Detection of human papillomavirus DNA in biopsies of human oral tissue

The correlation between human papillomavirus and oral lichen planus: A systematic review of the literature

INTRODUCTION

Oral lichen planus (OLP) is a chronic inflammatory disorder with cell-induced immunopathological responses and is considered a potential malignancy disorder in the oral cavity. Due to the high prevalence of OLP as well as the potential for malignancy, human papillomaviruses (HPVs) may play an important role in it. Although previous studies have explored the possible relationship between HPV and OLP, the findings have been conflicting and nonconclusive. This study aims to review the studies that investigated HPV-16 and HPV-18 in OLP.

METHODS AND MATERIALS

The research protocol followed the Preferred Reporting Items for Systematic Reviews (PRISMA2020) checklist. The online databases Pubmed, Scopus, Embase, Google Scholar, and Cochrane were searched using the following individual keywords: "OLP" OR "Oral Lichen Planus" OR "HPV" OR "Human Papillomavirus." The search strategy resulted in the selection of 80 articles. The articles were evaluated, and after duplication removal, 53 abstracts were reviewed, resulting in the selection of 25 studies according to inclusion and exclusion criteria. The risk of bias assessment was done by using the Modified Newcastle-Ottawa quality assessment scale. The overall prevalence of HPV in OLP lesions varied from 2.7% to 70%, depending on the type of diagnostic method used.

CONCLUSION

Despite the studies conducted on the relationship between OLP and HPV infection, there is still no conclusive evidence that HPV can play a role in the etiopathogenesis of OLP, either in clinical manifestations or in the malignant transformation of lesions.

Correlation between Oral Lichen Planus and Viral Infections Other Than HCV: A Systematic Review

OBJECTIVES

This review aimed to evaluate the correlation between viral infections (HPV, EBV, HSV-1, CMV) other than HCV and oral lichen planus to assess if there is sufficient evidence to establish if these viruses can play a role in the etiopathogenesis of the disease.

MATERIALS AND METHODS

We reviewed the literature using different search engines (PubMed, ISI Web of Science, and the Cochrane Library), employing MeSH terms such as "oral lichen planus" and "OLP" in conjunction with other terms. We utilized the Population, Intervention, Comparison, Outcomes, and Study design (PICOS) method to define our study eligibility criteria.

RESULTS

A total of 43 articles of the 1219 results initially screened were included in the study. We allocated the 43 selected items into four groups, according to each related virus: HPV, EBV, HSV-1, and CMV.

CONCLUSIONS

Heterogeneous results neither confirm nor exclude a direct correlation between the investigated viral infections and oral lichen planus etiopathogenesis and its feasible malignant transformation. Many viral agents can cause oral lesions and act as cancerizing agents. Future studies could be desirable to produce comparable statistical analyses and enhance the quantity and quality of the outcomes to promote the translation of research into clinical practice.

Oral lichen planus: a microbiologist point of view

Oral lichen planus (OLP) is a chronic disease of uncertain etiology, although it is generally considered as an immune-mediated disease that affects the mucous membranes and even the skin and nails. Over the years, this disease was attributed to a variety of causes, including different types of microorganisms. This review analyzes the present state of the art of the disease, from a microbiological point of view, while considering whether or not the possibility of a microbial origin for the disease can be supported. From the evidence presented here, OLP should be considered an immunological disease, as it was initially proposed, as opposed to an illness of microbiological origin. The different microorganisms so far described as putative disease-causing agents do not fulfill Koch’s postulates; they are, actually, not the cause, but a result of the disease that provides the right circumstances for microbial colonization. This means that, at this stage, and unless new data becomes available, no microorganism can be envisaged as the causative agent of lichen planus.

Detection of Human Papillomavirus 33 in Erosive Oral Lichen Planus

Background: A correlation is suggested between oral lichen planus (OLP) and the human papillomavirus (HPV) with possible malignant transformation potential in OLP. Objectives: The present study aimed at evaluating the prevalence of HPV-16 and HPV-18 as the most recognized oncogenic subtypes and relatively recently introduced subtype HPV33 in OLP samples. Methods: This retrospective study was carried out on 32 OLP samples (consisting of 12 reticular and 20 erosive forms) and 20 healthy oral mucosa samples. Polymerase chain reaction (PCR) was undertaken to identify HPV Deoxyribonucleic Acid (DNA). Subsequently, the samples positive for HPV DNA underwent PCR analysis again with the specific primers. The data were analyzed statistically by Fisher’s exact test regarding the significance level of lower than 0.05. Results: Eight out of 32 OLP samples (25%) and none of the 20 normal mucosa samples (0%) exhibited HPV DNA. The presence of HPV in the OLP group was significantly higher than that in the normal mucosa (P = 0.014). Also, all the samples that exhibited HPV DNA were registered as the erosive form. Besides, one sample (3.12%) exhibited the 873-bp band, which was attributed to HPV-18, and 7 samples (21.87%) exhibited the 300-bp band, which was attributed to HPV-33. Conclusions: Based on the recent findings in the current study of the Iranian population, the presence of high-risk HPV subtypes, whether primarily or as a secondary infection, can suggest the malignant transformation potential for the studied OLP samples. The exclusive presence of these subtypes in the erosive type of this lesion and the noticeable presence of HPV-33 might reflect this issue’s importance. However, further studies are necessary to evaluate the possibility of a higher proliferation rate of HPV in erosive lichen planus and identify its possible malignant transformation mechanism.

Association of Human Papillomavirus With Oral Lichen Planus and Oral Leukoplakia: A Meta-analysis

OBJECTIVES

To estimate the association of human papillomavirus (HPV) infection with oral lichen planus (OLP) and oral leukoplakia (OLK), and determine risk cofactors.

STUDY DESIGN

Seven databases were searched for case-control or cross-sectional studies of OLP and OLK with healthy controls, published between 1976 and 2020. The Meta package of R software was applied to calculate the pooled odds ratios (OR) and 95% confidence interval (CI).

RESULTS

Thirty-six articles were finally included. OLP and OLK cases had a higher association with HPV infection than controls (OLP: OR: 4.91, 95% CI: 2.76-8.72; OLK: OR: 2.51, 95% CI: 1.55-4.07). In subgroup analyses, the OR of HPV infection was higher with erosive lesions than with nonerosive lesions (OLP: OR: 5.36 and 3.47, respectively; OLK: OR: 3.34 and 3.21, respectively). Oral lesions were more strongly associated with HPV16/18 than with HPV6/11 (OLP: OR: 7.84 and 1.42, respectively; OLK: OR: 6.05 and 1.87, respectively) and varied by geographic region (OLP: OR: 4.01-7.02; OLK: OR: 1.46-27.13).

CONCLUSIONS

Oral HPV infection, particularly infection with HPV 16/18, was strongly associated with OLP and OLK. Risk cofactors included erosive lesions and geographic region.

The microbiology of oral lichen planus: Is microbial infection the cause of oral lichen planus?

Oral lichen planus (OLP) is a variant of lichen planus (LP), a common chronic mucocutaneous inflammatory disease. Cutaneous lesions of LP are self-limiting, but OLP lesions are non-remissive, alternating periods of exacerbation and quiescence, and only symptomatic treatments exist for OLP. The precise etiology and pathogenesis of OLP are hardly understood, which is a major obstacle to the development of new therapeutics for this disease. OLP is considered a T-cell-mediated inflammatory disease. Although various antigens have been considered, what actually triggers the inflammatory response of T cells is unknown. Suggested predisposing factors include genetic factors, stress, trauma, and infection. The aim of this review was to determine whether microbial infection can cause OLP. We first reviewed the association between OLP and microbial factors, including viral, fungal, and bacterial infections. In addition, each microbial factor associated with OLP was assessed by modified guidelines of Fredricks and Relman to determine whether it establishes a causal relationship. In conclusion, no microbial factor yet fulfills the guidelines to establish the causality of OLP. By focusing on the unclarified issues, however, the potential roles of microbial factors in the pathogenesis of OLP will be soon elucidated.

High risk human papillomavirus in the periodontium : A case control study

BACKGROUND

Human papilloma viruses (HPVs) are small DNA viruses that have been identified in periodontal pocket as well as gingival sulcus. High risk HPVs are also associated with a subset of head and neck carcinomas. It is thought that the periodontium could be a reservoir for HPV.

AIMS

1. Detection of Human Papilloma virus (HPV) in periodontal pocket as well as gingival of patients having localized chronic periodontitis and gingival sulcus of periodontally healthy subjects. 2. Quantitative estimation of E6 and E7 mRNA in subjects showing presence of HPV3. To assess whether periodontal pocket is a reservoir for HPV.

SETTINGS AND DESIGN

This case-control study included 30 subjects with localized chronic Periodontitis (cases) and 30 periodontally healthy subjects (controls). Two samples were taken from cases, one from periodontal pocket and one from gingival sulcus and one sample was taken from controls.

METHODS AND MATERIALS

Samples were collected in the form of pocket scrapings and gingival sulcus scrapings from cases and controls respectively. These samples were sent in storage media for identification and estimation of E6/E7 mRNA of HPV using in situ hybridization and flow cytometry.

STATISTICAL ANALYSIS

Statistical analysis was done by using, mean, percentage and Chi Square test. A statistical package SPSS version 13.0 was used to analyze the data. P value < 0.05 was considered as statistically significant.

RESULTS

pocket samples as well as sulcus samples for both cases and controls were found to contain HPV E6/E7 mRNAInterpretation and.

CONCLUSION

Presence of HPV E6/E7 mRNA in periodontium supports the hypothesis that periodontal tissues serve as a reservoir for latent HPV and there may be a synergy between oral cancer, periodontitis and HPV. However prospective studies are required to further explore this link.

HPV in Head and Neck Cancer-30 Years of History

The interesting history of papillomavirus (PV) research has been reviewed before. The history of human papillomavirus (HPV) in head and neck region starts in 1901 when the contagious transmission of warty lesions into the mouth via oral sex was described, although the confirmation of their viral etiology had to wait until 1907. Ullman was the first to associate the human wart virus with laryngeal warts. Parsons and Kidd described the natural history of oral PV infections in rabbits already in 1942, but these findings were corroborated in humans only recently. Koilocytotic atypia described by Koss and Durfee in 1956 was recognized as a sign of HPV infection in cervical precancer lesions only in 1976-1977 (Meisels and Fortin; Purola and Savia). This prompted systematic surveys of head and neck lesions for the detection of koilocytosis since the late 1970s, and the authors of this communication were the first to propose the HPV involvement in a subgroup of head and neck cancers. Brandsma and Abramson demonstrated HPV16 DNA in tonsillar SCCs in 1989. Since the early 2000s, HPV research of head and neck squamous cell carcinomas (HNSCC) has made impressive progress, confirming that the specific anatomic site plays a key role in determining the susceptibility to HPV infection. The most likely cancer sites associated with HPV are the base of the tongue and palatine tonsils, followed by oral cavity, larynx, and sinonasal mucosa. There is substantial geographic variation in HPV association with HNSCC. Patients with HPV-associated HNSCC are younger, and survival is better than in the absence of HPV.

The Magnitude of the Association between Human Papillomavirus and Oral Lichen Planus: A Meta-Analysis

Background

The role of human papilloma virus (HPV) in oral lichen planus (OLP) is controversial.

Objectives

The primary aim of the current study is to calculate the pooled risk estimates of HPV infection in OLP when compared with healthy controls.

Methods

Bibliographic searches were conducted in three electronic databases. Articles on the association between HPV and OLP were selected from case-control studies or cross-sectional studies, following predefined criteria. Pooled data were analyzed by calculating odds ratios (OR) and 95% confidence interval (CI).

Results

Of the 233 publications identified, 22 case-control studies met the inclusion criteria. Collectively, 835 cases and 734 controls were available for analysis. The summary estimate showed that OLP patients have significantly higher HPV prevalence (OR: 6.83; 95% CI: 4.15–11.27) than healthy controls. In subgroup analyses, the association of HPV and OLP varied significantly by geographic populations. The ORs ranged from 2.43 to 132.04. The correlation of HPV and erosive-atrophic oral lichen planus (EA-OLP) (OR: 9.34) was comparable and well above that of HPV and non-EA-OLP (OR: 4.32). Among HPV genotypes, HPV 16 showed an extremely strong association with OLP (OR: 11.27), and HPV 18 showed a relatively strong one (OR: 6.54).

Conclusion

In conclusion, a significant association was found between HPV and OLP. The strength of the association varied across geographic populations, clinical types of OLP, and HPV genotypes. The results suggest that HPV might play an important causal role in OLP and in its malignant to progression.

Emerging and changing viral diseases in the new millennium

Most viral infections encountered in resource‐rich countries are relatively trivial and transient with perhaps fever, malaise, myalgia, rash (exanthema) and sometimes mucosal manifestations (enanthema), including oral in some. However, the apparent benignity may be illusory as some viral infections have unexpected consequences – such as the oncogenicity of some herpesviruses and human papillomaviruses. Infections are transmitted from various human or animal vectors, especially by close proximity, and the increasing movements of peoples across the globe, mean that infections hitherto confined largely to the tropics now appear worldwide. Global warming also increases the range of movement of vectors such as mosquitoes. Thus recent decades have seen a most dramatic change with the emergence globally also of new viral infections – notably human immunodeficiency viruses (HIV) – and the appearance of some other dangerous and sometimes lethal infections formerly seen mainly in, and reported from, resource‐poor areas especially in parts of Asia, Latin America and Africa. This study offers a brief update of the most salient new aspects of the important viral infections, especially those with known orofacial manifestations or other implications for oral health care.

Association of Human Papilloma Virus 16 Infection and p53 Polymorphism among Tobacco using Oral Leukoplakia Patients: A Clinicopathologic and Genotypic Study

BACKGROUND

Human papillomavirus (HPV) and p53 alterations are speculated to play a role in carcinogenesis. This study was carried out to find out the association of HPV and p53 with precancerous lesions of the oral cavity such as leukoplakia: The objective of this study was to find the association among human papilloma virus (HPV) 16 infections and p53 polymorphism in tobacco using the oral leukoplakia patients.

METHODS

A total of 91 oral leukoplakia patients and 100 controls were randomly selected from the out-patient department of a tertiary care dental hospital of North-east India. Blood samples were drawn incisional biopsy was performed from the lesion proper and the tissue was processed for histopathological grading. Cytological smears were taken from the lesional site of leukoplakia patients and buccal mucosa of controls. The rate of HPV infection and p53 polymorphism was detected with the help of polymerase chain reaction, gel electrophoresis and deoxyribonucleic acid sequencing.

RESULTS

The rate of HPV 16 infection was found significantly high in the oral leukoplakia patients. No particular p53 genotype at exon 4 of codon 72 was found to be associated with oral leukoplakia, but "C" allele (proline) at exon 4 of codon 72 was significantly raised in these patients.

CONCLUSIONS

Oral leukoplakia, a well-known pre-cancerous lesion, has been shown to be associated with tobacco, but certain other factors like HPV infection and p53 polymorphism may play an important role in its development.

The importance of a proper selection area to be biopsied in nodular leukoplakia: a case report

Nodular leukoplakia is a non-homogeneous type of oral leukoplakia presenting a white surface with verrucous, nodular, ulcerated or erythematous features with a greater risk of malignant transformation when compared to the homogeneous type. Common sites of involvement include lip commissures, buccal mucosa and soft palate. It is often associated with epithelial dysplasia or carcinoma and requires detailed microscopic assessment and regular follow-up. The importance of a proper selection of the area to be biopsied and the close teamwork between a dentist and oral pathologist is the basis of providing an accurate final diagnosis.

Evidences suggesting involvement of viruses in oral squamous cell carcinoma

Oral cancer is one of the most common cancers and it constitutes a major health problem particularly in developing countries. Oral squamous cell carcinoma (OSCC) represents the most frequent of all oral neoplasms. Several risk factors have been well characterized to be associated with OSCC with substantial evidences. The etiology of OSCC is complex and involves many factors. The most clearly defined potential factors are smoking and alcohol, which substantially increase the risk of OSCC. However, despite this clear association, a substantial proportion of patients develop OSCC without exposure to them, emphasizing the role of other risk factors such as genetic susceptibility and oncogenic viruses. Some viruses are strongly associated with OSCC while the association of others is less frequent and may depend on cofactors for their carcinogenic effects. Therefore, the exact role of viruses must be evaluated with care in order to improve the diagnosis and treatment of OSCC. Although a viral association within a subset of OSCC has been shown, the molecular and histopathological characteristics of these tumors have yet to be clearly defined.

Detection of high-risk HPV in head and neck squamous cell carcinomas: comparison of chromogenic in situ hybridization and a reverse line blot method

Human papillomaviruses (HPVs) have been etiologically linked to a subset of head and neck squamous cell carcinomas (HNSCCs), generally arising in young patients without a history of tobacco smoking or alcohol use. These tumors typically lack mutations in TP53 and may show enhanced sensitivity to chemoradiation therapy with a correspondingly better overall prognosis. The determination of the HPV status in HNSCC therefore has therapeutic implications. We compared the Ventana ISH iView Blue Plus Detection Kit in situ hybridization (ISH) system and the Roche Linear Array HPV Genotyping Test for the detection of HPV in 98 formalin-fixed, paraffin-embedded HNSCC samples. A moderate concordance rate (70.4%) was observed between ISH and the Linear Array assays. ISH detected HPV in 39.8% of cases, whereas Linear Array detected HPV in 57.1% of cases. Sensitivity and specificity of ISH for detecting HPV in HNSCC specimens were determined to be 58.9% and 85.7%, respectively, using the Linear Array as the method of comparison (McNemar test, P=0.003). ISH offers the advantage of visual cell-type localization of viral infection but overall it is less sensitive than the polymerase chain reaction-based detection of HPV in HNSCC.

Human papillomavirus subtypes in oral lesions compared to healthy oral mucosa

BACKGROUND

Human papillomaviruses (HPV) are involved in the etiology of cervix cancer, but it is still unclear whether they play a role in related oral lesions.

OBJECTIVES

The presence of HPV in oral leukoplakia biopsies (n=50) and oral squamous carcinoma biopsies (n=50) was compared to normal oral mucosa swabs (n=50) for the purpose of indicating a possible etiological role for the virus.

STUDY DESIGN

DNA was extracted from tissue biopsies and from mucosa swabs of control samples. Nested PCR was performed with primers targeting conserved sequences within the capsid gene L1. PCR products were sequenced to identify the HPV genotype.

RESULT

The results reveal a profile of low-risk HPV genotypes in oral leukoplakia similar to that in healthy controls, while HPV was less frequently observed in oral squamous carcinoma.

CONCLUSIONS

HPV does not seem to represent an important causal factor for the development of oral leukoplakia or oral squamous carcinoma.

Human papillomavirus types 16 and 18 in epithelial dysplasia of oral cavity and oropharynx: a meta-analysis, 1985-2010

Human papillomavirus (HPV) types 16 and 18 are causally related to a sub-set of oral cavity and oropharyngeal squamous cell cancers. However, a clear estimate of the prevalence of HPV-16/18 in oral cavity and oropharyngeal dysplasia (OOPD) is not available. This literature review and meta-analysis was conducted to provide a prevalence estimate for HPV-16/18 in OOPD. Twenty-two studies that reported prevalence of HPV-16 and/or 18 in 458 OOPD lesions were analyzed. Meta-analysis was used to evaluate the prevalence of HPV-16/18 and logistic regression was used for stratified analysis by age, gender, and histological grade. The overall prevalence of HPV-16/18 in OOPD lesions was 24.5% [95% confidence interval (CI), 16.4-36.7%)]. The individual prevalence for HPV-16 alone was 24.4%. The prevalence of HPV-16/18 in oral cavity lesions alone was 25.3% (95% CI, 14.2-45.2%). The odds of detection of HPV-16/18 in dysplastic lesions in males were twice that of females [odds ratio (OR), 2.44]. HPV-16/18 were 3 times more common in dysplastic lesions (OR, 3.29; 95% CI, 1.95-5.53%) and invasive cancers (OR, 3.43; 95% CI, 2.07-5.69%), when compared to normal biopsies. There was no significant difference in HPV-16/18 rates between dysplastic lesions and cancers or between mild, moderate or severe dysplastic lesions. This meta-analysis provides a quantification of the prevalence of HPV types 16/18 in OOPD lesions. These results also support the assumption that HPV-16/18 infection occurs during the early phase of the oral cavity and oropharyngeal carcinogenesis.

Human papillomaviruses in oral carcinoma and oral potentially malignant disorders: a systematic review

OBJECTIVES

Human papillomavirus (HPV) in oral carcinoma (OSCC) and potentially malignant disorders (OPMD) is controversial. The primary aim was to calculate pooled risk estimates for the association of HPV with OSCC and OPMD when compared with healthy oral mucosa as controls. We also examined the effects of sampling techniques on HPV detection rates.

METHODS

Systematic review was performed using PubMed (January 1966-September 2010) and EMBASE (January 1990-September 2010). Eligible studies included randomized controlled, cohort and cross-sectional studies. Pooled data were analysed by calculating odds ratios, using a random effects model. Risk of bias was based on characteristics of study group, appropriateness of the control group and prospective design.

RESULTS

Of the 1121 publications identified, 39 cross-sectional studies met the inclusion criteria. Collectively, 1885 cases and 2248 controls of OSCC and 956 cases and 675 controls of OPMD were available for analysis. Significant association was found between pooled HPV-DNA detection and OSCC (OR = 3.98; 95% CI: 2.62-6.02) and even for HPV16 only (OR = 3.86; 95% CI: 2.16-6.86). HPV was also associated with OPMD (OR = 3.87; 95% CI: 2.87-5.21). In a subgroup analysis of OPMD, HPV was also associated with oral leukoplakia (OR = 4.03; 95% CI: 2.34-6.92), oral lichen planus (OR = 5.12; 95% CI: 2.40-10.93), and epithelial dysplasia (OR = 5.10; 95% CI: 2.03-12.80).

CONCLUSIONS

The results suggest a potentially important causal association between HPV and OSCC and OPMD.

Contemporary concepts in the diagnosis of oral cancer and precancer

This article addresses several issues in the approach to diagnosis of oral cancer. The term oral cancer is clarified. Key aspects of the biologic basis of development of oral cancer and the known risk factors associated with the disease are summarized. The clinical presentation of oral cancers and precancerous lesions and their histopathologic correlates is discussed. The importance of conventional tissue biopsy as the prevailing gold standard for diagnosis is emphasized. Other current technologies available for detecting and diagnosing oral cancer and premalignant lesions are acknowledged, and their respective strengths and weaknesses are discussed.

Human papillomavirus in cervical and head-and-neck cancer

Cervical cancer is a major cause of cancer mortality in women worldwide and is initiated by infection with high-risk human papillomaviruses (HPVs). High-risk HPVs, especially HPV-16, are associated with other anogenital cancers and a subgroup of head-and-neck cancers. Indeed, HPV infection could account for the development of head-and-neck cancer in certain individuals that lack the classical risk factors for this disease (tobacco and alcohol abuse). This Review summarizes the main events of the HPV life cycle, the functions of the viral proteins, and the implications of HPV infection on their hosts, with an emphasis on carcinogenic mechanisms and disease outcomes in head-and-neck cancer. The demonstration that HPVs have a role in human carcinogenesis has allowed the development of preventive and therapeutic strategies aimed at reducing the incidence and mortality of HPV-associated cancers.

Heat-shock protein expression and topical treatment with tacrolimus in oral lichen planus: an immunohistochemical study

Oral lichen planus (OLP) is a chronic inflammatory mucosal disease of unknown etiology. Usually asymptomatic, the disorder is occasionally complicated by extensive painful erosions. Topical corticosteroids are the mainstay of treatment, but a new topical therapy with tacrolimus has been described previously. The aim of the current study was to examine the expression of heat-shock protein 70 (HSP70) in biopsy specimens from 11 OLP lesions before and after topical treatment with tacrolimus. Immunostaining was performed with anti-HSP70 antibody as the primary layer. Clinically, there was a rapid improvement with topical tacrolimus treatment in 10 out of the 11 patients. The moderate increase in HSP70 expression after treatment with tacrolimus was not significant. It was concluded that topical tacrolimus has no effect on the expression of HSP70 in OLP.

Cell cycle dysregulation in oral cancer

The dysregulation of the molecular events governing cell cycle control is emerging as a central theme of oral carcinogenesis. Regulatory pathways responding to extracellular signaling or intracellular stress and DNA damage converge on the cell cycle apparatus. Abrogation of mitogenic and anti-mitogenic response regulatory proteins, such as the retinoblastoma tumor suppressor protein (pRB), cyclin D1, cyclin-dependent kinase (CDK) 6, and CDK inhibitors (p21(WAF1/CIP1), p27(KIP1), and p16(INK4a)), occur frequently in human oral cancers. Cellular responses to metabolic stress or genomic damage through p53 and related pathways that block cell cycle progression are also altered during oral carcinogenesis. In addition, new pathways and cell cycle regulatory proteins, such as p12(DOC-1), are being discovered. The multistep process of oral carcinogenesis likely involves functional alteration of cell cycle regulatory members combined with escape from cellular senescence and apoptotic signaling pathways. Detailing the molecular alterations and understanding the functional consequences of the dysregulation of the cell cycle apparatus in the malignant oral keratinocyte will uncover novel diagnostic and therapeutic approaches.

Human papilloma virus in squamous carcinoma of the head and neck: a study of cases in south east Scotland

Several studies have found human papillomavirus virus (HPV) in tissue from head and neck squamous cell carcinomas (HNSCCs), although the number of positive cases varies greatly from study to study. The extent and molecular epidemiology of HPV in HNSCC were assessed within cases drawn from southeast Scotland by performing broad-spectrum, real-time HPV polymerase chain reaction (PCR) on DNA extracted from 100 cases of HNSCC in formalin-fixed, paraffin wax-embedded material. All HPV-positive specimens were genotyped and sampled by laser capture microdissection. Pure samples of tumour, and, where possible, dysplastic and normal epithelium were then submitted for further HPV PCR and genotyping to investigate the sensitivity of the technique in small tissue samples. 10 of 100 cases tested positive for HPV, with 8 of these being derived from Waldeyer's ring. HPV DNA was found in adjacent epithelium in two of four cases where this was available. These findings confirm that HPV is likely to be involved in a subset of HNSCC in this population and that successful amplification of HPV nucleic acid is possible even using small amounts of paraffin wax-embedded tissue.

Human papillomavirus-16 in oral squamous cell carcinoma: Clinical correlates and 5-year survival

We examined 66 oral squamous cell carcinomas (OSCCs) for human papillomavirus-16 (HPV-16) infection to evaluate its prognostic significance. Cox regression analysis of 5-year survival demonstrated that patients without nodal metastasis or with intratumoural HPV-16 showed better prognoses compared with each counterpart. In Kaplan-Meier survival analysis, nodal status but not HPV-16 status was statistically significant. The 5-year survival rate of HPV-16 positive patients without nodal metastasis (94%) was extremely high, compared with that of HPV-16 negative patients with nodal metastasis (25%). These results suggest that HPV-16 status as well as nodal status may provide prognostic significance in patients with OSCC.

MICA and MICB overexpression in oral squamous cell carcinoma

BACKGROUND

The concentration of MICA in serum seems be a good candidate marker in cancer. Previous studies from our laboratory have shown that the polymorphic MIC gene may confer a risk for oral squamous cell carcinoma (OSCC). The study investigated the expression levels of MICA and MICB of OSCC patients and cancer cell lines.

MATERIAL AND METHODS

We used RT-PCR to analyze the mRNA expression of MICA and MICB in four oral cancer cell lines compared with three normal human oral keratinocyte (NHOK) cell lines and in tissues from 36 patients with OSCC comparing tumor tissue with non-cancerous matched tissue (NCMT).

RESULTS

Endogenous MICB mRNA expression in OSCC cell lines was significantly higher than that in NHOK (1.40 +/- 0.27 vs. 0.40 +/- 0.16; P = 0.04). In 20 of 36 sets of tissue from patients with OSCC, MICB mRNA expression was higher in the cancerous tissue than in the NCMT. The mean MICB mRNA expression in OSCC tissues was significantly higher than in NCMT (0.39 +/- 0.08 vs. 0.14 +/- 0.03, P = 0.009, paired t-test). A significantly lower MICA mRNA was found in patients who chewed areca nut compared with those who did not use areca (P = 0.001) and in patients with well-differentiated tumors compared with those with less well-differentiated tumors (P = 0.02).

CONCLUSION

MICA and MICB mRNA expression may be increased in OSCC but there appears to be individual variation.

Current controversies in oral lichen planus: Report of an international consensus meeting. Part 1. Viral infections and etiopathogenesis

Despite recent advances in understanding the immunopathogenesis of oral lichen planus (LP), the initial triggers of lesion formation and the essential pathogenic pathways are unknown. It is therefore not surprising that the clinical management of oral LP poses considerable difficulties to the dermatologist and the oral physician. A consensus meeting was held in France in March 2003 to discuss the most controversial aspects of oral LP. Part 1 of the meeting report focuses on (1) the relationship between oral LP and viral infection with special emphasis on hepatitis C virus (HCV), and (2) oral LP pathogenesis, in particular the immune mechanisms resulting in lymphocyte infiltration and keratinocyte apoptosis. Part 2 focuses on patient management and therapeutic approaches and includes discussion on malignant transformation of oral LP.

Marginal periodontium as a potential reservoir of human papillomavirus in oral mucosa

BACKGROUND

Although human papillomaviruses (HPVs) are associated with a number of proliferative epithelial lesions including squamous cell malignancies, they can also be detected in the normal oral mucosa in 10% to 20% of the adult population. However, the point of entry and the site of replication of HPV in the oral cavity are not known. Since the gingival pocket is the only site in the oral mucosa where basal cells, known to be targets of HPV at other mucosal sites, are normally exposed to the environment, we hypothesized that this could be the site of latent HPV.

METHODS

Gingival biopsies taken from 38 individuals with clinically diagnosed periodontal disease were examined. The presence of HPV DNA was studied by using nested PCR (polymerase chain reaction with MY09/MY11 and GP05+/GP06+ primers targeting the L1 region of HPV), followed by subsequent hybridization with a cocktail of 12 high-risk HPV oligoprobes and in situ hybridization (ISH) with probes for HPV screening and the HPV subtype 16.

RESULTS

In the present study, high-risk HPV types were detected in 26% (8/31) of the gingival biopsies with PCR. By using in situ hybridization, the viral DNA was localized to the coronal part of the junctional epithelium in the gingival pocket.

CONCLUSIONS

The results suggest that the periodontal pocket might serve as a reservoir of HPVs in oral mucosa. While having important implications in understanding the HPV transmission, this observation does not rule out the possibility that HPV may be involved in the initiation of periodontal disease.

Human papillomavirus-16 associated squamous cell carcinoma of the head and neck (SCCHN): A natural disease model provides insights into viral carcinogenesis

Uncertainty regarding the causality of human papillomaviruses (HPVs) in squamous cell carcinoma of the head and neck (SCCHN) necessitates better in vitro models. We carried out molecular analyses of a novel, naturally HPV-16-transformed SCCHN cell line (UPCI:SCC090) and show high copy number of HPV-16 DNA, present in a head to tail, tandemly repeated integrated state. Sequence analysis of the HPV-16 long control region (LCR) in UPCI:SCC090 revealed a deletion of 163 bp, removing a portion of the enhancer sequence, including the binding sites for the transcription factors YY1 and NF1. The E6 and E7 oncogenes of HPV-16 are expressed at high levels in this cell lines, as determined by quantitative reverse transcriptase-polymerase chain reaction (RT-PCR). UPCI:SCC090 contains wild-type tumour suppressor TP53 gene, and undetectable p53 protein, except after treatment with cisplatin, specific proteasome inhibitors or by E6 RNA interference, suggesting E6-dependent degradation of p53 in this cell line. The results of our studies are consistent with a causative role of HPV-16 in the pathogenesis of SCCHN.

Human papillomavirus in head and neck cancer: Molecular biology and clinicopathological correlations

Human papillomaviruses are known to cause cancers of the cervix and other anogenital tract sites. Epidemiologic and molecular pathology studies have also suggested that HPV infection may be associated with cancers of the head and neck. Modes of transmission of HPV infection in the head and neck region have not been fully resolved; however, perinatal transmission and an association between sexual behavior and risk for HPV-positive cancers have been presented. Among the HPV types infecting the mucosa, high-risk, intermediate-risk and low-risk genotypes are defined, depending on their presence in carcinoma or precursor lesions. The phylogenic groups of HPVs also showed a definite correlation with the morphology of head and neck tumors. The groups A6, A7, and A9 include viruses that are frequently demonstrated in basaloid and verrucosus squamous cell carcinomas known to associate with HPV infection. Integration of HPV DNA into the host cell genome occurs early in cancer development and is an important event in malignant transformation. There is a trend for patients with HPV-positive tumors to be nondrinkers or light drinkers, the majority of these patients are females, and the median age is lower than in the case of HPV-negative tumors, but this latter difference was not always statistically significant. In the Kaplan-Meier survival model, the HPV-positive verrucous and basaloid squamous cell carcinomas showed better survival rates than the HPV-negative typical squamous cell carcinomas. An increased radiocurability of HPV-positive head and neck squamous cell carcinoma (HNSCC) has also been demonstrated.

HPV DNA in clinically different variants of oral leukoplakia and lichen planus

OBJECTIVES

Our objectives were to determine the prevalence of human papillomavirus (HPV) infection in oral leukoplakia (OL) and oral lichen planus (OLP) in comparison with that in healthy oral mucosa, also conditionally to age, gender, smoking, and drinking habits of patients, so as to investigate any possible association of HPV infection with a specific clinical variant of OL or OLP.

STUDY DESIGN

We did research on HPV DNA in 68 cases of OL (homogeneous form [H] in 45 cases and nonhomogeneous form [non-H] in 23 cases), and in 71 cases of OLP (nonatrophic/erosive form [non-AE] in 27 cases, atrophic/erosive form [AE] in 44 cases). HPV DNA was investigated in exfoliated oral mucosa cells by nested PCR (nPCR: MY09-MY11/GP5-GP6) and the HPV genotype determined by direct DNA sequencing.

RESULTS

HPV DNA was found in 17.6% of OL, in 19.7% of OLP, and in 5.6% of controls, with a statistically significant higher risk of HPV infection in both lesion groups (for OL: P=.01; Odds Ratio [OR]=3.64; 95% CI: 1.21-10.80; for OLP: P=.005; OR=4.17; 95% CI: 1.41-12.18). Demographic variables analysis showed that the only significant association was between HPV status and current smoking in OL patients (OR'=3.40; 95% CI: 1.0-11.59). HPV DNA was found in 20% of H OL and 13% of non-H OL, without any association with the clinical variant (P=.73; OR=0.60; 95% CI: 0.14-2.48). HPV DNA was found in 18.5% of non-AE OLP and 20.4% of AE OLP, without any significant association with the clinical variant (P=.84; OR=1.13; 95% CI: 0.335-3.816). HPV-18 was the most frequently detected genotype (9/12 and 10/14 of HPV-positive OL and OLP, respectively), followed by HPV-16 (2/12 OL and 2/14 OLP), HPV-33 (1/12 OL), HPV-31 (1/14 OLP), and HPV-6 (1/14 OLP).

CONCLUSIONS

An increased risk of HPV infection was found in OL and OLP; however, no specific clinical variant of OL or OLP was noted to be associated with HPV infection. It is not possible to predict the likelihood of HPV infection from the clinical features of OL and OLP.

Low prevalence of HPV infection and its natural history in normal oral mucosa among volunteers on Miyako Island, Japan

OBJECTIVE

To investigate the prevalence of human papillomavirus (HPV) infection in normal oral mucosa, and to observe the natural history in the oral cavity in oral swab samples collected from healthy volunteers on Miyako Island, Okinawa, Japan.

STUDY DESIGN

The prevalence of HPV infection in oral buccal mucosa cell scrapes collected between 2000 and 2002 from a cohort of 668 healthy volunteers was determined. HPV DNA was detected by consensus polymerase chain reaction (PCR) using MY09/MY11 primers followed by direct cycle sequencing. Just over 2 years later the HPV-positive participants were reevaluated.

RESULTS

Of the 668 subjects, 662 samples were analyzed for HPV. HPV DNA was detected in 4 (0.6%) specimens. HPV type 16 (HPV16), HPV53, and HPV71, mucosal types, and HPV12, a cutaneous type, were all identified by direct sequencing. In the follow-up survey, the HPV71- and HPV12-positive participants again tested positive, while HPV DNA was not detected in the HPV16- and HPV53-positive participants.

CONCLUSION

The results of this study among healthy individuals from Miyako Island suggest that oral HPV infection is uncommon. In this cohort, HPV71 and HPV12 were persistent, while HPV16 and HPV53 were transient in normal oral mucosa.

The role of human papillomavirus in oral carcinogenesis

Human papillomavirus (HPV) infection with high-risk types 16 and 18 has widely been reported as one of the prominent mechanisms behind the development of cervical squamous cell carcinoma. Links between HPV and oral cavity cancer have been suggested as well, based on epidemiologic and molecular means, though the association is less well-established. It is likely that HPV plays a role in oral cavity carcinogenesis, though only in a small subset of cases. The difficulty in providing true causal evidence of HPV's role in oral cancer lies in our lack of understanding of the significance of mechanisms by which HPV leads to oral carcinogenesis, as well as limitations in the molecular analysis of HPV. Further studies are necessary for the contribution of HPV in oral cavity malignancy to be better demonstrated.

Mapping and analysis of HPV16 integration sites in a head and neck cancer cell line

Human papillomavirus (HPV) is a circular double-stranded DNA virus implicated in at least 90% of cervical and anogenital cancers and has been observed in approximately 20% of squamous cell carcinomas of the head and neck (SCCHN). Transcription of the viral oncogenes E6 and E7 is regulated by expression of the E2 protein. Disruption of the E2 gene sequence due to viral integration results in upregulation of E6 and E7, which promote tumorigenesis by abrogating p53 and pRb functions. HPV integration sites in cervical and anogenital cancers have been mapped primarily to chromosomal fragile sites and in some cases have been shown to integrate within tumor suppressor genes or other cancer-related genes. To study viral integration sites in SCCHN, we examined an HPV16-infected SCCHN cell line cultured from a tongue-base tumor. HPV fluorescence in situ hybridization (FISH) revealed multiple integrated viral DNA copies in blocks throughout the genome. Sequential FISH and spectral karyotyping identified integration sites on chromosomes 3, 6, 9q, 13q and t(1;8)(q;?). Restriction site-polymerase chain reaction (RS-PCR) was performed to identify the viral-cellular junctions. Sequence analyses confirmed integration sites at 9q31.1 and 6p21 and revealed a novel junction at 16p12.3. Subsequent chromosome breakage studies suggested that the observed viral-cellular integration sites may have occurred within common fragile sites. Additional studies using RT-PCR for E6--E7 viral transcripts showed oncoprotein expression from episomal and integrated viral sequences. Our results suggest that viral integration of HPV in SCCHN appears to occur nonrandomly through targeting specific chromosomal sequences prone to breakage.

Investigation into a possible association between oral lichen planus, the human herpesviruses, and the human papillomaviruses

BACKGROUND

Oral lichen planus (OLP) is a chronic relapsing cell-mediated condition of unknown etiology. The purpose of this study was to ascertain if the human herpesviruses (HHVs) or human papillomaviruses (HPVs) act as possible factors or co-factors in the pathogenesis of OLP.

METHODS

Thirty-eight histologically confirmed OLP and 20 normal control buccal mucosa tissue samples were analyzed. Polymerase chain reaction analysis was employed to detect members of the HHV and HPV families.

RESULTS

The Epstein-Barr virus and HHV-7 were detected in a small percentage of tissue samples. However, HPV-16 was detected in 26.3% of OLP samples and 0% of the normal control tissues. The epidermodysplasia verruciformis-related HPV types were detected in 42% of OLP samples and 45% of normal control samples.

CONCLUSION

The results of this study do not suggest a causative role for members of the HHV family in the pathology of OLP. However, a statistical association was found between HPV-16 presence and OLP.

Human papillomavirus type 16 and 18 DNA in oral squamous cell carcinoma and normal mucosa

The aim of this study was to ascertain the prevalence of HPV 16/18 DNA in oral squamous cell carcinoma (OSCC) vs. normal oral mucosa, and to correlate the virologic data with other factors obtained from the patients' records. One hundred and thirteen paraffin embedded tissue samples (73 OSCC and 40 normal oral mucosa) were studied using HPV type specific primer-mediated polymerase chain reaction (PCR). Seventy-four per cent (54/73) of OSCC and 55% (22/44) of normal oral mucosa were positive for HPV 16/18 DNA. Statistical analysis indicated there was a significant difference between HPV16/18 positive OSCC vs. normal oral mucosa (P=0.040), and that age (<60 years) and gender (male) were correlated with the presence of HPV16/18 in the tumour. No significant association was found between the presence of HPV and other risk factors, including tobacco use, alcohol use, tumour location, histologic grade or TNM staging. We found a significant association of HPV16/18 with oral squamous cell carcinoma. Also, HPV16/18 is a co-factor in oral carcinogenesis, particularly in male patients and patients under the sixth decade. In addition, we found that HPV infection is a common event in the normal oral mucosa.

Detection of human papillomavirus-16 and HPV-18 DNA in normal, dysplastic, and malignant oral epithelium

OBJECTIVE

Our aim was to clarify the association of human papillomavirus (HPV) with oral carcinogenesis, especially its early stage.

STUDY DESIGN

Tissue specimens of normal mucosa, epithelial dysplasia, oral squamous cell carcinoma (OSCC), and OSCC cell lines were examined for the presence of HPV-16 and HPV-18 E6 DNA by means of the polymerase chain reaction test.

RESULTS

The detection rate of HPV-16 in epithelial dysplasia (31/51) was higher than that in normal mucosa (16/44) and in OSCC (30/86) and was statistically different from that in OSCC. The cases that progressed from epithelial dysplasia to carcinoma showed a significantly higher HPV-16 detection rate than the other cases in both epithelial dysplasia and OSCC. HPV-16 and HPV-18 were detected only at early passages of 2 of 10 OSCC cell lines.

CONCLUSIONS

These results strongly suggest that HPV-16 may be involved in the early stages of the development of some oral carcinomas.

Risk of oral cancer associated with human papillomavirus infection, betel quid chewing, and cigarette smoking in Taiwan--an integrated molecular and epidemiological study of 58 cases

BACKGROUND

The association between oral squamous cell carcinoma (OSCC) and human papillomavirus (HPV) 6, 11, 16 and 18 is uncertain. Past reports varied in the methodology and results. We conducted this study using in situ PCR in situ hybridization (ISH) assay which was considered as the most sensitive method for detection of viral DNA. We undertook an epidemiologic survey about the history of betel quid chewing and cigarette smoking, since these habits are common in Taiwan.

METHODS

In situ PCR ISH was performed on the tumor specimens from 29 patients with OSCC and the oral mucosal specimens from 29 patients without OSCC. Their betel quid chewing and cigarette smoking histories were also reviewed.

RESULTS

HPV16, HPV18, betel quid chewing and cigarette smoking were statistically significant risk factors in univariate analysis. HPV6 and 11 were not. Multivariate analysis showed that HPV16 infection (adjusted Odds ratio = 11.20) and betel quid chewing (adjusted Odds ratio = 17.06) remained to be independent factors for OSCC.

CONCLUSIONS

Our results showed that HPV16 and betel quid chewing were two major risk factors for OSCC in Taiwan, indicating that they act through different mechanisms in the pathogenesis of OSCC.

Involvement of intact HPV16 E6/E7 gene expression in head and neck cancers with unaltered p53 status and perturbed pRb cell cycle control

We have identified parameters which define a causal role of HPV16 in head and neck cancer. Twenty-eight tumours which were typed positive for HPV16 DNA, were comprehensively analysed for expression of the viral oncogenes E6 and E7, the status of the p53 gene, and the protein status of pRb and p16(INK4a). In a subset of cases, we have searched for integrated viral DNA, and have determined the genomic status of the E6 gene. Expression of E6/E7 was found in 12 tumours most of which were derived from the oropharynx, whereas p53 mutations were present in 13 tumours from various sites. The tumours either carried p53 mutations but did not express E6/E7, or they did express E6/E7 but were p53-wild-type. Coexistence of E6/E7 expression with a mutated p53 was found in only one case. Strikingly, in most p53-mutated tumours without E6/E7 expression, we found the E6 gene to be disrupted. E6/E7 expression was associated with reduced pRb and overexpressed p16(INK4a). Viral-cellular fusion transcripts were found in two cases. Our data demonstrate that HPV16 DNA-positivity in head and neck cancers is not indicative of a causal role. A causal role of HPV16 in head and neck cancer is defined by: E6/E7 expression, viral integration with an intact E6 gene, and perturbation of pRb cell cycle control. Mostly, the p53 gene is wild-type.

Human papillomavirus as a risk factor for oral squamous cell carcinoma: a meta-analysis, 1982-1997

OBJECTIVE

Human papillomavirus (HPV) infection is a significant risk factor for uterine cervical carcinoma. However, the role of HPV infection in oral squamous cell carcinoma (OSCC) is less well defined. To determine the significance of the relationship of this virus in the progressive development of oral cancer, we estimated the risk of HPV detection in normal oral mucosa, precancerous oral tissue, and oral carcinoma using meta-analysis.

STUDY DESIGN

Case reports and clinical series published in English-language journals were retrieved by searching MEDLINE (January 1980-August 1998). Review articles were also examined to identify additional studies. Studies that used biochemical, immunologic, microscopic, or molecular analyses to detect HPV in tissue or cells derived from normal oral mucosa (n = 25), benign leukoplakia (n = 21), intraepithelial neoplasia (ie, dysplasia and carcinoma in situ; n = 27), and oral cancer (n = 94) were included in the meta-analysis. Information on sample size, age, sex, method of tissue preservation (ie, fresh, frozen, paraffin-embedded), assay, primer amplification region (early, late), high-risk versus low-risk genotype, and use of tobacco or alcohol was abstracted by one author (C.S.M.).

RESULTS

Data from 94 reports that analyzed 4680 samples were included in the meta-analysis. Analyses made by means of a random-effects model with and without adjustments for assay sensitivity showed increased probability of HPV detection in tissue with precancerous and cancerous features compared with normal mucosa. The likelihood of detecting HPV in normal oral mucosa (10.0%; 95% confidence interval [CI], 6.1%-14.6%) was significantly less than of detecting benign leukoplakia (22.2%; 95% CI, 15.7%-29.9%), intraepithelial neoplasia (26.2%; 95% CI, 19.6%-33.6%), verrucous carcinoma (29.5%; 95% CI, 23%-36.8%), and OSCC (46.5%; 95% CI, 37.6%-55.5%). Adjustment of findings for differences in assay sensitivity indicated that these estimates may be conservative. Overall, HPV was between 2 and 3 times more likely to be detected in precancerous oral mucosa and 4.7 times more likely to be detected in oral carcinoma than in normal mucosa. The pooled odds ratio for the subset of studies directly comparing the prevalence of HPV in normal mucosa and OSCC was 5.37, confirming the trend observed in the overall sample. The probability of detecting high-risk HPVs in OSCCs was 2.8 times greater than that of low-risk HPVs.

CONCLUSION

This meta-analysis indicates that HPV is detected with increased frequency in oral dysplastic and carcinomatous epithelium in comparison with normal oral mucosa. The findings provide further quantitative evidence that oral infection with HPV, particularly with high-risk genotypes, is a significant independent risk factor for OSCC.

Loss of heterozygosity at 7p in Wilms' tumour development

Chromosome 7p alterations have been implicated in the development of Wilms' tumour (WT) by previous studies of tumour cytogenetics, and by our analysis of a constitutional translocation (t(1;7)(q42;p15)) in a child with WT and radial aplasia. We therefore used polymorphic microsatellite markers on 7p for a loss of heterozygosity (LOH) study, and found LOH in seven out of 77 informative WTs (9%). The common region of LOH was 7p15-7p22, which contains the region disrupted by the t(1;7) breakpoint. Four WTs with 7p LOH had other genetic changes; a germline WT1 mutation with 11p LOH, LOH at 11p, LOH at 16q, and loss of imprinting of IGF2. Analysis of three tumour-associated lesions from 7p LOH cases revealed a cystic nephroma-like area also having 7p LOH. However, a nephrogenic rest and a contralateral WT from the two other cases showed no 7p LOH. No particular clinical phenotype was associated with the WTs which showed 7p LOH. The frequency and pattern of 7p LOH demonstrated in our studies indicate the presence of a tumour suppressor gene at 7p involved in the development of Wilms' tumour.

High-risk human papillomavirus types and squamous cell carcinoma in patients with respiratory papillomas

Respiratory papillomas (RPs) are benign, virally induced tumors of the larynx and respiratory epithelium that may obstruct the airway and tend to recur frequently. RPs are thought to be the result of infection with the human papillomaviruses (HPVs) types 6 and 11. We surveyed archival RP specimens to determine whether there were correlations of HPV type with patient characteristics or clinical course. Paraffin-embedded papilloma specimens of 45 different patients were analyzed. We assessed HPV types using the polymerase chain reaction with E6 consensus primers, hybrid capture assays (high or low risk), and dot blot hybridization of generic E6 PCR products with E6 type-specific oligonucleotide probes. The presence and type of HPV were correlated with patient data from a retrospective chart review. We found that RPs may have either low- or high-risk HPV types and some contain multiple HPV types. Respiratory infection with high-risk HPV apparently introduces a long-term risk of squamous cell carcinoma development, even in the absence of conventional cofactors. Low-risk HPV infection may also act in association with these cofactors to promote carcinogenesis. Our data also show a racial imbalance in RP that may indicate a difference in genetic resistance and/or susceptibility to HPV infection and the development of RP.

Detection of Epstein-Barr virus in oral scrapes in HIV infection, in hairy leukoplakia, and in healthy non-HIV-infected people

Epstein Barr virus (EBV) has been implicated in the pathogenesis of oral hairy leukoplakia (OHL). EBV is normally detected by lesional biopsy. The objectives of this study were to examine oral scrapes containing squamous epithelial cells (squames) from HIV-infected people with and without clinical lesions of OHL, and from healthy non-HIV-infected controls, for EBV-DNA by the polymerase chain reaction (PCR). EBV-DNA was detected in 65% of HIV-infected people and 20% of healthy HIV-negative controls but in HIV-infected individuals it was found as frequently in those without OHL as in those with. Moreover, EBV-DNA was not detected in all HIV-infected individuals, nor in all OHL. The results suggest that the presence or absence of detectable EBV-DNA in oral scrapes, though a guide, cannot be regarded as absolutely reliable in the diagnosis or exclusion of OHL.

Detection of HPV-16 genome in human oral cancers and potentially malignant lesions from India

The presence of high risk human papilloma virus (HPV) 16 and 18 was examined in 100 oral cancer patients of Indian descent, 80 patients with potentially malignant oral lesions and corresponding clinically normal mucosa from 48 of these patients. Additionally, presence of HPV-33, -6 and -11 was also studied in 86 oral cancers, 50 potentially malignant oral lesions and 30 corresponding normal oral mucosa. All the patients with oral cancer and oral lesions, were long term tobacco-chewers, and a majority of the patients were in Advanced Stages III and IV. The DNA samples were amplified by polymerase chain reaction (PCR) using HPV L1 consensus primers. Typing of HPV was performed by Southern hybridization analysis of the PCR products using HPV-16, -18, -33, -6 and -11 type specific oligonucleotide probes. HPV-16 was detected in 15 out of 100 (15%) oral tumours, 27 out of 80 (34%) potentially malignant lesions and 15 out of 48 (31%) of the corresponding normal mucosa in the patients with oral lesions. HPV-18 was not detected in any of the oral cancers, oral lesions and normal mucosa. HPV-33 and the low-risk HPV-6 and -11 were also not detected in the oral cancers, oral lesions and corresponding normal mucosa. A significantly higher prevalence of HPV-16 was observed in oral lesions (27 out of 80, 34%) as compared to oral cancers (15 out of 100, 15%). The observed difference of 19% (95% confidence interval [CI]: 6%, 31%), between these two proportions was statistically significant at the 5% level of significance. Our data indicates that HPV-16 may play a direct role in a certain proportion of oral cancers; whereas in a subpopulation of oral cancers HPV-16 infection may be vital in the early events associated with development of potentially malignant oral lesions, and the presence of the virus not essential in the progression of the oral lesion to frank malignancy.

Human papillomavirus and risk of oral cancer

Although human papillomavirus (HPV), a sexually transmitted virus, is established as a necessary cause for more than 95% of cervical carcinomas, the association with oral squamous cell carcinoma is less well delineated. The purpose of this study was to determine the frequency and types of HPV in squamous cells of a group of patients with newly diagnosed oral or pharyngeal cancer (n = 93) compared with an age- and gender-frequency-matched control group of patients with no history of oral cancer (n = 205). HPV was evaluated from a mouth rinse collection of cells in the oral cavity and tested by 32P-labeled HPV generic probes and DNA sequencing for HPV types. HPV was identified in 15% of the oral cancer cases but in fewer than 5% of the controls (P < .05). The risk of cancer associated with HPV infection was independent of tobacco and alcohol use (adjusted odds ratio [OR] = 3.70; 95% confidence interval [CI]: 1.47-9.32; P < .05). HPV types included similar and other types not identified previously in the genital tract. There was no statistically significant increased risk of cancer among former tobacco users (former vs. never users: adjusted OR = 0.67, 95% CI: 0.31-1.44, P < .05), but the risk was significantly increased for current users (current vs. never: adjusted OR = 2.63; 95% CI: 1.22-5.71; P < .05). Likewise, former alcohol users were not at increased risk of disease (former vs. never: adjusted OR = 1.78; 95% CI: 0.87-3.67), whereas current alcohol users were (current vs. never: adjusted OR = 2.57; 95% CI: 1.22-5.42; P < .05). HPV-related genital lesions (14.3% vs. 10.6%), oral-genital sexual behavior (42.4% vs. 45.2%), and number (11 or more) of sexual partners (23% v. 17%) were not significantly different between cases and controls. These data suggest that in addition to tobacco and alcohol, HPV plays a role in the development of oral cancer.

Etiology of cancer of the lip. A review

A range of environmental and host factors has been identified to explain the etiopathogenesis of squamous cell carcinoma of the lip. However, the definitive pathogenic pathway remains unclear. Carcinogenesis does not seem to be limited to a single agent, but rather to a complex multistep process of interactions between putative risk factors. In this paper, the currently available data regarding risk factors, considered to be causally related to the onset of lip cancer, are reviewed.

Human papillomavirus and head and neck cancer: epidemiology and molecular biology

BACKGROUND

Human papillomaviruses (HPV) are known to cause cancers of the cervix and other anogenital tract sites. Molecular biology has provided some evidence as to the specific mechanisms involved in the HPV-related carcinogenesis. Epidemiologic and molecular biology studies have also suggested that HPV infection may be associated with cancers of the head and neck.

METHODS

This review summarizes the biology of HPV and its potential etiologic role in head and neck cancer. Published reports were used to determine the prevalence of HPV in benign, precancerous, and neoplastic lesions of the oral cavity, pharynx, and larynx. The prevalence was also examined by head and neck site, HPV type, and method of HPV detection. In addition, the occurrence of HPV in normal head and neck tissue, epidemiologic factors related to HPV infection, and clinical implications are discussed.

RESULTS

Overall, the frequency of HPV in benign and precancerous lesions ranged from 18.5% to 35.9%, depending upon the detection methodology. Based upon the most sensitive method of detection, polymerase chain reaction (PCR), the overall prevalence of HPV in head and neck tumors was 34.5% (416 of 1205 tumors). The majority of HPV-positive tumors contained the "high risk" HPV types 16 (40.0%) and 18 (11.9%). Among head and neck sites, HPV was most often detected in tumors of the oral cavity (59%), followed by the pharynx (43%), and larynx (33%). The frequency of HPV positivity in oral samples from healthy individuals ranged from 1% to 60%. A limited number of descriptive and analytic epidemiologic studies have indicated that age (<60 years) and sex (male) were associated with the presence of HPV in the tumor, whereas tobacco and alcohol use were not. The relationship between HPV and survival is unclear, with few comprehensive studies currently available.

CONCLUSIONS

The prevalence of HPV, particularly the high-risk types, suggests a potential etiologic role for the virus in head and neck cancer. Molecular biology has provided important data on the interaction of the HPV oncoproteins with genes important in cell cycle control. Nonetheless, more basic research is needed to describe the physical state of the virus in a variety of cell types and the interaction with other genes. In addition, epidemiologic research is required to further understand the association between HPV and demographic and other risk factors as well as possible routes of transmission. Finally, much work is warranted to provide a definitive assessment of the prognostic significance of HPV in head and neck cancer.

Prevalence of human papillomavirus infection in premalignant and malignant lesions of the oral cavity in U.K. subjects: a novel method of detection

To evaluate the possible role of human papillomavirus (HPV) in oral neoplasms, 28 oral squamous cell carcinomas (SCC) and 12 potentially malignant lesions were analysed for the presence of HPV DNA. A nested polymerase chain reaction (PCR) approach, using two sets of HPV consensus primers to the L1 region, was used, which was able to detect a broad spectrum of HPV types. HPV DNA was detected in 14/28 (50%) carcinomas and 4/12 (33%) precancerous lesions. A novel approach based on labelling the PCR products with 32P and the separation of radioactively labelled products on an 8% polyacrylamide gel increased the sensitivity of the detection and enabled the identification of the HPV types. The typing of HPV was subsequently confirmed by direct DNA sequencing. HPV 6 and HPV 16 were the only HPV types detected and seven tumours harboured both types. Our results suggest that HPVs may be an important aetiological factor in the development of oral cancer. The detection procedure ensured sensitivity and consistency of the detection of low copy numbers of the virus DNA. The presence of HPV in 33% of premalignant tissues suggests that HPV infection may be an early event in the malignant transformation of oral SCC. There was no statistically significant association between viral infection and tumour grade or stage.

Update on oral lichen planus: etiopathogenesis and management

Lichen planus (LP) is a relatively common disorder of the stratified squamous epithelia, which is, in many ways, an enigma. This paper is the consensus outcome of a workshop held in Switzerland in 1995, involving a selection of clinicians and scientists with an interest in the condition and its management. The oral (OLP) eruptions usually have a distinct clinical morphology and characteristic distribution, but OLP may also present a confusing array of patterns and forms, and other disorders may clinically simulate OLP. Lesions may affect other mucosae and/or skin. Lichen planus is probably of multifactorial origin, sometimes induced by drugs or dental materials, often idiopathic, and with an immunopathogenesis involving T-cells in particular. The etiopathogenesis appears to be complex, with interactions between and among genetic, environmental, and lifestyle factors, but much has now been clarified about the mechanisms involved, and interesting new associations, such as with liver disease, have emerged. The management of lichen planus is still not totally satisfactory, and there is as yet no definitive treatment, but there have been advances in the control of the condition. There is no curative treatment available; immunomodulation, however, can control the condition. Based on the observed increased risk of malignant development, OLP patients should be offered regular follow-up examination from two to four times annually and asked to report any changes in their lesions and/or symptoms. Follow-up may be particularly important in patients with atrophic/ulcerative/erosive affections of the tongue, the gingiva, or the buccal mucosa. Much more research is required into the genetic and environmental aspects of lichen planus, into the premalignant potential, and into the possible associations with chronic liver, and other disorders. More clinical studies are required into the possible efficacy of immunomodulatory drugs such as pentoxifylline and thalidomide.