Association between human papillomavirus (HPV) and oesophageal squamous cell carcinoma: a meta-analysis. Epidemiol Infect. 2014;142:1119-1137. [PMID: 24721187 DOI: 10.1017/s0950268814000016]

Human papillomavirus infection and the risk of cancer at specific sites other than anogenital tract and oropharyngeal region: an umbrella review

BACKGROUND

Despite numerous studies having evaluated the associations between human papillomavirus (HPV) infection and risk of specific cancers other than anogenital tract and oropharyngeal, the findings are inconsistent and the quality of evidence has not been systematically quantified. We aimed to summarise the existing evidence as well as to evaluate the strength and credibility of these associations.

METHODS

We conducted an umbrella review of systematic reviews and meta-analyses of observational studies. PubMed, EMBASE, and Web of Science were searched from inception to March 2024. Studies with systematic reviews and meta-analyses that examined associations between HPV or HPV-associated genotypes infection and specific cancers were eligible for this review. The quality of the methodology was evaluated using A Measurement Tool to Assess systematic Reviews (AMSTAR). The credibility of the evidence was assessed using GRADE. The protocol was preregistered with PROSPERO (CRD42023439070).

FINDINGS

The umbrella review identified 31 eligible studies reporting 87 associations with meta-analytic estimates, including 1191 individual studies with 336,195 participants. Of those, 29 (93.5%) studies were rated as over moderate quality by AMSTAR. Only one association indicating HPV-18 infection associated with an increased risk of breast cancer (odds ratio [OR] = 3.48, 95% confidence interval [CI] = 2.24-5.41) was graded as convincing evidence. There were five unique outcomes identified as highly suggestive evidence, including HPV infection increased the risk of oral squamous cell carcinoma (OR = 7.03, 95% CI = 3.87-12.76), oesophageal cancer (OR = 3.32, 95% CI = 2.54-4.34), oesophageal squamous cell carcinoma (OR = 2.69, 95% CI = 2.05-3.54), lung cancer (OR = 3.60, 95% CI = 2.59-5.01), and breast cancer (OR = 6.26, 95% CI = 4.35-9.00). According to GRADE, one association was classified as high, indicating that compared with the controls in normal tissues, HPV infection was associated with an increased risk of breast cancer.

INTERPRETATION

The umbrella review synthesised up-to-date observational evidence on HPV infection with the risk of breast cancer, oral squamous cell carcinoma, oesophageal cancer, oesophageal squamous cell carcinoma, and lung cancer. Further larger prospective cohort studies are needed to verify the associations, providing public health recommendations for prevention of disease.

FUNDING

National Key Research and Development Program of China, Natural Science Foundation of China, Outstanding Scientific Fund of Shengjing Hospital of China Medical University, and 345 Talent Project of Shengjing Hospital of China Medical University.

Oral microbiota and oral squamous cell carcinoma: a review of their relation and carcinogenic mechanisms

Oral Squamous Cell Carcinoma (OSCC) is the most common type of head and neck cancer worldwide. Emerging research suggests a strong association between OSCC and the oral microbiota, a diverse community of bacteria, fungi, viruses, and archaea. Pathogenic bacteria, in particular Porphyromonas gingivalis and Fusobacterium nucleatum, have been closely linked to OSCC. Moreover, certain oral fungi, such as Candida albicans, and viruses, like the human papillomavirus, have also been implicated in OSCC. Despite these findings, the precise mechanisms through which the oral microbiota influences OSCC development remain unclear and necessitate further research. This paper provides a comprehensive overview of the oral microbiota and its relationship with OSCC and discusses potential carcinogenic pathways that the oral microbiota may activate or modulate are also discussed.

High-Risk Human Papillomavirus in Patients with Oral Carcinoma and Oral Potentially Malignant Disorders in Serbia-A Pilot Study

Background and Objectives: Oral squamous cell carcinoma (OSCC) accounts for about 95% of oral cancers. It represents a serious public health problem due to the high degree of morbidity and mortality, as well as multifactorial etiology. Human papillomavirus (HPV) infection is a well-documented risk factor for oropharyngeal carcinoma, but its role in oral carcinogenesis is still debatable. Our aim was to investigate the differences in the prevalence of high-risk HPV genotypes (HR-HPV) in patients with OSCC and oral potentially malignant disorders (OPMD) from that of healthy subjects. Materials and Methods: A total of 90 subjects were included in the cross-sectional study and divided into three groups of 30 patients each: (1) patients with OSCC, (2) patients with OPMD, and (3) healthy subjects. We examined the presence of 12 HR-HPV genotypes in the obtained biological material (oral swabs) using real-time PCR. Results: One or more of the 12 tested HR-HPV genotypes were detected in 5/30 patients with OSCC and 2/30 with OPMD, whereas no healthy subjects were positive for any of the tested genotypes. There was a statistically significant difference in nodal involvement between HPV-positive and HPV-negative patients with OSCC. Conclusions: Oral HR-HPV was detected in patients with oral premalignant and malignant lesions but not in healthy individuals, suggesting a possible role in oral carcinogenesis. Broad HR-HPV panel testing could increase the sensitivity of risk assessment and screening for OSCC.

Human papillomavirus in cancer: Infection, disease transmission, and progress in vaccines

Human papillomaviruses (HPVs) infect epithelial cells of human beings, and their replication cycle is associated with epithelial differentiation. More than 200 genotypes of HPVs were identified, and each of these HPVs shows distinct specificity for tissues and infection. HPV infection was involved in the development of lesions on the feet, genital warts and hands. The evidence of HPV infection revealed the role of HPVs in neck and head squamous cell carcinoma, esophageal cancer, cervical cancer, head and neck cancer, brain and lung tumours. The independent traditional risk factors, various clinical outcomes, and increased prevalence among certain populations and geographical regions have led increasing interest in HPV infection. The mode of HPVs transmission remains unclear. Moreover, in recent years, vertical transmission of HPVs was reported. This review concludes present knowledge about HPV infection, virulence strains, clinical significance of HPVs, and mode of transmission, and vaccination strategies.

Epidemiological evidence and association of human papillomavirus with esophageal cancer in northeastern Thailand: a case-control study

Recently, epidemiological evidence of high-risk human papillomavirus (hrHPV) and its association with the increasing risk of esophageal cancer (EC) have been described. However, the involvement of such a virus in the pathogenesis of EC is still inconclusive in the literature. Therefore, our objective was to clarify the epidemiology of HPV infections in primarily diagnosed EC cases and validate this correlation with hospital-based control patients using a retrospective study with a case-control model. Here, we reported that the overall prevalence of HPV DNA was statistically associated with an increased risk of EC (OR, 3.3; 95% CI, 2.5-4.3). Interestingly, a history of gastroesophageal reflux disease (GERD) was constituted and significantly associated with HPV prevalence (adjusted OR, 4.6; 95% CI, 2.2-9.5). Furthermore, our meta-analysis in public databases also indicated that the combined OR and 95% CI between HPV infection and EC risk were 3.31 and 2.53-4.34, respectively, with significant heterogeneity (I₂ = 78%). Variations in the geographic study, tissue type, and detection method remain potential predictors of heterogeneity. In addition, publication bias and sensitivity analysis were not observed, and the results exhibited stable outcomes. Collectively, we specify the recent epidemiological evidence in a validation of the distributed HPV, which might be statistically associated with an increased risk of EC. However, additional high-quality studies with larger sample sizes are needed to further verify the link between HPV and EC.

Subjective factors affecting prognosis of 469 patients with esophageal squamous cell carcinoma: a retrospective cohort study of endoscopic screening

Background

To date, no in-depth studies have focused on the impact of various clinical characteristics of esophageal squamous cell carcinoma (ESCC), including its association with subjective symptoms, on patient prognosis. We aimed to investigate the clinical factors that affect the prognosis of patients with ESCC and to clarify how subjective symptoms are related to prognosis.

Methods

We retrospectively evaluated the clinical records of 503 consecutive patients with ESCC from April 2011 to December 2019. Six established prognostic factors for ESCC (body mass index, alcohol drinking, cigarette smoking, sex, clinical stage, and age) and subjective symptoms were used to subgroup patients and analyze survival differences. Next, the patients were divided into two groups: a symptomatic group and an asymptomatic group. In the symptomatic group, differences in the incidence of subjective symptoms according to tumor size, tumor location, macroscopic tumor type, and clinical stage were examined. Finally, subjective symptoms were divided into swallowing-related symptoms and other symptoms, and their prognosis was compared.

Results

Multivariate Cox regression analysis identified sex [hazard ratio (HR) 1.778; 95% CI 1.004–3.149; p = 0.049], TNM classification (HR 6.591; 95% CI 3.438–12.63; p < 0.001), and subjective symptoms (HR 1.986; 95% CI 1.037–3.803; p = 0.0386) as independent risk factors for overall survival. In the symptomatic group, the mean time from symptom onset to diagnosis was 2.4 ± 4.3 months. The incidence of subjective symptoms differed by clinical stage, and the prognosis of patients with swallowing-related symptoms was significantly worse than that of patients with other symptoms.

Conclusion

The results of this study suggest that screening by upper gastrointestinal endoscopy, independent of subjective symptoms (especially swallowing-related symptoms), may play an important role in the early detection and improvement of prognosis of ESCC, although further validation in a large prospective study is needed.

Diagnostic and Therapeutic Uses of the Microbiome in the Field of Oncology

Cancer is a leading cause of death worldwide and it can affect almost every part of the human body. Effective screening and early diagnosis of cancers is extremely difficult due to the multifactorial etiology of the disease and delayed presentation of the patients. The available treatments are usually not specific to the affected organ system, leading to intolerable systemic side effects and early withdrawal from therapies. In vivo and in vitro studies have revealed an association of specific microbiome signatures with individual cancers. The cancer-related human microbiome has also been shown to affect the response of tissues to chemotherapy, immunotherapy, and radiation. This is an excellent opportunity for us to design specific screening markers using the microbiome to prevent cancers and diagnose them early. We can also develop precise treatments that can target cancer-affected specific organ systems and probably use a lesser dose of chemotherapy or radiation for the same effect. This prevents adverse effects and early cessation of treatments. However, we need further studies to exactly clarify and characterize these associations. In this review article, we focus on the association of the microbiome with individual cancers and highlight its future role in cancer screenings, diagnosis, prognosis, and treatments.

Viral Pathogens in Oesophageal and Gastric Cancer

Tumour virology was born with the discovery by Peyton Rous in 1911 of a filterable agent in chicken cellular extracts that caused neoplasia in healthy chickens. Universally, 20% of all human cancers have a viral aetiology. Viruses are involved at various stages of the carcinogenesis pathway, depending on the viral pathogen, and likely require co-factors. Multiple risk factors have been associated with oesophageal and gastric malignancy, including carcinogenic pathogens. These viruses and bacteria include human papillomavirus (HPV) [oesophageal cancer], Epstein-Barr virus (EBV) [proximal stomach cancer], and Helicobacter pylori (HP) [non-cardia stomach cancer]. Viruses such as EBV have been firmly established as causal for up to 10% of gastric cancers. HPV is associated with 13 to 35% of oesophageal adenocarcinoma but its role is unclear in oesophageal squamous cell carcinomas. The causal relationship between hepatitis B (HBV), cytomegalovirus (CMV), HPV, and John Cunningham (JCV) and gastric neoplasia remains indeterminate and warrants further study. The expression of viral antigens by human tumours offers preventive and therapeutic potential (including vaccination) and has already been harnessed with vaccines for HPV and HBV. Future goals include viral protein-based immunotherapy and monoclonal antibodies for the treatment of some of the subset of EBV and HPV-induced gastro-esophageal cancers.

Roles of Wnt/β-catenin signaling pathway related microRNAs in esophageal cancer

MicroRNAs (miRNAs) are endogenous, noncoding, single-stranded small RNAs that regulate expression of tumor suppressor genes and oncogenes and are involved in almost all tumor-related processes. MiRNA dysregulation plays an important role in the occurrence and development of esophageal cancer through specific signal pathways, including the Wnt/β-catenin signaling pathway, and is closely related to the malignant characteristics of esophageal cancer. The interaction between miRNAs and the Wnt/β-catenin signaling pathway, which is specifically expressed in esophageal cancer tissues, shows potential as a new biomarker and therapeutic target. This article reviews the role of miRNAs related to the Wnt pathway in the carcinogenesis of esophageal carcinoma and its role in Wnt signal transduction. The content of this review can be used as the basis for formulating or improving the treatment strategy of esophageal cancer.

Evidence of High-Risk Human Papillomavirus in Esophageal Cancer in East Azerbaijan Province, Northwest of Iran

Background

Human papillomavirus (HPV) is one of the most important viral agents associated with several classes of cancers in humans. The aim of this study was to investigate HPV in esophageal cancer in the East Azerbaijan province, northwest of Iran.

Methods

140 paraffin-embedded specimens of esophageal tissues were investigated using nested-polymerase chain reaction (nested-PCR) with primer designing for the L1 region of HPV genome. According to the pathological diagnosis, the samples were divided into two groups: 70 patients with esophageal cancer EADC (n = 35) and ESCC (n = 35) as the case group and those without tumour in esophagus tissue as a control (n = 70).

Results

HPV DNA was isolated from 20 (28.57%) of the 70 paraffin-embedded tissue specimens of esophagus cancer. Of these, 6 cases (17.14%) of EADC and 14 cases (40%) of ESCC were positive. In contrast, all cases of the control group were negative for the HPV genome. Sequence analysis revealed that HPV types 16 and 18 are the most frequent ones identified in this study.

Conclusion

The prevalence of HPV in esophageal cancer can vary depending on the geographical location and other factors. Based on the findings of this study, HPV infection may possibly have contributed to an increased risk of esophageal cancer in a group of patients in Tabriz.

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.

Epidemiology of Barrett's Esophagus and Esophageal Carcinoma

To care and treat patients with esophageal cancer, one must first understand the epidemiology of Barrett's esophagus (BE). BE is defined as the intestinal metaplasia occurring within the esophagus from normal squamous epithelium to abnormal specialized columnar epithelium. BE, while first described by Allison in 1948, was attributed to Norman Barrett in 1950, who reported a case of chronic peptic ulcer in the lower esophagus that was covered by columnar epithelium.

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.

Esophageal squamous cell carcinoma metachronous to head and neck cancers

BACKGROUND

In some HNSCC patients, a metachronous ESCC may develop. No information is available on the HNSCC-associated ESCCs microenvironment and etiology.

METHODS

Among 134 ESCCs surgically treated between 2009 and 2015, a series of 6 HNSCC-associated ESCCs was collected. A series of 12 sex-, age- and stage-matched ESCCs with no previous oncological medical history was selected for comparison. Histologic assessment of intratumoral inflammatory infiltration and immunohistochemistry for CD4, CD8, CD80, PD1, PD-L1 and p53 were performed. HPV detection/genotyping was assessed by PCR single step and reverse line blot.

RESULTS

HPV DNA was negative in all the HNSCC-associated ESCCs. In comparison to non-HNSCC-associated carcinomas, the 6 cases presented a lower lymphomonocytic infiltration, which also corresponded to a lower prevalence of CD4 + T cell infiltration and, 5/6 cases presented a PD-L1 CPS ≥ 1. All the HNSCC-associated ESCCs resulted positive for p53 immunostaining in ≥50 % of cancer cells.

CONCLUSION

Our study suggests that HPV infection is not an etiological factor associated to ESCC after HNSCC. On the other hand, p53 overexpression is a common finding. Moreover, our data suggest that an altered immune microenvironment, conditioned by a dysregulation in lymphomonocytic infiltration, may be a crucial factor allowing the occurrence of a metachronous ESCC.

Synergism of HPV and MNNG repress miR-218 promoting Het-1A cell malignant transformation by targeting GAB2

Dysregulation of microRNAs (miRNAs) is induced during tumorigenesis. Our previous research suggested that HPV and MNNG led to malignant transformation of esophageal epithelial cells. To investigate the regulation and function of miR-218(miR-218-5p) during the malignant transformation of esophageal epithelial cells, we found miR-218 was inhibited synergistically by HPV and MNNG, suppressing cell proliferation, migration and invasion by up-regulating 3' untranslated region (3'UTR) GAB2 in Het-1A-HPV-MNNG cells (malignant Het-1A cells induced by HPV and MNNG). A negative correlation was found between miR-218 and GAB2 mRNA expression in esophageal cancer patients and control people. GAB2 was up-regulated in Het-1A-HPV-MNNG cells. Further, down-expression of GAB2 reversed HPV&MNNG-mediated activation of migration and invasion and repressed SHP2/ERK and Akt/mTOR pathway signaling. In conclusion, miR-218 partially accounts for the prevention effect during malignant transformation of normal esophageal epithelial cells, which targets GAB2, which supplies the potential treatment in cancer therapy.

Human papillomavirus infection in esophageal squamous cell carcinoma and esophageal adenocarcinoma: a concise review

The causal link between high-risk human papillomavirus (hr-HPV) infection and cervical, anogenital, and some oropharyngeal malignancies has been established by both molecular and epidemiological data. The association between HPV and esophageal squamous cell carcinoma (ESCC) remains controversial, as is the true prevalence of HPV infection in ESCC. The wide range in reported rates reflects variability in the primary literature, with some larger scale case-control studies suggesting the infection rates range from 0% to 78%. Interactions between HPV and the Barrett's metaplasia-dysplasia-carcinoma sequence have been explored, and these studies have shown some conflicting data. Overall, systematic reviews have reported the prevalence of HPV-positive DNA in esophageal adenocarcinoma patients of between 13% and 35%. Postulated reasons for discrepancies in HPV prevalence rates in esophageal cancer include variations in testing methodology and assay sensitivities; technical issues, including the lack of a gold-standard primer; types of specimens utilized (fresh-frozen versus formalin-fixed tissue); geographical variation; cross-contamination; and small sample sizes. Thus, efforts must be undertaken to (1) standardize HPV testing, ideally in a central laboratory and utilizing tests that detect viral transcriptional activity; (2) avoid cross-contamination; and (3) recruit large numbers of patients to accurately ascertain HPV rates in esophageal malignancy.

The Oral Microbiome and Cancer

There is mounting evidence that members of the human microbiome are highly associated with a wide variety of cancer types. Among oral cancers, oral squamous cell carcinoma (OSCC) is the most prevalent and most commonly studied, and it is the most common malignancy of the head and neck worldwide. However, there is a void regarding the role that the oral microbiome may play in OSCC. Previous studies have not consistently found a characteristic oral microbiome composition associated with OSCC. Although a direct causality has not been proven, individual members of the oral microbiome are capable of promoting various tumorigenic functions related to cancer development. Two prominent oral pathogens, Porphyromonas gingivalis, and Fusobacterium nucleatum can promote tumor progression in mice. P. gingivalis infection has been associated with oro-digestive cancer, increased oral cancer invasion, and proliferation of oral cancer stem cells. The microbiome can influence the evolution of the disease by directly interacting with the human body and significantly altering the response and toxicity to various forms of cancer therapy. Recent studies have shown an association of certain phylogenetic groups with the immunotherapy treatment outcomes of certain tumors. On the other side of the coin, recently it has been a resurgence in interest on the potential use of bacteria to cure cancer. These kinds of treatments were used in the late nineteenth and early twentieth centuries as the first line of defense against cancer in some hospitals but later displaced by other types of treatments such as radiotherapy. Currently, organisms such as Salmonella typhimurium and Clostridium spp. have been used for targeted strategies as potential vectors to treat cancer. In this review, we briefly summarize our current knowledge of the role of the oral microbiome, focusing on its bacterial fraction, in cancer in general and in OSCC more precisely, and a brief description of the potential use of bacteria to target tumors.

Relationships of early esophageal cancer with human papillomavirus and alcohol metabolism

BACKGROUND

It is well known that an alcohol consumption habit together with inactive heterozygous aldehyde dehydrogenase-2 (ALDH2) is an important risk factor for the development of esophageal squamous cell carcinoma (ESCC). It remains controversial whether human papillomavirus (HPV) infection contributes to the occurrence/development of ESCC. There has been no study in which the relationship between ESCC and HPV in addition to alcohol dehydrogenase-1B (ADH1B) and ALDH2 genotypes was evaluated.

AIM

To evaluate relationships between HPV infection and development of esophageal cancer, particularly early esophageal cancer, based on ADH1B/ALDH2 polymorphisms.

METHODS

We conducted an exploratory retrospective study using new specimens, and we enrolled 145 patients who underwent endoscopic resection for superficial ESCC and had been observed for more than two years by both physical examination and endoscopic examination in Hokkaido University Hospital. Saliva was collected to analyze genetic polymorphisms of ADH1B/ALDH2. We performed in situ hybridization for resected specimens to detect HPV by using an HPV type 16/18 probe.

RESULTS

HPV was detected in 15 (10.3%) of the 145 patients with ESCC. HPV-positive rates in inactive ALDH2*1/*2 and ALDH2*1/*1 + *2/*2 were 10.8% and 9.8%, respectively (P = 1.00). HPV-positive rates in slow-metabolizing ADH1B*1/*1 and ADH1B*1/*2 + *2/*2 were 12.0% and 10.0%, respectively (P = 0.72). HPV-positive rates in the heavy or moderate alcohol consumption group and the light or rare consumption group were 11.1% and 8.7%, respectively (P = 0.68). HPV-positive rates in the heavy smoking group and the light or no smoking group were 11.8% and 8.3%, respectively (P = 0.59). The 3-year incidence rates of secondary ESCC or head and neck cancer after initial treatment in the HPV-positive and HPV-negative groups were 14.4% and 21.4% (P = 0.22), respectively.

CONCLUSION

In the present situation, HPV status is considered to be less important than other risk factors, such as alcohol consumption, smoking habit, ADH1B/ALDH2 polymorphisms, and HPV status would therefore have no effect on ESCC risk management.

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.

The Oral Microbiome and Cancer

There is mounting evidence that members of the human microbiome are highly associated with a wide variety of cancer types. Among oral cancers, oral squamous cell carcinoma (OSCC) is the most prevalent and most commonly studied, and it is the most common malignancy of the head and neck worldwide. However, there is a void regarding the role that the oral microbiome may play in OSCC. Previous studies have not consistently found a characteristic oral microbiome composition associated with OSCC. Although a direct causality has not been proven, individual members of the oral microbiome are capable of promoting various tumorigenic functions related to cancer development. Two prominent oral pathogens, Porphyromonas gingivalis, and Fusobacterium nucleatum can promote tumor progression in mice. P. gingivalis infection has been associated with oro-digestive cancer, increased oral cancer invasion, and proliferation of oral cancer stem cells. The microbiome can influence the evolution of the disease by directly interacting with the human body and significantly altering the response and toxicity to various forms of cancer therapy. Recent studies have shown an association of certain phylogenetic groups with the immunotherapy treatment outcomes of certain tumors. On the other side of the coin, recently it has been a resurgence in interest on the potential use of bacteria to cure cancer. These kinds of treatments were used in the late nineteenth and early twentieth centuries as the first line of defense against cancer in some hospitals but later displaced by other types of treatments such as radiotherapy. Currently, organisms such as Salmonella typhimurium and Clostridium spp. have been used for targeted strategies as potential vectors to treat cancer. In this review, we briefly summarize our current knowledge of the role of the oral microbiome, focusing on its bacterial fraction, in cancer in general and in OSCC more precisely, and a brief description of the potential use of bacteria to target tumors.

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.

Managing Squamous Cell Esophageal Cancer

This article reviews the pathophysiology, risk factors, clinical presentation/diagnosis, and management of SCC.

Inhibitory Effects of (-)-Epigallocatechin-3-gallate on Esophageal Cancer

There is epidemiological evidence showing that drinking green tea can lower the risk of esophageal cancer (EC). The effect is mainly attributed to tea polyphenols and their most abundant component, (−)-epigallocatechin-3-gallate (EGCG). The possible mechanisms of tumorigenesis inhibition of EGCG include its suppressive effects on cancer cell proliferation, angiogenesis, DNA methylation, metastasis and oxidant stress. EGCG modulates multiple signal transduction and metabolic signaling pathways involving in EC. A synergistic effect was also observed when EGCG was used in combination with other treatment methods.

Endoscopic findings and esophageal cancer incidence among Fanconi Anemia patients participating in an endoscopic surveillance program

BACKGROUND AND AIMS

The primary clinical characteristics of Fanconi Anemia (FA) include typical physical features, progressive bone marrow failure, and an increased incidence of neoplasms, including esophageal carcinoma. Currently, there are no data regarding endoscopic findings or the interval time to malignancy in these patients. Data about the contribution of Human Papilloma Virus (HPV) to esophageal carcinoma is conflicting. Our objective is to document the upper gastrointestinal (GI) findings at baseline, document cancer incidence, and evaluate the role of HPV among these cancers.

METHODS

We reviewed endoscopic and clinical data of FA subjects who participated in active surveillance before cancer diagnosis. Incident esophageal cancers were stained for HPV ^p16 protein.

RESULTS

Eight FA patients were included (men 62.5%; median age at first endoscopy 20 years, median endoscopies number: 5.5). At baseline, 8/8 had endoscopic evidence for reflux esophagitis. In 3/8 the reflux esophagitis was mild and in 5/8 it was moderate or severe. During the follow up time (median time 4.5 years 2/8 developed Barrett's esophagus and 2/8 patients had incident esophageal squamous cell carcinoma during follow up, at intervals of eight and eighteen months from the previous upper endoscopy. Both cancers stained negative for HPV ^P16.

CONCLUSIONS

FA subjects have both an extremely high risk for esophageal cancer within short intervals and a very high prevalence of reflux esophagitis with various severities. Active surveillance programs in specialized centers including annual upper endoscopies should be considered in these patients.

Allergies and the Subsequent Risk of Cancer among Elderly Adults in the United States

BACKGROUND

Allergic conditions may prevent some cancers by promoting immune surveillance. We examined associations of allergic rhinitis, asthma, and eczema with cancer risk among elderly Americans.

METHODS

We used Surveillance Epidemiology and End Results (SEER)-Medicare linked data to perform a case-control study. Cases were individuals with first cancer diagnosed in SEER registries (1992-2013, ages 66-99; N = 1,744,575). Cancer-free controls (N = 100,000) were randomly selected from Medicare and matched on sex, age, and selection year. Allergic conditions were identified using Medicare claims, and logistic regression was used to estimate adjusted ORs (aOR) with significance gauged with a Bonferroni P cutoff (P < 0.00034).

RESULTS

Allergic rhinitis, asthma, and eczema were present in 8.40%, 3.45%, and 0.78% of controls, respectively. For allergic rhinitis, strong inverse associations (aORs, 0.66-0.79) were observed for cancers of the hypopharynx, esophagus (squamous cell), cervix, tonsil/oropharynx, and vagina/vulva. More modest but significant inverse associations were noted for cancers of the esophagus (adenocarcinoma), stomach, colon, rectosigmoid/rectum, liver, gallbladder, lung, uterus, bladder, and miscellaneous sites. Associations were stronger in analyses requiring a dispensed medication to confirm the presence of allergic rhinitis. Asthma was associated with reduced risk of liver cancer [aOR 0.82; 95% confidence interval (CI), 0.75-0.91], whereas eczema was associated with elevated risk of T-cell lymphoma (aOR, 4.12; 95% CI, 3.43-4.95).

CONCLUSIONS

Inverse associations with allergic rhinitis are present for multiple cancers and require etiologic investigation.

IMPACT

Understanding of mechanisms by which allergic conditions reduce cancer risk may advance cancer prevention and treatment.

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.

Human papillomavirus infection and colorectal cancer in the Chinese population: a meta-analysis

AIM

Human papillomavirus (HPV) infection has been reported in colorectal cancer in many studies. We conducted a meta-analysis to assess the association between HPV infection and colorectal cancer/adenomas in the Chinese population.

METHOD

Relevant studies up to January 2018 were searched in PubMed, EMBASE, China National Knowledge Infrastructure and the Wanfang database. We used a random effects model to determine the prevalence of HPV and odds ratios (ORs) with 95% confidence intervals (CIs). The I² statistic and P-value from the Cochrane Q-test were used to describe the heterogeneity.

RESULTS

Ten case-control studies involving 766 colorectal cancer patients and 470 controls were included in the meta-analysis. Among the colorectal cancer patients, the pooled prevalence was 0.45 (95% CI 0.36-0.53). The pooled estimate for OR was 10.78 (95% CI 4.22, 27.53). Among the 193 patients with colorectal adenoma, the pooled prevalence and OR were 0.31 (95% CI 0.24-0.37) and 2.03 (95% CI 0.79, 5.26), respectively. The prevalence of HPV 16 and HPV 18 among HPV-positive cancers ranged from 57.9% to 100% and 0% to 39.7%, respectively.

CONCLUSION

The results indicated that HPV infection, especially HPV 16 and HPV 18, is associated with colorectal cancer in the Chinese population.

Modifiable factors and esophageal cancer: a systematic review of published meta-analyses

There are marked differences in the etiology of the major histological types of esophageal cancer (EC)-squamous cell carcinomas (ESCC) and adenocarcinomas (EAC). This study aimed to summarize the current scientific knowledge on modifiable risk factors for EC, by histological type, through a systematic review of meta-analyses referenced in PubMed and ISI Web of Knowledge. We identified 100 meta-analyses on risk factors for ESCC (n = 54), EAC (n = 43), or EC (n = 51). ESCC risk significantly increased with alcohol and maté drinking, smoking, red and processed meat consumption and human papillomavirus infection, while it was negatively associated with body mass index and consumption of fruit, vegetables, white meat, folate, and some carotenoids. Cessation of drinking and smoking significantly reduced ESCC risk. For EAC, an increased risk was reported for smoking, body mass index, and red and processed meat consumption, while risk decreased with Helicobacter pylori infection, low/moderate alcohol drinking, physical activity, and consumption of fruit, vegetables, folate, fiber, beta-carotene, and vitamin C. Differences in results between meta-analyses and mechanisms underlying some of the associations found are discussed. This work reinforces the importance of a separate assessment of EC subtypes to allow for a proper evaluation of incidence trends and planning of prevention/control interventions.

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.

Endoscopic diagnosis and treatment of early esophageal squamous neoplasia

Esophageal cancer is one of the leading causes of cancer-related death and is associated with high morbidity and mortality. It carries a poor prognosis as more than half of patients present with advanced and unresectable disease. One contributing factor is the increased risk of lymph node metastases at early stages of disease. As such, it is essential to detect squamous cell neoplasia (SCN) at an early stage. In order to risk stratify lesions, endoscopists must be able to perform image enhanced endoscopy including magnification and Lugol’s chromoendoscopy. The assessment of both the horizontal extent and depth of any lesion is also of utmost importance prior to treatment. Endoscopic mucosal resection and submucosal dissection remain the standard of care with literature supportive their respective use. Radiofrequency ablation and other endoscopic treatments are currently available although should not be considered first line at this time. Our objective is to review the current options for the endoscopic diagnosis and treatment of esophageal SCN.

The Relation of HPV Infection and Expression of p53 and p16 Proteins in Esophageal Squamous Cells Carcinoma

GOAL: To investigate the HPV prevalence and characterize the expression of potential molecular surrogate markers of HPV infection in esophageal squamous cell carcinoma.

MATERIALS AND METHODS: The prevalence of HPV in individuals with and without esophageal cancer (EC) was determined by using multiplex PCR; p16 and p53 protein levels were assessed by immunohistochemistry (IHC).

RESULTS: High-risk HPV (hr-HPV) was found in the same frequency (13.8%) in esophageal squamous cell carcinoma (ESCC) and in healthy individuals. The p53 expression was positive in 67.5% of tumor tissue, 20.0% of adjacent non-tumoral tissue and 1.8% of normal esophageal tissue. p16 was positive in 11.6% of esophageal cancer cases and 4.7% of adjacent non-tumoral tissue. p16 was undetectable among control group samples. p53 and p16 levels were not significantly associated with the HPV status.

CONCLUSIONS: These results suggest that hr-HPV types are not associated with the development of ESCC and that p53 and p16 protein expression have no relationship with HPV infection in normal or cancerous esophagus.

Vaccination Expectations in HNSCC

HPV-associated head and neck squamous cell carcinoma (HNSCC), more specifically the incidence of oropharyngeal cancer, is dramatically increasing in industrialized countries. According to what has been learned from anogenital vaccination programs, there are reasons to believe that current human papillomavirus (HPV) vaccinations may be potentially effective also against HNSCC. However, before specific results on HNSCC are available, one must keep in mind that carcinogenesis in the head and neck region may differ from that of the anogenital tract. Furthermore, the current evidence supports the view that HPV infection is much more complex than simply a sexually transmitted disease. HPV is present in the semen, placenta and in the newborns, and these infections of the newborns create cell-mediated immunity (CMI) against HPV, including the T memory cells. Acquisition of HPV infection in early life will rise new series of questions in the field of HPV vaccination.

Human papillomavirus as a potential risk factor for gastric cancer: a meta-analysis of 1,917 cases

Background

Human papillomaviruses (HPVs) are causally associated with the tumorigenesis of several classes of cancers. However, the prevalence of HPV in gastric cancer (GC) has not yet been systematically reviewed. Hence, a meta-analysis was conducted to estimate the HPV prevalence in patients with GC, and its potential etiologic significance was assessed.

Methods

The pooled HPV prevalence and 95% confidence intervals (CIs) were estimated among all GC patients. Heterogeneity was described by using the I² statistic. Sources of heterogeneity were explored by meta-regression and stratified analyses. The meta-influence was applied to evaluate the influence of a single study on the pooled estimates. Odds ratios (ORs) and 95% CIs were computed for case–control studies. For research providing clinicopathological parameters of age, sex, pathological, differentiated, and clinical stages, and HPV subtypes, the corresponding pooled ORs and 95% CIs were also calculated.

Results

Thirty studies were included in the current meta-analysis, involving 1,917 patients with GC and 576 controls. The pooled HPV prevalence was 28.0% (95% CI: 23.2%, 32.7%) among all the patients with GC, and the I² was 96.9% (P<0.001). A pooled OR of 7.388 (95% CI: 3.876, 14.082) was achieved based on 15 case–control studies (I²=56.7%, P=0.004). Moreover, the HPV prevalence was significantly higher in patients from China than in those from non-Chinese regions (31% vs 9%, I²=95.0%, P<0.001). The pooled prevalence of HPV16 was 21% in GC tissues, and the pooled prevalence of HPV18 was 7% with an OR of 3.314 (95% CI =1.617, 6.792). HPV16 was 3 times more frequently detected than HPV18.

Conclusion

HPV could play a potential role in the pathogenesis of GC. A causal relationship can be confirmed only by detecting HPV in the cells of GC precursor lesions (gastric dysplasia or adenoma). In addition, this study might be beneficial for expounding the potential etiologic significance of molecular mechanism of gastric tumorigenesis and providing opinions regarding precautionary measures.

Subtyping sub-Saharan esophageal squamous cell carcinoma by comprehensive molecular analysis

Esophageal squamous cell carcinoma (ESCC) is endemic in regions of sub-Saharan Africa (SSA), where it is the third most common cancer. Here, we describe whole-exome tumor/normal sequencing and RNA transcriptomic analysis of 59 patients with ESCC in Malawi. We observed similar genetic aberrations as reported in Asian and North American cohorts, including mutations of TP53, CDKN2A, NFE2L2, CHEK2, NOTCH1, FAT1, and FBXW7. Analyses for nonhuman sequences did not reveal evidence for infection with HPV or other occult pathogens. Mutational signature analysis revealed common signatures associated with aging, cytidine deaminase activity (APOBEC), and a third signature of unknown origin, but signatures of inhaled tobacco use, aflatoxin and mismatch repair were notably absent. Based on RNA expression analysis, ESCC could be divided into 3 distinct subtypes, which were distinguished by their expression of cell cycle and neural transcripts. This study demonstrates discrete subtypes of ESCC in SSA, and suggests that the endemic nature of this disease reflects exposure to a carcinogen other than tobacco and oncogenic viruses.

Human papillomavirus and gastrointestinal cancer: A review

Human papillomavirus (HPV) is one of the most common sexually transmitted infections worldwide. Exposure to HPV is very common, and an estimated 65%-100% of sexually active adults are exposed to HPV in their lifetime. The majority of HPV infections are asymptomatic, but there is a 10% chance that individuals will develop a persistent infection and have an increased risk of developing a carcinoma. The International Agency for Research on Cancer has found that the following cancer sites have a strong causal relationship with HPV: cervix uteri, penis, vulva, vagina, anus and oropharynx, including the base of the tongue and the tonsils. However, studies of the aetiological role of HPV in colorectal and esophageal malignancies have conflicting results. The aim of this review was to organize recent evidence and issues about the association between HPV infection and gastrointestinal tumours with a focus on esophageal, colorectal and anal cancers. The ultimate goal was to highlight possible implications for prognosis and prevention.

p16 Expression as a Surrogate Marker for HPV Infection in Esophageal Squamous Cell Carcinoma can Predict Response to Neo-Adjuvant Chemotherapy

BACKGROUND

Esophageal squamous cell carcinoma (ESCC) is a common cancer in the north east of India. The present study concerned the prevalence of human papilloma virus (HPV) in the ESCC in north eastern India and its impact on response to chemotherapy.

MATERIALS AND METHODS

p16 expression, a surrogate marker for HPV infection was assessed in 101 pre-treatment biopsies of locally advanced ESCC, reported from a comprehensive cancer centre in north east India, using immunohistochemistry. All patients received neo-adjuvant chemotherapy. Response was assessed clinically and histopathologically with attention to p16 expression.

RESULTS

p16 was expressed in 22% of ESCC (22 out of 101) and was more prevalent in patients who were more than 45 years of age (P=0.048). p16 positive tumors appeared more commonly in the upper 2/3 of the thoracic esophagus (18 in 22). Nine of the 22 (41%) p16 positive tumors achieved pathologic complete response following neo-adjuvant chemotherapy (P=0.008). There was a trend towards reduced mortality in this group (P=0.048). Some 9 of the 20 (45%) patients who achieved pathologic complete response were p16 positive.

CONCLUSIONS

Expression of p16 in ESCC correlates with higher rate of pathologic complete remission in patients undergoing neo adjuvant chemotherapy and could be a predictive marker for response assessment.

Human papillomavirus infection and the malignant transformation of sinonasal inverted papilloma: A meta-analysis

A growing number of molecular epidemiological studies have been conducted to evaluate the association between human papillomavirus (HPV) infection and the malignancy of sinonasal inverted papilloma (SNIP). However, the results remain inconclusive. Here, a meta-analysis was conducted to quantitatively assess this association. Case-control studies investigating SNIP tissues for presence of HPV DNA were identified. The odds ratios (ORs) and 95% confidence intervals (CIs) were calculated by the Mantel-Haenszel method. An assessment of publication bias and sensitivity analysis were also performed. We calculated a pooled OR of 2.16 (95% CI=1.46-3.21, P<0.001) without statistically significant heterogeneity or publication bias. Stratification by HPV type showed a stronger association for patients with high-risk HPV (hrHPV) types, HPV-16, HPV-18, and HPV-16/18 infection (OR=8.8 [95% CI: 4.73-16.38], 8.04 [95% CI: 3.34-19.39], 18.57 [95% CI: 4.56-75.70], and 26.24 [4.35-158.47], respectively). When only using PCR studies, pooled ORs for patients with hrHPV, HPV-16, and HPV18 infection still reached statistical significance. However, Egger's test reflected significant publication bias in the HPV-16 sub-analysis (P=0.06), and the adjusted OR was no longer statistically significant (OR=1.65, 95%CI: 0.58-4.63). These results suggest that HPV infection, especially hrHPV (HPV-18), is significantly associated with malignant SNIP.

Diet, nutrition, and cancer: past, present and future

Despite the potentially important roles of diet and nutrition in cancer prevention, the evidence to support these roles is widely perceived by the public and health professionals as being inconsistent. In this Review, we present the issues and challenges in conducting and interpreting diet-cancer research, including those relating to the design of epidemiological studies, dietary data collection methods, and factors that affect the outcome of intervention trials. Approaches to improve effect estimates, such as the use of biomarkers to improve the accuracy of characterizing dietary exposures, are also discussed. Nutritional and dietary patterns are complex; therefore, the use of a reductionist approach to investigations, by focusing on specific nutrients, can produce misleading information. The effects of tumour heterogeneity and the failure to appreciate the nonlinear, U-shaped relationship between micronutrients and cancer in both observational studies and clinical trials are discussed. New technologies and investigational approaches are enabling the exploration of complex interactions between genetic, epigenetic, metabolic, and gut-microbial processes that will inform our knowledge of the diet-cancer relationship. Communicating the status of the evolving science in the context of the overall scientific evidence base, and evidence-based dietary recommendations for cancer prevention, should be emphasized in guidance for the public and for individual patients.

Recent Advances From Basic and Clinical Studies of Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the most aggressive squamous cell carcinomas and is highly prevalent in Asia. Alcohol and its metabolite, acetaldehyde, are considered definite carcinogens for the esophagus. Polymorphisms in the aldehyde dehydrogenase 2 gene, which encodes an enzyme that eliminates acetaldehyde, have been associated with esophageal carcinogenesis. Studies of the mutagenic and carcinogenic effects of acetaldehyde support this observation. Several recent large-scale comprehensive analyses of the genomic alterations in ESCC have shown a high frequency of mutations in genes such as TP53 and others that regulate the cell cycle or cell differentiation. Moreover, whole genome and whole exome sequencing studies have frequently detected somatic mutations, such as G:C→A:T transitions or G:C→C:G transversions, in ESCC tissues. Genomic instability, caused by abnormalities in the Fanconi anemia DNA repair pathway, is also considered a pathogenic mechanism of ESCC. Advances in diagnostic techniques such as magnifying endoscopy with narrow band imaging or positron emission tomography have increased the accuracy of diagnosis of ESCC. Updated guidelines from the National Comprehensive Cancer Network standardize the practice for the diagnosis and treatment of esophageal cancer. Patients with ESCC are treated endoscopically or with surgery, chemotherapy, or radiotherapy, based on tumor stage. Minimally invasive treatments help improve the quality of life of patients who undergo such treatments. We review recent developments in the diagnosis and treatment of ESCC and advances gained from basic and clinical research.

Type-specific detection of human papillomaviruses in Kazakh esophageal squamous cell carcinoma by genotyping both E6 and L1 genes with MALDI-TOF mass spectrometry

BACKGROUND

Many studies have suggested a relationship between human papillomavirus (HPV) infection and the risk of esophageal squamous cell carcinoma (ESCC). However, findings are inconclusive, potentially because of geographic heterogeneity and variations in detection methods.

OBJECTIVES

We sought to further investigate the prevalence of HPV with a new detection method, the MassARRAY Sequenom technique, in esophageal squamous cell carcinomas occurring in patients belonging to Kazakh populations in Xinjiang, China.

STUDY DESIGN

In the present study, a novel genotyping method for detecting 30 HPV genotypes, specifically by genotyping both the HPV E6 and L1 genes with multiplex PCR using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) (PCR-MS) was first adopted to evaluate HPV genotypes in 89 esophageal cancer samples and 49 matched adjacent normal esophageal tissues.

RESULTS

Six HPV genotypes (HPV6, HPV16, HPV33, HPV39, HPV51, and HPV82) were present in at least 51.7% of the esophageal carcinoma tissues, which was significantly greater than 28.6% prevalence among controls (P < 0.05). HPV16 was the most common of all the genotypes investigated (HPV16 prevalence in carcinoma tissue: 49.4%; odds ratio 3.02, 95% confidence interval 1.39-6.53). HPV-positive ESCC patients were generally younger than HPV-negative patients (P = 0.04). In addition, HPV infection was more common in cases of well-differentiated and shallower invasive depth.

CONCLUSIONS

Based on this new detection method, our findings reiterate the possibility that HPV infection (especially HPV16) may be involved in the etiology of esophageal carcinoma in the Kazakh populations and that HPV E6 gene positivity may be associated with prognosis of patients.

HPV-16 E6 promotes cell growth of esophageal cancer via downregulation of miR-125b and activation of Wnt/β-catenin signaling pathway

High-risk human papillomavirus (HPV) is a possible cause of esophageal cancer. However, the molecular pathogenesis of HPV-infected esophageal cancer remains unclear. The expression levels of some microRNAs including miR-125b have been negatively correlated with HPV infection, and miR-125b downregulation is associated with tumorigenesis. In addition, Wnt/β-catenin signaling pathway has been suggested to play an important role in esophageal cancer (EC). We examined miR-125b and Wnt/β-catenin signaling pathway in HPV-16 E6 promoted tumor progression in EC. HPV-16 E6 transfection decreased markedly the expression levels of miR-125b and promoted the colony formation in the Eca 109 and Kyse 150 cell lines, and restoration of miR-125b expression level antagonized the increased colony formation in HPV-16 E6 transfected cell lines. We also demonstrated that overexpression of E6 upregulated the Wnt/β-catenin signaling activity via modulating the multiple regulators including TLE1, GSK3β, and sFRP4. Overexpression of miR-125b restored the expression levels of these proteins. Expression of miR-125b was lower in HPV-16 E6 positive esophageal cancer tissues, and was negatively correlated with E6 mRNA levels. Our results indicate that HPV-16 E6 promotes tumorigenesis in EC via down-regulation of miR-125b, and this underlying mechanism may be involved in the activation of the Wnt/β-catenin signaling pathway.

Comprehensive Genomic Profiling of Advanced Esophageal Squamous Cell Carcinomas and Esophageal Adenocarcinomas Reveals Similarities and Differences

BACKGROUND

Esophageal squamous cell carcinomas (ESCCs) and esophageal adenocarcinomas (EACs) account for >95% of esophageal malignancies and represent a major global health burden. ESCC is the dominant histology globally but represents a minority of U.S. cases, with EAC accounting for the majority of U.S.

CASES

The patient outcomes for advanced ESCC and EAC are poor, and new therapeutic options are needed. Using a sensitive sequencing assay, we compared the genomic profiles of ESCC and EAC with attention to identification of therapeutically relevant genomic alterations.

METHODS

Next-generation sequencing-based comprehensive genomic profiling was performed on hybridization-captured, adaptor ligation-based libraries to a median coverage depth of >650× for all coding exons of 315 cancer-related genes plus selected introns from 28 genes frequently rearranged in cancer. Results from a single sample were evaluated for all classes of genomic alterations (GAs) including point mutations, short insertions and deletions, gene amplifications, homozygous deletions, and fusions/rearrangements. Clinically relevant genomic alterations (CRGAs) were defined as alterations linked to approved drugs and those under evaluation in mechanism-driven clinical trials.

RESULTS

There were no significant differences by sex for either tumor type, and the median age for all patients was 63 years. All ESCCs and EACs were at an advanced stage at the time of sequencing. All 71 ESCCs and 231 EACs featured GAs on profiling, with 522 GAs in ESCC (7.4 per sample) and 1,303 GAs in EAC (5.6 per sample). The frequency of clinically relevant GAs in ESCC was 94% (2.6 per sample) and 93% in EAC (2.7 per sample). CRGAs occurring more frequently in EAC included KRAS (23% EAC vs. 6% ESCC) and ERBB2 (23% EAC vs. 3% ESCC). ESCC samples were enriched for CRGA in PIK3CA (24% ESCC vs. 10% EAC), PTEN (11% ESCC vs. 4% EAC), and NOTCH1 (17% ESCC vs. 3% EAC). Other GAs that differed significantly between histologic tumor types included SMAD4 (14% EAC vs. 1% ESCC), RB1 (14% ESCC vs. 2% EAC), SOX2 (18% ESCC vs. 1% EAC), and NFE2L2 (24% ESCC vs. 1% EAC).

CONCLUSION

ESCC and EAC share similarly high frequencies of overall and clinically relevant genomic alterations; however, the profiles of genomic alterations in the two diseases differ widely, with KRAS and ERBB2 far more frequently altered in EAC compared with ESCC and with mammalian target of rapamycin (MTOR) pathway genes (PIK3CA and PTEN) and NOTCH1 more frequently altered in ESCC compared with EAC. Comprehensive genomic profiling highlights the promise of identifying clinically relevant genomic alterations in both ESCC and EAC and suggests new avenues for molecularly directed therapies in esophageal cancer.

Human papillomavirus tumor infection in esophageal squamous cell carcinoma

The association between human papillomavirus (HPV) and esophageal squamous cell carcinoma (ESCC) has been recognized for over three decades. Recently, multiple meta-analyses have drawn upon existing literature to assess the strength of the HPV-ESCC linkage. Here, we review these analyses and attempt to provide a clinically-relevant overview of HPV infection in ESCC. HPV-ESCC detection rates are highly variable across studies. Geographic location likely accounts for a majority of the variation in HPV prevalence, with high-incidence regions including Asia reporting significantly higher HPV-ESCC infection rates compared with low-incidence regions such as Europe, North America, and Oceania. Based on our examination of existing data, the current literature does not support the notion that HPV is a prominent carcinogen in ESCC. We conclude that there is no basis to change the current clinical approach to ESCC patients with respect to tumor HPV status.

Viruses, Other Pathogenic Microorganisms and Esophageal Cancer

BACKGROUND

Esophageal cancer (EC) is the eighth most prevalent malignant tumor and the sixth leading cause of cancer mortality throughout the world. Despite the technical developments in diagnosis and treatment, the 5-year survival rate is still low. The etiology of EC remains poorly understood; multiple risk factors may be involved and account for the great variation in EC incidence in different geographic regions.

SUMMARY

Infection with carcinogenetic pathogens has been proposed as a risk factor for EC. This review explores the recent studies on the association of human papillomavirus (HPV), Epstein-Barr virus (EBV), Helicobacter pylori and esophageal bacterial biota with EC.

KEY MESSAGE

Among the above-mentioned pathogens, HPV most likely contributes to esophageal squamous cell carcinoma (ESCC) in high-risk populations. New techniques are being applied to studies on the role of infection in EC, which will inevitably bring novel ideas to the field in the near future.

PRACTICAL IMPLICATIONS

Multiple meta-analyses support the finding of a higher HPV detection rate in regions associated with high risk for ESCC compared to low-risk areas. A potential role of HPV in the rise of esophageal adenocarcinoma (EAC) was proposed recently. However, further studies are required before a firm conclusion can be drawn. Less work has been done in studying the association between EBV and ESCC, and the results are quite controversial. H. pylori infection is found to be inversely related to EC, which is probably due to the reduced incidence of gastroesophageal reflux disease. Analysis of the esophageal bacterial biota revealed distinct clusters of bacteria in normal and diseased esophagi. A type II microbiome rich in Gram-negative bacteria potentially contributes to EAC by inducing chronic inflammation. Novel findings from such studies as these may benefit public health by justifying anti-infection measures to prevent EC.