Human papillomavirus in oral exfoliated cells and risk of head and neck cancer

Risk factors for oral HPV infection among a high prevalence population of HIV-positive and at-risk HIV-negative adults

INTRODUCTION

Human papillomavirus (HPV) is an important risk factor for oropharyngeal cancer. Individuals with human immunodeficiency virus (HIV) have higher oral HPV prevalence but the risk factors for oral HPV infection are not well understood for either HIV-positive or HIV-negative individuals.

METHODS

This study was nested within the Multicenter AIDS Cohort Study (MACS; men) and Women Interagency HIV Study (WIHS; women) cohorts. Exfoliated oral epithelial cells were collected from 379 HIV-positive and 266 at-risk HIV-negative individuals using a rinse and gargle with Scope mouthwash. Samples were tested for 36 types of HPV DNA using PGMY09/11 consensus primers and reverse line blot hybridization. Risk factors for oral HPV infection were explored using logistic regression with generalized estimating equations in this cross-sectional analysis.

RESULTS

Prevalent oral HPV infection was common (34%), including HPV16 infection in 5.7% of participants. HIV-positive individuals had increased odds of prevalent oral HPV infection compared with HIV-negative individuals [adjusted OR = 2.1; 95% confidence interval (CI), 1.6-2.8]. Risk factors for prevalent oral HPV differed in HIV-positive and HIV-negative participants. Among HIV-negative individuals, higher number of recent oral sex or rimming partners were strong risk factors for prevalent oral HPV infection (each P(trend) < 0.01). In contrast, among HIV-positive individuals, lower CD4 T-cell count (P(trend) < 0.001) and higher number of lifetime sexual partners (P(trend) = 0.03) were strong risk factors.

CONCLUSIONS

Oral HPV prevalence was elevated in HIV-positive individuals after controlling for differences in cigarette smoking and sexual behavior, supporting the possibility that HIV may affect the natural history of oral HPV.

IMPACT

Immunosuppression may contribute to increased persistence or progression of oral HPV infection.

UM-SCC-104: a new human papillomavirus-16-positive cancer stem cell-containing head and neck squamous cell carcinoma cell line

BACKGROUND

Few human papillomavirus (HPV)(+) head and neck squamous cell carcinoma (HNSCC) cell lines exist. We established University of Michigan-squamous cell carcinoma-104 (UM-SCC-104), a new HPV(+) HNSCC cell line from a recurrent oral cavity tumor, and characterized it for the presence of cancer stem cells (CSCs).

METHODS

Tumor cells were tested for biomarker expression by immunohistology, and the presence of HPV was assessed by several methods.

RESULTS

UM-SCC-104 has a unique genotype, contains HPV-16, and expresses E6/E7. Inoculation of aldehyde dehydrogenase (ALDH)(+) and ALDH(-) cells in an immunocompromised mouse resulted in tumor growth from the ALDH(+) cells after 6 weeks that recapitulated the histology of the primary, whereas ALDH(-) cells did not produce tumors.

CONCLUSION

UM-SCC-104, a new HPV-16, CSC-containing HNSCC cell line will aid in studying recurrent HPV(+) tumors. The aggressive nature of this tumor is consistent with high uniform expression of epidermal growth factor receptor (EGFR) and a functionally significant proportion of ALDH(+) CSCs.

Human papillomavirus and rising oropharyngeal cancer incidence in the United States

PURPOSE

Recent increases in incidence and survival of oropharyngeal cancers in the United States have been attributed to human papillomavirus (HPV) infection, but empirical evidence is lacking.

PATIENTS AND METHODS

HPV status was determined for all 271 oropharyngeal cancers (1984-2004) collected by the three population-based cancer registries in the Surveillance, Epidemiology, and End Results (SEER) Residual Tissue Repositories Program by using polymerase chain reaction and genotyping (Inno-LiPA), HPV16 viral load, and HPV16 mRNA expression. Trends in HPV prevalence across four calendar periods were estimated by using logistic regression. Observed HPV prevalence was reweighted to all oropharyngeal cancers within the cancer registries to account for nonrandom selection and to calculate incidence trends. Survival of HPV-positive and HPV-negative patients was compared by using Kaplan-Meier and multivariable Cox regression analyses.

RESULTS

HPV prevalence in oropharyngeal cancers significantly increased over calendar time regardless of HPV detection assay (P trend < .05). For example, HPV prevalence by Inno-LiPA increased from 16.3% during 1984 to 1989 to 71.7% during 2000 to 2004. Median survival was significantly longer for HPV-positive than for HPV-negative patients (131 v 20 months; log-rank P < .001; adjusted hazard ratio, 0.31; 95% CI, 0.21 to 0.46). Survival significantly increased across calendar periods for HPV-positive (P = .003) but not for HPV-negative patients (P = .18). Population-level incidence of HPV-positive oropharyngeal cancers increased by 225% (95% CI, 208% to 242%) from 1988 to 2004 (from 0.8 per 100,000 to 2.6 per 100,000), and incidence for HPV-negative cancers declined by 50% (95% CI, 47% to 53%; from 2.0 per 100,000 to 1.0 per 100,000). If recent incidence trends continue, the annual number of HPV-positive oropharyngeal cancers is expected to surpass the annual number of cervical cancers by the year 2020.

CONCLUSION

Increases in the population-level incidence and survival of oropharyngeal cancers in the United States since 1984 are caused by HPV infection.

Hypoxia inducible factor-1 alpha expression is increased in infected positive HPV16 DNA oral squamous cell carcinoma and positively associated with HPV16 E7 oncoprotein

Background

There is increasing evidence for the role of High Risk (HR) Human PapillomaVirus (HPV) in the pathogenesis of Oral Squamous Cell Carcinoma (OSCC). The E6 and E7 oncogenes from HR HPVs are responsible for the deregulation of p53 and pRB proteins involved in cell cycle and apoptotic pathways. In cell lines experiments, the HPV E7 protein seems to be able to enhance Hypoxia Inducible Factor-1 alpha (HIF-1α) activity, normally involved in the response to hypoxia and able to enhance angiogenesis.

Results

We studied tumor specimens from 62 OSCC; a higher prevalence of tumors in TNM stage II and also in pT2 class between OSCC infected positive HPV16 DNA than non-infected ones was observed. HIF-1α positivity was detected throughout the analysed fields, not associated with areas of necrosis and also observed in cells immediately adjacent to blood vessels. A significant increase in mean values of the HIF-1α labeling indexes was observed for pT1-T2, as well for stage I-II, in the infected positive HPV16 DNA tumors than non-infected ones. HIF-1α and HPV16 E7 labeling indexes showed a significantly positive correlation which suggested a positive association between HPV16 E7 and HIF-1α expression.

Conclusions

In our specimens HIF-1α immunoreactivity hints for an O₂-independent regulatory mechanism in infected positive HPV16 DNA tumors, especially for pT1-T2 and stage I-II tumors, suggesting a very early involvement in the development of HPV-induced OSCC. HIF-1α and HPV16 E7 labeling indexes suggest also a positive association between the two proteins in infected positive HPV16 DNA OSCC.

Oral human papillomavirus infection in women with cervical HPV infection: new data from an Italian cohort and a metanalysis of the literature

A key issue in oral HPV infection is whether it can be associated with a genital HPV infection, or whether it can be considered as an independent event. This analysis evaluated the frequency and type-concordance of oral HPV infection in women with cervical HPV infection by means of: (i) a cross-sectional study on a sample (n=98) of Italian women; and (ii) a literature-based metanalysis, including the experimental study the subject of this Paper and nine other published studies (n=1017), which also examined the influence of oral sampling procedure (oral brushing vs oral rinse) and HIV status on oral HPV detection. The prevalence of oral HPV infection in the Italian study was 14.3% (95% CI: 7.4-21.2); the prevalence of type-concordance was 21.4% (95% CI: 0.0-43.6) and it was only marginally significant (P=0.05). The prevalence of oral HPV infection in the metanalysis was estimated as 18.1% (95% CI: 10.3-25.9); the prevalence of type-concordance was 27.0% (95% CI: 12.3-41.7), and it was statistically significant (P=0.002). The metanalysis also showed that the oral sampling procedure was not a determinant of HPV detection; however, HIV status increased the likelihood of oral HPV infection (HIV-positive vs negative: 27.2%; 95% CI: 22.1-32.2 vs 15.5%; 95% CI: 6.9-24.2) and type-concordance (HIV-positive vs negative: 46.8%; 95% CI: 34.7-58.9 vs 15.6%; 95% CI: 0.8-30.4). Oral HPV infection and type-concordance in women with cervical HPV infection are more prevalent than could be expected by chance; this finding is consistent with the notion of a degree of dependence of the oral site on the cervical site. Furthermore, oral HPV prevalence and type-concordance are influenced by immunity.

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

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

Development of a PCR assay to detect papillomavirus infection in the snow leopard

Background

Papillomaviruses (PVs) are a group of small, non-encapsulated, species-specific DNA viruses that have been detected in a variety of mammalian and avian species including humans, canines and felines. PVs cause lesions in the skin and mucous membranes of the host and after persistent infection, a subset of PVs can cause tumors such as cervical malignancies and head and neck squamous cell carcinoma in humans. PVs from several species have been isolated and their genomes have been sequenced, thereby increasing our understanding of the mechanism of viral oncogenesis and allowing for the development of molecular assays for the detection of PV infection. In humans, molecular testing for PV DNA is used to identify patients with persistent infections at risk for developing cervical cancer. In felids, PVs have been isolated and sequenced from oral papillomatous lesions of several wild species including bobcats, Asian lions and snow leopards. Since a number of wild felids are endangered, PV associated disease is a concern and there is a need for molecular tools that can be used to further study papillomavirus in these species.

Results

We used the sequence of the snow leopard papillomavirus UuPV1 to develop a PCR strategy to amplify viral DNA from samples obtained from captive animals. We designed primer pairs that flank the E6 and E7 viral oncogenes and amplify two DNA fragments encompassing these genes. We detected viral DNA for E6 and E7 in genomic DNA isolated from saliva, but not in paired blood samples from snow leopards. We verified the identity of these PCR products by restriction digest and DNA sequencing. The sequences of the PCR products were 100% identical to the published UuPV1 genome sequence.

Conclusions

We developed a PCR assay to detect papillomavirus in snow leopards and amplified viral DNA encompassing the E6 and E7 oncogenes specifically in the saliva of animals. This assay could be utilized for the molecular investigation of papillomavirus in snow leopards using saliva, thereby allowing the detection of the virus in the anatomical site where oral papillomatous lesions develop during later stages of infection and disease development.

Determination of the relationship between Basal cell carcinoma and human papilloma virus, based on immunohistochemistry staining method

Background:

Basal cell carcinoma (BCC) is the most common skin cancer among Caucasians, and in most cases, occurs in the sun-exposed areas. In recent years, in addition to many other etiologies such as exposure to UV radiation, and occasionally xeroderma pigmentosa, burns, tattoos, and pox scars, human papillomavirus (HPV) is also considered to have an etiologic role. Different studies were conducted with varied results in this regard.

Aims:

We evaluate this plausible relationship between HPV and BCC by means of immunohistochemistry (IHC) staining method.

Methods:

This is an analytic cross-sectional study in which 160 samples were selected randomly consisting of 80 BCC lesions and 80 safe margins. Sampling was done among paraffin-embedded blocks in pathology ward of Kashani and Alzahra hospitals, Isfahan-Iran, from 2004-2007. A section of each block was IHC stained for HPV immunoreactivity (DAKO, Denmark). This was followed by microscopic evaluation in terms of being positive or negative.

Results:

Fifty seven point five percent of the samples belonged to men and the others to women. In 10%, HPV marker was positive, both in lesion and margin. In 83.8% neither the lesions nor the margins were immunoreactive for HPV. Only in 5 cases (6.3%) the lesion was positive and the margin was negative for this marker. There was no case of immunoreactivity for HPV marker in margins, while it was negative in lesions. Our study results followed by McNemar analysis did not show a significant relationship between BCC incidence and HPV existence. This was consistent in both genders (P > 0.05, power > 90%).

Conclusion:

In this study we did not find a significant relationship between BCC and HPV, but based on review of articles it appears that large multicentric studies are to be conducted in this regard.

The role of human papillomavirus in the pathogenesis of head & neck squamous cell carcinoma: an overview

Cancer statistics report an increased incidence of OSCC and OPSCC around the world. Though improvements in screening and early diagnosis have dramatically reduced the incidence of this neoplasm in recent years, the 5-year-disease-free survival, is still poor, specially for oropharyngeal cancer, despite the great scientific and financial efforts. Recently, several papers showed that HPV may be involved at least in the pathogenesis of a subgroup of oral and cervical SCC, leading to distinct molecular characteristics compared with HPV-negative ones. Nevertheless, OPSCCs associated with HPV infection seem to show a better prognosis and affect younger patients (< 40 yrs.), especially females. Therefore, there is the need to properly assess oropharyngeal SCC subgroups: 1) not HPV associated/classic oral SCC: less responsive to anticancer drugs: needs novel post-surgical treatment; 2) HPV associated/oral SCC: needs several management options and suitable "target" therapy against the virus, and/or immune-stimulating therapy. Further issues are: 1) the disclosure of putative targets for more efficient molecular therapy, which may work as cervical cancer post-surgical treatment, in anticipation of the effects of "global prevention" performed by WHO anti-HPV vaccination programs; 2) careful identification of precancerous lesions in both sites; dysplasia is currently treated by excisional or ablative procedures, which don't consider the concept of field carcinogenesis. In fact, it is probable that near or far from an excised precancerous lesion new foci of cell transformation may exist, which are not yet macroscopically evident, but, if detected, would put the patient into a high risk subgroup.Comparing findings reported in the recent literature, the data of this state of the art about HPV might add useful informations concerning oropharyngeal carcinogenesis. Moreover, our review would be useful in order to define novel perspectives of treatment choice for Head & Neck cancer patients, by combining well known chemotherapeutical drugs with new molecular "target" therapy.

High prevalence of oral human papillomavirus infection in Fanconi's anemia patients

BACKGROUND

Fanconi's anemia (FA) is a rare recessive genetic disorder characterized by bone marrow failure, developmental and congenital abnormalities, which frequently evolves to aplastic anemia and neoplasias, primarily acute leukemia and head-neck carcinomas. Risk of malignancies increases after hematopoietic stem cell transplantation (HSCT), and the role of human papillomavirus (HPV) in FA carcinogenesis have been proposed.

OBJECTIVE

To investigate prevalence of oral HPV in FA patients without oral malignant lesions.

MATERIALS AND METHODS

After oral examination, 76 subjects without detectable oral malignant lesions were included and classified in four groups: 20 FA submitted to HSCT (I), 22 FA not submitted to HSCT (II), 18 severe aplastic anemia (SAA) submitted to HSCT (III) and 16 healthy subjects (IV). Liquid-based cytology sampling, HPV screening by polymerase chain reaction and genotyping by reverse hybridization were performed.

RESULTS

The HPV detection rates were: group I 35%, group II 27.3%, group III 38% and group IV 6.25%. Prevalence of high risk HPV types, mainly HPV16, was detected. Compared with control group, suggestions for increased likelihood of being HPV infected in SAA (OR = 9.55, 95% CI: 1.01-125.41) and FA patients submitted to HSCT (OR = 8.08, 0.83-72.29) emerged.

CONCLUSION

Patients without oral malignant lesions submitted to HSCT, have high prevalence of oral HPV. HPV screening and close follow up should be considered in these patients.

[Prophylactic and therapeutic vaccines against human papilloma virus]

Infection with human papilloma virus (HPV) has been identified as the cause of recurrent papillomatosis and of a subgroup of squamous cell carcinomas of the head and neck. A change in prevalence of these lesions, especially for oropharyngeal carcinoma, can be expected as a consequence of the introduction of prophylactic HPV vaccines for young women, targeting the most frequent high- and low-risk HPV subtypes. Vaccination for the major low-risk HPV types has proven to be highly effective against genital warts and activity against papillomatosis can be expected. The possibilities of prophylactic HPV vaccination as well as new developments and the rationale for therapeutic vaccines are discussed on the basis of the current literature.

Use of a linear array for the detection of human papillomavirus genotypes in head and neck cancer

CONTEXT

Tumors of the head and neck commonly arise from the squamous and respiratory mucosa that lines the nasal and oral cavity, sinuses, pharynx, and larynx. The rate of oropharyngeal cancers diagnosed among Americans younger than 50 years is increasing. Infection of the oropharynx and tonsils by the human papillomavirus (HPV) has been linked to preneoplasia and cancer.

OBJECTIVES

To evaluate the Roche Linear Array HPV Genotyping test kit to identify, and then specifically genotype, HPV in formalin-fixed, paraffin-embedded tissues.

DESIGN

We evaluated the performance of this assay for accuracy, for intra-assay and interassay precision, and for its limit of detection, using materials with known HPV status. Sixteen tumor tissues with the following origins were evaluated: 1 ocular, 1 hypopharynx, 8 tonsil, 1 retromolar trigone, 3 tongue, 1 anal, and 1 lymph node. DNA from formalin-fixed, paraffin-embedded tumor sections was isolated and amplified in duplicate, with positive and negative controls, using primers specific to the polymorphic L1 region of the HPV genome. Thirty-seven genotypes were tested using the linear array. The amplified product (450 base pairs) was visualized by gel electrophoresis and, if positive, reflexed to HPV genotyping.

RESULTS

Nine of the 16 tumors analyzed were HPV positive. The detected genotypes included HPV 6, 16, and 69.

CONCLUSIONS

The Roche Linear Array HPV Genotyping test is an easy-to-use method for determining HPV genotype in the routine analysis of formalin-fixed, paraffin-embedded tumors. This assay is robust and can be performed routinely in a clinical laboratory setting.

Impact of HPV in Oropharyngeal Cancer

The incidence of oropharyngeal cancers has increased in the western world and Human Papilloma Virus (HPV) has been recognised as a risk factor in the last decades. During the same period the prevalence of HPV in oropharyngeal tumours has increased and HPV has been suggested responsible for the increase. The HPV-positive tumours are today recognized as a distinct subset of head and neck cancers with its own clinopathological and risk profile and have a significantly improved prognosis regardless of treatment strategy. This review summarizes current knowledge regarding human papillomavirus biology, oncogenic mechanisms, risk factors, and impact of treatment.

Emerging drugs to treat squamous cell carcinomas of the head and neck

IMPORTANCE OF THE FIELD

Head and neck squamous cell carcinoma (HNSCC) is the eighth leading cause of cancer death worldwide. Despite advances in surgery and chemoradiation therapy, there has been little improvement in survival rates over the past 4 decades. Additionally, surgery and chemoradiotherapy have serious side effects. The development of agents with greater efficacy and tolerability is needed.

AREAS COVERED IN THIS REVIEW

EGFR is the only proven molecular target for HNSCC therapy. Cetuximab, the sole FDA-approved molecular targeted HNSCC therapy, and other potential targeted therapies are being evaluated in preclinical, clinical and post-marketing studies. Here, we review the emerging targets for biological agents in HNSCC and the rationale for their selection.

WHAT THE READER WILL GAIN

Key information in the development of new drug targets and the emergence of new biomarkers are discussed. Readers will gain insight regarding the limitations of current therapies, the impact of recently approved targeted therapies and the influence that predictive biomarkers will have on drug development.

TAKE HOME MESSAGE

The head and neck cancer drug market is rapidly evolving. Coordination between drug and biomarker development efforts may soon yield targeted therapies that can achieve the promise of personalized cancer medicine.

Screening for human papillomavirus in basaloid squamous carcinoma: utility of p16(INK4a), CISH, and PCR

This study compares p16( INK4a) immunohistochemistry (IHC), HPV chromogenic in situ hybridization (ISH), and HPV polymerase chain reaction (PCR) genotyping for detection of HPV infection in basaloid squamous carcinoma (BSCC). A retrospective histopathological analysis of 40 BSCC from a single institution was carried out. p16 IHC, HPV DNA extraction and ISH, and HPV PCR genotyping were performed, and there was excellent agreement between all 3 methods of HPV detection. Analysis of variance yielded no significant differences between the results of the 3 tests ( P = .354) and Pearson product-moment correlation coefficients calculated for each pair of tests demonstrated direct correlation (r = .61 for PCR and IHC, r = .61 for PCR and ISH, and r = 1.00 for ISH and IHC). This supports the use of p16(INK4a) IHC as an initial screening tool for HPV infection in BSCC, while definitive evidence of HPV DNA can be sought subsequently with PCR or CISH.

HPV-associated head and neck cancer: a virus-related cancer epidemic

A rise in incidence of oropharyngeal squamous cell cancer--specifically of the lingual and palatine tonsils--in white men younger than age 50 years who have no history of alcohol or tobacco use has been recorded over the past decade. This malignant disease is associated with human papillomavirus (HPV) 16 infection. The biology of HPV-positive oropharyngeal cancer is distinct with P53 degradation, retinoblastoma RB pathway inactivation, and P16 upregulation. By contrast, tobacco-related oropharyngeal cancer is characterised by TP53 mutation and downregulation of CDKN2A (encoding P16). The best method to detect virus in tumour is controversial, and both in-situ hybridisation and PCR are commonly used; P16 immunohistochemistry could serve as a potential surrogate marker. HPV-positive oropharyngeal cancer seems to be more responsive to chemotherapy and radiation than HPV-negative disease. HPV 16 is a prognostic marker for enhanced overall and disease-free survival, but its use as a predictive marker has not yet been proven. Many questions about the natural history of oral HPV infection remain under investigation. For example, why does the increase in HPV-related oropharyngeal cancer dominate in men? What is the potential of HPV vaccines for primary prevention? Could an accurate method to detect HPV in tumour be developed? Which treatment strategies reduce toxic effects without compromising survival? Our aim with this review is to highlight current understanding of the epidemiology, biology, detection, and management of HPV-related oropharyngeal head and neck squamous cell carcinoma, and to describe unresolved issues.

Human papillomavirus-mediated carcinogenesis and HPV-associated oral and oropharyngeal squamous cell carcinoma. Part 2: Human papillomavirus associated oral and oropharyngeal squamous cell carcinoma

Human papillomavirus (HPV) infection of the mouth and oropharynx can be acquired by a variety of sexual and social forms of transmission. HPV-16 genotype is present in many oral and oropharyngeal squamous cell carcinomata. It has an essential aetiologic role in the development of oropharyngeal squamous cell carcinoma in a subset of subjects who are typically younger, are more engaged with high-risk sexual behaviour, have higher HPV-16 serum antibody titer, use less tobacco and have better survival rates than in subjects with HPV-cytonegative oropharyngeal squamous cell carcinoma. In this subset of subjects the HPV-cytopositive carcinomatous cells have a distinct molecular profile. In contrast to HPV-cytopositive oropharyngeal squamous cell carcinoma, the causal association between HPV-16 and other high-risk HPV genotypes and squamous cell carcinoma of the oral mucosa is weak, and the nature of the association is unclear. It is likely that routine administration of HPV vaccination against high-risk HPV genotypes before the start of sexual activity will bring about a reduction in the incidence of HPV-mediated oral and oropharyngeal squamous cell carcinoma. This article focuses on aspects of HPV infection of the mouth and the oropharynx with emphasis on the link between HPV and squamous cell carcinoma, and on the limitations of the available diagnostic tests in identifying a cause-and-effect relationship of HPV with squamous cell carcinoma of the mouth and oropharynx.

The role of human papillomavirus in head and neck cancer

Over the last 20 years, there has been increasing awareness of a subset of squamous cell carcinomas of the head and neck (HNSCC), i.e. HPV-positive HNSCC. These cancers seem to differ somewhat from HPV-negative HNSCC. Patients with HPV-positive HNSCC tend to be younger and have a lower intake of tobacco and alcohol. Distinct molecular profiles separate them from HPV-negative cancers and show similarities with HPV-positive cervical SCC. There is evidence that HPV-positive HNSCC is a sexually transmitted disease. Patients with HPV-positive HNSCC are often diagnosed at a late stage with large cystic lymph nodes in the neck. HPV-positive HNSCC show an affinity for the oropharynx, especially the tonsils and the base of the tongue, and tend to show low differentiation histopathologically. There is a better prognosis regardless of the treatment regimen for HPV-positive HNSCC compared with HPV-negative HNSCC, and this seems to be related to the immune system. Whether the new vaccines for HPV will protect not only against cervical cancer but also against HPV-positive HNSCC remains unknown.

Tobacco and alcohol use increases the risk of both HPV-associated and HPV-independent head and neck cancers

Tobacco, alcohol, and human papillomavirus (HPV) are major risk factors for head and neck cancer (HNC), but it is unclear whether there are two distinct HNC risk groups, one associated with HPV and the other with tobacco/alcohol. Because HPV-positive HNC are clinically distinct from HPV-negative cases in treatment response and with more favorable prognoses, determining whether these differences result from infection alone or in association with other HNC risk factors is important for developing future therapeutic strategies. Incident cases of HNC (n = 201) and age-gender frequency-matched controls (n = 324) were recruited to assess anti-HPV VLP (virus like particles) antibodies 16, 18, 31, and 33. Multivariate logistic regression and stratified analyses were used to calculate adjusted odds ratios (OR). HPV-seronegative and seropositive/heavy tobacco users had similar increased adjusted risks of HNC (HPV-seronegative OR = 2.6, 1.4-5.0; HPV-seropositive OR = 2.3, 1.1-4.8), as did HPV-seronegative (OR = 4.3, 2.1-9.1) versus HPV-seropositive/heavy alcohol users (OR = 3.9, 1.6-9.4). Similar HPV/tobacco/alcohol risk profiles also were seen in oropharyngeal and oral cavity tumor sites. Our finding that tobacco/alcohol use increased the risk of HNC in both HPV-seropositive and HPV-seronegative individuals is consistent with the observation that HPV infection is not a sufficient cause of HNC but requires the accumulation of additional cellular changes.

Head and neck squamous cell carcinomas in HIV-positive patients: a preliminary investigation of viral associations

Oncogenic human papillomaviruses (HPVs) are associated with oropharyngeal squamous cell carcinoma (SCC). Infection with human immunodeficiency virus (HIV) increases susceptibility to opportunistic infections and viral-promoted cancers. The prevalences of HPV, herpes simplex virus (HSV), Epstein-Barr virus (EBV), and human herpesvirus-8 (HHV-8) have not been established for head and neck squamous cell carcinoma in HIV-positive patients (HIV+ HNSCC). We have observed that HIV+ HNSCC tend to contain numerous multinucleated tumor giant cells, this finding has not been described previously. The goal of this study is to test for these oncogenic viruses in a small cohort of retrospectively identified patients with HIV infection, and to compare histologically these cancers to a control group of HNSCC patients. Tumors were reviewed histologically and compared to a control group of 102 patients with HNSCC (serologically untyped or HIV negative). Polymerase chain reaction (PCR) was performed on formalin-fixed, paraffin-embedded HIV+ HNSCC samples from combined 25 patients in two institutions. In situ hybridization was performed to identify EBV (EBER) and immunohistochemistry was performed to detect HSV-1, HSV-2, HHV-8, and HIV-related proteins (Nef, p24). The study sample consisted of 34 HIV+ patients with HNSCC from Montefiore Medical Center, and six HIV+ HNSCC patients from Hospital Clinic, University of Barcelona; 24 (60%) men and 16 (40%) women. The larynx was most commonly involved (65%, n = 26); followed by the oropharynx (22.5%, n = 9). Four carcinomas arose from the oral cavity (10%) and one from the nasal cavity (2.5%). Histologically, multinucleated tumor giant cells were more common in the HIV+ group (39/40, 97.5%) than the control group (27/102, 26%, p 0.001, chi-square). HPV was detected in 6 of 25 (24%) HNSCC tumors by PCR, five were typed as HPV 16 and one as HPV 26/69; five of these tumors (83%) were located in the oropharynx. EBV, HSV-1, HSV-2, and HHV-8 were detected only infrequently in tumor cells. Nef protein was detected in tumor cells in 7 of 21 (33.3%) cases; p24 was not detectable in 6 tumors studied. There were no significant associations between HPV positive tumors and co-infections with other viruses. This study is consistent with other reports that suggest an increased incidence of laryngeal carcinoma for HIV+ patients. HPV was detected in 24% of HIV+ HNSCC, however, the number of tumors with amplifiable DNA (n = 25) is too small to allow for conclusions. EBV, HSV-1, HSV-2, and HHV-8 are uncommon in HIV+ HNSCC; it is unlikely that these viruses have a promoting effect. MNTCG are significantly common in HIV+ HNSCC, but there is overlap in MNTCG counts with the control group and therefore this finding cannot be used as a biomarker of HIV infection.

Human papillomavirus, p16 and p53 expression associated with survival of head and neck cancer

Background

P16 and p53 protein expression, and high-risk human papillomavirus (HPV-HR) types have been associated with survival in head and neck cancer (HNC). Evidence suggests that multiple molecular pathways need to be targeted to improve the poor prognosis of HNC. This study examined the individual and joint effects of tumor markers for differences in predicting HNC survival. P16 and p53 expression were detected from formalin-fixed, paraffin-embedded tissues by immunohistochemical staining. HPV DNA was detected by PCR and DNA sequencing in 237 histologically confirmed HNC patients.

Results

Overexpression of p16 (p16+) and p53 (p53+) occurred in 38% and 48% of HNC tumors, respectively. HPV-HR was detected in 28% of tumors. Worse prognosis was found in tumors that were p53+ (disease-specific mortality: adjusted hazard ratios, HR = 1.9, 95% CI: 1.04-3.4) or HPV- (overall survival: adj. HR = 2.1, 1.1-4.3) but no association in survival was found by p16 status. Compared to the molecular marker group with the best prognosis (p16+/p53-/HPV-HR: referent), the p16-/p53+/HPV- group had the lowest overall survival (84% vs. 60%, p < 0.01; HR = 4.1, 1.7-9.9) and disease-specific survival (86% vs. 66%, p < 0.01; HR = 4.0, 1.5-10.7). Compared to the referent, the HRs of the other six joint biomarker groups ranged from 1.6-3.4 for overall mortality and 0.9-3.9 for disease-specific mortality.

Conclusion

The p16/p53/HPV joint groups showed greater distinction in clinical outcomes compared to results based on the individual biomarkers alone. This finding suggests that assessing multiple molecular markers in HNC patients will better predict the diverse outcomes and potentially the type of treatment targeted to those markers.

Oropharyngeal cancer: a potential consequence of concomitant HPV and HIV infection

PURPOSE OF REVIEW

Oral human papillomavirus (HPV) infection is the principal cause of a distinct form of oropharyngeal cancer (OPCA) that has been rising in incidence in the United States since 1973, particularly among young men. The possible contribution of the HIV-epidemic to this increase is unclear.

RECENT FINDINGS

Incidence rates for HPV-related OPCA increased with age and were strongly influenced by year of birth in the United States (cohort effect). Persons with HIV/AIDS are at increased risk ( approximately two to six-fold) for OPCA relative to the general population. However, this excess risk may be attributable to tobacco smoking rather than the three-fold higher prevalence of oral HPV infection in this population. Consistent with a viral attribution, however, is the apparent increase in risk of OPCA with severity of AIDS-related immunosuppression. Analogous to other HPV-related cancers (e.g. cervical and anal cancer), trends over time do not appear to be influenced by highly active antiretroviral (HAART) therapy.

SUMMARY

Healthcare providers may encounter HPV-related OPCA more frequently among individuals with HIV/AIDS as this population ages and due to the strong birth cohort effects observed in the general population. However, there is no evidence in support of different incidence trends over time among persons with and without HIV/AIDS.

Human papillomavirus (HPV) type 18 induces extended growth in primary human cervical, tonsillar, or foreskin keratinocytes more effectively than other high-risk mucosal HPVs

Mucosal high-risk (HR) human papillomaviruses (HPVs) that cause cervical and other anogenital cancers also are found in approximately 25% of head and neck carcinomas (HNCs), especially those arising in the oropharynx and the tonsils. While many HR HPV types are common in anogenital cancer, over 90% of HPV-positive HNCs harbor HPV type 16 (HPV-16). Using a quantitative colony-forming assay, we compared the ability of full-length mucosal HPV genomes, i.e., the low-risk HPV-11 and HR HPV-16, -18, and -31, to persist in and alter the growth of primary human keratinocytes from the foreskin, cervix, and tonsils. The HR HPV types led to the formation of growing keratinocyte colonies in culture independent of the site of epithelial origin. However, HPV-18 induced colony growth in all keratinocytes >4-fold more effectively than HPV-16 or HPV-31 and >20-fold more efficiently than HPV-11 or controls. HPV-11-transfected or control colonies failed to expand beyond 32 to 36 population doublings postexplantation. In contrast, individual HR HPV-transfected clones exhibited no apparent slowdown of growth or "crisis," and many maintained HPV plasmid persistence beyond 60 population doublings. Keratinocyte clones harboring extrachromosomal HR HPV genomes had shorter population doubling times and formed dysplastic stratified epithelia in organotypic raft cultures, mirroring the pathological features of higher-grade intraepithelial lesions, yet did not exhibit chromosomal instability. We conclude that, in culture, the HR HPV type, rather than the site of epithelial origin of the cells, determines the efficacy of inducing continued growth of individual keratinocytes, with HPV-18 being the most aggressive mucosal HR HPV type tested.

Oral sexual behaviors associated with prevalent oral human papillomavirus infection

Oral human papillomavirus (HPV) infection is a cause of oropharyngeal cancer. We investigated whether sexual behaviors that elevated the odds of oropharyngeal cancer developing in a case-control study similarly elevated the odds of oral HPV infection developing among control patients. HPV infection was detected in 4.8% of 332 control patients from an outpatient clinic and in 2.9% of 210 college-aged men (age range, 18-23 years). Among control patients, the odds of infection developing independently increased with increases in the lifetime number of oral (P = .007, for trend) or vaginal sex partners (P = .003, for trend). Among college-aged men, the odds of oral HPV infection developing increased with increases in the number of recent oral sex partners (P = .046, for trend) or open-mouthed kissing partners (P = .023, for trend) but not vaginal sex partners. Oral sex and open-mouthed kissing are associated with the development of oral HPV infection.

Human papillomavirus type 16 and 18 in primary lung cancers--a meta-analysis

Lung cancer is the leading cause of cancer mortality worldwide. A possible carcinogenic role of human papillomavirus (HPV) has been investigated for >20 years and has major clinical and public health implications. We performed a meta-analysis to assess the prevalence of HPV16 and HPV18 in primary lung cancers (2435 subjects from 37 published studies). The overall HPV prevalence ranged from 0.0 to 78.3% with large heterogeneity across geographic regions and histological tissue types. A higher proportion, 50% (7/14), of the European studies reported low or no HPV prevalence (0-10%) compared with the Asian studies, 22% (4/18). When the analysis was limited to HPV16 and HPV18 prevalence, a higher prevalence in Asia (HPV16 = 11.6% and HPV18 = 8.8%) than in Europe (HPV16 = 3.5% and HPV18 = 3.6%) was observed. Studies using HPV-specific primers resulted in higher prevalence rates than consensus HPV primers (HPV16: Asia = 13% and Europe = 6%; HPV18: Asia = 13% and Europe = 5%). Further studies are needed to elucidate the role of HPV in lung carcinogenesis with careful thought given to study design and laboratory detection methods for a more accurate assessment of HPV status in lung tumors.

Molecular pathology of head and neck cancer: implications for diagnosis, prognosis, and treatment

The prototypic head and neck squamous cell carcinoma (HNSCC) arises from the mucosal lining of the upper aerodigestive tract, demonstrates squamous differentiation microscopically, involves older men with a long history of cigarette smoking and alcohol consumption, and is treated by multimodality therapy. HNSCC has long been regarded as a uniform disease process requiring a methodical and unwavering therapeutic approach. Divergence in epidemiologic trends among HNSCCs arising from different anatomic sites has introduced a view that, morphologic repetition aside, head and neck cancers form a heterogeneous group. This view has been supported at the molecular genetic level. A more complete understanding of the molecular genetics of head and neck cancer is providing new insights into long-held but poorly comprehended concepts such as field cancerization and is introducing various biomarkers with potential application for diagnosing, staging, monitoring, and prognosticating HNSCC.

[Human papillomavirus and cancer of the oropharynx. Molecular interaction and clinical implications]

One-third of the cases of oropharyngeal squamous cell carcinoma (OSCC) contain oncogenic human papillomavirus (HR-HPV). Epidemiologic and molecular evidence underlines the causal role of HR-HPV in these tumors, which can be defined as HPV-related OSCC. These tumors differ from chemical/toxin-induced OSCC in several biological aspects, including specific molecular and genetic alterations. This leads to a characteristic clinical profile of HPV-related OSCC. Sexual risk factors play a role; however, the knowledge about natural infection and the rate of persistence of HR-HPV in the oropharynx is marginal. It is shown that the distinct biological behavior of the HPV-related subset of oropharyngeal tumors results in a more favorable prognosis. This might be the result of a better response to chemotherapy and radiotherapy. However, further studies are needed to show whether it will be possible to reliably select patients for individualized therapy depended on the HPV status of their tumors. Therefore, we think it will be mandatory to consider and stratify HPV status in the design of prospective clinical trials in the future.

Demographic and risk factors in patients with head and neck tumors

The association between human papillomavirus (HPV) infection and the development of head and neck cancer has been documented recently. In this study on 86 head and neck cancer patients and 124 controls, data regarding demographics, behavioral risk factors, and risks related to HPV exposure were collected. HPV detection was carried out using polymerase chain reaction in the tumors and in oral exfoliated cells, and HPV typing by a reverse line blot assay specific for 37 HPV types. Sera were tested by an enzyme-linked immunosorbent assay specific for HPV proteins. Head and neck cancer cases report significantly more oral-anal contact (P = 0.02) and tobacco and alcohol use than controls (P = 0.001; P = 0.02, respectively). High-risk HPV DNA was detected in 43% of oral washings of cases and 4% of controls (P < 0.0001). The association between the presence of high-risk HPV DNA in oral exfoliated cells and in tumor tissues was statistically significant (adjusted P < 0.0001). The prevalence of HPV-specific antibodies was significantly higher in cases than in controls (adjusted P < 0.0001). These results provide epidemiological and immunological evidence for HR HPV as a strong risk factor (OR = 44.3, P < 0.0001) for head and neck cancer, even after controlling for age, tobacco and alcohol use. The detection of high-risk HPV DNA in oral exfoliated cells and HPV-specific antibodies in serum can be considered as clinically relevant surrogate markers for the presence of a HPV-associated head and neck cancer, with a high sensitivity (83%) and specificity (88%).

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.

Genomewide gene expression profiles of HPV-positive and HPV-negative oropharyngeal cancer: potential implications for treatment choices

OBJECTIVE

To study the difference in gene expression between human papillomavirus (HPV)-positive and HPV-negative oral cavity and oropharyngeal squamous cell carcinoma (OSCC).

DESIGN

We used Affymetrix U133 plus 2.0 arrays to examine gene expression profiles of OSCC and normal oral tissue. The HPV DNA was detected using polymerase chain reaction followed by the Roche LINEAR ARRAY HPV Genotyping Test, and the differentially expressed genes were analyzed to examine their potential biological roles using the Ingenuity Pathway Analysis Software, version 5.0.

SETTING

Three medical centers affiliated with the University of Washington.

PATIENTS

A total of 119 patients with primary OSCC and 35 patients without cancer, all of whom were treated at the setting institutions, provided tissues samples for the study.

RESULTS

Human papillomavirus DNA was found in 41 of 119 tumors (34.5%) and 2 of 35 normal tissue samples (5.7%); 39 of the 43 HPV specimens were HPV-16. A higher prevalence of HPV DNA was found in oropharyngeal cancer (23 of 31) than in oral cavity cancer (18 of 88). We found no significant difference in gene expression between HPV-positive and HPV-negative oral cavity cancer but found 446 probe sets (347 known genes) differentially expressed in HPV-positive oropharyngeal cancer than in HPV-negative oropharyngeal cancer. The most prominent functions of these genes are DNA replication, DNA repair, and cell cycling. Some genes differentially expressed between HPV-positive and HPV-negative oropharyngeal cancer (eg, TYMS, STMN1, CCND1, and RBBP4) are involved in chemotherapy or radiation sensitivity.

CONCLUSION

These results suggest that differences in the biology of HPV-positive and HPV-negative oropharyngeal cancer may have implications for the management of patients with these different tumors.

Oral human papillomavirus infection before and after treatment for human papillomavirus 16-positive and human papillomavirus 16-negative head and neck squamous cell carcinoma

PURPOSE

Oral human papillomavirus (HPV) infection is a risk factor for head and neck squamous cell carcinoma (HNSCC), and is a concern for patients with HPV-positive HNSCC and their partners. The prevalence of oral HPV infection before and after cancer therapy was investigated among patients with HPV16-positive and HPV16-negative HNSCC.

EXPERIMENTAL DESIGN

Serial oral rinse samples (ORS) were collected from a cohort of 135 HNSCC cases as frequently as every 3 months for up to 3 years. Tumor HPV status was determined by HPV16 in situ hybridization. HPV was detected in ORS by consensus PCR and line blot hybridization. The HPV16 variants in positive oral rinse-tumor pairs were determined by sequencing. The odds of oral HPV infection among HPV16-positive and HPV16-negative cases were compared by use of generalized estimating equations.

RESULTS

Patients were followed for a median of 21 months and provided a median of 4 samples. Forty-four of 135 patients had HPV16-positive tumors. HPV16-positive cases were more likely than HPV16-negative cases to have an oral HPV infection detected before (odds ratio, 8.6; 95% confidence interval, 3.5-21) and after therapy (OR, 2.9; 95% confidence interval, 1.1-7.4). Oral infections by HPV16 and other high-risk, but not low-risk, types were more common among HPV16-positive cases both before and after therapy. Most HPV16 variants in ORS were European, unique, and identical to that in the tumor. Persistence of a type-specific oral infection was demonstrable for as long as 5 years.

CONCLUSION

Oral high-risk HPV infections are more frequent among patients with HPV16-positive than HPV16-negative HNSCC, consistent with a behavioral and/or biological disposition to infection.

Burden of potentially human papillomavirus-associated cancers of the oropharynx and oral cavity in the US, 1998-2003

BACKGROUND

As human papillomavirus (HPV) vaccination becomes widely available in the US for cervical cancer prevention, it may also affect the rates of other cancers potentially associated with HPV. The objective of the current study was to describe the incidence rates of oropharyngeal and oral cavity cancers in the US with a focus on anatomic sites potentially associated with HPV infection.

METHODS

Incident cases diagnosed between 1998 and 2003 identified through 39 population-based registries that participate in the National Program of Cancer Registries and/or the Surveillance, Epidemiology, and End Results Program were examined. The incidence rates of potentially HPV-associated oropharyngeal and oral cavity cancers by various characteristics were estimated. The 1998 through 2003 trends in these rates were also compared with rates for sites not previously shown to be associated with HPV (comparison sites).

RESULTS

In all, 44,160 cases of potentially HPV-associated cancers of the oropharynx and oral cavity were identified, including 19,239 (43.6%) tonsillar, 16,964 (38.4%) base of tongue, and 7957 (18.0%) other oropharyngeal cancers. The incidence rates for these sites were highest among blacks, and higher among non-Hispanics and men than among Hispanics and women. The annual incidence rates of potentially HPV-associated cancers of the tonsil and base of tongue both increased significantly from 1998 through 2003 (annual percentage change [APC], 3.0; P < .05 for both sites), whereas the incidence rates of cancer at the comparison sites generally decreased.

CONCLUSIONS

The results of the current study provide baseline incidence rates of potentially HPV-associated cancers of the oropharynx and oral cavity that can be compared with rates after the widespread implementation of the HPV vaccination.

Does pretreatment seropositivity to human papillomavirus have prognostic significance for head and neck cancers?

BACKGROUND

Human papillomavirus (HPV) is a risk factor for head and neck cancers (HNC), yet HPV-associated tumors have better prognosis than HPV-negative tumors.

METHODS

We evaluated whether pretreatment presence of antibodies to HPV capsids [virus-like particles (VLP)] or to HPV-16 oncoproteins E6 and E7 was a predictor of HPV-positive HNC and clinical outcomes. Sera from 156 HNC patients were tested for antibodies to HPV-16-derived antigens using ELISA. HPV-16 in tumors was evaluated by PCR and DNA sequencing.

RESULTS

HPV-16 antibodies were found in 33% with HPV-16 VLP, 21% with HPV-16 E6, and 21% with E7. HPV-16 was detected in 26% of tumors. There was a strong correlation between detection of HPV-16 tumor DNA and antibodies to HPV-16 E6 or E7 (kappa = 0.7) but not to HPV-16 VLP (kappa = 0.4). Multivariate analyses showed significantly better disease-specific survival in seropositive HPV-16 VLP [hazard ratio (HR), 0.4; 95% confidence interval (95% CI), 0.1-0.9], HPV-16 E6 (HR, 0.1; 95% CI, 0.02-0.5), and HPV-16 E7 (HR, 0.3; 95% CI, 0.1-0.9) cases. Less disease recurrence occurred among those with antibodies to both E6 and E7 compared with those negative to both (P = 0.003). There was better disease-specific survival in patients who were E6 positive at baseline and remained positive at follow-up compared with individuals who were E6 negative at both time points (P = 0.03; kappa = 0.9).

CONCLUSIONS

The presence of antibodies to HPV-16 E6 and E7 is associated with HPV in tumor cells and with better clinical outcomes. These findings suggest that the presence of E6/E7 antibodies before treatment is predictive of better clinical outcomes and that they may serve as biomarkers for selecting targeted therapeutic modalities developed for HPV-associated tumors.

Distinct distribution of HPV types among cancer-free Afro-Caribbean women from Tobago

Human papillomavirus (HPV), a sexually transmitted virus causes cervical carcinomas, and is associated with approximately 36% of oropharyngeal tumours where HPV16 is the predominant genotype. The cervical cancer incidence rate in Trinidad and Tobago is about two times higher than the worldwide rate. We have for the first time determined the prevalence and type distribution of cervical HPV infections among cancer-free Afro-Caribbean women from Tobago, and compared it with the HPV subtypes observed in their oral cavity. Thirty-five per cent of the women were cervical HPV positive. The most common high-risk type detected in the cervix was HPV45 rather than HPV16 and 18. The prevalence of HPV infection in the oral mucosa was 6.6%. The distribution of HPV genotypes in healthy Tobagonian women is different from that reported in studies conducted in European and North American populations. This may have important implications for vaccine introduction in this and other Afro-Caribbean countries.

Human papillomavirus-related diseases: oropharynx cancers and potential implications for adolescent HPV vaccination

Molecular and epidemiological data now support an etiologic role for oncogenic human papillomavirus (HPV) in oral cancers in women and men. Recent studies have demonstrated an increase in the incidence of HPV-associated oral cancers in the United States. Moreover, the incidence rates for these cancers are higher in men than women. Oral HPV infections acquired through oral sex appear to be the principal risk factor for HPV-associated oral cancers. Despite reports in the popular press that the prevalence of oral sexual behaviors is increasing in the adolescent population, trends in these behaviors over time are largely unavailable. However, data indicate that oral-genital contact is frequently practiced among adolescents; adolescents do not typically consider this a risky behavior. The majority of oral cancers (approximately 90%) caused by HPV are identified as HPV 16 positive. Therefore, HPV-associated oral cancers could be prevented by a prophylactic vaccine if the vaccine were demonstrated to be capable of preventing oral HPV 16 infection. These findings have created new potential opportunities for the primary prevention of oral cancers.

The E8--E2 gene product of human papillomavirus type 16 represses early transcription and replication but is dispensable for viral plasmid persistence in keratinocytes

A conserved E8(wedge)E2 spliced mRNA is detected in keratinocytes transfected with human papillomavirus type 16 (HPV-16) plasmid DNA. Expression of HPV-16 E8--E2 (16-E8--E2) is independent of the major early promoter, P97, and is modulated by both specific splicing events and conserved cis elements in the upstream regulatory region in a manner that differs from transcriptional regulation of other early viral genes. Mutations that disrupt the predicted 16-E8--E2 message also increase initial HPV-16 plasmid amplification 8- to 15-fold and major early gene (P97) transcription 4- to 5-fold over those of the wild type (wt). Expressing the 16-E8--E2 gene product from the cytomegalovirus (CMV) promoter represses HPV-16 early gene transcription from P97 in a dose-dependent manner, as detected by RNase protection assays. When expressed from the CMV promoter, 16-E8--E2 also inhibits the amplification of an HPV-16 plasmid and a heterologous simian virus 40 (SV40) ori plasmid that contains E2 binding sites in cis. In contrast, cotransfections with HPV-16 wt genomes that express physiologic levels of 16-E8--E2 are sufficient to repress HPV-16 plasmid amplification but are limiting and insufficient for the repression of SV40 amplification. 16-E8--E2-dependent repression of HPV-16 E1 expression is sufficient to account for this observed inhibition of initial HPV-16 plasmid amplification. Unlike with other papillomaviruses, primary human keratinocytes immortalized by the HPV-16 E8 mutant genome contain more than eightfold-higher levels of unintegrated plasmid than the wt, demonstrating that 16-E8(wedge)E2 limits the viral copy number but is not required for plasmid persistence and maintenance.

Potentially malignant disorders of the oral and oropharyngeal mucosa; terminology, classification and present concepts of management

In a recently held WHO workshop it has been recommended to abandon the distinction between potentially malignant lesions and potentially malignant conditions and to use the term potentially malignant disorders instead. Of these disorders, leukoplakia and erythroplakia are the most common ones. These diagnoses are still defined by exclusion of other known white or red lesions. In spite of tremendous progress in the field of molecular biology there is yet no single marker that reliably enables to predict malignant transformation in an individual patient. The general advice is to excise or laser any oral of oropharyngeal leukoplakia/erythroplakia, if feasible, irrespective of the presence or absence of dysplasia. Nevertheless, it is actually unknown whether such removal truly prevents the possible development of a squamous cell carcinoma. At present, oral lichen planus seems to be accepted in the literature as being a potentially malignant disorder, although the risk of malignant transformation is lower than in leukoplakia. There are no means to prevent such event. The efficacy of follow-up of oral lichen planus is questionable. Finally, brief attention has been paid to oral submucous fibrosis, actinic cheilitis, some inherited cancer syndromes and immunodeficiency in relation to cancer predisposition.

Distinct risk factor profiles for human papillomavirus type 16-positive and human papillomavirus type 16-negative head and neck cancers

BACKGROUND

High-risk types of human papillomavirus (HPV), including HPV-16, cause a subgroup of head and neck squamous cell carcinomas (HNSCCs). We examined whether the risk factors for HPV-16-positive HNSCCs are similar to those for HPV-16-negative HNSCCs in a hospital-based case-control study.

METHODS

Case subjects (n = 240) diagnosed with HNSCC at the Johns Hopkins Hospital from 2000 through 2006 were stratified by tumor HPV-16 status as determined by in situ hybridization. Two control subjects (n = 322) without cancer were individually matched by age and sex to each HPV-16-positive and HPV-16-negative case subject. Data on risk behaviors were obtained by use of audio computer-assisted self-interview technology. Multivariable conditional logistic regression models were used to estimate the odds ratios (ORs) for HPV-16-positive HNSCC and HPV-16-negative HNSCC associated with risk factors. All statistical tests were two-sided.

RESULTS

HPV-16 was detected in 92 of 240 case subjects. HPV-16-positive HNSCC was independently associated with several measures of sexual behavior and exposure to marijuana but not with cumulative measures of tobacco smoking, alcohol drinking, or poor oral hygiene. Associations increased in strength with increasing number of oral sex partners (P(trend) = .01) and with increasing intensity (joints per month, P(trend) = .007), duration (in years, P(trend) = .01), and cumulative joint-years (P(trend) = .003) of marijuana use. By contrast, HPV-16-negative HNSCC was associated with measures of tobacco smoking, alcohol drinking, and poor oral hygiene but not with any measure of sexual behavior or marijuana use. Associations increased in strength with increasing intensity (cigarettes per day), duration, and cumulative pack-years of tobacco smoking (for all, P(trend) < .001), increasing years of heavy alcohol drinking (> or = 15 years of 14 drinks per week; P(trend) = .03), and increasing number of lost teeth (P(trend) = .001). Compared with subjects who neither smoked tobacco nor drank alcohol, those with heavy use of tobacco (> or = 20 pack-years) and alcohol had an increased risk of HPV-16-negative HNSCC (OR = 4.8, 95% confidence interval [CI] = 1.8 to 12) but not of HPV-16-positive HNSCC (OR = 0.67, 95% CI = 0.29 to 1.9).

CONCLUSIONS

HPV-16-positive HNSCCs and HPV-16-negative HNSCCs have different risk factor profiles, indicating that they should be considered to be distinct cancers.

Presence of HPV DNA in convalescent salivary rinses is an adverse prognostic marker in head and neck squamous cell carcinoma

Human papillomavirus (HPV) 16 is present in up to 60% of patients with head and neck squamous cell carcinoma (HNSCC) and confers a favorable prognosis in terms of recurrence and mortality. Previous reports demonstrated that HPV-16 DNA can be detected in the initial salivary rinses from these patients. In this study, we assessed the feasibility of post-treatment HPV DNA shed from the oral mucosa as a prognostic marker for persistent/recurrent head and neck cancer. Fresh tumor samples and pre- and post-treatment salivary rinses were collected from 59 patients with HNSCC. HPV-16 E6 and E7 DNA copy number in these samples were quantified by real time PCR. Twenty of 59 patients (33.9%) were HPV-16 positive in their tumors before treatment. Four of 20 HPV tumor positive patients ultimately developed recurrence, and two of these four patients were HPV-16 positive in surveillance salivary rinses (sensitivity=50%). Of the 39 (66.1%) HPV-16 negative patients on initial clinical presentation and the 16 HPV-16 positive patients who did not recur, none were HPV-16 positive in salivary rinses after treatment (specificity=100%). HPV-16 presence in follow-up salivary rinses preceded clinical detection of disease recurrence by an average of 3.5 months. Patients with presence of HPV-16 DNA in surveillance salivary rinses are at significant risk for recurrence. Quantitative measurement of salivary HPV-16 DNA has promise for surveillance and early detection of recurrence.

HUMAN PAPILLOMAVIRUS ASSOCIATION WITH HEAD AND NECK CANCERS: UNDERSTANDING VIRUS BIOLOGY AND USING IT IN THE DEVELOPMENT OF CANCER DIAGNOSTICS

The link between human papillomaviruses and human cervical cancers has long been established. However, human papillomaviruses (HPVs) are now being detected in another type of cancer, not previously associated with this virus, head and neck squamous cell carcinoma (HNSCC). This review will focus on experimental data supporting the view that HPVs contribute to the etiology of a subset of HNSCC. We further put forth the argument that HPV-associated HNSCC deserves to be recognized as a distinct disease in the clinic and as such needs to be appropriately diagnosed. We offer an overview of studies that have helped dissect the role of HPVs in HNSCC and that may be helpful in the development of new diagnostic tools for discriminating this type of HNSCC.

Gene expression profiles in HPV-infected head and neck cancer

Epidemiological and laboratory evidence indicate that, in addition to tobacco and alcohol, human papillomaviruses (HPV) play an important aetiological role in a subset of head and neck squamous cell carcinoma (HNSCC). To evaluate the molecular pathogenesis of HPV-infected HNSCC, we compared gene expression patterns between HPV-positive and -negative HNSCC tumours using cDNA microarrays. Tumour tissue was collected from 42 histologically confirmed HNSCC patients from an inner-city area of New York. Total DNA and RNA were extracted and purified from frozen tumour samples and gene expression levels were compared to a universal human reference RNA standard using a 27 323 cDNA microarray chip. HPV detection and genotyping were performed using an MY09/11-PCR system and RT-PCR. HPV was detected in 29% of HNSCC tumours. Most harboured only HPV16 and expressed the HPV16-E6 oncogene. HPV prevalence was highest in pharyngeal tumours (45%). Gene expression patterns that differentiated HPV-positive from negative tumours were compared by supervised classification analysis, and a multiple-gene signature was found to predict HPV16 prevalence in primary HNSCC with a false discovery rate < 0.2. Focusing on never-smokers, we further identified a distinct subset of 123 genes that were specifically dysregulated in HPV16-positive HNSCC. Overexpressed genes in HPV-positive HNSCC tumours included the retinoblastoma-binding protein (p18), replication factor-C gene, and an E2F-dimerization partner transcription factor (TFDP2) that have also been found to be overexpressed in cervical cancer. An additional subset of genes involved in viral defence and immune response, including interleukins and interferon-induced proteins, was found to be down-regulated in HPV-positive tumours, supporting a characteristic and unique transcriptional profile in HPV-induced HNSCC.