[Determination of human papillomavirus in oral leukoplakia,oral lichen planus and oral squamous cell carcinoma]

OBJECTIVE

To investigate the possibility for human papillomavirus (HPV) infection to be a predictable signal for the carcinogenesis of oral mucosa by comparing the prevalences of HPV in each stage of oral mucosal carcinogenesis and to compare the sensitivity differences of the two methods in detecting HPV infection in oral cavity.

METHODS

The hybrid capture (HC-II) was used to detect infection of HPV in 255 samples taken from 12 cases of healthy oral mucosa, 211 cases of patients with pathological diagnosis and 32 cases of patients with clinical diagnosis. The diagnosed cases included 8 cases of benign lesions of the oral mucosa, precancerous lesions [74 cases of oral leukoplakia (OLK) with hyperplasia and 42 cases of OLK with oral epithelial dysplasia (OED)], 91 cases of precancerous condition [oral lichen planus (OLP)] and 28 cases of oral squamous cell carcinoma (OSCC). And in situ hybridization (ISH) was used to detect infection of HPV in 33 cases of OSCC and 76 cases of OLK, including 30 cases of hyperplasia, 15 cases of mild OED, 15 cases of moderate OED and 16 cases of severe OED.

RESULTS

The prevalence of HPV in OLP samples was higher (12.12%, 8/66) than that of OLK (2.59%, 3/116) (χ(2)=4.666, P=0.031) and OSCC(7.14%, 2/28, χ(2)=0.513, P=0.474). The prevalence of HPV in OSCC (7.14%, 2/28) was higher than that of OLK (2.59%, 3/116), and no significant difference was found. There was only one case of smoke spot and statistical analysis was not carried out. ISH was used to detect type 16/18 and type 31/33 HPV DNA in 109 cases of oral mucosal lesions in paraffin sections and only one case of OSCC was HPV positive. Thirty-seven cases were detected by HC-II and ISH methods at the same time. The same negative results by the two methods were found in 94.6% samples (35/37). In the other two samples, one was OSCC with early infiltration and the other was OLK with hyperplasia, The HC-II results were positive while the ISH results were negative. The patients with OLP and HPV testing results were followed up and the average follow-up period was (36.2 ± 10.5) months. It was found that three of them had a malignant transformation, and the malignant transformation rate of HPV positive patients was 12.50% (1/8), which was higher than that of HPV negative patients (3.45%, 2/58), and the difference was not statistically significant, P=0.249.

CONCLUSION

HC-II assay was more sensitive in detecting HPV infection of oral mucosal lesions than ISH. The results of this study showed that there was insufficient evidence for taking HPV infection as a predictor of OLK carcinogenesis. Patients suffering from OLP were in a precancerous condition. The prevalence of HPV in OLP patients of this study was higher than that in OLK and OSCC patients, suggesting that for some reason, OLP patients were susceptible to HPV. HPV testing can be considered as routine in patients with OLP, and HC-II assay was recommended. And patients with OLP and HPV positive should be followed up regularly.

Retrospective case-control study of viral pathogen screening in proliferative verrucous leukoplakia lesions

OBJECTIVE

This study aimed to survey the presence of known oncoviruses in oral biopsies from patients diagnosed with the aetiologically undetermined proliferative verrucous leukoplakia and compare results to those from milder oral leukoplakia (OL) cases, oral squamous cell carcinoma, a common outcome of the lesions of interest, and healthy controls.

DESIGN

Blind, retrospective, case-control study.

SETTING

A stomatology unit in an academic Hospital and a Public Health laboratory.

PARTICIPANTS

Forty patients were divided in four groups. Ten patients had been diagnosed with proliferative verrucous leukoplakia, 10 with OL and 10 with OSCC, and 10 were healthy subjects.

MAIN OUTCOME MEASURES

The presence or absence of oncovirus DNA was assayed with the amplification of viral genetic markers using PCR and subsequent gel electrophoresis confirmation. Amplified fragments were sequenced and identified bioinformatically.

RESULTS

No DNA from the herpesvirus, papillomavirus or polyomavirus species was detected in the samples.

CONCLUSIONS

No association between proliferative verrucous leukoplakia and target viruses was detected. A higher throughput viral metagenomic approach may prove valuable for future analyses, as it would not be restricted to a priori knowledge of potential targets.

[Papillomavirus in the genesis of oral leukoplakia]

Immunohistochemical examination of the proliferative activity of cells was made investigating the expression of Ki-67 protein and the location of proteins associated with epithelial cell papillomavirus infection involving P16(INK4a) and HPV16 proteins in different cell areas of the intact mucosa, in leukoplakia with the signs of hyperplasia and dysplasia, and in squamous cell carcinoma. There was a positive correlation between the proliferative activity of cells in the parabasal cell areas and the expression of P16(INK4a) protein in oral leukoplakia with the signs of hyperplasia (r(s)=0.397; p=0.018). In oral leukoplakia with dysplastic changes, there was a positive correlation between the proliferation of cells in the parabasal and prickle cell layers and the location of HPV type 16 antigens (r(s)=0.515; p=0.041 and r(s)=0.651; p=0.006). Detection of papillomavirus infection in leukoplakia can solve not only the problems with its genesis, but this is also a morphological basis for the effective prevention and treatment of this common oral mucosal disease.

Low prevalence of high risk genotypes of human papilloma virus in normal oral mucosa, oral leukoplakia and verrucous carcinoma

OBJECTIVE

Squamous Cell Carcinoma (SCC) is the most common malignancy of the oral cavity and Verrucous Carcinoma (VC) is its least invasive form with no metastasis potential. Leukoplakia (clinical term for hyperkeratosis and acanthosis with and without dysplasia) is the most common pre-malignant lesion of the oral cavity. Human Papilloma Virus (HPV) has been recognized as an etiologic factor for mentioned lesions. In this study the relationship between high risk types of this virus (HPV(HR)) with VC and Leukoplakia is investigated.

MATERIALS AND METHOD

Forty-one paraffin-embedded blocks including 21 VC, 20 leukoplakias in addition to 18 normal oral mucosal tissues as the control group were studied by Polymerase Chain Reaction (PCR) to detect HPV 16, 18, 31 and 33.

RESULTS

In three specimens of VCs (14.3%) HPV(HR) was detected. Each of these contained both HPV 16 and 18. All three positive specimens belonged to women older than 65 and were obtained from the vestibule of the mandible. Neither Leukoplakia nor normal mucosa showed HPV presence. No significant relationship between HPV and VC was found compared with the control group (p = 0.23).

CONCLUSION

This study did not show relationship between HPV and leukoplakia. Although no statistically significant relationship was found between HPV and VC, but considering sample size limitation for such uncommon cases, its presence in three cases of 14 makes more investigations to overcome the controversies necessary.

Prevalence and relationship of human papilloma virus type 16 and type 18 with oral squamous cell carcinoma and oral leukoplakia in fresh scrappings: a PCR study

INTRODUCTION

It has been always an area of diffuse clarity when you study malignancy and its pathogenesis. Recently, it has invited lot of interest among the researchers about the possibility of role of viruses in the initiation of carcinogenesis. Recent advances in the field of molecular biology and biotechnology have solved some problems with regard to pathogenesis. Human papilloma virus (HPV) and its role in the initiation of malignancy in the cervix is proven almost beyond doubt.

OBJECTIVES

The present study is aimed at the role of two types of HPV 16 and 18 in the initiation of oral premalignant and squamous cell carcinoma. The study also aims at using polymerase chain reaction (PCR) in finding out the prevalence of these types diagnosed histologically as oral leukoplakia and oral squamous cell carcinoma and prevalence of its association with the habit of tobacco use.

MATERIALS AND METHODS

In the present study, 45 patients having histopathologically confirmed oral squamous cell carcinoma in the age range of 32-85 years were selected along with 20 histopathologically confirmed oral leukoplakia in the age range 22-66 years. All the samples were subjected to polymerase chain reaction. The PCR reaction was carried out in PTC 200 thermo-cycler [MJ Research Inc, Watertown, MA, USA].

RESULTS

The site prevalence and co-infection rate of these two types of viruses are being analyzed using very simple non-invasive scrapings obtained from fresh scrapings and found to be really high. It was also observed that 73.3% (33/45) of the oral squamous cell carcinoma patients were positive for oral HPV type 16 while 71.1% (32/45) were positive for HPV type 18 infection and 57.7% (26/45) were found to have both HPV type 16 and HPV type 18 infections.

CONCLUSIONS

HPV type 16, 18, and co-infection of both types showed high prevalence in oral squamous cell carcinoma.The prevalence of HPV type 18 was found to be higher than HPV type 16 and co-infection in oral leukoplakia. It was observed that the tongue and palate lesions in the oral squamous cell carcinoma patients showed high prevalence of HPV type 16, type 18, and co-infection compared with other sites.

Variant haplotypes at XRCC1 and risk of oral leukoplakia in HPV non-infected samples

BACKGROUND

One of the mechanisms in human papillomavirus (HPV)-related carcinogenesis is inhibition of DNA repair by HPV oncoprotein. In this study, we investigated whether polymorphisms at XRCC1, one of the DNA repair loci, could modulate the risk of tobacco-related leukoplakia and cancer in HPV-infected individuals.

METHODS

Tissue DNA from 83 oral cancer, 91 leukoplakia and 100 healthy controls were screened for HPV 16/18 infection and polymorphisms at XRCC1 by PCR-RFLP to estimate the risk of diseases independently and jointly.

RESULTS

Human papillomavirus infection was significantly associated with increased risk of leukoplakia and cancer (OR = 2.8, 95% CI = 1.2-6.5 and OR = 5.5, 95% CI = 1.6-19, respectively). Independently, genotypes at three polymorphic sites on XRCC1 did not modulate the risk of diseases but pooled variant haplotypes increased the risk of leukoplakia in overall and HPV non-infected (OR = 1.8, 95% CI = 1.2-2.8; OR = 2.2, 95% CI = 1.2-4.0, respectively) samples but not that of cancer.

CONCLUSION

The association between variant haplotypes at XRCC1 and risk of leukoplakia is pronounced in non-infected individuals since HPV oncoprotein could inhibit directly the DNA repair activity of XRCC1. But more samples of leukoplakia and cancer are essential to validate these results.

Genotypic determination by PCR-RFLP of human papillomavirus in normal oral mucosa, oral leukoplakia and oral squamous cell carcinoma samples in Madrid (Spain)

BACKGROUND

Human papillomaviruses (HPVs), especially genotypes 16 and 18, are considered to be human carcinogens by the International Agency for Research on Cancer (IARC). They are the most important etiological agents of uterine cervix cancer but their true role in oral carcinogenesis is controversial.

OBJECTIVES

To detect the presence of HPV genome genotypes in oral leukoplakia and oral squamous cell carcinoma (OSCC) and analyze their relationship with clinicopathological variables.

MATERIALS AND METHODS

Presence of genome ofHPV types 6, 11, 16, 18, 31, 33, 39, 42, 45, and 52 was studied by polymerase chain reaction in samples of normal mucosa (30 controls), oral leukoplakia (35 cases) and OSCC (33 cases). Results were compared between groups and differences were examined in relation to clinical and histological variables.

RESULTS

HPV genome was detected in 23.3% of controls, 45.7% of oral leukoplakias, and 39.4% of OSCCs. Only HPV-16 was significantly (p=0.0005) more frequently detected in leukoplakias (40%) and OSCCs (33.3%) versus controls (0%). No significant relationship was found between the presence of viral genome and the main clinicopathological variables.

CONCLUSION

According to these findings, the presence of HPV-16 is significantly associated with oral leukoplakia and OSCC lesions, therefore in our setting this virus may be a carcinogenic element in this disease.

Detection of human papillomavirus in oral squamous cell carcinoma, leukoplakia and lichen planus in Thai patients

Although tobacco, alcohol abuse and betel nut chewing habit are well recognized risk factors for oral squamous cell carcinoma (OSCC), there is evidence to indicate that human papillomavirus (HPV) may also play some inducing role. The purpose of this study was to investigate the presence of HPV in Thai patients with oral squamous cell carcinoma, leukoplakia and lichen planus using the polymerase chain reaction (PCR). Biopsies of oral squamous cell carcinoma, leukoplakia and lichen planus were obtained from 65 patients, 15 males and 50 females, aged between 30- 88 years old. Extracted DNA was evaluated for HPV infections by PCR analysis using consensus primers specific for L1 region of HPV. Only one sample (1.54%) was positive, suggesting that HPV may not play an important role in this group of Thai patients.

Epstein-Barr virus in oral proliferative verrucous leukoplakia and squamous cell carcinoma: A preliminary study

The aim of this study was to analyze proliferative verrucous leukoplakia (PVL) and oral squamous cell carcinoma (OSCC) for the possible presence of Epstein-Barr virus (EBV). We studied three groups: Sub-Group 1 was composed of 10 patients with PVL, (6 of whom had developed OSCC); Sub-Group 2 comprised 5 patients with OSCC but no preceding PVL; and Sub-Group 3 were 5 controls with clinically normal oral mucosa. Oral biopsies from all cases were examined for Epstein-Barr virus (EBV) by nested PCR. EBV was detected in 60% of Sub-Group 1 patients (PVL ) and in 40% of Sub-Group 2 (OSCC), but in 0% of Sub-Group 3 (controls).

Highly sensitive detection of HPV-DNA in paraffin sections of human oral carcinomas

BACKGROUND

Although human papillomavirus (HPV) infection has been shown to be a significant carcinogen in cervical squamous cell carcinoma (SCC), its significance in oral SCC remains unclear.

METHODS

We developed highly sensitive detection methods for HPV to elucidate the prevalence and localization of HPV in paraffin sections from human oral SCC using modified in situ polymerase chain reaction (PCR) and in situ hybridization AT tailing (ISH-AT). Analyses revealed a high prevalence of several HPV types (HPV-16, -18, -22, -38 and -70) under optimal conditions. The ISH-AT method can be used as an alternative to in situ PCR.

RESULTS

Various staining patterns were observed in the 20 cases examined, and HPV-positive cells were localized within the surface epithelium as well as in neoplastic cells. We demonstrated that HPV-DNA could be detected in paraffin sections using either the method of in situ PCR or ISH, providing an appropriate primer and probe are used.

CONCLUSION

These results suggest that HPV infection could be one of several risk factors being involved in oral SCC.

Lack of association between proliferative verrucous leukoplakia and human papillomavirus infection

PURPOSE

To analyze proliferative verrucous leukoplakia (PVL) for the presence of human papillomavirus (HPV) in different stages of the disease.

MATERIALS AND METHODS

We studied 13 patients with PVL. In 10 patients (76.9%), a lesional biopsy was taken and frozen at -40 degrees C. Four patients were instructed to mouth rinse with sterile sera. The biopsy and rinse samples were analyzed for HPV by PCR.

RESULTS

We did not detect HPV infection in the PVL tissue or in the oral rinse of any of the 13 patients in any stage of the disease analyzed, neither in oral squamous cell carcinoma nor in the simple hyperkeratosis.

CONCLUSION

There was no association between PVL and HPV infection in our patients.

Human papillomaviruses in oral squamous cell carcinoma and pre-cancerous lesions detected by PCR-based gene-chip array

Human papillomavirus (HPV) infection is a significant risk factor for uterine cervical carcinoma. Many studies have also demonstrated the presence of HPV in oral epithelia tissue, but the role of HPV infection in oral squamous cell carcinoma (OSCC) is still controversial. The aim of this study was to determine the frequency and type of HPV in OSCC and oral pre-cancerous lesions. DNA samples were collected by cytobrushing from 51 patients with OSCC, 46 with oral pre-cancerous lesions and 90 normal controls. Nested polymerase chain reaction and gene-chip arrays were used to identify the HPV types in the samples. In pre-cancerous lesions, there was a higher frequency of HPV of any type (14/46, OR = 2.844, CI = 1.186-6.816, P = 0.0216) and of low-risk HPV types (9/46, OR = 5.529, CI = 1.597-19.14, P = 0.0096) than in control samples. The prevalence of high-risk types was significantly higher in OSCC than in control lesions (11/51 vs 8/90, OR = 2.819, CI = 1.051-7.558, P = 0.0420) but this was not the case for HPV of any type (13/51 vs 12/90, OR = 2.244, CI = 0.9266-5.337, P = 0.1066). High-risk HPV types are prevalent in OSCC and may play a role in its progression, while low-risk types are associated with oral pre-cancerous lesions.

No evidence of hepatitis C virus infection in Serbian patients with oral leukoplakia

BACKGROUND

A review of the literature reveals controversy regarding the relationship between hepatitis C virus (HCV) infection and oral leukoplakia (OL). The aim of this study was to determine the frequency of HCV antibodies in patients with OL and control subjects resident in Serbia.

METHODS

In this cross-sectional study 73 consecutive patients with histologically proven OL and 90 control subjects, whose age and gender were matched, were examined for the presence of serological evidence of chronic hepatic disease, hepatitis B surface antigen (HBsAg) and anti-HCV seropositivity.

RESULTS

None of the patients with OL or control subjects had antibodies to HCV or HBsAg. All patients with OL and control subjects had normal liver function.

CONCLUSION

The present data indicate that patients with OL resident in Serbia do not have evidence of HCV or HBV infection.

Interplay between human papilloma virus infection and p53 gene alterations in head and neck squamous cell carcinoma of an Indian patient population

AIM

To investigate the complex interplay between human papilloma virus (HPV) infection and p53 gene alteration in 92 head and neck squamous cell carcinoma (HNSCC) and 28 leukoplakia samples from eastern India.

METHODS

DNA isolated from the patient samples was subjected to HPV detection, loss of heterozygosity (LOH) analysis of the chromosome 17p region harbouring p53, genotyping at the p53 codon 72 locus and sequencing of the entire p53 gene to identify somatic mutations. Codon 72 heterozygotes carrying the p53 mutation were further cloned and resequenced to identify the allele harbouring the mutation.

RESULTS

HPV positivity in the HNSCC samples was 69%; 21% of the HNSCC were found to harbour p53 mutations in the coding region of the gene. The absence of the p53 mutation in HPV positive tumours was statistically significant compared to the HPV negative tumours (p = 0.01), but the same did not hold true for p53 LOH (p = 1.0). Among the germline p53 codon 72 heterozygotes, the Pro allele was preferentially lost (p = 0.02) while the Arg allele was mutated in the majority of cases. The risk of HPV mediated tumourigenesis increased with the increase in number of Arg alleles at the codon 72 locus.

CONCLUSION

It is proposed that genetic and epigenetic alteration of p53 follow distinct pathways during the development of HNSCC from normal epithelium via dysplasia. The p53 mutation and HPV mediated p53 inactivation possibly constitute two independent pathways of tumourigenesis.

Biopsy vs. superficial scraping: detection of human papillomavirus 6, 11, 16, and 18 in potentially malignant and malignant oral lesions

BACKGROUND

Several epidemiologic studies have shown a broad variation in the prevalence of human papillomavirus (HPV) in oral precancerous tissues and oral carcinomas.

METHODS

Biopsies and superficial scrapes of lesions, clinically suspected of HPV infection, were taken from patients with potentially malignant and malignant oral lesions, and subject to HPV DNA detection by PCR-Southern blot analysis.

RESULTS

From 22 patients with potentially malignant and malignant lesions analyzed, 41% of the biopsies were HPV DNA positive, whereas 95-100% of the superficial scrapes were positive (McNemar, P < 0.0001). Clinical presumption of HPV infection detected 67% (P < 0.0001) of the HPV DNA positive cases compared with 48% (P < 0.0001) determined by cytology and histopathology. The prevalence of HPV 6, 11, 16 and 18 in the oral mucosa was studied in 59 individuals. While 9% of normal controls were HPV DNA positive, 100% of the patients with potentially malignant and malignant lesions were HPV DNA positive, and the prevailing genotype was HPV 16 followed by HPV 18.

CONCLUSIONS

The higher HPV DNA detection rate in superficial oral scrapes than in biopsies suggests that accurate epidemiological information on oral HPV infection/oral carcinogenesis depends not only on the DNA detection technique, but also on the tissue/cell sampling procedure.

Incidence of human papillomavirus infection in oral leukoplakia. Indications for a viral aetiology

Epidemiological and experimental studies have indicated a possible role of human papillomavirus (HPV) in the etiopathogenesis of oral premalignant lesions and tumors. The aim of this study was to establish the incidence of HPV infection and the typing of genotypes in some patients with nonmalignant oral cavity pathology and healthy subjects. We selected 80 subjects affected by the following pathologies: oral leukoplakia (20), squamous cell papilloma (6), various forms of stomatitis (30), lichen planus (15), burning mouth syndrome (BMS, 9). Ten healthy subjects were used as control. The patients underwent a brushing directly on the lesion or on the lower gums and on the dorsal surface of the tongue and a new, sensitive method of in situ hybridization (ISH) with colorimetric signal amplification was used for HPV detecting. The samples were tested with a Mix probe, which identifies most of the HPV genotypes and, in positive cases, the specific probe for the 6-11, 31-33-51 and 16-18 genotypes, was used. Leukoplakia and papilloma were , therefore, associated with the HPV infection, differently from the other pathologies and healthy oral mucosa (chi-squared < 0.005). In conclusion, according to our findings, HPV is a specific risk factor for the development of oral premalignant lesions.

Use of fuzzy neural networks in modeling relationships of HPV infection with apoptotic and proliferation markers in potentially malignant oral lesions

To evaluate in oral leukoplakia the relationship between HPV infection and markers of apoptosis (bcl-2, survivin) and proliferation (PCNA), also conditionally to age, gender, smoking and drinking habits of patients, by means of Fuzzy neural networks (FNN) system 21 cases of oral leukopakia, clinically and histologically diagnosed, were examined for HPV DNA presence, bcl-2, survivin and PCNA expression. 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. All markers were investigated by means of standardised immunohistochemistry procedure. Data were analysed by chi-square test, crude OR and the 95% CI; in blindness, FNN was applied. HPV DNA was found in 8/21 OL (38.1%); survivin, PCNA, and tobacco smoking were associated in univariate analysis (p = 0.04) with HPV DNA status. HPV-18 was the most frequently detected genotype (6/8), followed by HPV-16 (2/8). FNN revealed that survivin and PCNA, both being expressed in all of OL HPV+ve, were associated with HPV infection. In conclusion, the FNN allowed to hypothesise a model of specific variables associated to HPV infection in OL. The relevance of survivin and PCNA suggest that they may be involved in HPV-mediated deregulation of epithelial maturation and, conversely, that HPV may have a role in the expression level of these two markers. FNN system seems to be an effective tool in the analysis of correlates of OL and HPV infection.

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.

Proliferative verrucous vs conventional leukoplakia: no significantly increased risk of HPV infection

Proliferative verrucous leukoplakia (PVL) is a very aggressive form of oral leukoplakia (OL) with high morbidity and mortality rates, hypothesised to be linked to HPV infection. This study aimed to determine the presence of HPV DNA in PVL in comparison with OL, and in relation to social-demographical variables (age, gender, smoking and drinking habits) in an Italian multi-centric hospital-based study. The study group consisted of 58 cases of PVL and 90 cases of OL as controls (47 homogeneous (H) and 43 non-homogeneous (non-H) form), both recruited from four Italian cohorts. HPV DNA was identified in exfoliated mucosal cells by nested PCR (nPCR) with MY09/MY11 and GP5+/GP6+ primer pairs and the HPV genotype determined by direct DNA sequencing. HPV DNA was found in 24.1% (14/58)of PVL and in 25.5% (23/90) of OL; there was thus no significant difference found between PVL and OL (both forms) for risk of HPV infection (OR=0.93; 95% IC:0.432-1.985). Similarly, in both groups of PVL and OL lesions, no statistic association was found between any demographical variable considered and HPV infection. HPV-18 was the most frequently detected genotype in all tissues, being found in 78.5% and 60.8% of HPV+ve PVL and OL, respectively. Other more rarely detected genotypes were HPV-16 (28.6% in PVL and 13% in OL), HPV-6 (17.4% in OL) and HPV-53 (8.8% in OL). PVL does not appear more likely to be associated to HPV infection than conventional OL lesions.

HPV DNA and survivin expression in epithelial oral carcinogenesis: a relationship?

HPV has been thought to be involved in the development of several oral diseases, such as premalignant mucosal lesions and oral carcinoma. Survivin is a recently characterized IAP protein, which is abundantly expressed in most solid and haematological malignancies, but undetectable in normal adult tissues. Aim of this study was to investigate survivin expression and HPV presence in oral premalignant lesions and oral carcinoma. 47 samples of oral tissue including 11 squamous cell carcinomas (OSCC), 16 oral leukoplakias (OL) and 20 normal oral mucosa specimens, after investigation of HPV presence by nested PCR (consensus MY/GP primers) and viral genotype identification by direct sequencing were investigated by immunohistochemistry to detect survivin expression. Survivin expression was evident in 4/7 (57.1%) HPV+ and 4/4 (100%) HPV- OSCC, 6/7 (85.7%) HPV+ and 5/9 (55.5%) HPV- OL and in 0/20 (0%) control samples. Data showed high levels of survivin expression in HPV-positive SCCs, even if mean values were lower than HPV-negative ones, which in particular showed survivin expression in 100% of cases. Conversely, survivin expression was greater in HPV+ precancerous lesions than in HPV- ones. Our findings suggest that survivin may be involved in HPV- mediated deregulation during maturation of squamous epithelium through modulation of the apoptotic processes and, conversely, HPV may have a direct or indirect effect on the regulation of the survivin expression level. In particular, the results of this study suggest distinguishing between cancerous and precancerous oral lesions with respect to survivin expression when HPV infection is present. The most unfavourable behaviour is likely to be for the HPV- OSCC.

Human papillomavirus 6/11, 16 and 18 in oral carcinomas and benign oral lesions

We have examined 118 oral squamous cell carcinomas, 72 oral leukoplakias, 12 cases of cheilitis and 65 of oral lichen planus for the presence of human papillomavirus (HPV) 6/11, 16 and 18 DNA by PCR/Southern blot hybridization. HPV DNA were found in 51/118 carcinomas (43.2%), in 16/72 (22.2%) leukoplakias, 3/12 (25.0%) cheilitic lesions and 10/65 (15.4%) lichen planus cases. These differences were even stronger when analyzing separately for the high-risk types HPV 16 and 18 as compared to low-risk types 6/11. HPV 16 and 18 DNA were present in 41/118 (34.7%) oral carcinomas, 12/72 (16.7%) leukoplakias, 2/12 (16.7%) cheilitic lesions and 6/65 (9.2%) lichen planus. In contrast to this, oral carcinomas displayed the lowest HPV 6/11 detection rate (4.2%), compared with 11.1% for leukoplakias, 8.3% for cheilitic lesions and 7.7% in lichen planus. These results indicate a successive increase of the detection rate of HPV 16 and 18 from low level in non or questionably preneoplastic lesions (lichen planus) to preneoplastic lesions (leukoplakia and cheilitis) and to oral carcinoma. In conclusion, our results suggest an association of oral carcinogenesis and infection with the high-risk HPV types 16 and 18.

Lack of association between hepatitis C virus and oral epithelial dysplasia in British patients

Oral lichen planus may be a premalignant condition. An association between hepatitis C virus (HCV) infection and oral lichen planus has been described in Southern European and Japanese patients, and recently an association between HCV and oral squamous cell carcinoma was suggested from a study of Japanese patients. The present study investigated the frequency of chronic liver disease and HCV infection in UK patients with oral epithelial dysplasia (OED), a known premalignant disorder. Subjects included 75 patients with histologically proven OED and 110 healthy controls. Liver function and IgG antibodies to HCV were examined serologically. No patient with OED or control subject had serological evidence of hepatic disease, and anti-HCV antibodies were detected in only two (2.6%) of the 75 patients with OED, none of the controls being HCV seropositive. It is concluded that in the UK there is no association between HCV infection and OED.

[Presence of human papillomavirus in malignant oral lesions]

The purpose of this study was to investigate the prevalence of human papillomavirus 6/11 and 16/18 in patients, with oral lesions clinically diagnosed as leucoplakia, attending the School of Dentistry, University of São Paulo State/UNESP, Brazil. After paraffin embedded process, in the sections staining with H&E, 30 biopsies were screened and separated on 3 groups: 10 oral lesions without dysplasia, 10 with dysplasia, and 10 with invasive squamous cell carcinoma. The lesions with dysplasia were classified in agreement with Van Der Wall's histopathological standard method. Oral lesions were investigated for the presence of human papillomavirus (HPV) by in situ hybridization with wide-spectrum, 6/11 and 16/18 biotinylated probes. HPV 16/18 was found in 20% (n = 2) of the leucoplakia with severe-degree dysplasia. The presence of HPV 16/18 in malignant lesions suggests its importance as a risk factor for oral carcinogenesis.

[Human papillomavirus (HPV) in laryngeal leukoplakia]

Epidemiological data and results of molecular studies suggest that human papillomavirus could be considered a risk factor for the upper respiratory tract cancers. HPV infection plays also the important role in the laryngeal precancerous states. Six out of 16 studied cases of laryngeal leukoplakia revealed presence of HPV DNA (37.5%). In situ hybridisation technique was used for the detection of viral DNA.

Oral proliferative verrucous leukoplakia (PVL); open trial of surgery compared with combined therapy using surgery and methisoprinol in papillomavirus-related PVL

Proliferative verrucous leukoplakia (PVL) is a unique oral white lesion in which human papillomavirus (HPV) may play a role. PVL behaves far more aggressively than other forms of leukoplakia with a high rate of recurrence after surgical excision, and relentless progression to verrucous hyperplasia and to verrucous or squamous cell carcinomas. The treatment of PVL is usually by surgery, but there is often early recurrence. This study was an open trial of surgery in 25 patients with oral HPV-positive PVL, compared with combined therapy using surgery and methisoprinol in another group of 25 patients with oral PVL. Six months postoperatively there was a significant difference, with 18 recurrences in the patients treated by surgery alone compared to only two recurrences in the patients treated also with methisoprinol (isoprinosine or inosine pranobex), a synthetic agent with immunomodulatory properties and some antiviral activity against HPV. Eighteen months postoperatively there were no further recurrences in the patients treated by surgery alone but another two recurrences in the patients treated with methisoprinol. Overall, by 18 months follow-up, there were 18 recurrences in the group treated by surgery alone, compared with four in those also receiving methisoprinol. The use of this antiviral agent appeared to offer a significant enhancement to the surgical management of PVL.

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.

Papillary lesions of the oral cavity: relationship to human papillomaviruses

Human papillomaviruses are a group of genetically related organisms that infect stratified squamous epithelium. Unlike many other viruses that infect oral epithelium and induce lysis of the cells they penetrate, HPVs induce proliferative changes in these cells that result in both benign and malignant tumors. The common skin wart (verruca vulgaris) is induced by HPV 2 and 4. Genital warts (condylomas) and the common solitary oral papilloma are associated with HPV 6 and 11. Either HPV 13 or 32 causes focal epithelial hyperplasia. All of these wart-like lesions are benign growths of the stratified squamous lining of the oral cavity and lips and can be treated by surgical excision or laser ablation. HPV 16 and other less frequently encountered genotypes are associated with uterine cervix cancer in 95 percent to 98 percent of cases, and the evidence for a causal role is robust. There are emerging data that implicate HPV in certain subsets of oral cancer, particularly those that arise in the oropharynx/tonsillar region. Some instances of the various histologic subtypes subsumed under proliferative verrucous leukoplakia and verrucous carcinoma also harbor HPV.

Proliferative verrucous leukoplakia of the gingiva

OBJECTIVE

The purpose of this study was to describe the clinical-pathologic features of what appears to be a gingival form of proliferative verrucous leukoplakia.

STUDY DESIGN

Ten adult patients with recurrent and histologically progressive gingival leukoplakias who were diagnosed and treated at the University of California, San Francisco between 1994 and 1999, comprised the subject group for this investigation. Clinical and microscopic features were reviewed. Proliferation indices and p53 expression were evaluated immunohistochemically, and the presence of human papillomavirus (HPV) DNA was determined by using polymerase chain reaction (PCR) amplification.

RESULTS

Lesions presented as solitary or regional flat/papillary/verrucal leukoplakias of the free and attached gingiva (tooth-bearing areas only). With time, flat lesions developed a papillary or verruciform profile. Although lesions were recurrent, they were confined to the gingiva, and multiple lesions did not develop. Half the patients used tobacco, and HPV could not be detected by using PCR. Microscopically, 6 cases began as hyperkeratotic lesions, and 4 initially exhibited a psoriasiform pattern with a marked inflammatory component. With recurrences, the lesions became progressively atypical histologically. The proliferation indices for these lesions showed modest increases over normal epithelium, and positive p53 staining was evident in 4 of 10 cases, indicating a disruption of the keratinocyte cell cycle in these lesions. The mechanism associated with the positive p53 staining (protein binding to wild type p53 versus mutation of the p53 gene) was not determined. Lesions recurred after conservative scalpel or laser excision, and many developed into verrucous or squamous cell carcinoma.

CONCLUSIONS

Proliferative verrucous leukoplakia of the gingiva (PVLG) appears to be a subset of oral proliferative verrucous leukoplakia. It can be characterized as a solitary, recurring, progressive white patch that develops a verruciform architecture and may not be associated with HPV. PVLG has an unpredictable course and is at risk for development into verrucous or squamous cell carcinoma. Currently, there is no way to determine or predict which gingival white lesions will follow the clinical course described for this group of patients with PVLG.

Epstein-Barr virus: the first human tumor virus and its role in cancer

The Epstein-Barr virus (EBV) is classically associated with three malignancies, Burkitt's lymphoma. B-cell lymphoproliferative syndromes, and nasopharyngeal carcinoma, and, more recently, with Hodgkin's disease, T-cell lymphomas, and gastric carcinoma, as well as being the causal agent for infectious mononucleosis. The relation of the virus to the malignancies varies from primary etiologic agent to necessary or contributory cofactor. Clonal EBV episomes are found in all the malignant conditions. EBV infects both epithelial and lymphoid cells, providing a pathobiological basis for these diverse associations. Most of the malignancies occur after years of viral dormancy and are accompanied or triggered by viral reactivation, in contrast to infectious mononucleosis, which results from primary infection with EBV. The EBV-associated malignancies offer insights into the causation and early detection of cancer. The molecular virology and pathobiology of EBV infection states provide the basis for the specific diagnosis of these diseases and a framework for new therapies.

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.

Epstein-Barr virus in tobacco-induced oral cancers and oral lesions in patients from India

We examined 103 oral squamous cell carcinomas (OSCC), 100 oral lesions consisting primarily of leukoplakia (82 cases), and 76 clinically normal mucosa specimens from the contralateral site in the oral cavity of individuals with oral lesions, for the presence of Epstein-Barr virus (EBV). Polymerase chain reaction (PCR) was used to amplify a 239 bp fragment of the BamHIL region of the EBV genome, followed by Southern blot hybridization with EBV oligonucleotide probe to increase further the specificity and sensitivity of the assay system. Since EBV seropositivity is frequent in populations, we also examined the peripheral blood cells (PBC) from 141 patients (50 oral cancer patients, 91 patients with oral lesions) for the presence of EBV. We detected EBV in 25 of 103 (25%) OSCC, 13 of 100 (13%) oral lesions, 3 of 76 (4%) clinically normal mucosa samples and 10 of 141 (7%) PBC. Our results indicate that EBV may contribute as one of the multiple factors in oral cancers, in a certain proportion of Indian patients.

Human herpesvirus-6 (HHV-6) DNA and virus-encoded antigen in oral lesions

Archival oral tissues comprising 51 squamous cell carcinomas, 18 non-malignant lesions and 7 normal mucosa samples were investigated for human herpesvirus-6 (HHV-6)-encoded antigens and HHV-6 DNA. The virus-specific antigens were detected by an immunohistochemical method using monoclonal antibodies. Two further techniques used for HHV-6 DNA detection included the polymerase chain reaction (PCR) with virus-specific primers and in situ hybridization using digoxigenin-labelled oligonucleotides specific for HHV-6A and HHV-6B genotypes. A high proportion (79-80%) of the squamous cell carcinomas were positive for HHV-6 with the various detection methods. In cases of lichen planus and leukoplakia a high prevalence rate (67-100%) was noted with in situ hybridization and immunohistochemical techniques but a lower proportion (22-33%) was detected with the PCR method. All 7 normal tissues tested were negative for HHV-6. The HHV-6 variant B was found in 60% of the oral carcinoma tissues analysed. The study demonstrates the frequent presence of HHV-6 in neoplastic and non-malignant lesions of the oral cavity. While the role of HHV-6 in oral mucosal tissues remains to be determined, the in vitro tumorigenic potential of the virus suggests a possible role in the etiopathogenesis of oral lesions.

Morphometric study of nucleolar organiser regions (AgNOR) in HPV-associated precancerous lesions and microinvasive carcinoma of the oral cavity

A morphometric study of silver-stained nucleolar organiser regions (NOR) was performed on histological sections from routinely paraffin-embedded blocks of 26 oral biopsy specimens (21 cases of leukoplakia consisting of 13 low, 4 moderate, 4 severe degree of dysplasia, and 5 cases of microinvasive carcinomas). In situ hybridisation (ISH) for HPV-DNA was performed on serial sections of the same samples. The following parameters were studied: V NOR (single AgNOR volume per nucleus), TV NOR (total AgNOR volume per nucleus), and R.I. (AgNOR's roundness index). The results highlight that not all the morphometric features of AgNORs allow the discrimination between lesions with dysplasia of low, moderate and severe degree and microinvasive carcinoma. TV NOR appeared useful, while the other morphometric parameters appeared statistically not significant i differentiating between the different lesions. These findings suggest that high values of TV NOR in oral dysplasia could represent a risk marker, identifying a subgroup of lesions with a worse prognosis, constituting then a possible indication for rigorous clinical management and/or for complex treatment of these HPV-associated preneoplastic lesions.

Prevalence of Epstein-Barr virus in oral squamous cell carcinomas, premalignant lesions and normal mucosa--a study using the polymerase chain reaction

Epstein-Barr virus (EBV) prevalence was assessed in 12 clinically normal oral mucosas, nine premalignant lesions, 36 oral squamous cell carcinomas (OSCCs) and a human papillomavirus (HPV) 16 positive cell line, derived from an OSCC studied. The polymerase chain reaction (PCR) with two pairs of primers with different sensitivities was used. With primers specific for the BamHIW repeat, EBV was found in 100% of OSCCs, in 77.8% of premalignant lesions and in 8.3% of clinically normal oral mucosas (P = 0.0001). Using primers specific for the single copy BNLF-1 gene, EBV was detected in 50% of OSCC and in none of the premalignant lesions. No statistically significant associations could be established among EBV presence and clinico-pathological data of OSCC. The cell line derived from an HPV/EBV-positive carcinoma did not reveal EBV DNA. The higher prevalence of EBV in OSCCs and premalignant lesions may be due to increased EBV shedding, possibly due to associated immunodepression in these patients, rather than its clonal presence in the neoplastic cells.

Mutated and wild-type p53 expression and HPV integration in proliferative verrucous leukoplakia and oral squamous cell carcinoma

The frequencies of overexpression and mutation in the p53 tumor suppressor gene were examined in proliferative verrucous leukoplakia and oral squamous cell carcinoma with immunohistochemistry and single-strand conformation polymorphism analysis of DNA fragments amplified by polymerase chain reaction. Ten samples each of normal oral mucosa, proliferative verrucous leukoplakia, and squamous cell carcinoma were immunostained with antibodies against p53 protein; 8 of 10 cases of proliferative verrucous leukoplakia cases and 7 of 10 cases of oral squamous cell carcinoma were positive for p53 protein. Minimal staining was observed in normal oral tissues. The quantified labeling indexes demonstrated a range that corresponded to lesion progression. Single-strand conformation polymorphism analysis revealed p53 gene mutations within exons 5 to 8 in 40% (4 of 10) of the squamous cell carcinoma samples. Two of the 4 mutated squamous cell carcinoma samples lacked p53 expression. No p53 mutations were detected in proliferative verrucous leukoplakia tissues. Human papillomavirus 16 was identified in 2 of 7 p53 positive oral squamous cell carcinoma samples. Human papillomavirus 16 and 18 were identified in two of eight p53 positive proliferative verrucous leukoplakia samples. One p53 negative squamous cell carcinoma sample was positive for human papillomavirus 16 and had a mutation in exon 6 of the p53 gene. Human papillomavirus infection along with p53 expression plays a yet to be defined role in the pathogenesis of a limited number of cases of proliferative verrucous leukoplakia and squamous cell carcinoma. p53 immunohistochemistry, p53 gene mutations, and human papillomavirus infection prevalence do not provide a means to differentiate between leukoplakia and carcinoma and do not provide a predictive test for progression of leukoplakia to carcinoma.

[High-risk HPV types in oral and laryngeal papilloma and leukoplakia]

BACKGROUND

Juvenile and adult laryngeal papillomas (JLP and ALP) and oral papillomas (OP) are important benign tumors of the head and neck. Laryngeal leukoplakia (LL) may be a precancerous lesion. The etiology of the papillomas is associated with human papillomavirus infection (HPV). The important noxes for the development of laryngeal leukoplakias are nicotine, alcohol, and HPV. Adult laryngeal papillomas and OP can also undergo malignant conversion. Today, there is no marker known to distinguish in progressive lesions and in those which show a regression. Different types of HPV were detected in head and neck cancer too. There is a important similarity to the genesis of cervical cancer. The 77 known HPV types were divided into benign types, e.g., 6 and 11, and those with oncogene potential, e.g., 16, 18, 31, 33, and 35. The detection of oncogene HPV may be a sensitive marker for prognosis of primary benign lesions.

PATIENTS AND METHODS

In this study, the presence of HPV genomes 6, 11, 16, 18, 31, 33, and 35 in 17 JLP, 27 ALP, 15 OP, and 11 LL was examined. DNA extracted from archived samples embedded in paraffin was amplified using the E6 specific polymerase chain reaction (PCR). The products were visualized by electrophoresis, and positive identification was achieved by Southern blot analysis and hybridization to specific biotinylated oligonucleotide.

RESULTS

Our data show the presence of HPV 6/11 in all JLP (17 of 17), in all ALP (27 of 27), in 13 of 15 (87%) OP, and in seven of 11 (63%) LL. The "malignant" types HPV 16, 18, and 33 were found in six of 27 (22%) of the ALP, in three of 15 (20%) of the OP, and in four of 11 (36%) of the LL. the dominant type was HPV 16, HPV 31 and 35 were not detectable. Three ALP, one OP, and the four LL of the cases with oncogene HPV showed histologic features of moderate dysplasia.

CONCLUSIONS

The role of HPV in malignant transformation of infected cells remains unclear. It is well known that the carcinogenesis must depend on promoters such as alcohol, tobacco, and metabolites of chronic inflammations. All patients with positive biopsies confirming HPV 16, 18, or 33 must receive special care to prevent the development of a carcinoma.

[Clinical polymorphism in Epstein-Barr virus infection]

Several diseases was associated with Epstein Barr virus (EBV) infection. In the next three cases, the clinical course was unusual . Case I: Polyclonal hypergammaglobulinemia, female 47 years old, she had systemic lupus erythematosus and clinical data of infectious mononucleosis but she evolved to a polyclonal gammopathy with IgM predominantly against EBV. Case II: Demyelinating encephalitis, male, 32 years old with central neurological alterations, IgM antibodies against EBV and demyelinating lesion in magnetic resonance image in brain steam. Case III. Villous leukoplakia, male, 40 years old developed right tonsil tumor. He had IgM antibodies against EBV. The antiviral and immunomodulator treatment (specific for each case) done a satisfactory clinical response in the three patients.

Detection and analysis of human papillomavirus 16 and 18 homologous DNA sequences in oral lesions

The prevalence of human papillomavirus (HPV) 16 and 18 was investigated in oral lesions of the population of northeast China including squamous cell carcinomas (SCCs), candida leukoplakias, lichen planuses and papillomas, by southern blot hybridization with polymerase chain reaction (PCR). Amplified HPV16 and 18 E6 DNA was analyzed by cycle sequence. HPV DNA was detected in 14 of 45 SCCs (31.1%). HPV18 E6 DNA and HPV16 E6. DNA were detected in 24.4% and 20.0% of SCCs. respectively. Dual infection of both HPV 16 and HPV 18 was detected in 6 of 45 SCCs (13.3%), but not in other oral lesions. HPV 18 E6 DNA was also detected in 2 of 3 oral candida leukoplakias, but in none of the 5 papillomas. Our study indicated that HPV 18 infection might be more frequent than HPV 16 infection in oral SCCs in northeast Chinese, dual infection of high risk HPV types was restricted in oral SCCs, and that HPV infection might be involved in the pathogenesis of oral candida leukoplakia.

Human papillomavirus-associated oral epithelial dysplasia (koilocytic dysplasia): an entity of unknown biologic potential

Intraepithelial neoplasia of the female genital tract has long been associated with human papillomavirus infection. To date, there have been no previously published studies of oral dysplasia that have identified light microscopic features predictive of the presence of human papillomavirus. We identified a variant of oral epithelial dysplasia, koilocytic dysplasia, that exhibited light microscopic features suggestive of HPV infection. To determine if these microscopic features were specifically correlated with human papillomavirus infection, DNA in situ hybridization for human papillomavirus 6/11, 16/18, and 31/33/51 was performed on 31 lesions diagnosed histologically as koilocytic dysplasia. Seventeen matched control cases of conventional oral epithelial dysplasia were also analyzed for human papillomavirus. Human papillomavirus DNA was detected significantly more often (p < 0.001) in koilocytic dysplasia (80.6%) than conventional oral epithelial dysplasia (0.0%). Positive cases of koilocytic dysplasia contained either intermediate-risk (31/33/51) or high-risk (16/18) human papillomavirus types whether or not they contained low-risk human papillomavirus types (6/11). The histologic and clinical presentation of koilocytic dysplasia was unique. Lesions demonstrated koilocytes and other microscopic characteristics of human papillomavirus infection, as well as features of conventional epithelial dysplasia. A striking male predominance was noted, as was a relatively young average age of presentation (39.0 years). On the basis of our preliminary analysis, we conclude that oral koilocytic dysplasia represents a unique pathologic entity and that the presence of human papillomavirus can be predicted on light microscopy with at least 80% accuracy. The clinical significance and potential for malignant transformation of koilocytic dysplasia remain to be investigated.

Human papillomavirus in oral premalignant lesions

The aetiology of oral premalignant lesions is generally accepted to be multifactorial. Tobacco and alcohol are established as important cofactors in malignant development in the oral cavity, but in addition microorganisms, such as human papillomavirus (HPV), have gained much interest over the past decade. For many years, HPV has been accepted as an important cofactor in the development of cervical cancer, originating from a mucous membrane with similarities to the oral mucosa. 49 patients with oral premalignant lesions and 20 control patients with normal oral mucosa and no history of HPV infection were examined for the presence of HPV by immune histochemical staining using the peroxidase anti-peroxidase technique (PAP), DNA-DNA in situ hybridisation (ISH), and polymerase chain reaction (PCR) analysed by Southern blot hybridisation with an HPV 16 specific probe. The investigations revealed that HPV was found in 62.5% of the verrucous leucoplakias, 50.0% of the erythroplakias, 45.5% of the homogeneous leucoplakias, 33.3% of erythroleucoplakias and in 12.5% of the nodular leucoplakias. An overall HPV detection rate in the examined premalignant lesions was 40.8% and no patients in the control sample were positive. Concerning oral cancer development, it seems likely that HPV may be a cofactor, as 100% of patients who developed oral cancers within 4-12 years were all positive for HPV, one being positive for HPV 16.

Human papillomavirus expression in oral mucosa, premalignant conditions, and squamous cell carcinoma: a retrospective review of the literature

OBJECTIVES

The literature of human papillomavirus detection in normal oral mucosa and oral lesions associated with the dysplastic progression of epithelium was reviewed to help define the role of this virus in the development of oral squamous cell carcinoma.

STUDY DESIGN

All available data from published studies were analyzed by chi-square test for association between the human papillomavirus and age, gender, race, DNA type, location, lesional dysplastic progression, method of detection, tissue preservation, and use of tobacco and alcohol.

RESULTS

Human papillomavirus was identified with increasing frequency in normal oral mucosa (13.5%), benign leukoplakia (14.8%), intraepithelial neoplasia (18.5%), squamous carcinoma (26.2%), and verrucous carcinoma (27%). It was detected in oral squamous cell carcinoma significantly (p < 0.005) more often (37.1%; 122 of 329) in studies that used a high sensitivity assay (polymerase chain reaction) than studies that used moderate sensitivity assays (25.2%; 84 of 334) (e.g., Southern blot hybridization) and low sensitivity assays (16.9%; 61 of 362) (e.g., immunohistochemistry, in situ hybridization). Human papillomavirus DNA was detected significantly more often (p < 0.001) in frozen oral squamous cell carcinoma (51.6%; 115 of 223) than paraffin-embedded tissue (21.7%; 136 of 628). High-risk human papillomaviruses (2, 16, 18) were detected in 81.4% of OSCCs that contained the virus compared with low-risk human papillomavirus genotypes (6, 11) in 17.9% of oral squamous cell carcinoma that contained the human papillomavirus (p < 0.001). In studies that analyzed the use of chemical cofactors, the use of tobacco and alcohol (87.3%) was associated more often with oral squamous cell carcinoma than the presence of human papillomavirus (51.3%), however, the difference was not significant.

CONCLUSION

High-risk human papillomavirus genotypes have a significant association with oral squamous cell carcinoma. However, the presence of this virus in a high proportion of oral normal mucosa makes the virus alone a poor prognosticator of progression to malignancy.

Detection of Epstein-Barr virus early replicative phase using monoclonal antibody BZ-1 in oral hairy leukoplakia and other hyperkeratotic oral mucosal lesions: a retrospective study

The early replicative phase of Epstein-Barr virus (EBV) was detected by immunohistochemistry, in addition to routine histology with hematoxylin eosin staining, in formalin fixed, paraffin-embedded archive specimens of 97 hyperkeratotic lesions including oral hairy leukoplakia (HL) in order to assess whether EBV is specific to HL, or if it occurs in other hyperkeratotic lesions of the oral mucosa. Monoclonal antibody (MAb) BZ-1 directed against the BZLF-1 gene product of EBV was used for immunostaining by the avidin-biotin peroxidase technique. The reaction was visualized with DAB/H2O2 solution and counterstained with PAS stain to detect any coexisting of hyphae of Candida. Eight lesions were reactive with BZ-1, confirming a diagnosis of HL, although the total number of lesions with koilocytoid features was 33. Seventy percent of the patients with confirmed HL lesions were HIV-seropositive, and 50% of the HL lesions were associated with Candida hyphae. One third of the lesions with koilocytoid features were associated with hyphae of Candida. Only one renal transplant patient had HL, confirmed by a positive BZ-1 reaction, although 60% of the hyperkeratotic lesions showed koilocytoid features in a subgroup of 15 patients with renal transplants.

Association between proliferative verrucous leukoplakia and infection with human papillomavirus type 16

Proliferative verrucous leukoplakia (PVL) is a recently described clinical entity characterized by multifocal oral lesions that frequently progress to oral cancer despite abstinence from tobacco use by most patients. To determine if this condition is associated with human papillomavirus (HPV), a polymerase chain reaction (PCR) for HPV DNA was performed on 9 lesions from 7 patients with PVL, histologically diagnosed with focal keratosis (1), papilloma (1), epithelial dysplasia (5) and squamous cell cancer (2). Eight (89%) were HPV positive, 7 for HPV 16. For comparison, we studied 55 non-PVL-associated oral specimens, including 24 oral squamous cell cancers. Of the cancers, 8 (33%) were HPV positive, 4 for HPV 16. These data suggest that HPV 16 infection may play an important role in the pathogenesis of PVL-associated oral dysplasia and possibly cancer, but is found in only a small proportion of the more common, non-PVL associated-oral lesions.

Oral leukoplakia

Leukoplakia has evolved as a clinico-pathologic concept over many years, with the current clinical designation being accepted worldwide. Reflective of the biology of leukoplakia is the concept of cellular atypia and epithelial dysplasia. Adding to a better understanding of leukoplakia in general has been the definition of relevant clinical subsets which, in some cases, includes etiology (snuff), while in other cases a verrucous clinical appearance will suggest a more aggressive anticipated behavior pattern. Tobacco usage, in many of its forms, remains the prime etiologic factor; however, other considerations also apply. More recently, the potential etiologic role of Candida albicans has been stressed, as well as its possible role in carcinogenesis. So-called oral hairy leukoplakia has been defined in relation to a possible Epstein-Barr viral infection, usually in the immunosuppressed patient. Other viruses, human papilloma virus in particular, have been implicated in leukoplakia, while genetic alterations involving tumor suppressor elements (p53) have also been investigated. Finally, the management of this common condition remains a variable and includes local, topical, and systemic therapies such as anti-oxidants, carotenoids, and retinoids.

Epstein-Barr virus in the proliferative diseases of squamous epithelium in the oral cavity

The presence of Epstein-Barr virus was analyzed in 79 cases of oral epithelial proliferative diseases by polymerase chain reaction, in situ hybridization for Epstein-Barr virus-deoxyribonucleic acid and Epstein-Barr virus-encoded small messenger ribonucleic acid and immunohistochemistry for Epstein-Barr virus latent membrane protein. These lesions were histologically categorized as invasive squamous cell carcinoma (n = 36), carcinoma in situ (n = 10), verrucous carcinoma (n = 4), leukoplakia (n = 19), and papilloma (n = 10). Epstein-Barr virus genomes were detected in 19 squamous cell carcinoma (52.8%), four carcinoma in situ (40%), and one leukoplakia (5.3%); none of the verrucous carcinoma or papilloma cases were positive with polymerase chain reaction. By deoxyribonucleic acid in situ hybridization, positive signals were observed in the nuclei of cancer cells in 10 cases, in infiltrating lymphocytes in three, and both in one case. In patients with carcinoma in situ, only a single case was positive. In one case of leukoplakia positive signals were found in upper and middle layer squamous cells. The results by Epstein-Barr virus-encoded small messenger ribonucleic acid in situ hybridization revealed the same distribution as that by deoxyribonucleic acid in situ hybridization. Latent membrane protein was expressed only in the epithelial cells of leukoplakia but not in cases with squamous cell carcinoma and carcinoma in situ. These findings suggest that Epstein-Barr virus infection of oral squamous epithelium may be carcinogenic; alternatively, the virus may merely exist in epithelial cells of squamous cell carcinoma, carcinoma in situ, and leukoplakia as a passenger.