Active HSV-1 immunization prevents the cocarcinogenic activity of HSV-1 in the oral cavity of hamsters

Herpes Simplex Virus Infection Presenting as a Piriform Sinus Mass

Evidence is accumulating that herpes simplex virus (HSV) infection is implicated in oncogenesis. HSV antigens have been observed in some oral cancers. We present the case of a 62-year-old man who presented with dysphagia, odynophagia, and dysphonia and who was found on computed tomography (CT) to have a mass in his piriform sinus. We suspected a malignancy, but histopathology of biopsy specimens revealed that the mass exhibited the classic signs of the HSV cytopathic effect, including the presence of intranuclear inclusion bodies, ballooning degeneration of epithelial cells, and a ground-glass appearance of some nuclei. The patient responded well to antiviral therapy, and posttherapy CT revealed that the mass had resolved completely. To the best of our knowledge, this is the first report in the literature of a case of HSV infection presenting as a piriform sinus mass.

Oral squamous cell carcinoma; from an hypothesis about a virus, to concern about possible sexual transmission

Nearly two decades ago, we produced the first evidence for the presence of viral nucleic acids in oral squamous cell carcinoma (OSCC) tissues, hypothesising that there may be a viral involvement in at least some OSCC. Subsequently, human papillomaviruses (HPV) in particular have been implicated in OSCC. Antibody responses to HPV are seen and HPV-DNA detected in tumors by us and many others, the virus being mainly HPV-16, the genotype associated with ano-genital cancer. HPV are seen by in situ hybridisation only in tumour and premalignant tissue but not in surrounding normal mucosa suggesting HPV has a causal relationship. HPV may also be integrated in the host genome, further suggesting a causal role. Studies of patients with OSCC have suggested possible sexual transmission of HPV. Recent studies have indicated that HPV may be aetiologically important particularly in some types of oropharyngeal cancer, at least in tonsillar carcinogenesis, and may represent an alternative pathway in carcinogenesis to the established factors of tobacco and alcohol. We have come a very long way in the two decades since our first suggestion of a viral aetiopathogenesis was greeted with incredulity, and data from on-going studies by the International Agency for Research on Cancer, Johns Hopkins Oncology Center and others are eagerly awaited.

Prevalence of herpes simplex virus in malignant laryngeal lesions

OBJECTIVE

To determine the prevalence of herpes simplex virus (HSV) in malignant laryngeal lesions.

STUDY DESIGN

Retrospective review.

MATERIALS AND METHODS

Paraffin-embedded, histologically confirmed specimens containing benign laryngeal lesions, squamous cell carcinoma of the larynx, and squamous cell carcinoma of the oral cavity were identified from archived surgical specimens. Biopsies of normal-appearing oral cavity tissue were also obtained from fresh-frozen cadavers. These tissues were analyzed for the presence of HSV DNA using polymerase chain reaction techniques. Patient charts were reviewed for patient demographics, risk factors, stage, clinical course, treatment, and outcome.

RESULTS

HSV was detected in nine laryngeal squamous cell carcinomas (75%) and in none of the benign laryngeal lesions (P = .0001). HSV was also found in three oral cavity squamous cell carcinomas (25%) and in none of the controls (P = .049).

CONCLUSION

HSV is more prevalent in squamous cell carcinoma of the larynx and oral cavity than in their respective control groups, suggesting a role for carcinogenesis. HSV is more prevalent in squamous cell carcinoma of the larynx than of the oral cavity. Further studies to determine the role of HSV as a cocarcinogen and its interrelationship with other environmental factors in laryngeal cancer are warranted.

Attenuation of the natural course of herpes simplex virus infection in human oral epithelial cell cultures by smokeless tobacco extracts suggests the possibility of a synergistic mechanism for carcinogenesis

High prevalence of both tobacco use and latent herpes simplex virus type 1 suggests the opportunity for synergism between these agents as cocarcinogens. In this study, postprimary human oral epithelial cell cultures were infected with herpes simplex virus type 1 pretreated with 2% extracts of either loose leaf, moist, or dry snuffs. Cultures were subsequently periodically exposed to the tobacco. Parameters measured included percentage of cultures undergoing active virus production, onset and time course of cytopathic effects, and concentration of virus released into the media over time. Results showed inhibition of both herpes simplex virus-mediated cell lysis and viral replication by tobacco extracts. This is the first time that these phenomena have been demonstrated in normal human oral epithelial cells. The work described here provides evidence to support a hypothesis that herpes simplex virus type 1 and smokeless tobacco may act synergistically in oral carcinogenesis.

Oncogenes, tumor suppressors and viruses in oral squamous carcinoma

The pathogenesis of oral squamous cell carcinoma involves recognised carcinogens in tobacco and/or alcohol but other factors, including viruses, may also have a role. This paper reviews the gene changes revealed in oral carcinoma, the evidence implicating viruses, and mechanisms whereby viruses may affect gene function.

Viruses in the aetiology of oral carcinoma? Examination of the evidence

This paper examines the evidence for an aetiological role for viruses in the development of oral carcinoma. Several viruses have been sought in oral cancer and evidence found for some, particularly herpes simplex and human papillomavirus. However, the evidence also suggests that these viruses are ubiquitous agents and a number of criteria must be met before these potentially oncogenic agents can reliably be implicated in human carcinogenesis. In contrast, there is no evidence that viruses such as adenovirus, Epstein-Barr virus, and retroviruses play any role in oral carcinogenesis.

Viruses and chronic disorders involving the human oral mucosa

Viruses have been implicated in the etiology of several chronic disorders of the oral mucosa. Most of these associations have been with DNA viruses, particularly certain herpesviruses, which are associated, for example, with some cases of erythema multiforme and with hairy leukoplakia. Papillomaviruses are associated with various papillomatous lesions, focal epithelial hyperplasia, and possibly with some carcinomas. Viruses may possibly be associated with recurrent aphthae, Behçet's syndrome, and some dermatoses. The literature concerning these possible associations is reviewed. However, much more research needs to be done before the full story of viral associations with oral mucosal disorders can be written.