A Meta-Analysis and Systematic Review on the Association between Human Papillomavirus (Types 16 and 18) Infection and Esophageal Cancer Worldwide

Role of the Microbiome in the Diagnosis and Management of Gastroesophageal Cancers

PURPOSE

Stomach and esophageal cancers are among the highest mortality from cancers worldwide. Microbiota has an interplaying role within the human gastrointestinal (GI) tract. Dysbiosis occurs when a disruption of the balance between the microbiota and the host happens. With this narrative review, we discuss the main alterations in the microbiome of gastroesophageal cancer, revealing its potential role in the pathogenesis, early detection, and treatment.

RESULTS

Helicobacter pylori plays a major role the development of a cascade of preneoplastic conditions ranging from atrophic gastritis to metaplasia and dysplasia, ultimately culminating in gastric cancer, while other pathogenic agents are Fusobacterium nucleatum, Bacteroides fragilis, Escherichia coli, and Lactobacillus. Campylobacter species (spp.)'s role in the progression of esophageal adenocarcinoma may parallel that of Helicobacter pylori in the context of gastric cancer, with other esophageal carcinogenic agents being Escherichia coli, Bacteroides fragilis, and Fusobacterium nucleatum. Moreover, gut microbiome could significantly alter the outcomes of chemotherapy and immunotherapy. The gut microbiome can be modulated through interventions such as antibiotics, probiotics, or prebiotics intake. Fecal microbiota transplantation has emerged as a therapeutic strategy as well.

CONCLUSIONS

Nowadays, it is widely accepted that changes in the normal gut microbiome causing dysbiosis and immune dysregulation play a role gastroesophageal cancer. Different interventions, including probiotics and prebiotics intake are being developed to improve therapeutic outcomes and mitigate toxicities associated with anticancer treatment. Further studies are required in order to introduce the microbiome among the available tools of precision medicine in the field of anticancer treatment.

Infectious pathogens and risk of esophageal, gastric and duodenal cancers and ulcers in China: A case-cohort study

Infection by certain pathogens is associated with cancer development. We conducted a case-cohort study of ~2500 incident cases of esophageal, gastric and duodenal cancer, and gastric and duodenal ulcer and a randomly selected subcohort of ~2000 individuals within the China Kadoorie Biobank study of >0.5 million adults. We used a bead-based multiplex serology assay to measure antibodies against 19 pathogens (total 43 antigens) in baseline plasma samples. Associations between pathogens and antigen-specific antibodies with risks of site-specific cancers and ulcers were assessed using Cox regression fitted using the Prentice pseudo-partial likelihood. Seroprevalence varied for different pathogens, from 0.7% for Hepatitis C virus (HCV) to 99.8% for Epstein-Barr virus (EBV) in the subcohort. Compared to participants seronegative for the corresponding pathogen, Helicobacter pylori seropositivity was associated with a higher risk of non-cardia (adjusted hazard ratio [HR] 2.73 [95% CI: 2.09-3.58]) and cardia (1.67 [1.18-2.38]) gastric cancer and duodenal ulcer (2.71 [1.79-4.08]). HCV was associated with a higher risk of duodenal cancer (6.23 [1.52-25.62]) and Hepatitis B virus was associated with higher risk of duodenal ulcer (1.46 [1.04-2.05]). There were some associations of antibodies again some herpesviruses and human papillomaviruses with risks of gastrointestinal cancers and ulcers but these should be interpreted with caution. This first study of multiple pathogens with risk of gastrointestinal cancers and ulcers demonstrated that several pathogens are associated with risks of gastrointestinal cancers and ulcers. This will inform future investigations into the role of infection in the etiology of these diseases.

Current Status and Future Prospects for Esophageal Cancer

Esophageal cancer (EC) is the ninth most common cancer and the sixth leading cause of cancer deaths worldwide. Esophageal squamous cell carcinoma (ESCC) and esophageal adenocarcinoma (EAC) are the two main histological subtypes with distinct epidemiological and clinical features. While the global incidence of ESCC is declining, the incidence of EAC is increasing in many countries. Decades of epidemiologic research have identified distinct environmental exposures for ESCC and EAC subtypes. Recent advances in understanding the genomic aspects of EC have advanced our understanding of EC causes and led to using specific genomic alterations in EC tumors as biomarkers for early diagnosis, treatment, and prognosis of this cancer. Nevertheless, the prognosis of EC is still poor, with a five-year survival rate of less than 20%. Currently, there are significant challenges for early detection and secondary prevention for both ESCC and EAC subtypes, but Cytosponge™ is shifting this position for EAC. Primary prevention remains the preferred strategy for reducing the global burden of EC. In this review, we will summarize recent advances, current status, and future prospects of the studies related to epidemiology, time trends, environmental risk factors, prevention, early diagnosis, and treatment for both EC subtypes.

Human papillomavirus is an important risk factor for esophageal carcinoma in a Chinese population

Purpose

Different types of HPV have been associated with cancer in humans, but the role of HPV in esophageal cancer (EC) is controversial. The purpose of this study was to evaluate the correlation between HPV infection and EC in the Chinese population and to provide the scientific basis for the future prevention, control, early diagnosis, and treatment strategies of EC in China.

Methods

PCR detected HPV infection in 1112 esophageal cancer tissue samples, and 89 HPV-positive samples were detected by genotyping. Proximity ligation assays (PLAs) and immunohistochemistry were used to detect the expression of HPV E6 and E7 proteins. Real-time fluorescent quantitative PCR was used to detect the integration of HPV16 E6. The level of HPV-specific antibody IgG in serum was detected by ELISA and PLA.

Results

The positive rates of HPV L1, HPV16, HPV18, hpv16 + 18 E6 and hpv16/18 E6 in 1,112 EC tissue samples were 77.6%, 41.4%, 27.2%, 14.2% and 55.4% respectively. Multiple HPV subtypes were detected in HPV-positive EC samples. PLA showed that E6 and E7 were expressed in EC109 and formed complexes with p53 and pRb, respectively. Immunohistochemistry showed that the positive rates of hpv16 + 18 E6 and E7 in HPV-positive EC samples were 56.4% and 37.0%, respectively. HPV-DNA integration rate in HPV-positive EC tissues (88.79%) was higher than that in adjacent tissues (54.17%). HPV antibody was found in the serum of EC patients by a serological test.

Conclusion

The study suggests that HPV, especially HPV16 and HPV18, the infection may be a risk factor for EC in the Chinese population and that the E6 protein may play a key role in HPV-associated malignancies. These results may be important for the prevention and treatment of HPV-positive EC in China.

Human Papillomavirus Infection and Oropharyngeal and Gastrointestinal Cancers: A Causal Relationship?

The human papillomavirus (HPV) is one of the most common sexually transmitted infections worldwide. The risk of being infected at least once in a lifetime among both men and women is estimated to be 50%. Although the majority of HPV infections are asymptomatic and improve within 2 years, approximately 10% of individuals develop a persistent infection and have an increased risk of developing carcinomas. The association of HPV and genital cancer is well established. However, there is evidence that HPV may also be associated with other cancers, including those of the gastrointestinal system. The aim of this review is to organize the current evidence of associations between HPV infections and oropharyngeal and gastrointestinal cancers, including the following: oropharyngeal, esophageal, gastric, colorectal, and anal cancers. A comprehensive review of the most up-to-date medical literature concluded that an HPV infection might have a role in the oncogenesis of gastrointestinal tract cancers. HPV may have a causal relationship with oropharyngeal and esophageal squamous cell cancers. However, the association between HPV and gastric and colorectal cancers is weaker. The development of cancer in the oropharyngeal and gastrointestinal tract is usually multifactorial, with HPV having a role in at least a subset of these cancers. HPV infections pose a big challenge due to their burden of infection and their oncogenic potential.

The Involvement of Human Papilloma Virus in Gastrointestinal Cancers

Human Papilloma Virus (HPV) is one of the most common sexually transmitted infections worldwide. HPV infection has a strong relationship with the onset of cervix uteri, vagina, penis, anus, and oropharynx, but also tonsils and tongue cancers. Some epidemiological data indicate that except for gynecologic cancers, HPV infection can be one of the risk factors associated with a greater risk of induction and progression of gastrointestinal cancers. Data, however, remain contradictory and definite conclusions cannot be drawn, so far. The following review aims to organize recent evidence and summarize the current state of knowledge regarding the association between HPV infection and gastrointestinal tumors primarily focusing on esophageal, liver, gastric, colorectal, and anal cancers.

Gastrointestinal tumors and infectious agents: A wide field to explore

Infection is currently one of the main contributors to carcinogenesis. In fact, the International Agency for Research on Cancer has categorized eleven biological agents as group I carcinogens. It is estimated that around 16% of the 12.7 million new cancers diagnosed in 2008 were attributable to infectious agents. Although underdeveloped regions carry the highest incidence rates, about 7.4% of infection-related cancer cases occur in developed areas. Physicians are increasingly aware of the potential carcinogenic role of common virus like the Human Papilloma virus in cervical cancer, or the hepatitis B and C viruses in hepatocarcinoma. However, the carcinogenic role of several other infectious agents is less recognized. Given that gastrointestinal malignancies carry an overall poor prognosis, a better understanding of the carcinogenic mechanisms triggered by infectious agents is key to decrease the rate of cancer related deaths. Preventive measures directed to such infections would ideally impact survival. In this paper we review the main pathogenic mechanisms related to the development of gastrointestinal malignancies induced by infectious microorganisms and other pathogens which are currently under investigation.

Frequency of Human Papillomavirus Detection in Chagasic Megaesophagus Associated or Not with Esophageal Squamous Cell Carcinoma

BACKGROUND

Chagasic megaesophagus (CM) as well as the presence of human papillomavirus (HPV) has been reported as etiological factors for esophageal squamous cell carcinoma (ESCC).

OBJECTIVE

We assessed the prevalence of HPV DNA in a series of ESCCs associated or not with CM. Data obtained were further correlated to the pathological and clinical data of affected individuals.

METHODS

A retrospective study was performed on 92 formalin-fixed and paraffin-embedded tissues collected from patients referred to 3 different hospitals in São Paulo, Brazil: Barretos Cancer Hospital, Barretos, São Paulo; Federal University of Triângulo Mineiro, Uberaba, Minas Gerais; and São Paulo State University, Botucatu, São Paulo. Cases were divided into 3 groups: (i) 24 patients with CM associated with ESCC (CM/ESCC); (ii) 37 patients with ESCC without CM (ESCC); and (iii) 31 patients with CM without ESCC (CM). Detection of HPV DNA was assessed in all samples by a genotyping assay combining multiplex polymerase chain reaction and bead-based Luminex technology.

RESULTS

We identified a high prevalence of high-risk HPV in patients in the CM group (12/31, 38.8%) and CM/ESCC (8/24, 33.3%), compared to individuals in the ESCC group (6/37, 16.3%). The individuals in the groups with cancer (ESCC and CM/ESCC) had a higher frequency of HPV-16 (4/9, 44.5% and 2/8, 25.0%). The other types of high-risk HPVs detected were HPV-31, 45, 51, 53, 56, 66, and 73. We also observed in some samples HPV coinfection by more than one viral type. Despite the high incidence of HPV, it did not show any association with the patient's clinical-pathological and molecular (TP53 mutation status) characteristics.

CONCLUSION

This is the first report of the presence of HPV DNA in CM associated with ESCC. HPV infection was more presence in megaesophagus lesions. Further studies are needed to confirm and better understand the role of persistent HPV infection in patients with CM.

IS THERE CORRELATION BETWEEN HUMAN PAPILLOMAVIRUS (HPV) AND ESOPHAGEAL EPIDERMOID CARCINOMA?

Background:

Currently, persistent human papillomavirus (HPV) infection has been related in some geographic regions as a risk factor for esophageal squamous cell carcinoma. It results in the immunoexpression of the p16 protein, which has been used as marker of the oncogenic lineage by this etiological agent.

Aim:

To correlate epidemiological aspects of esophageal squamous cell carcinoma with the prevalence of HPV infection.

Methods:

Fifty-eight cases were analyzed and submitted to histopathological and immunohistochemical analysis by p16.

Results:

Of the 58 cases evaluated, 40 were men and 18 women, with a mean age of 63.2 years. p16 immunoexpression was positive in 46.55%.

Conclusion:

The prevalence of HPV infection is high in esophageal squamous cell carcinoma presenting in almost half of the cases (46.55%), without gender differentiation.

Viruses and esophageal cancer

Esophageal adenocarcinoma (EAC) has had the fastest increasing incidence of any solid tumor in the United States in the last 30 years. Long standing gastroesophageal reflux disease is a well-established risk factor with strong associations with obesity, alcohol and tobacco. However, there are likely additional contributing factors. Viruses such as human papillomavirus, ebstein-barr virus and herpes simplex virus have been implicated in the pathogenesis of esophageal cancer. This review will discuss the known literature linking viruses to esophageal adenocarcinoma and consider future relationships such as identifying prognostic and predictive molecular biomarkers to guide therapies.

Early esophageal squamous cell carcinoma in a western series is not associated with active HPV infection

Few data are available concerning human papillomavirus (HPV) in early esophageal squamous cell carcinoma (ESCC) in Western population. Our study intended to determine the prevalence of HPV infection and the histological characteristics in such early tumors. A monocentric and retrospective study was conducted including 86 patients with early ESCC treated by endoscopic resection or esophagectomy, from 2012 to 2018. Histopathological prognostic criteria were evaluated. Immunohistochemistry for p16 and p53 and an HPV mRNA in situ hybridization were performed. The tumors were composed of 25 (29%) in situ carcinomas, 21 (24%) intramucosal carcinomas, and 40 (47%) submucosal carcinomas, of which 34 had a deep infiltration (> 200 μm). Emboli, present in 12 cases, were associated with deep infiltration. P16-positive ESCC accounted for 21% of the patients. It was not correlated with active HPV infection as no cases were found to be positive in RISH analysis for RNA detection of this virus. However, there was a correlation between p16 expression and alcohol or tobacco consumption. The only histopathological criterion correlated with p16 positivity was marked inflammatory infiltrate. Local or distant neoplastic recurrence occurred in 25% of patients. Overall survival was 95.8% and local or metastatic recurrence-free survival was 75%. There was a correlation between positive resection margins and tumor recurrence. In contrast to oropharynx carcinoma, our study showed that ESCC were not associated with an active HPV infection, highlighting the negligible role of this virus in early ESCC carcinogenesis in the Western world.

Linking gut microbiota with the human diseases

The human gut is rich in microbes. Therefore, it is of interest to document data to link known human diseases with the gut microbiota. Various factors like hormones, metabolites and dietary habitats are responsible for shaping the microbiota of the gut. Imbalance in the gut microbiota is responsible for the pathogenesis of various disease types including rheumatoid arthritis, different types of cancer, diabetes mellitus, obesity, and cardiovascular disease. We report a review of known data for the correction of dysbiosis (imbalance in microbe population) towards improved human health.

Prevalence and Association of Human Papillomavirus with Esophageal Squamous Cell Carcinoma in Iran: A Systematic Review and Meta-Analysis

BACKGROUND

Human papillomavirus (HPV) can infect the epithelium of the esophagus, but so far there is no reliable and comprehensive evidence about the prevalence and association of HPV with esophageal cancer in Iran, as high incidence region. This study aimed to evaluate the prevalence and association of HPV with esophageal squamous cell carcinoma (ESCC) in Iran.

METHODS

Relevant English and Persian articles published up to Aug 2017 and indexed in databases were reviewed. Frequency of HPV genotypes in ESCC cases and controls was surveyed according to regions of Iran. Data were meta-analyzed with random effects models using Comprehensive Meta-Analysis software.

RESULTS

Overall, 14 studies were eligible including 1444 samples (1062 ESCC cases and 382 controls). HPV was positive in 269 (25.32%) of 1062 ESCC cases and in 65 (17.01%) of 382 controls. Total prevalence of HPV in both groups was estimated 0.256 (95%CI, 0.208%-0.310%). The prevalence of HPV-16 and HPV-18 was estimated 0.121 (95%CI: 0.087-0.183) and 0.046 (95%CI; 0.023-0.088), respectively. The difference in HPV prevalence in different regions of Iran was statistically significant (Q=18.20, df =4, P=0.001). In 6 case-control studies, the pooled odds ratio was estimated 1.99 (95%CI; 0.916-4.315).

CONCLUSION

High-risk HPVs were observed in ESCC cases and controls from different regions of Iran. The odds ratio indicates that the HPV infection in ESCC cases was approximately 2 fold more than the controls. More case-control studies in other populations with larger sample size are necessary.

Anti-Cancer Vaccine for HPV-Associated Neoplasms: Focus on a Therapeutic HPV Vaccine Based on a Novel Tumor Antigen Delivery Method Using Endogenously Engineered Exosomes

Some human papillomavirus (HPV) genotypes are universally recognized as major etiological agents not only of ano-genital tumors but also of head and neck cancers, which show increasing incidence. The evaluation of current and future therapeutic approaches against HPV-induced tumors is a global health priority, despite an effective prophylactic vaccine against 7 of the 12 genotypes involved in the etiology of tumors being currently available. In this review, we present the main anti-HPV therapeutic approaches in clinical experimentation, with a focus on a novel tumor antigen delivery method using engineered exosomes, that we recently developed. Our system allows the induction of an efficient unrestricted cytotoxic T lymphocyte (CTL) immune response against the HPV16-E7 tumor-associated antigen, with the formation of endogenously engineered exosomes, i.e., nanovesicles spontaneously released by all cell types. Immunogenic exosomes are uploaded with HPV16-E7 due to the fusion with a unique exosome-anchoring protein referred to as Nefmut. Intramuscular injection of a DNA vector expressing the fusion protein generates exosomes sufficiently immunogenic to elicit a potent anti-16E7 CTL immune response. The approach is described here and the advantages over other existing methodologies are reported.

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.

Oral Alpha, Beta, and Gamma HPV Types and Risk of Incident Esophageal Cancer

Background: Several studies have examined association between human papillomaviruses (HPV) and esophageal cancer, but results have been inconsistent. This is the first prospective study to investigate associations between α, β and γ HPV detection in the oral cavity and risk of esophageal cancer.Methods: We conducted a nested case-control study among 96,650 cancer-free participants in the American Cancer Society Cancer Prevention Cohort and the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial. Incident esophageal cancer cases (n = 125) were identified during an average 3.9 years of follow-up. Three controls per case (n = 372) were selected and matched on age, sex, race/ethnicity, and time since mouthwash collection. α, β, and γ HPV DNA in oral samples were detected using a next-generation sequencing assay. Conditional logistic regression models were used to estimate OR and 95% confidence intervals (CIs), adjusting for smoking and alcohol consumption. Statistical significance was evaluated using permutation test.Results: Prevalence of oral α, β, and γ HPV was 18.4%, 64.8%, and 42.4% in cases and 14.3%, 55.1%, and 33.6% in controls, respectively. Oral HPV16 detection was not associated with esophageal cancer (OR = 0.54, 95% CI, 0.1-4.84) and none of the esophageal squamous cell carcinoma cases (n = 28) were HPV16 positive. Some oral HPV types were more common in cases than controls; however, none of the associations were statistically significant.Conclusions: Although HPVs in the oral cavity are very common, this study showed no evidence of association between oral HPVs and esophageal cancer.Impact: Oral HPVs may not contribute to risk of esophageal cancer. Cancer Epidemiol Biomarkers Prev; 27(10); 1168-75. ©2018 AACR.

Human Gut Microbiota and Gastrointestinal Cancer

Human gut microbiota play an essential role in both healthy and diseased states of humans. In the past decade, the interactions between microorganisms and tumors have attracted much attention in the efforts to understand various features of the complex microbial communities, as well as the possible mechanisms through which the microbiota are involved in cancer prevention, carcinogenesis, and anti-cancer therapy. A large number of studies have indicated that microbial dysbiosis contributes to cancer susceptibility via multiple pathways. Further studies have suggested that the microbiota and their associated metabolites are not only closely related to carcinogenesis by inducing inflammation and immune dysregulation, which lead to genetic instability, but also interfere with the pharmacodynamics of anticancer agents. In this article, we mainly reviewed the influence of gut microbiota on cancers in the gastrointestinal (GI) tract (including esophageal, gastric, colorectal, liver, and pancreatic cancers) and the regulation of microbiota by diet, prebiotics, probiotics, synbiotics, antibiotics, or the Traditional Chinese Medicine. We also proposed some new strategies in the prevention and treatment of GI cancers that could be explored in the future. We hope that this review could provide a comprehensive overview of the studies on the interactions between the gut microbiota and GI cancers, which are likely to yield translational opportunities to reduce cancer morbidity and mortality by improving prevention, diagnosis, and treatment.

Human Gut Microbiota and Gastrointestinal Cancer

Human gut microbiota play an essential role in both healthy and diseased states of humans. In the past decade, the interactions between microorganisms and tumors have attracted much attention in the efforts to understand various features of the complex microbial communities, as well as the possible mechanisms through which the microbiota are involved in cancer prevention, carcinogenesis, and anti-cancer therapy. A large number of studies have indicated that microbial dysbiosis contributes to cancer susceptibility via multiple pathways. Further studies have suggested that the microbiota and their associated metabolites are not only closely related to carcinogenesis by inducing inflammation and immune dysregulation, which lead to genetic instability, but also interfere with the pharmacodynamics of anticancer agents. In this article, we mainly reviewed the influence of gut microbiota on cancers in the gastrointestinal (GI) tract (including esophageal, gastric, colorectal, liver, and pancreatic cancers) and the regulation of microbiota by diet, prebiotics, probiotics, synbiotics, antibiotics, or the Traditional Chinese Medicine. We also proposed some new strategies in the prevention and treatment of GI cancers that could be explored in the future. We hope that this review could provide a comprehensive overview of the studies on the interactions between the gut microbiota and GI cancers, which are likely to yield translational opportunities to reduce cancer morbidity and mortality by improving prevention, diagnosis, and treatment.

Factors associated with the high prevalence of oesophageal cancer in Western Kenya: a review

Oesophageal carcinoma (OC) is highly prevalent in Western Kenya especially among the members of the Kalenjin community who reside in the Northern and Southern areas of the Rift Valley. Previous authors have suggested potential association of environmental and genetic risk factors with this high prevalence. The environmental factors that have been suggested include contamination of food by mycotoxins and/or pesticides, consumption of traditional alcohol (locally referred to “Busaa” and “Chan’gaa”), use of fermented milk (“Mursik”), poor diet, tobacco use and genetic predisposition. The aim of this paper is to critically examine the potential contribution of each of the factors that have been postulated to be associated with the high prevalence of the disease in order to establish the most likely cause. We have done this by analyzing the trends, characteristics and behaviours that are specifically unique in the region, and corroborated this with the available literature.

From our findings, the most plausible cause of the high incidence of OC among the Kalenjin community is mycotoxins, particularly fumonisins from the food chain resulting from poor handling of cereals; particularly maize combined with traditional alcohol laced with the toxins interacting synergistically with other high-risk factors such as dietary deficiencies associated alcoholism and viral infections, especially HPV. Urgent mitigating strategies should be developed in order to minimize the levels of mycotoxins in the food chain.

Epidemiology, etiology, and prevention of esophageal squamous cell carcinoma in China

Esophageal cancer is one of the most fatal diseases worldwide mainly because of its rapid progression and poor prognosis. Although the incidence of esophageal adenocarcinoma has markedly risen in North America and Europe in the past several decades, esophageal squamous cell carcinoma is still the predominant subtype of esophageal cancer, especially in China. It accounts for more than 90% of all esophageal squamous cell carcinoma cases in China. Geographical differentiation is one of the most distinctive characteristics of esophageal cancer. The progression, risk factors, and prognosis of these two subtypes of esophageal cancer differ. This study reviews the epidemiology, etiology, and prevention of esophageal squamous cell carcinoma in China, thereby providing systematic references for policy-makers who will decide on issues of esophageal cancer prevention and control.