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

Prevalence of high-risk human papillomavirus in oral squamous cell carcinoma with or without chewing habits

Oral cancer (OC) is the most common cancer in Pakistani males and the second most common in females. Major risk factors include peculiar chewing habits, human papillomavirus (HPV) infection and molecular pathways. However, less data is available for this avertible cancer regarding its association with high-risk HPV (HR-HPV) and chewing habits in this region. Therefore, this study was done to determine the prevalence of HR-HPV in oral squamous cell carcinoma (OSCC) and its correlation with p16 and chewing habits. Formalin-fixed paraffin-embedded (FFPE) biopsy specimens of 186 samples were tested for HR-HPV type 16/18 by PCR, followed by p16 immunostaining (IHC) in a subset of cases (n = 50). Appropriate statistical tests were applied to find the association between HR-HPV/p16 and peculiar chewing habits with significance criteria of p<0.05 with 95% CI. HR-HPV (type 16 &18) was present in seven out of 186 cases (3.8%). Of these seven cases, five were positive for HPV16, whereas two were positive for HPV16/18. The overall expression of p16 protein in 50 samples was 38% (n = 19), and among these 19-IHC positive samples, 26% were positive for HR-HPV DNA. No significant association was found between HR-HPV positivity and p16 and chewing habits (p>0.05). It was concluded that HR-HPV prevalence in OSCC was very low in our population, with no statistically significant correlation with p16 and chewing habits. These results suggest the role of HR-HPV as an independent risk factor in OSCC in the local setting.

Therapeutic strategy for oncovirus-mediated oral cancer: A comprehensive review

Oral cancer is a neoplastic disorder of the oral cavities, including the lips, tongue, buccal mucosa, and lower and upper gums. Oral cancer assessment entails a multistep process that requires deep knowledge of the molecular networks involved in its progression and development. Preventive measures including public awareness of risk factors and improving public behaviors are necessary, and screening techniques should be encouraged to enable early detection of malignant lesions. Herpes simplex virus (HSV), human papillomavirus (HPV), Epstein-Barr virus (EBV), and Kaposi sarcoma-associated herpesvirus (KSHV) are associated with other premalignant and carcinogenic conditions leading to oral cancer. Oncogenic viruses induce chromosomal rearrangements; activate signal transduction pathways via growth factor receptors, cytoplasmic protein kinases, and DNA binding transcription factors; modulate cell cycle proteins, and inhibit apoptotic pathways. In this review, we present an up-to-date overview on the use of nanomaterials for regulating viral proteins and oral cancer as well as the role of phytocompounds on oral cancer. The targets linking oncoviral proteins and oral carcinogenesis were also discussed.

Infection with Human Papilloma Virus (HPV) and risk of subsites within the oral cancer

BACKGROUND

The aim of this study was to investigate the relationship between high-risk genotypes of Human Papilloma Virus (HPV) and cancer of different subsites of the oral cavity.

MATERIAL AND METHODS

A pooled analysis of five studies included on the International Head and Neck Cancer Epidemiology (INHANCE) Consortium was conducted. HPV 16 and HPV 18 were considered. Adjusted odds ratios (ORs) and corresponding 95 % confidence intervals (CIs) for HPV and each oral cavity subsites were simultaneously estimated using multinomial logistic regression models.

RESULTS

The analysis included 1157 cases and 3272 controls. This study showed a slightly higher prevalence of HPV infection among oral cancer cases than controls. In particular, an increased risk of other and not otherwise specified (NOS) sites within the oral cavity, oral tongue, palate and floor of mouth cancer was observed for overall HPV16 positivity (OR = 1.66, 95 % CI: 1.01-2.72; OR = 1.97, 95 % CI: 1.36-2.85; OR = 2.48, 95 % CI: 1.50-4.11; OR = 2.71, 95 % CI: 1.06-6.95, respectively). In particular, HPV16E7 was related to cancer of floor of mouth, oral cavity NOS and palate (OR = 2.71, 95 % CI: 1.06-6.95; OR = 3.32, 95 % CI:1.53-7.19; OR = 3.34, 95 % CI:1.38-8.06). Results were inconsistent for HPV18 due to low prevalence of infection.

CONCLUSION

Our study suggests that HPV16 infection may increase the risk of developing floor of mouth, gum, tongue, and palate cancers.

CLINICAL RELEVANCE

Subjects with HPV infection have a higher risk of cancer from all sites of the oral cavity.

The Prevalence of High- and Low-Risk Types of HPV in Patients with Squamous Cell Carcinoma of the Head and Neck, Patients with Chronic Tonsillitis, and Healthy Individuals Living in Poland

Human papillomavirus (HPV) is a virus with the potential to infect human epithelial cells and an etiological agent of many types of cancer, including head and neck cancer. The aim of the study was to determine the prevalence of HPV infection in patients with head and neck squamous cell carcinoma (HNSCC), patients with chronic tonsillitis, and healthy individuals, and to establish high- and low-risk HPV genotypes in these groups. The objectives also comprised the delineation of the relationship between the infection with high- or low-risk HPV subtypes and clinicopathological and demographic characteristics of the study groups. This study was composed of 76 patients diagnosed with HNSCC, 71 patients with chronic tonsillitis, and 168 cases without either of these conditions (the control group). HPV detection and identification of subtypes were performed on isolated DNA using a test which allowed detection of 33 common high-risk and low-risk HPV subtypes. The prevalence of HPV infection was 42.1%, 25.4%, and 37.5% in HNSCC, chronic tonsillitis, and control groups, respectively. HPV 16 was the most prevalent genotype in all groups and the non-oncogenic HPV 43/44 was frequent in HNSCC patients. This analysis provides insight into the prevalence of oral oncogenic and non-oncogenic HPVs in patients with head and neck cancer, patients with chronic tonsillitis and healthy individuals, and leads to the conclusion that further investigations are warranted to examine a larger cohort of patients focusing on high- and low-risk HPV genotypes. Efforts should be focused on screening and prevention strategies, and therefore, it is important to introduce tools for effective detection of HPV genotypes. Furthermore, given the role of vaccines against oral HPV infection, our observations lead to the suggestion that HPV vaccination should be of considerable importance in public health strategies.

Prevalence of Human Papillomavirus (HPV) 16 and 18 in Oral Malignant and Potentially Malignant Disorders: A Polymerase Chain Reaction Analysis - A Comparative Study

Introduction:

Human papillomavirus (HPV) are now being increasingly associated as a cause of oral squamous cell carcinomas (OSCC). This study was designed to evaluate the prevalence of HPV in Pelizaeus-Merzbacher disease (PMD) and OSCC using polymerase chain reaction that might help in better understanding of the role played by this virus in the oncogenic process even from its evolution stage.

Materials and Methods:

Formalin-fixed paraffin-embedded tissue samples (n = 40) of OSCC and mild, moderate, and severe dysplasia were used for this study. DNA was quantified and checked for purity spectrophotometrically. Statistical analysis was performed using SPSS software and statistical significance was assessed using Fischer's exact test (p < 0.05 was considered significant).

Results:

High-risk (HR)-HPV-16 was found to be positive in 35% of OSCC cases which showed a statistically significant association of HPV 16 with OSCC. Verrucous carcinoma had predominant HPV 16 infection (60%), followed by SCC with 40%. However, this association was not statistically significant. None of the OSCC samples were infected with HPV 18. Among the PMD, we found only 5% showing HR-HPV 16 infection which was not significant.

Discussion:

Although OSCC is attributed to tobacco and alcohol consumption, a significant proportion of OSCC cases have been demonstrated to contain HPV types. The high-risk HPV type 16 tends to be the most predominant type detected in cases of OSCC.

Human Papillomavirus 16 and 18 Infection in Oral Cancer in Thailand: A Multicenter Study

Objectives:

To identify the prevalence of high-risk human papillomavirus (HPV) genotypes 16 and 18 among patients with oral squamous cell carcinoma (OSCC) in Thailand and investigate the associations of p16 expression and HPV16/18 with the demographic, clinicopathologic, and risk parameters.

Materials and Methods:

A total of 403 formalin-fixed paraffin-embedded OSCC specimens from four centers in four regions were obtained. p16 expression was evaluated by immunohistochemistry. The detection of HPV16/18 DNA was performed by polymerase chain reaction.

Results:

Of all, 172 specimens (42.7%) were presented with amplifiable extracted DNA. Among these, 62.8% were positive for p16, 8.1% were positive for HPV16/18, and 5.8% were positive for both methods. Of all HPV-positive specimens, HPV18 was detected in 57.1%; HPV16 in 14.3%; and HPV16 and 18 (co-infection) in 28.6%. The prevalence of HPV16/18 varied between centers, with the highest rate in the northern center (20.0%). There was no significant correlation between p16 expression and HPV16/18. There were no significant associations of p16 expression and/or HPV16/18 with all variables.

Conclusions:

The prevalence of HPV16/18 infection in OSCC geographically varied in Thailand, with the highest rate in the northern region. Poor correlation between p16 and HPV16/18 suggests p16 not be used as a surrogate marker for HPV-positive OSCC.

Assessing the nature of the association of human papillomavirus in oral cancer with and without known risk factors

Background

Published studies assessing the association of human papillomavirus (HPV) and oral cancer, often include cases with additional confounders such as alcohol, tobacco, thus, precluding the assessment of HPV as a independent risk factor. Further apart from eliciting the mere presence of HPV, it is vital that the nature of the association is delineated for eliciting a causal inference. Thus, the present study assessed the presence and nature of the association of HPV in oral cancer cases with and without known risk factors.

Methods

The study compares the prevalence of HPV in oral cancer cases with known risk factors (group 1, n=15) to oral cancer (group 2, n=15) and oral epithelial dysplasia (group 3, n=15) cases with no known risk factors using PCR. Cases which are positive for HPV were subjected to p16 and p53 immunostaining to determine potential causal inference.

Results

HPV 16 was detected in only 1 case of group I, 3 cases of group II, and was absent in group III. HPV 18 was negative in all the 3 groups. All the HPV positive cases were negative for p16 and positive for p53 immunostaining.

Conclusions

Only a minor proportion of oral cancer cases without risk factors were positive for HPV 16. Even among these HPV 16 positive cases, the immunostaining profile (p53 positive and p16 negative) excludes the involvement of E6 and E7 mediated carcinogenesis. Thus even the weak HPV association noted in the present study cases may not be of causal nature.

High Human Papillomavirus DNA loads in Inflammatory Middle Ear Diseases

Background. Previous studies reported human papillomaviruses (HPVs) in middle ear tumors, whereas these viruses have been poorly investigated in chronic inflammatory middle ear diseases. We investigated HPVs in non-tumor middle ear diseases, including chronic otitis media (COM). Methods. COM specimens (n = 52), including chronic suppurative otitis media (CSOM) (n =38) and cholesteatoma (COMC) (n = 14), as well as normal middle ear (NME) specimens (n = 56) were analyzed. HPV sequences and DNA loads were analyzed by quantitative-PCR. HPV genotyping was performed by direct sequencing. Results. HPV DNA was detected in 23% (12/52) of COM and in 30.4% (17/56) of NME (p > 0.05). Specifically, HPV DNA sequences were found in 26.3% (10/38) of CSOM and in 14.3% (2/14) of COMC (p > 0.05). Interestingly, the HPV DNA load was higher in COMC (mean 7.47 copy/cell) than in CSOM (mean 1.02 copy/cell) and NME (mean 1.18 copy/cell) (P = 0.03 and P = 0.017 versus CSOM and NME, respectively). HPV16 and HPV18 were the main genotypes detected in COMC, CSOM and NME. Conclusions. These data suggest that HPV may infect the middle ear mucosa, whereas HPV-positive COMCs are associated with higher viral DNA loads as compared to NME.

Molecular Diagnostics in Human Papillomavirus-Related Head and Neck Squamous Cell Carcinoma

The incidence of human papillomavirus (HPV)-related head and neck squamous cell carcinoma continues to increase. Accurate diagnosis of the HPV status of a tumor is vital, as HPV+ versus HPV- tumors represent two unique biological and clinical entities with different treatment strategies. High-risk HPV subtypes encode oncoproteins E6 and E7 that disrupt cellular senescence and ultimately drive tumorigenesis. Current methods for detection of HPV take advantage of this established oncogenic pathway and detect HPV at various biological stages. This review article provides an overview of the existing technologies employed for the detection of HPV and their current or potential future role in management and prognostication.

Quantitative polymerase chain reaction-based detection of HPV 16 E6 and E7 DNA in oral squamous cell carcinoma

BACKGROUND

Although human papillomavirus (HPV) is considered as a causative factor in oral squamous cell carcinoma (OSCCs), its pathogenetic role is not well established. Moreover, a limited number of studies have compared the techniques of detecting the HPV infection in OSCC. This study aimed at the detection of HPV 16 E6 and E7 DNA in OSCC by quantitative polymerase chain reaction (qPCR) technique.

METHODOLOGY

This retrospective study included 297 tissue sections obtained from histopathologically confirmed OSCC patients. The classification of tumors as poorly differentiated, moderately differentiated and well differentiated was performed by H&E staining following the WHO criteria for OSCC. The presence of HPV infection was detected by p16^INK4A expression, conventional PCR technique, HPV 16 E6, and E7 by qPCR and flow cytometry. All statistical analysis was performed using MedCalc software v.16.4.3. P < 0.05 is considered as statistically significant.

RESULTS

Of 297 samples, 128 samples were found to be HPV-positive by p16. Of total 128 HPV-positive samples, PCR, E6, and E7 qPCR were positive in 19, 97, and 98 samples, respectively. qPCR techniques were found highly significant in the detection of moderately differentiated (P < 0.0001) and widely differentiated (P < 0.0001) cases. The positivity of E6 qPCR increased as the p16 expression increased. A significant variation in E6 DNA copies was observed in different grades of p16 expression (P < 0.0001). However, overall E7 (5.4 × 10⁵ copies/μL) DNA copies were higher than E6 (7.7 × 10³ copies/μL).

CONCLUSION

qPCR detection of HPV infection is a fast, reliable, and accurate technique gives valuable information about the infection status in terms of viral load.

Human papillomavirus and oral squamous cell carcinoma: A review of HPV-positive oral squamous cell carcinoma and possible strategies for future

Oral squamous cell carcinoma (OSCC) is a common cancer worldwide. Besides tobacco use and alcohol consumption, human papillomavirus (HPV) infection has also been identified as a risk factor for OSCC recently. The OSCC incidence has increased in recent years, especially among younger women. The purpose of this article is to review clinical and epidemiological studies on the association between HPV infection and OSCCs, and the efficacy of HPV vaccine, so as to provide possible policy implications for preventing HPV-positive OSCC. It is necessary to review the present related body of knowledge to determine whether the association between HPV infection and OSCC has been thoroughly studied. The study was based on literature review. Studies were identified using electronic databases including MEDLINE, PubMed, EMBASE, etc. The inclusion and exclusion criteria were based on consultation from a panel of experts in this area and carefully designed. Based on a systematic review of literatures, HPV infection is a possible cause for the incidence of HPV-positive OSCCs. The prevalence of HPV infection possibly contributed to the increasing trends of HPV-positive OSCCs. Oral HPV infection is a form of HPV transmission. Oral sex behaviors and open-mouthed kissing are probably reasons for oral HPV infection. We also have some epidemiological evidences proving that HPV vaccine provides a possible solution for preventing oral HPV infection. Increased awareness of HPV-positive OSCCs is essential due to the severity of this problem. Biological and epidemiological data regarding the link between sexual behavior and HPV-associated cancers indicate a probable connection, although definitive data are needed. Future studies are needed to investigate the mechanisms of how HPV infection causes HPV-positive OSCCs, whether HPV vaccine provides a prevention for OSCCs, and other important issues.

Roles of Human Papillomaviruses and p16 in Oral Cancer

Head and neck cancer, including oral cancer, is the sixth most common cancer in humans worldwide. More than 90% of oral cancers are of squamous cell carcinoma type. Recent studies have shown a strong relationship between human papillomavirus (HPV) infection and head and neck cancer, especially oropharyngeal squamous cell carcinoma (OPSCC) and oral squamous cell carcinoma (OSCC). Moreover, the incidence of HPV-related OSCC appears to be on the rise while HPV-unrelated OSCC tends to have stabilized in the past decades. p16, a tumor suppressor gene, normally functions as a regulator of the cell cycle. Upon infection with high-risk types of HPV (HR-HPV), particularly types 16, 18, 31, 33, 34, 35, 39, 51, 52, 56, 58, 59, 66, 68, and 70, the expression of p16 is aberrantly overexpressed. Therefore, the expression of p16 is widely used as a surrogate marker for HPV infection in head and neck cancer.

Absence of high-risk HPV 16 and 18 in Chinese patients with oral squamous cell carcinoma and oral potentially malignant disorders

BACKGROUND

The critical role of human papillomavirus (HPV) in cancer has been recognized, but the involvement of HPV in oral squamous cell carcinoma (OSCC) and oral potentially malignant disorders (OPMD) is still controversial. The aim of this study was to identify and verify the prevalence of high-risk HPV infection (HPV16 and 18) in Chinese patients with OSCC or OPMD using real-time PCR and DNA sequencing.

METHODS

Paired tissue and serum DNA samples were extracted from 40 Chinese patients with OSCC and 59 with OPMD. A SYBR Green-based real-time PCR assay was developed to detect the E6 gene of HPV16 and HPV18. Suspicious positive samples were then sequenced to eliminate false positives.

RESULTS

We found that none of the tissue and serum samples of OSCCs and OPMDs were positive for HPV16 E6 or 18 E6, using both real-time PCR and DNA sequencing. Overall, 3 of 198 (1.52 %) and 7 of 198 (3.54 %) samples were false-positive for HPV16 E6 and HPV18 E6, respectively, using real-time PCR.

CONCLUSION

The lack of HPV16 and HPV18 detected in this study indicates that high-risk HPV 16 and 18 infections are uncommon in Chinese patients with OSCC and OPMD. Real-time PCR followed by DNA sequencing for HPV DNA detection is an effective strategy to rule out false positives.

HPV-associated head and neck cancers in the Asia Pacific: A critical literature review & meta-analysis

BACKGROUND

Malignancies of the upper aero-digestive tract are a major public health problem, especially in the Asia Pacific. Certain Human papillomaviruses (HPVs) are well-established risk factors for carcinoma of the uterine cervix and for a subset of head and neck carcinomata: however their true importance in different populations and anatomical subsites remains unclear. The major risk factors in Asia Pacific remain smoked/smokeless tobacco, areca nut, alcohol abuse and poor diet, with limited evidence for HPVs. We review published studies of association of HPV with anatomical site-specific Head & Neck Squamous Cell Carcinoma (HNSCC) in these populations and attempt a meta-analysis.

MATERIALS AND METHODS

From MEDLINE/PubMed/WEB-of SCIENCE/EMBASE/Scopus databases we found 67 relevant studies with a total of 7280 cases: 15 case-control studies met our inclusion criteria for meta-analysis, totaling 1106 cases & 638 controls. HPV detection rates, sample site and size, and methods of tissue preservation and HPV detection were tabulated for each study.

RESULTS

Studies were heterogeneous in terms of sample selection and method of detection of HPVs. Most were of limited quality. Averaging data from 67 studies of HNSCC, the prevalence of HPV of any subtype is approximately 36%. PCR (polymerase chain reaction) was the most used detection method and HPV16 the most common genotype reported. Meta-analyses of case-control studies from this region reveal significant heterogeneity but suggest higher HPV prevalence in oropharyngeal cancer (OR: 14.66; 95%CI: 6.09-35.26) compared to oral cavity cancer and laryngeal cancer; (OR: 4.06; 95%CI: 3.05-5.39 & OR: 3.23; 95%CI: 1.37-7.61) respectively.

CONCLUSION

In view of the significant association of HPV with HNSCC, studies with accurate subsite classification and more sensitive detection methods are necessary. Accurate data from this geographical region are essential to inform public health policies and treatment decisions, especially as studies from Europe and North America reveal HPV-driven cancers to be less aggressive, permitting treatment de-intensification.

Squamous cell carcinoma of the head and neck outside the oropharynx is rarely human papillomavirus related

OBJECTIVES/HYPOTHESIS

The incidence of human papillomavirus (HPV)-driven disease beyond the oropharynx varies greatly in the reported literature.

STUDY DESIGN

Case series.

METHODS

Two hundred twenty-one samples were strictly classified to the subsites of oral cavity, larynx, or hypopharynx at the time of primary surgery. Formalin-fixed paraffin-embedded samples were subjected to a validated, tiered, diagnostic algorithm of p16 immunohistochemistry, high-risk HPV in situ hybridization, and quantitative polymerase chain reaction for HPV E6 DNA. An additional 60 oropharyngeal cases acted as an internal biological control.

RESULTS

An incidence of 4% of HPV-driven cases was observed across the subsites outside the oropharynx compared to 70% of tumors confined within it.

CONCLUSIONS

This is the first reporting of a broad range of nonoropharyngeal HPV rates using this validated diagnostic algorithm. It remains unclear whether patients with HPV-driven disease originating outside the oropharynx enjoy the same survival advantage apparent in those patients with oropharyngeal squamous cell carcinomas.

LEVEL OF EVIDENCE

4 Laryngoscope, 124:2739-2744, 2014.

Association of Epstein-Barr virus infection with oral squamous cell carcinoma in a case-control study

BACKGROUND

Besides the well-known risk factors, Epstein-Barr virus (EBV) might play a significant role in oral squamous cell carcinoma (OSCC). To explore the role of EBV in OSCC, the prevalence of EBV infection in oral exfoliated cells of OSCC cases and controls in northeastern Thailand was investigated, and the association of EBV in tumor lesion cells was further confirmed.

METHODS

Oral exfoliated cells were collected from OSCC cases and non-cancer controls. Cells from tumor lesions were taken from OSCC patients for further strong confirmation of the association of EBV with OSCC. EBV DNA was detected by polymerase chain reaction (PCR) using primers specific for EBV DNA polymerase. The EBV DNA positive samples were confirmed further by nested PCR.

RESULTS

Epstein-Barr virus was detected in the oral exfoliated cells of 45.05% of OSCC patients and 18.08% of the non-cancer control (P < 0.001). Similarly, EBV was detected in 32.5% of the tumor lesions. Betel quid chewing was statistically significantly associated with EBV prevalence (OR = 2.08), whereas no association with tobacco smoking and alcohol consumption. Alcohol consumption and betel quid chewing were significantly associated with OSCC (OR = 3.05 and OR = 5.05, respectively), but tobacco smoking was not associated. Interestingly, EBV was significantly associated with OSCC (OR = 3.76).

CONCLUSIONS

Epstein-Barr virus prevalence is associated with OSCC and seems to be enhanced by betel quid chewing, suggesting that EBV may, together with betel quid chewing, act as an important etiological risk factor of OSCC.

PCR based detection of HPV 16 and 18 genotypes in normal oral mucosa of tobacco users and non-users

There is increasing evidence of a causal association between human papillomavirus (HPV) and oral squamous cell carcinoma (OSCC). Several studies have shown that HPV is associated with increased risk of oral cancer independent of exposure to tobacco and alcohol. The association is valid for HPVs 16 and 18, which generally are considered high risk types, because they have been detected in oral dysplastic lesions and cancers. We determined the baseline prevalence of HPVs 16 and 18 in normal oral mucosa of individuals with and without tobacco habit. PCR was used for DNA collected by oral smears to detect HPV 16/18 DNA in normal oral mucosa of 60 healthy individuals who were assigned to two groups of 30 subjects each. One group had a tobacco habit, the other did not. The tobacco user group comprised individuals who were tobacco chewers only. Sixty-five percent of individuals were positive for HPV 16/18 DNA, but HPV 16/18 positivity was less in individuals with tobacco habit than in those without tobacco habit. No significant association was found between the presence of HPVs and gender, age or duration of chewing habit, or between groups with and without a tobacco habit. We propose that HPVs16 and 18 commonly are present in normal oral mucosa and emphasize the importance of distinguishing clinical, subclinical and latent HPV infections when investigating HPVs and OSCC.

Detection and typing of human papillomaviruses (HPV) in malignant, dysplastic, nondysplastic and normal oral epithelium by nested polymerase chain reaction, immunohistochemistry and transitional electron microscopy in patients of northern Greece

OBJECTIVES

To evaluate the role of HPV in oral carcinogenesis, we examined the prevalence of HPV in malignant, potentially malignant and normal oral epithelium and studied the relation of HPV prevalence with other factors obtained from the patient's records.

MATERIALS AND METHODS

Our material consisted of 291 tissue specimens from 258 individuals. From every individual formalin fixed and paraffin embedded tissues were examined by nested Polymerase Chain Reaction (NPCR) for the detection of HPV DNA and by immunohistochemistry (IHC) for the in situ detection of HPV L1 protein. Positive PCR products were sequenced in order to type HPVs. Also 33 fresh tissues were obtained, fixed and used to detect HPV particles by transitional electron microscopy (TEM).

RESULTS

HPV was detected in 32.9% of the tissue specimens by NPCR, in 4.7% by immunohistochemistry and in 28.1% by TEM. In detail, by nested PCR HPV L1 DNA was detected in 40% of normal tissues, 40% of fibromas, 35.8% of non-dysplastic leukoplakias, 31.6% of dysplastic leukoplakias and 22.2% of oral squamous cell carcinomas. The HPV viral load of 96.5% of the samples was very low (1 viral copy per 10(2)-10(4) cells). HPV16 prevails in all histological groups in 89-100%.

CONCLUSION

We conclude that HPV does not seem, from the specific sample examined, to play a substantial role in oral carcinogenesis. However, it cannot be excluded that HPV could be involved in oral carcinogenesis only in cases with high viral load or at early stages of carcinogenesis possibly through the hit-and-run mechanism.

Prevalência do papilomavírus humano (HPV) em Belém, Pará, Brasil, na cavidade oral de indivíduos sem lesões clinicamente diagnosticáveis

Trata-se de um estudo transversal com o objetivo de verificar a prevalência do HPV na cavidade oral de indivíduos sem lesões clinicamente diagnosticáveis e quais são os tipos encontrados neles. Foram analisadas 166 amostras em pacientes maiores de 18 anos de idade, residentes no Estado do Pará, Brasil. As amostras foram coletadas por meio de raspado com escova estéril na cavidade oral. Para a detecção da presença do HPV, foi utilizada a técnica da reação em cadeia da polimerase (PCR). As amostras infectadas pelo HPV foram tipadas para HPV 6, 11, 16, 18, 31, 33, 35, 52 e 58. Os resultados encontrados indicaram a presença de HPV em 40 amostras (24,1%). Três amostras (7,5%) foram positivas para HPV 6; cinco (12,5%), para HPV 18; e uma (2,5%), para HPV 58.

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.

Human papilloma virus testing in oropharyngeal squamous cell carcinoma: what the clinician should know

High risk Human Papilloma virus (HR-HPV) associated oropharyngeal cancers are on the increase. Although, the scientific community is aware of the importance of Human Papilloma Virus (HPV) testing, there is no consensus on the assays that are required to reliably identify HR-HPV related tumors. A wide range of methods have been developed. The most widely used techniques include viral DNA detection, with polymerase chain reaction (PCR) or In Situ Hybridization, and p16 detected by immunohistochemistry. However, these tests provide different information and have their own specific limitations. In this review, we summarize these different techniques, in light of the recent literature. p16 Overexpression, which is an indirect marker of HPV infection, is considered by many head and neck oncologists to be the most important marker for patient stratification. We describe the frequent lack of concordance of this marker with other assays and the possible reasons for this. The latest developments in HPV testing are also reported, such as the RNAscope™ HPV test, and how they fit into the existing framework of techniques. HPV testing must not be considered in isolation, as there are important interactions with other parameters, such as tobacco exposure. This is an important and rapidly evolving field and is likely to become pivotal to staging and choice of treatment of oropharyngeal carcinoma in the future.

Human papillomavirus-32-associated focal epithelial hyperplasia accompanying HPV-16-positive papilloma-like lesions in oral mucosa

Human papillomavirus infection can cause a variety of benign or malignant oral lesions, and the various genotypes can cause distinct types of lesions. To our best knowledge, there has been no report of 2 different human papillomavirus-related oral lesions in different oral sites in the same patient before. This paper reported a patient with 2 different oral lesions which were clinically and histologically in accord with focal epithelial hyperplasia and oral papilloma, respectively. Using DNA extracted from these 2 different lesions, tissue blocks were tested for presence of human papillomavirus followed by specific polymerase chain reaction testing for 6, 11, 13, 16, 18, and 32 subtypes in order to confirm the clinical diagnosis. Finally, human papillomavirus-32-positive focal epithelial hyperplasia accompanying human papillomavirus-16-positive oral papilloma-like lesions were detected in different sites of the oral mucosa. Nucleotide sequence sequencing further confirmed the results. So in our clinical work, if the simultaneous occurrences of different human papillomavirus associated lesions are suspected, the multiple biopsies from different lesions and detection of human papillomavirus genotype are needed to confirm the diagnosis.

Human papillomavirus in non-oropharyngeal head and neck cancers: a systematic literature review

Perhaps one of the most important developments in head and neck oncology of the past decade is the demonstration that patients with human papillomavirus (HPV)-mediated oropharyngeal cancers have significantly improved outcomes, compared to HPV-negative counterpart patients. This has become the basis for clinical trials investigating the impact on "treatment deintensification" for patients with HPV-mediated oropharyngeal cancers. Unfortunately, the significance of HPV in non-oropharyngeal head and neck cancers is much less certain. Our goal is to systematically review the published data regarding the role HPV in carcinomas of the oral cavity, larynx, sinonasal tract and nasopharynx with respect to HPV detection frequency, viral activity, and association with outcome. We also present preliminary data on HPV16/18 transcriptional status in oral cavity carcinomas, as well as salivary gland neoplasia, as determined by nested reverse transcription PCR for HPV E6/E7 RNA. The weighted prevalence (WP) of HPV DNA detection in 4,195 oral cavity cancer patients is 20.2 %, (95 % CI 16.0 %, 25.2 %). HPV16 is the most common type detected. Importantly, no data currently demonstrates a significant association between the presence of HPV DNA and improved outcome. The WP of HPV DNA in 1,712 laryngeal cancer patients is 23.6 %, (95 % CI 18.7 %, 29.3 %). Similarly, no association has yet been demonstrated between HPV DNA status and outcome. The WP of HPV DNA detection in 120 sinonasal cancer patients is 29.6 % (95 % CI 17.8 %, 44.9 %), and in 154 nasopharyngeal carcinoma patients is 31.1 %, (95 % CI 20.3 %, 44.5 %). Recent preliminary data also suggests an association between HPV and certain salivary gland neoplasms. The clinical significance of these findings is unclear. The published data strongly support the need for studies on patients with oral and laryngeal carcinomas that will be powered to find any differences in clinical outcome with respect to HR-HPV and p16 overexpression.

Epidemiology of human papillomavirus-related head and neck cancer

Human papillomavirus (HPV) is now recognized to cause a subset of head and neck squamous cell carcinomas (HNSCC). Although excessive tobacco and alcohol use continue to be important risk factors for HNSCC, epidemiologic studies suggest that more than 25% of HNSCC are now caused by HPV. The incidence of HPV-related HNSCC is increasing, highlighting the need to understand the oral HPV infections causing these cancers. This article reviews the evidence for a causal association between HPV and HNSCC, examines the changing epidemiologic trends of HNSCC, and discusses what is currently known about oral HPV infection, natural history, and transmission.

Biopsy vs. brushing: comparison of two sampling methods for the detection of HPV-DNA in squamous cell carcinoma of the oral cavity

BACKGROUND

HR HPV infection was proposed as aetiological factor of oral squamous cell carcinomas (OSCC). HPV frequency in OSCC is highly variable, due to the discrepancy in oral sampling procedures, HPV testing methods and inclusion criteria regarding tumour site (strictly oral cavity vs. nearby structures). Our aim was to compare HPV DNA frequency and type-specific distribution in paired cytological and histological samples of SCC strictly located in oral cavity. The correlation between HPV detection rate by each method of sampling and demographical, behavioural and clinical-pathological variables was also examined.

PATIENTS AND METHODS

HPV DNA was detected in brushed cells and formalin-fixed paraffin-embedded biopsies obtained from 83 consecutive unselected immunocompetent adults with OSCC. HPV DNA detection was performed in all samples by nPCR followed by direct DNA sequencing and the assay INNO-LiPA HPV Genotyping. Univariate and multivariate statistics were used, including Cohen κ index to evaluate agreement between two methods and association between HPV infection and demographical, behavioural and clinical-pathological variables for each method of sampling (p<0.05 statistically significant).

RESULTS

HPV DNA was detected in 15.7% (13/83) of brushings and 12.1% (10/83) of biopsies (p>0.05). High risk HPV 51, 16 and 39 were genotypes more frequently detected, especially among biopsies; no concordance between two methods was found (Cohen κ index=0.04, p=0.34).

CONCLUSION

A fraction of OSCC could be linked to HR HPV infection in the Mediterranean area. Although without a statistical significance, biopsy specimen demonstrated more accurate for HR HPV detection than brushing in OSCC.

Interaction between Chronic Inflammation and Oral HPV Infection in the Etiology of Head and Neck Cancers

Incidences of oral tongue, base of the tongue, and tonsil cancers have been increasing steadily in many parts of the world in spite of declining rates of tobacco use over the last four decades. A better understanding of the etiology, interactions between risk factors, and new approaches to prevention and treatment are necessary to change this course. This paper will present evidence supporting a potential role of chronic inflammation in the etiologies of oral human papillomavirus infection and head and neck squamous cell carcinoma, and it will discuss the implications for prevention and treatment.

HPV-16/18 detection does not affect the prognosis of head and neck squamous cell carcinoma in younger and older patients

Recently, high-risk human papillomavirus (HPV) has emerged as a possible agent associated with head and neck squamous cell carcinoma (HNSCC) in younger patients. Therefore, the purpose of the present study was to assess the effect of age on the distribution of HPV-16/18 in HNSCC, together with the impact of the virus on patient prognosis. A longitudinal prospective study was used adjusted for age, gender, TNM staging, smoking status and alcohol consumption. HPV was detected by PCR with consensus primers. Results showed there was no difference in the frequency of HPV-16/18 positivity when younger patients were compared to the older patients. No association was found among high-risk HPV positivity, gender, smoking habit and anatomical site. High-risk HPV was associated with advanced TNM in bivariate analyses; however, it did not impact on survival. Only TNM staging was associated with risk of mortality. Our study supports the theory that age does not affect the presence of HPV-16/18 in HNSCC and has no impact on patient prognosis. The incidence of HNSCC among patients under the age of 45 years is reportedly on the increase worldwide. The factors associated with HNSCC in younger adults are not well established. Findings of this study indicate that HPV-16/18 may not play a role in HNSCC patients under the age of 45 years.

Human papillomavirus coinfection in the oral cavity of HIV-infected children

Aim

To identify the early presence of human papillomavirus (HPV) DNA in the oral cavity of HIV-infected children.

Methods

The study group comprised 50 HIV-infected children and 50 healthy aged paired controls. Oral mucosa samples were collected by swab, and a 450 bp HPV DNA fragment was amplified by PCR, using degenerate consensus primers directed to the L1 gene. HPV typing was performed using specifics primers for types 6/16 and 11/18.

Results

All HPV co-infected children had vertical transmission of HIV. HPV DNA was detected in 6/50 (12.0%) of HIV children and three control group individuals 3/50 (6.0%) (p>0.01). In the HIV group, one had type 11, in the control group one had co-infection of types 11/16, and the others had type 16 and 18.

Conclusions

Based upon the results, it is concluded that HPV DNA may be present in HIV disease, but no association with immunosuppression, delivery, or medical records (CD4 cell count, viral load and use of highly active antiretroviral therapy) was observed, and no differences could be observed between the groups either.

Are oral and dental diseases linked to cancer?

OBJECTIVE

Infection and inflammation play a role in carcinogenesis, and highly prevalent oral and dental diseases have been significantly linked to some types of cancer. This article reviews current literature in this area.

MATERIALS AND METHODS

Open literature review using the PubMed database and focused on publications from 2000 to 2010.

RESULTS

Numerous potential mechanisms are implicated in the oral disease/carcinogenesis paradigm, including infection- and inflammation-associated cell pathology and microbial carcinogen metabolism. Poor oral hygiene is associated with oral cancer, but there is also evidence of a possible link between oral or dental infections and malignancies in general.

CONCLUSION

Oral infections may trigger malignant transformation in tissues of the mouth and other organs. However, scientific evidence to date remains weak and further well-conducted studies are warranted before cancer can be properly added to the list of oral infection-related systemic diseases.

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.

p16 INK4A overexpression is frequently detected in tumour-free tonsil tissue without association with HPV

AIMS

Oncogenic human papillomavirus (HPV) type 16 has been strongly associated with tonsillar squamous cell carcinoma (TSCC) and appears to be of prognostic significance. Because HPV+ TSCC also accumulates p16(INK4A), this cyclin-dependent kinase inhibitor has been proposed as a potential biomarker for HPV in clinical diagnosis. The aim of this study was to determine the prevalence of HPV in tumour-free tonsillar tissue and the value of p16(INK4A) overexpression in predicting its presence.

METHODS AND RESULTS

p16(INK4A) overexpression was detected by immunohistochemistry in tissue sections of tumour-free tonsils of 262 patients. They were treated for non-oncological reasons (snoring or chronic/recurrent tonsillitis) consisting of tonsillectomy. Genomic DNA isolated from these tissues was subjected to HPV-specific polymerase chain reaction (PCR) analysis. p16(INK4A) immunoreactivity was detected in 28% of samples in both crypt epithelium (49/177) and lymphoid germinal centres (52/187), which correlated with each other (P < 0.0001). No reactivity was observed in superficial squamous cell epithelium. HPV16 and 18 were detected by PCR analysis in 2/195 cases (1%), which, however, were negative on fluorescence in situ hybridization analysis and discrepant on p16(INK4A) immunostaining.

CONCLUSIONS

No proof was found for the presence of HPV in tumour-free tonsil tissue, despite increased p16(INK4A) expression in a quarter of tonsil cases. Other mechanisms than HPV infection are therefore implicated in p16(INK4A) up-regulation.

Human papillomavirus in the etiology of head and neck carcinomas

BACKGROUND

For more than 20 years, infection with the human papillomavirus (HPV) has been of a matter of interest not only to gynecologists but also to maxillofacial surgeons and othorhinolaryngologists. HPV is generally known to be involved in cervical cancer. Recently, there are many clinical studies pointed out the potentially dangerous connection between HPV infection and head and neck carcinomas (HNC). HPV infection was identified as a possible etiological factor in 15-30% of HNC.

METHODS

Aim of this article is to summarize the recent knowledge about the HPV infection with regards to etiology of head and neck cancer.

RESULTS

It has been proven that HPV infection is related to development of head and neck cancer and that the sexual behavior has played an important role in the viral transmission. HNC of viral etiology have been observed mostly in younger people; their curability is difficult and prognosis serious.

CONCLUSION

Beside the well known correlation between developing of new head and neck cancer and bad habits (smoking, alcohol abuse, poor oral hygiene etc.) we should take into consideration the sexual promiscuity and alternative sexual practices. Vaccination against cervical cancer, recommended to young women, should be extended to their male partners to prevent the virus transmission and decrease the HNC incidence.

The role of HPV type in Recurrent Respiratory Papillomatosis

OBJECTIVE

Human Papillomavirus (HPV) 6 and 11 are the aetiological agents responsible for Recurrent Respiratory Papillomatosis (RRP). There is general consensus that HPV11 results in more aggressive disease compared to HPV6.

METHOD

Pubmed was searched using the terms respiratory papillomatosis, HPV 6 and HPV11. Comparisons were made in the outcomes of HPV6 versus HPV11 positive RRP disease.

RESULTS

There are numerous sub-types or variants of both HPV6 and HPV11. These sub-types have different activities at least in-vitro. The numbers of different HPV types within RRP tissue may be more extensive than initially appeared. This depends specifically upon the HPV types tested for.

CONCLUSION

The clinical differences between HPV6 and HPV11 disease may not be accurately predictable as these viruses exist in numerous sub-types. Also, RRP tissue may contain more than one subtype or even be co-infected with other viruses that may influence outcome. In-vitro studies upon cell lines are a reasonable starting point for evaluation of these differences.

Epithelial maturation and molecular biology of oral HPV

Human papillomavirus (HPV) is widespread and can cause latent infection in basal cells, with low HPV DNA copy-number insufficient for transmission of infection; can cause subclinical infection that is active but without clinical signs; or can cause clinical infection leading to benign, potentially malignant or malignant lesions. The HPV cycle is influenced by the stage of maturation of the infected keratinocytes, and the production of virions is restricted to the post-mitotic suprabasal epithelial cells where all the virus genes are expressed.Low-risk HPV genotypes are associated with the development of benign oral lesions, whereas high-risk HPV genotypes are implicated in the development of malignant epithelial neoplasms. The rôle of high-risk HPV as a causative agent in epithelial malignancy is different at different anatomical sites: it is almost invariably implicated in squamous cell carcinoma of the uterine cervix, fairly frequently implicated in squamous cell carcinoma of the oropharynx, and it is seldom implicated in squamous cell carcinoma of the mouth.

Laryngopharyngeal Reflux with Sore Throat: An Ultrastructural Study of Oropharyngeal Epithelium

Objectives:

We performed an electron microscopic ultrastructural study of oropharyngeal epithelium in patients with laryngopharyngeal reflux (LPR) and sore throat to evaluate whether dilatation of intercellular spaces could be traced at this level.

Methods:

The study included 20 patients with LPR and sore throat and 5 control subjects. The patients were subjected to upper gastrointestinal tract endoscopy and flexible pharyngolaryngoscopy. Oropharyngeal biopsy specimens were taken from the patients and controls for ultrastructural study by transmission electron microscopy.

Results:

The entire group of patients with LPR showed dilatation of intercellular spaces essentially at the squamous basal and suprabasal levels in their oropharyngeal biopsy specimens, whereas none of the control subjects showed such a morphological marker.

Conclusions:

Dilatation of intercellular spaces as a morphological marker can be traced in patients with LPR and sore throat at the level of the oropharynx. This contributes to a better understanding of the pathophysiology of LPR. If this finding is confirmed in a large series, it will represent a cost-effective, relatively noninvasive method for diagnosis of LPR.

Controversies surrounding human papilloma virus infection, head & neck vs oral cancer, implications for prophylaxis and treatment

Head & Neck Cancer (HNC) represents the sixth most common malignancy worldwide and it is historically linked to well-known behavioural risk factors, i.e., tobacco smoking and/or the alcohol consumption. Recently, substantial evidence has been mounting that Human Papillomavirus (HPV) infection is playing an increasing important role in oral cancer. Because of the attention and clamor surrounding oral HPV infection and related cancers, as well as the use of HPV prophylactic vaccines, in this invited perspective the authors raise some questions and review some controversial issues on HPV infection and its role in HNC, with a particular focus on oral squamous cell carcinoma.

The problematic definition and classification of HNC will be discussed, together with the characteristics of oral infection with oncogenic HPV types, the frequency of HPV DNA detection in HNC, the location of HPV-related tumours, the severity and prognosis of HPV-positive HNC, the diagnosis of oral HPV infection, common routes of oral infection and the likelihood of oro-genital HPV transmission, the prevention of HPV infection and novel therapeutic approaches.

Detection of HPV DNA and immunohistochemical expression of cell cycle proteins in oral carcinoma in a population of Brazilian patients

This study investigated the presence of human papillomavirus (HPV) DNA and viral types in 33 cases of oral squamous cells carcinoma (OSCC) and compared the immunohistochemical expression of the cell-cycle markers p21 and pRb between cases of the disease with and without HPV. DNA was extracted from paraffin-embedded tissue and amplified by PCR for the detection of HPV DNA. Viral typing was performed by dot blot hybridization. Immunohistochemistry was performed by the streptavidin-biotin technique. HPV DNA was detected in 11 (33.33%) of the 33 cases. The prevalent viral type was HPV 18 (81.81%). A significant association was observed between the presence of HPV and immunohistochemical expression of pRb, but not between p21 expression and the presence of the virus. The low frequency of detection of HPV DNA in OSCC suggests a possible participation of the virus in the development and progression of only a subgroup of these tumors.