates up to 95%. The most frequent comorbidities after EA repair are dysphagia (72%) and gastroesophageal reflux (GER) (67%). Chronic GER after EA repair might lead to mucosal damage, esophageal stricturing, Barrett’s esophagus and eventually esophageal adenocarcinoma. Several long-term follow-up studies found an increased risk of Barrett’s esophagus and esophageal carcinoma in EA patients, both at a relatively young age. Given these findings, the recent ESPGHAN-NASPGHAN guideline recommends routine endoscopy in adults born with EA. We report a series of four EA patients who developed a carcinoma of the gastrointestinal tract: three esophageal carcinoma and one colorectal carcinoma in a colonic interposition. These cases emphasize the importance of lifelong screening of the upper gastrointestinal tract in EA patients.

PAX9 regulates squamous cell differentiation and carcinogenesis in the oro-oesophageal epithelium

PAX9 is a transcription factor of the PAX family characterized by a DNA-binding paired domain. Previous studies have suggested a potential role of PAX9 in squamous cell differentiation and carcinogenesis of the oro-oesophageal epithelium. However, its functional roles in differentiation and carcinogenesis remain unclear. In this study, Pax9 deficiency in mouse oesophagus promoted cell proliferation, delayed cell differentiation, and altered the global gene expression profile. Ethanol exposure downregulated PAX9 expression in human oesophageal epithelial cells in vitro and mouse forestomach and tongue in vivo. We further showed that PAX9 was downregulated in human oro-oesophageal squamous cell carcinoma (OESCC), and its downregulation was associated with alcohol drinking and promoter hypermethylation. Moreover, ad libitum feeding with a liquid diet containing ethanol for 40 weeks or Pax9 deficiency promoted N-nitrosomethylbenzylamine-induced squamous cell carcinogenesis in mouse tongue, oesophagus, and forestomach. In conclusion, PAX9 regulates squamous cell differentiation in the oro-oesophageal epithelium. Alcohol drinking and promoter hypermethylation are associated with PAX9 silencing in human OESCC. PAX9 downregulation may contribute to alcohol-associated oro-oesophageal squamous cell carcinogenesis. Copyright © 2017 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Inhibition of the development of N-nitrosomethylbenzylamine-induced esophageal tumors in rats by strawberries and aspirin, alone and in combination

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is one of two subtypes of esophageal cancer, with high incidence and mortality rates in developing countries.

OBJECTIVE

The current study investigated the potential chemoprotective effects of strawberries and aspirin against the development of rat esophageal papillomas, the precursors to ESCC.

METHODS

Using a prevention model, we administered study diets to rats before, during, and after N-nitrosomethylbenzylamine (NMBA) treatment. The effects of the four diets were evaluated: the control diet, 5% strawberry powder in the control diet, 0.01% aspirin in the drinking water, and the combination of strawberries and aspirin. At week 25, we euthanized all the rats and collected their esophagi to quantify tumor incidence, multiplicity, and burden, as well as for molecular analysis.

RESULTS

Both strawberries and aspirin significantly decreased esophageal tumor multiplicity, with the combination causing the most robust suppression. Aspirin alone and the combination decreased the total tumor burden in the esophagus. None of the diets had a significant effect on tumor incidence or the expression of COX-1 and COX-2. Strawberries and aspirin, alone and in combination, significantly suppressed squamous epithelial cell proliferation (PCNA).

CONCLUSIONS

Strawberries, aspirin, and their combination exhibit chemoprotective effects against NMBA-induced esophageal tumors in rats.