Human papillomavirus infection and loss of heterozygosity in esophageal squamous cell carcinoma

Overview of Risk Factors for Esophageal Squamous Cell Carcinoma in China

(1) Background: China has the highest esophageal squamous cell carcinoma (ESCC) incidence areas in the world, with some areas of incidence over 100 per 100,000. Despite extensive public health efforts, its etiology is still poorly understood. This study aims to review and summarize past research into potential etiologic factors for ESCC in China. (2) Methods: Relevant observational and intervention studies were systematically extracted from four databases using key terms, reviewed using Rayyan software, and summarized into Excel tables. (3) Results: Among the 207 studies included in this review, 129 studies were focused on genetic etiologic factors, followed by 22 studies focused on dietary-related factors, 19 studies focused on HPV-related factors, and 37 studies focused on other factors. (4) Conclusions: ESCC in China involves a variety of factors including genetic variations, gene-environment interactions, dietary factors like alcohol, tobacco use, pickled vegetables, and salted meat, dietary behavior such as hot food/drink consumption, infections like HPV, poor oral health, gastric atrophy, and socioeconomic factors. Public health measures should prioritize genetic screening for relevant polymorphisms, conduct comprehensive investigations into environmental, dietary, and HPV influences, enhance oral health education, and consider socioeconomic factors overall as integral strategies to reduce ESCC in high-risk areas of China.

A viral map of gastrointestinal cancers

Cancers of the gastrointestinal tract (GIT) are expected to account for approximately 20% of all cancers in 2017. Apart from their high incidence, GIT cancers show high mortality rates, placing these malignancies among the most prominent public health issues of our time. Cancers of the GIT are the result of a complex interplay between host genetic factors and environmental factors and frequently arise in the context of a continued active inflammatory response. Several tumor viruses are able to elicit such chronic inflammatory responses. In fact, several viruses have an impact on GIT tumor initiation and progression, as well as on patients' response to therapy and prognosis, through direct and indirect mechanisms. In this review, we have gathered information on different viruses' rates of infection, viral-driven specific carcinogenesis mechanisms and viral-related impact on the prognosis of cancers of the GIT (specifically in organs that have an interface with the environment - esophagus, stomach, intestines and anus). Overall, while some viral infections show a strong causal relation with specific gastrointestinal cancers, these represent a relatively small fraction of GIT malignancies. Other types of cancer, like Esophageal Squamous Cell Carcinoma, require further studies to confirm the carcinogenic role of some viral agents.

Association between human papillomavirus (HPV) and oesophageal squamous cell carcinoma: a meta-analysis

SUMMARY

The oncogenic potential of human papillomaviruses (HPV) is well known in the context of cervical carcinoma; however, their role in the development of oesophageal squamous cell carcinoma (OSCC) is less clear. We aimed to determine the extent of the association between HPV infection and OSCC. A comprehensive literature search found 132 studies addressing HPV and OSCC in human cases, and a meta-analysis was performed using a random-effects model. There was evidence of an increased risk of OSCC in patients with HPV infection [odds ratio (OR) 2·69, 95% confidence interval (CI) 2·05-3·54]. The prevalence of HPV in OSCC was found to be 24·8%. There was an increased risk associated with HPV-16 infection (OR 2·35, 95% CI 1·73-3·19). Subgroup analyses showed geographical variance, with Asia (OR 2·94, 95% CI 2·16-4·00), and particularly China (OR 2·85, 95% CI 2·05-3·96) being high-risk areas. Our results confirm an increase in HPV infection in OSCC cases.

Systematic review with meta-analysis: the association between human papillomavirus infection and oesophageal cancer

BACKGROUND

Human papillomavirus (HPV) infection might be one of the potential risk factors for oesophageal cancer. However, the previous epidemiological findings were heterogeneous.

AIM

To explore the association between HPV infection and oesophageal cancer risk by means of meta-analysis.

METHODS

Studies on HPV infection and oesophageal cancer were identified, the prevalence of HPV infection and its association with oesophageal cancer risk were quantitatively summarised by meta-analysis.

RESULTS

A total of 8990 oesophageal squamous cell carcinoma (SCC) patients and 174 oesophageal adenocarcinomas patients were evaluated from 76 included studies. Summarised HPV prevalence in oesophageal SCC was 22.2% [95% confidence interval (CI), 18.3-26.7%], HPV-16 was the most frequently observed subtype with a summarised prevalence of 11.4% (95% CI: 8.2-15.7%). With respect to oesophageal adenocarcinoma, HPV prevalence was 35.0% (95% CI, 13.2-65.7%) and HPV-16 prevalence was 11.4% (95% CI: 8.2-15.7%). Due to the limited number of included studies on oesophageal adenocarcinoma, association analyses were performed to oesophageal SCC only. Significant association was observed between HPV infection and oesophageal SCC with a summarised odds ratio of 3.32 (95% CI, 2.26-4.87). According to HPV-16, the strength of the association was found to be 3.52 (95% CI, 2.04-6.07).

CONCLUSIONS

Human papillomavirus infection was observed to be associated with an increased risk of oesophageal SCC in this meta-analysis. However, due to the evident heterogeneity observed between the included studies and the strength of the association not as strong as observed for cervical cancer and laryngeal cancer, further studies are needed to clarify the relation and its underlying mechanisms.

Role of human papillomaviruses in esophageal squamous cell carcinoma

Esophageal cancer (EC) is responsible for almost half a million deaths worldwide annually and has a multifactorial etiology, which may account for its geographical variation in incidence. In the last 30 years the potential of human papillomaviruses (HPV) as oncogenes or co-factors in the tumorigenic process of esophageal squamous cell carcinoma (ESCC) has been widely studied. While the etiology of HPV in cervical and certain other anogenital and aerodigestive cancers has been established, results regarding its role in EC have been largely inconclusive. A causal association can be evaluated only with a case-control study, where normal controls are compared to ESCC cases for the presence of HPV. We reviewed all studies investigating ESCC tissue for HPV DNA and identified 139 that met our inclusion criteria, of which only 22 were case-control studies. Our results support previous findings of higher levels of HPV detection in high-risk ESCC regions than in areas of low risk. In addition, we confirm that the role of HPV in ESCC remains unclear, despite an accumulation of studies on the subject. The variations in investigative technique, study design and sample types tested may account for the lack of consistency in results. There is a need for a meta-analysis of all case-control studies to date, and for large, well-designed case-control studies with adequate power to investigate the association. The potential benefits of prophylactic HPV vaccines could be evaluated if HPV is identified as an etiological factor in EC, highlighting the need for further research in this area.