Antibodies against oncoproteins E6 and E7 of human papillomavirus types 16 and 18 in patients with head-and-neck squamous-cell carcinoma

Relevance of Human Papillomaviruses in Head and Neck Cancer-What Remains in 2021 from a Clinician's Point of View?

Human papillomaviruses (HPV) cause a subset of head and neck cancers (HNSCC). HPV16 predominantly signs responsible for approximately 10% of all HNSCC and over 50% of tonsillar (T)SCCs. Prevalence rates depend on several factors, such as the geographical region where patients live, possibly due to different social and sexual habits. Smoking plays an important role, with non-smoking patients being mostly HPV-positive and smokers being mostly HPV-negative. This is of unparalleled clinical relevance, as the outcome of (non-smoking) HPV-positive patients is significantly better, albeit with standard and not with de-escalated therapies. The results of the first prospective de-escalation studies have dampened hopes that similar superior survival can be achieved with de-escalated therapy. In this context, it is important to note that the inclusion of p16^INK4A (a surrogate marker for HPV-positivity) in the 8th TMN-classification has only prognostic, not therapeutic, intent. To avoid misclassification, highest precision in determining HPV-status is of utmost importance. Whenever possible, PCR-based methods, still referred to as the "gold standard”, should be used. New diagnostic antibodies represent some hope, e.g., to detect primaries and recurrences early. Prophylactic HPV vaccination should lead to a decline in HPV-driven HNSCC as well. This review discusses the above aspects in detail.

Investigating the association between serum human papillomavirus type 16 E7 antibodies and risk of head and neck cancer

Human papillomavirus (HPV) is recognized as a major cause of oropharyngeal cancer (OPC) in Western countries. Less is known regarding its contribution to the OPC occurring in Asia. The current study aimed to investigate the association between antibody responses to HPV16 E7 and head and neck cancer (HNC) risk in a hospital‐based case–control study conducted in Taiwan with 693 HNC cases and 1,035 controls. A positive association was observed between seropositivity to HPV16 E7 and OPC risk, whereas no significant association was found in the non‐OPC cases. The increased OPC risk associated with seropositivity to HPV16 E7 was more significant among nonbetel quid or noncigarette users. Seropositivity to HPV16 E7 showed moderate agreement with P16 expression in OPC. OPC patients that were seropositive to HPV16 E7 or p16 positive were more highly educated and less likely to use alcohol, betel quids, and cigarettes compared to HPV16 E7 seronegative or p16 negative OPC patients. Furthermore, patients with p16 positive OPC were more likely to be women compared to patients with p16 negative OPC, likely owing to the low prevalence of alcohol, betel quid, and cigarette users among women. Overall, this study suggested that similar to Western countries, HPV may also be an important risk factor of OPC in Taiwan. With the declining consumption of betel quids and cigarettes in Taiwan, a higher percentage of OPC cases in Taiwan will be attributed to HPV in the future. Public health measures, including HPV vaccination, need to be implemented to prevent the occurrence of HPV‐positive OPC.

The current study found a a positive association between seropositivity to HPV16 E7 and oropharyngeal cancer risk. This study suggested that similar to Western countries, HPV may also be an important risk factor of OPC in Taiwan.

ePCL Electrospun Microfibrous Layers for Immune Assays: Sensitive ELISA for the Detection of Serum Antibodies Against HPV16 E7 Oncoprotein

Human papillomavirus (HPV) type 16 is the etiologic agent of more than 50% anal/cervical cancers and about 20% oropharyngeal cancers. HPV16 E6 and E7 oncogenes favor the transformation and are essential for maintaining the transformed status. Serum anti-E6 and anti-E7 antibodies appear to have prognostic significance for HPV-associated cancers. However, most of the previous attempts to establish diagnostic tools based on serum detection of E6 and/or E7 antibodies have been unsuccessful, mainly due to the low accuracy of applied tests. This paper reports on a feasibility study to prove the possibility to easily immobilize HPV16 E7 onto electrospun substrates for application in diagnostic tools. In this study, poly(ε-caprolactone) electrospun scaffolds (called ePCL) are used to provide a microstructured substrate with a high surface-to-volume ratio, capable of binding E7 proteins when used for enzyme-linked immunosorbent assay (ELISA) tests. ePCL functionalized with E7 exhibited superior properties compared to standard polystyrene plates, increasing the detection signal from serum antibodies by 5-6 times. Analysis of the serum samples from mice immunized with HPV16 E7 DNA vaccine showed higher efficiency of this new anti-E7 ePCL-ELISA test vs control in E7-specific antibody detection. In addition, ePCL-E7-ELISA is prepared with a relatively low amount of antigen, decreasing the manufacturing costs.

HNSCC: Tumour Antigens and Their Targeting by Immunotherapy

Head and neck squamous cell carcinomas (HNSCC) are a heterogeneous group of malignant tumours typically caused by alcohol and tobacco consumption, although an increasing number of HNSCC arise due to persistent infection with high-risk human papilloma virus (HPV). The treatment of HNSCC remains challenging, and the first-line setting is focused on surgery and chemoradiotherapy. A substantial proportion of HNSCC patients die from their disease, especially those with recurrent and metastatic disease. Among factors linked with good outcome, immune cell infiltration appears to have a major role. HPV-driven HNSCC are often T-cell rich, reflecting the presence of HPV antigens that are immunogenic. Tumour-associated antigens that are shared between patients or that are unique to an individual person may also induce varying degrees of immune response; studying these is important for the understanding of the interaction between the host immune system and the cancer. The resulting knowledge is critical for the design of better immunotherapies. Key questions are: Which antigens lead to an adaptive immune response in the tumour? Which of these are exploitable for immunotherapy? Here, we review the current thinking regarding tumour antigens in HNSCC and what has been learned from early phase clinical trials.

Human Papillomavirus Prevalence in Oral and Oropharyngeal Rinse and Gargle Specimens of Dental Patients and of an HIV-Positive Cohort from Pretoria, South Africa

Introduction

Studies on HPV prevalence in the head and neck region of South Africans are sparse. Of the available reports in the literature, there were no studies on the association between HPV-DNA presence in the mouth and oropharynx in relation to high-risk behaviours such as oral sex practice or tobacco and alcohol use.

Materials and Methods

Following ethical clearance and informed consent, patients attending a regional HIV-management clinic and patients attending a dental hospital were recruited to this study. The participants completed an interview-based questionnaire obtaining demographic information, data on HIV serostatus, and behavioural data including sexual practices and tobacco and alcohol use, and a rinse-and-gargle specimen was taken. Specimens were analysed for HPV DNA on 3 separate PCR/qPCR platforms. Statistical analyses were performed for associations between the study group and categorical variables, HPV status, and data from the questionnaires.

Results

Of 221 participants, 149 were from a general population and 72 from the HIV-management clinic. Smokers comprised 29.4% of the sample, and 45.2% of participants reported to have ever used alcohol. Open mouth kissing during teenage years was confirmed by 64.7% of participants, 40.3% have given oral sex with their mouth, and 44.8% confirmed to have received oral sex from their partner's mouth. Seven participants (3.2%) had detectable α-HPV DNA, and 1 (0.4%) had detectable β-HPV DNA in their rinse-and-gargle specimens. Two participants were from the HIV-management clinic and 6 from the general dental population (overall 3.6%).

Conclusion

Five high-risk HPV, 2 low-risk HPV, and one β-HPV types were detected. The low prevalence of 3.6% compares well to similar studies in different cohorts studied in South Africa and falls within the global oral/oropharyngeal prevalence spectrum. Only 4 participants, all from the HIV-management clinic, had palatine tonsils. No significant relationships were found between HPV presence and demographic data or sexual, oral sexual, tobacco use, or alcohol use, and no associations were seen with numbers of sexual and oral-sex partners.

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

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

Luciferase-Based Detection of Antibodies for the Diagnosis of HPV-Associated Head and Neck Squamous Cell Carcinoma

Point-of-care tests are needed for the screening of head and neck squamous cell carcinoma (HNSCC) and other malignancies. Luciferase immunoprecipitation systems (LIPS), employing light-emitting proteins, were used to examine serum antibodies against several cancer-associated targets in blood donor controls and subjects with colon cancer (CC) and HNSCC. The assessment of antibodies against the wild type p53 tumor antigen showed that approximately 25% of the CC and 20% of the HNSCC patients were seropositive. In addition, humoral responses against two p53 mutants, p53-R175H and p53-R273H, generally tracked the antibody responses seen against wild type p53. Analysis of antibodies against highly specific biomarkers of HPV-16-associated malignancy, E2, E6, and E7 oncoproteins, revealed no seropositivity in blood donors and CC patients. However, 45% (9/20) of the HNSCC patients showed E6 seropositivity, which overlapped all the detectable E2 (40%; 8/20) and E7 seropositive subjects (35%; 7/20). Using neodymium magnets, ultrarapid LIPSTICKS testing of HPV-16 E6 antibodies in <60 s per HNSCC sample demonstrated almost the same diagnostic performance (40% sensitivity and 100% specificity) as LIPS testing in 2.5 h. While additional improvements and standardization are needed, these results highlight the possibility of using these approaches for the diagnosis of HPV-16-associated HNSCC.

Prognostic value of posttreatment HPV-specific antibodies in patients with oropharyngeal tumors

BACKGROUND

The presence of human papillomavirus (HPV)-specific antibodies in patients with head and neck cancer at enrollment has prognostic significance. In cervical carcinoma patients, the decrease of HPV E6/E7-specific antibodies appears to be associated with a better prognosis.

METHODS

This prospective study with follow-up focused on the persistence and prognostic value of antibodies specific for HR HPV-derived VLPs and HPV16 E6/E7 oncoproteins in patients with oropharyngeal cancers. In this study, we analyzed sera of 93 patients taken a year after the end of treatment and sera from 58 of these patients taken up to 14 years after treatment.

RESULTS

The level of HPV-specific antibodies decreased on the 1-year follow-up and the decrease during the long follow-up was statistically significant. For HPV16 E7 antibodies the decrease was steeper in nonrecurrent patients. While the level of antibodies at enrollment was not predictive of recurrences, the decrease of HPV16 E6 antibodies at 1-year follow up was associated with better overall as well as disease-specific survival of patients.

CONCLUSIONS

The data suggest that the pretreatment level of HPV-specific antibodies is not predictive of the occurrence of recurrences but the decrease HPV16 E6 antibodies on the 1-year follow-up is predictive of better survival of HN patients.

HPV, hypoxia and radiation response in head and neck cancer

Over the last decades, the incidence of human papilloma virus (HPV) positive head and neck squamous-cell carcinoma (HNSCC) has significantly increased. Infection with high-risk HPV types drives tumourigenesis through expression of the oncoproteins E6 and E7. Currently, the primary treatment of HNSCC consists of radiotherapy, often combined with platinum-based chemotherapeutics. One of the common features of HNSCC is the occurrence of tumour hypoxia, which impairs the efficacy of radiotherapy and is a negative prognostic factor. Therefore, it is important to detect and quantify the severity of hypoxia, as well as develop strategies to specifically target hypoxic tumours. HPV-positive tumours are remarkably radiosensitive compared to HPV-negative tumours and consequently the HPV-positive patients have a better prognosis. This provides an opportunity to elucidate mechanisms of radiation sensitivity, which may reveal targets for improved therapy for HPV-negative head and neck cancers. In this review, we will discuss the differences between HPV-positive and HPV-negative head and neck tumours and methods of hypoxia detection and targeting in these disease types. Particular emphasis will be placed on the mechanisms by which HPV infection impacts radiosensitivity.

Profiling of serum antibodies against human papillomavirus antigens in Korean women with cervical intraepithelial neoplasia and cervical cancer

Sero-epidemiological studies of human papillomavirus (HPV) have been undertaken over the last two decades. In this study, the prevalences of nine serum antibodies (anti-E6, E7 and L1 antibodies of HPV types 16, 18, and 58) were evaluated in normal (control) Korean women and women with cervical intraepithelial neoplasia (CIN) I, CIN II, CIN III, and cervical cancer. The frequencies of all types of anti-HPV antibodies were higher in the CIN stages and cervical cancer than in normal women, and those of anti-HPV16 E6 and E7, anti-HPV18 E6 and E7, and anti-HPV58 E7 antibodies were higher in the cervical cancer group than in the CIN stages. The frequencies of antibodies against HPV16, 18, and 58 E7 tended to increase with increasing severity of cervical lesions. However, there were few differences in the frequencies of antibodies against the L1 antigens of HPV16, 18 and 58 in cervical cancer versus CIN stages. The anti-HPV antibodies were detected in 26.5% of normal, 46.3% of CIN I, 62.5% of CIN II, 51.6% of CIN III, and 75% of cancers when any of the nine antigens was used as a criterion. Correlations between HPV DNA positivity and seropositivity for anti-HPV E6, E7, or L1 antibodies were found only in HPV16 DNA-positive cervical cancers for anti-HPV16 E6 and L1 antibodies. In addition, strong positive correlations in seropositivity were found between anti-HPV16 E7 and anti-HPV58 E7 antibodies, and between anti-HPV18 E6 and anti-HPV58 E6 antibodies. These findings should advance global profiling of the seroprevalences of antibodies against HPV antigens.

Evaluation of type-specific antibodies to high risk-human papillomavirus (HPV) proteins in patients with oropharyngeal cancer

OBJECTIVES

High risk human papillomavirus (HR-HPV) infection leads to a subgroup of oropharyngeal cancer (OPSCC) characterized by improved treatment response. However an universally accepted definition of an HR-HPV-attributable cancer is lacking.

METHODS

Detailed, type-specific HPV antibody responses were analyzed by multiplex serology in HR-HPV-attributable OPSCC patients, defined by p16^INK4A overexpression and HR-HPV DNA detection by PCR amplification and sequencing.

RESULTS

Fifty patients were prospectively enrolled. 26/50 (52%) tumor samples were positive for both p16^INK4A expression and HR-HPV DNA (22 HPV16, 4 HPV33). Seropositivity was present in 26/26 HPV-attributable OPSCC and one p16^INK4A-positive/HPV DNA-negative case. The sensitivity and specificity to diagnose an HR-HPV-attributable tumor was 100% and 96%, respectively for anti-E6 reactivity, 82% and 100%, respectively for anti-E2 reactivity, and clearly lower for anti-E7, anti-E1, anti-E4 and anti-L1-reactivity. 3yr-overall (OS) and disease specific survival (DSS) was higher in patients with HR-HPV-attributable tumors (OS 88% vs 64%, p=0.02; DSS 90% vs 80%, p=0.07) and seropositive patients (OS 88% vs 62%, p=0.01; DSS 92% vs 78%, p=0.05) than HR-HPV-negative or seronegative patients.

CONCLUSIONS

Detection of HR-HPV type-specific antibodies highly correlated with HPV-attributable OPSCC and was associated with better survival. HR-HPV antibodies are promising diagnostic, prognostic and potentially screening markers in HR-HPV-attributable OPSCC.

Serum biomarkers of polyomavirus infection and risk of lung cancer in never smokers

BACKGROUND

Lung cancer in never smokers is a significant contributor of cancer mortality worldwide. In this analysis, we explored the role of nine human polyomaviruses, including JC virus (JCV), BK virus (BKV) and Merkel cell virus (MCV), in lung cancer development in never smokers as there are data to support that polyomaviruses are potentially carcinogenic in the human lung.

METHODS

We used multiplex serology to detect serum antibodies to polyomaviruses in a nested case-control design combining lung cancer cases and controls from four cohort studies - NYU Women's Health Study (NYU-WHS), Janus Serum Bank, Shanghai Women's Health Study and Singapore Chinese Health Study (SCHS).

RESULTS

The final analyses included 511 cases and 508 controls. Seroprevalence for each polyomavirus showed significant heterogeneity by study, but overall there were no statistically significant differences between cases and controls. In total, 69.1% of the cases and 68.7% of the controls were seropositive for JCV VP1 antibody. Seropositivity for BKV was higher at 89.0% in cases and 89.8% in controls and lower for MCV at 59.3% in cases and 61.6% in controls. Similar results were obtained after adding an additional retrospective case-control study (Xuanwei study) to the analysis.

CONCLUSIONS

Our results do not support the hypothesis that seropositivity for polyomaviruses is associated with increased lung cancer risk in never smokers. Future research to evaluate relationship between polyomavirus infection and lung carcinogenesis should focus more on evaluating the presence of virus or viral nucleic acids (DNA or RNA) in lung tumour samples.

Mucosal alpha-papillomaviruses are not associated with esophageal squamous cell carcinomas: Lack of mechanistic evidence from South Africa, China and Iran and from a world-wide meta-analysis

Epidemiological and mechanistic evidence on the causative role of human papillomaviruses (HPV) in esophageal squamous cell carcinoma (ESCC) is unclear. We retrieved alcohol- and formalin-fixed paraffin-embedded ESCC tissues from 133 patients seropositive for antibodies against HPV early proteins, from high-incidence ESCC regions: South Africa, China and Iran. With rigorous care to prevent nucleic acid contamination, we analyzed these tissues for the presence of 51 mucosotropic human alpha-papillomaviruses by two sensitive, broad-spectrum genotyping methods, and for the markers of HPV-transformed phenotype: (i) HPV16/18 viral loads by quantitative real-time PCR, (ii) type-specific viral mRNA by E6*I/E6 full-length RT-PCR assays and (iii) expression of cellular protein p16(INK4a). Of 118 analyzable ESCC tissues, 10 (8%) were positive for DNA of HPV types: 16 (4 tumors); 33, 35, 45 (1 tumor each); 11 (2 tumors) and 16, 70 double infection (1 tumor). Inconsistent HPV DNA+ findings by two genotyping methods and negativity in qPCR indicated very low viral loads. A single HPV16 DNA+ tumor additionally harbored HPV16 E6*I mRNA but was p16(INK4a) negative (HPV16 E1 seropositive patient). Another HPV16 DNA+ tumor from an HPV16 E6 seropositive patient showed p16(INK4a) upregulation but no HPV16 mRNA. In the tumor tissues of these serologically preselected ESCC patients, we did not find consistent presence of HPV DNA, HPV mRNA or p16(INK4a) upregulation. These results were supported by a meta-analysis of 14 other similar studies regarding HPV-transformation of ESCC. Our study does not support the etiological role of the 51 analyzed mucosotropic HPV types in the ESCC carcinogenesis.

HPV Serum Antibodies as Predictors of Survival and Disease Progression in Patients with HPV-Positive Squamous Cell Carcinoma of the Oropharynx

PURPOSE

Oropharyngeal carcinoma positive for human papillomavirus type 16 (HPV16) has a significantly better prognosis than oropharyngeal carcinoma unrelated to HPV. Within HPV16-positive oropharyngeal carcinoma, biomarkers of prognosis are urgently needed to individualize care. We hypothesized that serum antibodies specific to HPV16, the major HPV type causing oropharyngeal carcinoma, have biologic relevance and are potential biomarkers for improved prognosis among patients with HPV16-positive oropharyngeal carcinoma.

EXPERIMENTAL DESIGN

IgG antibodies to the HPV16 antigens E1, E4-E7, L1, L2, and the N-terminal and C-terminal fragments of E2 (NE2, CE2) were quantified using a custom programmable enzyme-linked immunosorbent assay. Sera were obtained at diagnosis from 209 oropharyngeal carcinoma patients (96 HPV16-positive). The ratios of median fluorescent intensity (MFI) for each antigen to MFI for control GST protein were determined. Kaplan-Meier survival curves and Cox proportional hazards regression were used to determine survival differences between groups. ROC curves were used to determine the best combination of E antibodies to predict disease recurrence.

RESULTS

E1, NE2, and E6 antibody positivity were all strongly associated with improved overall and progression-free survival in the entire cohort and in patients with known HPV16-positive tumors (P < 0.05). For both overall and progression-free survival among HPV-positive patients, hazard ratios were 0.2 for NE2, 0.3 for E1, and 0.3 for E6 antibody positivity.

CONCLUSIONS

We identified three HPV16-specific antibodies that are associated with improved overall and progression-free survival in patients with HPV-related oropharyngeal carcinoma. These results suggest that differential serologic responses in patients may reflect differential biologic processes within the host and tumor and may have prognostic value.

[Immunotherapy in head and neck cancer]

The physiological immune response to malignant cells is based on the interaction of antigen-presenting cells, such as dendritic cells and macrophages, with T and B lymphocytes. CD8(+) effector and natural killer cells are primarily responsible for tumor cell lysis. Tumor cells exploit several mechanisms to influence the body's immune system and promote development and progress of solid head and neck malignancies. Via regulatory T cells, myeloid-derived suppressor cells, tumor-associated macrophages, and cancer-associated fibroblasts, tumor cells promote development of suppressive signaling pathways that enable tumor progression. Novel immune therapeutics aim to influence these signaling pathways. Current studies are investigating agents which influence immune-stimulating or immune-suppressive cytokines, as well as drug-based Toll-like receptor activation and vaccination in head and neck cancer. Development of monoclonal antibodies allows for direct and highly specific binding of therapeutics to cell receptors - recently discovered immune checkpoint receptors are particularly intriguing targets. Monoclonal antibodies directed specifically toward T cell-stimulating receptors such as CD28 and CD134, or immunosuppressive receptors CTLA-4 and PD-1, are currently under investigation and have shown promising results.

Human papillomavirus tumor infection in esophageal squamous cell carcinoma

The association between human papillomavirus (HPV) and esophageal squamous cell carcinoma (ESCC) has been recognized for over three decades. Recently, multiple meta-analyses have drawn upon existing literature to assess the strength of the HPV-ESCC linkage. Here, we review these analyses and attempt to provide a clinically-relevant overview of HPV infection in ESCC. HPV-ESCC detection rates are highly variable across studies. Geographic location likely accounts for a majority of the variation in HPV prevalence, with high-incidence regions including Asia reporting significantly higher HPV-ESCC infection rates compared with low-incidence regions such as Europe, North America, and Oceania. Based on our examination of existing data, the current literature does not support the notion that HPV is a prominent carcinogen in ESCC. We conclude that there is no basis to change the current clinical approach to ESCC patients with respect to tumor HPV status.

Human Papillomavirus 16 E6 Antibodies in Individuals without Diagnosed Cancer: A Pooled Analysis

BACKGROUND

The increasing incidence of oropharyngeal cancer in many developed countries has been attributed to human papillomavirus type 16 (HPV16) infections. Recently, HPV16 E6 serology has been identified as a promising early marker for oropharyngeal cancer. Therefore, characterization of HPV16 E6 seropositivity among individuals without cancer is warranted.

METHODS

A total of 4,666 controls were pooled from several studies of cancer and HPV seropositivity, all tested within the same laboratory. HPV16 E6 seropositive controls were classified as having (i) moderate [mean fluorescent intensity (MFI) ≥ 484 and <1,000] or (ii) high seroreactivity (MFI ≥ 1,000). Associations of moderate and high HPV16 E6 seroreactivity with (i) demographic risk factors; and seropositivity for (ii) other HPV16 proteins (E1, E2, E4, E7, and L1), and (iii) E6 proteins from non-HPV16 types (HPV6, 11, 18, 31, 33, 45, and 52) were evaluated.

RESULTS

Thirty-two (0.7%) HPV16 E6 seropositive controls were identified; 17 (0.4%) with moderate and 15 (0.3%) with high seroreactivity. High HPV16 E6 seroreactivity was associated with former smoking [odds ratio (OR), 5.5; 95% confidence interval (CI), 1.2-51.8], and seropositivity against HPV16 L1 (OR, 4.8; 95% CI, 1.3-15.4); E2 (OR, 7.7; 95% CI, 1.4-29.1); multiple HPV16 proteins (OR, 25.3; 95% CI, 2.6-119.6 for three HPV16 proteins beside E6) and HPV33 E6 (OR, 17.7; 95% CI, 1.9-81.8). No associations were observed with moderate HPV16 E6 seroreactivity.

CONCLUSIONS

High HPV16 E6 seroreactivity is rare among individuals without diagnosed cancer and was not explained by demographic factors.

IMPACT

Some HPV16 E6 seropositive individuals without diagnosed HPV-driven cancer, especially those with seropositivity against other HPV16 proteins, may harbor a biologically relevant HPV16 infection.

Seropositivity of HPV 16 E6 and E7 and the risk of oral cancer

OBJECTIVES

The objective of the study was to determine the prevalence of HPV seropositivity among patients with oral squamous cell carcinoma (OSCC) and healthy individuals and to correlate the association between HPV 16 seropositivity and risk of OSCC.

MATERIALS AND METHODS

HPV 16 E6 and E7 plasmids were constructed for the production of recombinant protein, which was used as the antigen in ELISA. HPV ELISA was performed on serum samples from 50 healthy individuals and 50 patients with OSCC.

RESULTS

Using the HPV ELISA, 30% (OR = 2.25, 95% CI = 0.85-5.93) and 18% (OR = 1.61, 95% CI = 0.53-4.92) of patients with oral cancer were found to be HPV 16 E6 and E7 seropositive, respectively. Significant association was found between HPV 16 seropositivity and increased risk of OSCC in men, but not in male subjects. A similar trend was observed in non-betel quid chewers.

CONCLUSIONS

Potential associations between HPV 16 E6/E7 seropositivity and oral cancer were revealed in men and non-betel quid chewer subjects, suggesting a possible etiological role of HPV 16 in subgroup of patients with OSCC in Malaysia.

HPV infection in esophageal squamous cell carcinoma and its relationship to the prognosis of patients in northern China

Purpose. Human papillomavirus (HPV) as a risk factor for esophageal squamous cell carcinoma (ESCC) has previously been studied, but importance of HPV status in ESCC for prognosis is less clear. Methods. A total of 105 specimens with ESCC were tested by in situ hybridization for HPV 16/18 and immunohistochemistry for p16 expression. The 5-year overall survival (OS) and progression-free survival were calculated in relation to these markers and the Cox proportional hazards model was used to determine the hazard ratio (HR) of variables in univariate and multivariate analysis. Results. HPV was detected in 27.6% (29) of the 105 patients with ESCC, and all positive cases were HPV-16. Twenty-five (86.2%) of the 29 HPV-positive tumors were stained positive for p16. HPV infected patients had better 5-year rates of OS (65.9% versus 43.4% among patients with HPV-negative tumors; P = 0.002 by the log-rank test) and had a 63% reduction in the risk of death (adjusted HR = 0.37, 95% CI = 0.16 to 0.82, and P = 0.01). Conclusions. HPV infection may be one of many factors contributing to the development of ESCC and tumor HPV status is an independent prognostic factor for survival among patients with ESCC.

Evidence of the causal role of human papillomavirus type 58 in an oropharyngeal carcinoma

Persistent human papillomavirus infection (HPV) is recognized as an important etiologic factor for a subset of head and neck squamous cell carcinomas (SCC), especially those arising from the oropharynx. Whereas HPV16 accounts for the majority of HPV DNA-positive oropharyngeal SCC, infections with other mucosal high-risk HPV types are quite rare and biological data demonstrating their causal involvement are insufficient. Here we present the first case of an oropharyngeal SCC driven by HPV type 58. A 69-year-old Caucasian woman presented with an enlarged and firm left tonsil. A computed tomography scan showed a left tonsillar mass, extending to the soft palate and the glossotonsillar sulcus. The patient underwent extended radical tonsillectomy and ipsilateral selective neck dissection. Pathology confirmed an infiltrating, poorly differentiated SCC of the left tonsil with node metastasis (pT2N1). Adjuvant external beam radiation therapy (60 Grays (Gy)) was administered. After 1 year of follow-up, the patient is well with no evidence of cancer recurrence. HPV analyses of the tumor tissue by BSGP5+/6+ -PCR/MPG, targeting 51 mucosal HPV types, showed single positivity for HPV type 58. Presence of HPV58 E6*I RNA demonstrated biological activity of the virus in the tumor tissue, and presence of serum antibodies to HPV58 oncoproteins E6 and E7 indicated presence of an HPV58-driven cancer. Overexpression of cellular protein p16INK4a and reduced expression of pRb, two cellular markers for HPV-induced cell transformation, were observed. Exons 4-10 of TP53 showed no mutations or polymorphisms. The presence of HPV58 as single HPV infection in combination with a broad variety of direct and indirect markers of HPV transformation provides comprehensive evidence that this oropharyngeal SCC was driven by HPV58.

Evaluation of human papillomavirus antibodies and risk of subsequent head and neck cancer

PURPOSE

Human papillomavirus type 16 (HPV16) infection is causing an increasing number of oropharyngeal cancers in the United States and Europe. The aim of our study was to investigate whether HPV antibodies are associated with head and neck cancer risk when measured in prediagnostic sera.

METHODS

We identified 638 participants with incident head and neck cancers (patients; 180 oral cancers, 135 oropharynx cancers, and 247 hypopharynx/larynx cancers) and 300 patients with esophageal cancers as well as 1,599 comparable controls from within the European Prospective Investigation Into Cancer and Nutrition cohort. Prediagnostic plasma samples from patients (collected, on average, 6 years before diagnosis) and control participants were analyzed for antibodies against multiple proteins of HPV16 as well as HPV6, HPV11, HPV18, HPV31, HPV33, HPV45, and HPV52. Odds ratios (ORs) of cancer and 95% CIs were calculated, adjusting for potential confounders. All-cause mortality was evaluated among patients using Cox proportional hazards regression.

RESULTS

HPV16 E6 seropositivity was present in prediagnostic samples for 34.8% of patients with oropharyngeal cancer and 0.6% of controls (OR, 274; 95% CI, 110 to 681) but was not associated with other cancer sites. The increased risk of oropharyngeal cancer among HPV16 E6 seropositive participants was independent of time between blood collection and diagnosis and was observed more than 10 years before diagnosis. The all-cause mortality ratio among patients with oropharyngeal cancer was 0.30 (95% CI, 0.13 to 0.67), for patients who were HPV16 E6 seropositive compared with seronegative.

CONCLUSION

HPV16 E6 seropositivity was present more than 10 years before diagnosis of oropharyngeal cancers.

Human papillomavirus infections and upper aero-digestive tract cancers: the ARCAGE study

BACKGROUND

Human papillomavirus (HPV) is causally implicated in a subset of cancers of the upper aero-digestive tract (UADT).

METHODS

Associations between type-specific HPV antibodies were examined among 1496 UADT cancer case subjects and 1425 control subjects by estimating odds ratios (ORs) in logistic regression analyses adjusted for potential confounders. The agreement between serology and tumor markers of HPV infection, including presence of HPV DNA and p16 expression, were examined in a subset of tumors.

RESULTS

HPV16 L1 seropositivity was associated with increased risk of oral cavity and oropharyngeal cancer (OR = 1.94, 95% confidence interval [CI] = 1.03 to 3.65; OR = 8.60, 95% CI = 5.21 to 14.20, respectively). HPV16 E6 antibodies were present in 30.2% of oropharyngeal case subjects and only 0.8% of control subjects (OR = 132.0, 95% CI = 65.29 to 266.86). Combined seropositivity to HPV16 E6 and E7 was rare (n = 1 of 1425 control subjects). An agreement of 67% was observed between HPV16 E6 serology and the corresponding presence of an HPV-related cancer: four of six HPV DNA-positive/p16-overexpressing tumors were HPV16 E6 antibody positive. An HPV16 independent association was observed for HPV18 and oropharyngeal cancer (OR = 8.14, 95% CI = 2.21 to 29.99 for HPV18 E6 seropositivity) and HPV6 and laryngeal cancer (OR = 3.25, 95% CI = 1.46 to 7.24 for HPV6 E7 seropositivity).

CONCLUSIONS

These results confirm an important role for HPV16 infection in oropharyngeal cancer. HPV16 E6 antibodies are strongly associated with HPV16-related oropharyngeal cancers. Continuing efforts are needed to consider both HPV serology and p16 staining as biomarkers relevant to the etiology and natural history of HPV16-related oropharyngeal tumors. These results also support a marginal role for HPV18 in oropharyngeal cancer and HPV6 in laryngeal cancer.

Biomarkers of HPV in head and neck squamous cell carcinoma

Human papillomavirus (HPV) is an accepted cause of head and neck squamous cell carcinoma (HNSCC), and patients with HPV-associated HNSCC have a favorable prognosis. Currently, there is no general guidance on the most appropriate biomarkers for clinical assessment of HPV in these malignancies. We compared PCR-based and serologic HPV assays, as well as p16 immunohistochemistry, individually and in combination in a single population-based study to assess their associations with overall survival among patients with HNSCC, and thus their potential value as biomarkers. HPV16 serology was determined for 488 patients; immunohistochemical detection of p16 expression in tumors was conducted in a subset of 233 cases, and PCR-based methods to assess the presence of HPV16 DNA in a subset of 179 cases of tumors. Considering each biomarker individually in the subset of patients studied for all endpoints, seropositivity for the E6 and E7 proteins was significantly associated with enhanced all-cause survival in oropharyngeal disease [HR(E6/E7+) = 0.1, 95% confidence interval (CI) = 0.02-0.3]. Neither the presence of HPV16 DNA nor p16 immunostaining was associated with significant enhanced overall survival in oropharyngeal disease (HR(DNA) = 0.9, 95% CI = 0.3-2.9; HR(p16) = 0.3, 95% CI = 0.1-1.1). However, the combination of HPV-positive DNA and E6 or E7 serology was associated with enhanced overall survival in oropharyngeal disease (HR(DNA+/E6/E7+) = 0.1, 95% CI = 0.02-1.0), whereas E6/E7 seronegative patients with evidence of HPV in tumor DNA did not show any evidence of favorable survival (HR(DNA+/E6-/E7-) = 3.4, 95% CI = 0.6-18.1). Furthermore, patients with p16 staining and E6 or E7 seropositivity had favorable survival from oropharyngeal disease (HR(p16+/E6/E7+) = 0.1, 95% CI = 0.02-0.4), whereas patients who were p16 positive and E6/E7 seronegative had significantly increased hazard of all causes of death (HR(p16+/E6-/E7-) = 3.1, 95% CI = 1.2-7.7). A stronger association of HPV presence with prognosis (assessed by all-cause survival) is observed when "HPV-associated" HNSCC is defined using tumor status (HPV DNA status or P16) and HPV E6/E7 serology in combination rather using tumor HPV status alone.

The Cancer-Associated Virus Landscape in HIV Patients with Oral Hairy Leukoplakia, Kaposi's Sarcoma, and Non-Hodgkin Lymphoma

Although HIV-positive patients are at higher risk for developing a variety of infection-related cancers, the prevalence of infections with the seven known cancer-associated viruses has not been studied. Luciferase immunoprecipitation systems were used to evaluate antiviral antibodies in four 23-person groups: healthy blood donors and HIV-infected patients with oral hairy leukoplakia (OLP), Kaposi's sarcoma (KS), or non-Hodgkin lymphoma (NHL). Antibody profiling revealed that all HIV-positive individuals were strongly seropositive for anti-gp41 and antireverse transcriptase antibodies. However, anti-p24 HIV antibody levels were highly variable and some OLP and KS patients demonstrated weak or negative responses. Profiling two EBV antigens revealed no statistical difference in antibody levels among the three HIV-infected groups. A high frequency of KSHV infection was detected in HIV patients including 100% of KS, 78% of OLP, and 57% of NHL patients. Most HIV-infected subjects (84%) showed anti-HBV core antibodies, but only a few showed antibodies against HCV. MCV seropositivity was also common (94%) in the HIV-infected individuals and KS patients showed statistically higher antibody levels compared to the OLP and NHL patients. Overall, 68% of the HIV-infected patients showed seropositivity with at least four cancer-associated viruses. Antibody profiles against these and other infectious agents could be useful for enhancing the clinical management of HIV patients.

InterSCOPE study: Associations between esophageal squamous cell carcinoma and human papillomavirus serological markers

BACKGROUND

The role of human papillomavirus (HPV) in the causation of esophageal squamous cell carcinoma is unclear. We examined the associations between esophageal squamous cell carcinoma and 28 centrally measured HPV serological markers in serum from six existing case-control studies conducted in regions with differing background risks of esophageal cancer.

METHODS

We used centralized multiplex serology to test serum samples from 1561 case subjects and 2502 control subjects from six case-control studies for antibodies to the major HPV capsid protein (L1) and/or the early proteins E6 and/or E7 of eight high-risk, two low-risk, and four cutaneous HPV types. Study-specific odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were estimated using conditional logistic regression with adjustment for smoking, alcohol consumption, and other potential confounders. Pooled odds ratios and 95% confidence intervals were calculated using either a linear mixed-effects approach or a joint fixed-effects approach. All statistical tests were two-sided.

RESULTS

We found statistically significant associations between esophageal squamous cell carcinoma and antibodies to E6 for HPV16 (OR = 1.89, 95% CI = 1.09 to 3.29, P = .023) and HPV6 (OR = 2.53, 95% CI = 1.51 to 4.25, P < .001) but not for other tested HPV types. There were no statistically significant associations between esophageal squamous cell carcinoma and antibodies to E7 for any of the tested HPV types. Simultaneous seropositivity for HPV16 E6 and E7 was rare (four case subjects, two control subjects; OR = 5.57, 95% CI = 0.90 to 34.35; P = .064). We also found statistically significant associations between esophageal squamous cell carcinoma and capsid antibodies for the high-risk mucosal type HPV33 L1 (OR = 1.30, 95% CI = 1.00 to 1.69; P = .047) and the low-risk mucosal types HPV6 (OR = 1.22, 95% CI = 1.05 to 1.42; P = .010) and HPV11 (OR = 1.30, 95% CI = 1.09 to 1.56, P = .0036).

CONCLUSIONS

We found limited serological evidence of an association between esophageal squamous cell carcinoma and HPV in the populations studied. Although HPV does not appear to be an important risk factor for esophageal squamous cell carcinoma, we cannot exclude the possibility that certain HPV types may be involved in a small subset of cancers.

Serum antibodies to the HPV16 proteome as biomarkers for head and neck cancer

BACKGROUND

Human papillomavirus (HPV) type 16 is associated with oropharyngeal carcinomas (OPC). Antibodies (Abs) to HPV16 E6 and E7 oncoproteins have been detected in patient sera; however, Abs to other early HPV-derived proteins have not been well explored.

METHODS

Antibodies to the HPV16 proteome were quantified using a novel multiplexed bead assay, using C-terminal GST-fusion proteins captured onto Luminex beads. Sera were obtained from untreated patients with OPC (N=40), partners of patients with HPV16+ OPC (N=11), and healthy controls (N=50).

RESULTS

Oropharyngeal carcinomas patients with known virus-like capsid particle+ Abs had elevated serum Abs to HPV16 E1, E2, E4, E6, and E7, and L1 antibody levels, but not E5. The ratios of specific median fluorescence intensity to p21-GST compared with controls were E1: 50.7 vs 2.1; E4: 14.6 vs 1.3; E6: 11.3 vs 2.4; E7: 43.1 vs 2.6; and L1: 10.3 vs 2.6 (each P≤0.01). In a validation cohort, HPV16 E1, E2, and E7 antibody levels were significantly elevated compared with healthy control samples (P≤0.02) and partners of OPC patients (P≤0.01).

CONCLUSION

Patients with HPV16+ OPC have detectable Abs to E1, E2, and E7 proteins, which are potential biomarkers for HPV-associated OPC.

Human papillomavirus serologic follow-up response and relationship to survival in head and neck cancer: a case-comparison study

Background

Human papillomavirus high risk (HPV-HR) type 16 is a significant risk factor for head and neck cancers (HNC) independent of tobacco and alcohol. The purpose of this study was to determine whether antibody levels to the HPV-16 oncoproteins E6 and E7 measured in sera collected at baseline (BL) prior to treatment and at two post-treatment follow-up (FU) visits were associated with HNC risk factors or prognosis.

Methods

Presence of antibodies to HPV-16 E6 and E7 was evaluated in 109 newly diagnosed HNC cases with BL and FU blood samples, using the enzyme-linked immunosorbent assay (ELISA).

Results

HPV-16 E6 and/or E7 seropositive HNC cases were associated with higher risk in younger patients (≤ 55 years), more sexual partners (≥ 10), oropharyngeal cancer, worse stage at diagnosis, poorer grade, and nodal involvement. Between BL and FU (median = 8.3 months), there were decreased antibody levels for seropositive E6 (73% vs. 27%, p = 0.02) and seropositive E7 patients (65% vs. 35%, p = 0.09) with 5% of BL E6 and 35% of BL E7 seropositive patients converting to negative status at FU. Overall mortality (OM) was significantly worse among BL E6 seronegative patients than among BL seropositive patients (40.2% vs.13.6%, p = 0.01). There were no disease specific (DS) deaths among BL E6 seropositive vs. 24% in BL E6 seronegative patients (p = 0.01). BL E7 seronegative patients also had higher mortality than BL seropositive patients (OM: 38.2% vs. 20.0%, p = 0.04; DS: 22.5% vs. 5.6%, p = 0.07).

Conclusion

These findings are the first to follow post-treatment OD levels of HPV-16 E6 and E7 in HNC and suggest that these HPV antibodies may be potential prognostic markers of survival in HNC patients.

Oral human papillomavirus in healthy individuals: a systematic review of the literature

BACKGROUND

Human papillomavirus type 16 (HPV16) is a common infection in the anogenital tract. HPV16 DNA detected in oral specimens has recently been identified as a risk factor for some oropharyngeal cancers. The reported prevalence of oral HPV infection from individual studies is highly variable.

METHODS

We systematically reviewed and abstracted data from published studies (n = 18) that detected oral HPV DNA in 4581 cancer-free subjects to determine the pooled prevalence (and 95% confidence intervals [CI]) of HPV16, carcinogenic HPV, and any HPV.

RESULTS

1.3% (95% CI: 1.0-1.7%) of 3977 healthy subjects had oral HPV16, 3.5% (95% CI: 3.0-4.1) of 4441 subjects had carcinogenic HPV, and 4.5% (95% CI: 3.9-5.1) of 4070 subjects were positive for any HPV. Oral HPV16 accounted for 28% of all HPV detected in the oral region. Men (47 of 1017) and women (117 of 3690) had nearly exactly the same prevalence of any oral HPV detected (4.6% vs. 4.4%, respectively).

CONCLUSIONS

HPV-16, a common anogenital infection, was rarely detected in oral specimens. However, a small but noteworthy proportion of healthy individuals have oral HPV infections with types known to cause cancer in the oral region.

Human papilloma virus and female lung adenocarcinoma

Lung cancer is the leading cause of cancer among women worldwide, and adenocarcinoma is the most common histological subtype among non-smoking women. Previous studies showed that human papillomavirus (HPV) infection may relate to the tumorigenesis of pulmonary adenocarcinoma. Women with anogenital malignancy have a higher risk of lung cancer, which raises the possibility of HPV transmission from the cervix to the lung. Two postulated pathways are discussed in this work. First, HPV may infect the female cervix and then move to the lung by blood circulation. The second transmission route is the HPV infection of oral cavity resulting from dangerous sexual contacts, and subsequently transmitted to the lung. This chapter also reviews the techniques for detecting the existence, subtypes, and viral load of HPV. Future studies are needed to demonstrate the causal inference between HPV infection and the risk of female lung adenocarcinoma.

Advances and Perspectives in the Molecular Diagnosis of Head and Neck Cancer

BACKGROUND: Head and neck squamous cell carcinoma (HNSCC) is a debilitating and lethal disease. Despite significant advances in radiotherapy and surgical management, the 5-year survival rate for head and neck cancer has remained a dismal 50%. Advances in early detection have been made, but to improve patient outcomes better biomarkers and targeted therapeutic agents are needed. Novel biomarkers can improve early detection and provide data to optimize therapeutic strategy and patient survival, and could lead to potentially effective targeted therapies. OBJECTIVE: Report the advances in the discovery of novel biomarkers for HNSCC, and review the potential utility of biomarkers in the molecular diagnosis of HNSCC. METHODS: A review of the English literature (PubMed) from 1980 to 2009. RESULTS/CONCLUSION: Currently the most widely accepted biomarker for HNSCC is high risk HPV status. EGFR is another promising biomarker, however, further research is necessary to determine its prognostic benefit. A large number of promising biomarker candidates are currently being evaluated including epigenetic, expression, and genomic based markers. Studies to validate the sensitivity and specificity of these biomarkers in clinical samples from adequately powered prospective cohorts are needed for successful translation of these findings into potential molecular diagnostic, prognostic, and therapeutic biomarkers for 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.

Human papillomavirus in HNSCC: recognition of a distinct disease type

Strong epidemiologic and molecular data now support the conclusion that human papillomavirus (HPV) infection is responsible for a distinct form of head and neck squamous cell carcinoma (HNSCC), independent from the traditional risk factors of tobacco and alcohol use. Patients with HPV-positive HNSCC have a different clinical presentation and better clinical outcomes than those with HPV-negative HNSCC. A diagnosis of HPV-positive HNSCC is associated not only with therapeutic relevance, but also has important implications for future prevention and screening strategies.

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.

The role of viruses in squamous cell carcinoma of the oropharyngeal mucosa

The development of squamous cell carcinomas of the oropharyngeal mucosa may involve many factors, including viruses. This review examines the evidence that viruses could be involved in the etiology of oral cancer, and shows that the evidence for a role of different viruses varies from very weak to very persuasive. Papillomaviruses are probably involved in the etiology of some carcinomas, particularly those of the oropharynx, and some herpes viruses may be involved as well. On the other hand some viruses can cause cancer in experimental situations but not in humans. Thus the importance of viruses in oral cancer is not always clear and must be evaluated with care. Those viruses that are associated with the disease provide targets for therapy and for diagnostic assays.

Characterization of humoral immune responses against p16, p53, HPV16 E6 and HPV16 E7 in patients with HPV-associated cancers

The cellular tumor suppressor p16 is strongly overexpressed in cervical cancers and precancers. We have previously demonstrated that infiltrating T lymphocytes reactive against p16 can be found in cervical cancer patients. Here, we analyzed whether p16 induces humoral immune responses. Sera of patients with cervical cancer, oropharyngeal cancer, colorectal cancer and autoimmune disease were included. A total of 919 sera were analyzed, including 486 matched sera from a cervical cancer case control study. p16 antibodies were analyzed in Western blot and a newly developed peptide ELISA covering the complete p16 protein. In addition, a Luminex-based multiplex assay was used for simultaneous detection of antibodies directed against p16, p53, HPV16 E6 and HPV16 E7. In all entities, only low p16 antibody reactivity was observed. Epitope mapping revealed 2 predominant epitope regions of the p16 protein. No significant difference in p16 antibody frequency (OR = 0.9; 95% CI = 0.6-1.3) and p53 antibody frequency (OR = 0.6; 95% CI = 0.3-1.2) was found between patients and healthy controls in the cervical cancer case control study. Antibodies against the HPV16 oncoproteins E6 and E7 were detected more frequently in cervical cancer patients when compared with healthy controls (E6 OR = 27.8; 95% CI = 11.1-69.7, E7 OR = 5.7; 95% CI = 2.9-11.1). In conclusion, despite the strong expression of p16 and the observed induction of cellular immune responses, antibody reactivity against p16 was observed only at very low levels independent of the disease background.

Human papillomavirus therapeutic vaccines in head and neck tumors

Head and neck cancer represents one of the most challenging diseases as the mortality remains high despite advances in early diagnosis and treatment. Human papillomavirus has been implicated in a third of head and neck squamous cell carcinomas and human papillomavirus type 16 is strongly associated with carcinomas arising from the oropharynx, the tonsil being the preferred infected site. Novel therapeutic approaches including immunotherapy are currently under investigation. Immune vaccines developed against human papillomavirus in the genital area are already available and could simultaneously protect other anatomical localizations; however, prophylactic vaccines are expected to be effective in reducing the incidence of tumors after many years and, therefore, there is an urgent need to improve therapeutic interventions, such as immunotherapy. To date, human papillomavirus therapeutic vaccines are either at the preclinical level or at early phase human trials for genital pathologies. Nevertheless, accumulating evidence from animal and clinical studies suggests that the enhancement of specific and innate immune responses is effective in clearance of the human papillomavirus infection, promoting a cautious optimism regarding the achievement of an efficacious immunotherapy. This article reviews what has been achieved and what remains to be done in the field for the development of future viral vaccines in head and neck tumors.

Human papillomavirus seropositivity and risks of head and neck cancer

We examined antibody response to VLP HPV-16, HPV-16 E6 and E7 antibodies as potential seromarkers of HPV-related head and neck cancer (HNC). The study included 204 HNC cases and 326 controls evaluated for HPV presence in sera using ELISAs for anti-HPV VLP antibodies and HPV-16 E6 and/or E7 antibodies, and in tumor tissue using PCR and DNA sequencing. Anti-HPV-16 VLP was detected in 33.8% of cases and 22.4% of controls, anti-E6 in 20.6% of cases and 0.9% of controls and anti-E7 in 18.6% of cases and 0.6% of controls. HPV-16 DNA was detected in 26.1% of tumors. The adjusted risk of HNC was elevated among those seropositive for HPV-16 VLP (odds ratio (OR) = 1.7, 1.1-2.5), E6 (OR = 32.8, 9.7-110.8) or E7 (OR = 37.5, 8.7-161.2). Compared to HPV DNA-negative/seronegative cases, tumor HPV-16 cases had increased risk of detection with anti-VLP antibodies (OR = 6.8, 3.1-14.9). The odds were more pronounced among cases seropositive for E6 (OR = 69.0, 19.3-247) or E7 (OR = 50.1, 14.7-171). Antibodies against E6 or E7 were associated with risk of cancer in the oral cavity (OR = 5.1, 1.2-22.4) and oropharynx (OR = 72.8, 16.0-330), and with disease characteristics: stage, grade and nodal status. Anti-E6 and/or E7 antibodies were found in 74% of tumor HPV-16 positive cases but in only 5% of tumor HPV-negative cases (K =0.7, 0.6-0.8) suggesting good correlation between the serologic marker and HPV tumor status. Antibodies to HPV-16 E6 and/or E7 represent a more specific biomarker than anti-HPV-16 VLP of an HPV-related HNC. Because of the survival advantage of HPV-related HNC, HPV-16 E6/E7 detection may be useful in therapy targeted for HPV-related tumors.

Human papillomavirus infection and oral cancer: a case-control study in Montreal, Canada

The objective of the present study was to examine the association between human papillomavirus (HPV) infection and risk of developing oral cancer. The investigation followed a hospital-based case-control design. Cases consisted of newly diagnosed patients with squamous cell carcinoma of the oral cavity and oropharynx. Controls were frequency matched to cases on gender, age, and hospital. Subjects were interviewed to elicit information on putative risk factors. Oral exfoliated cells were tested for detection of HPV DNA by the PGMY09/11 polymerase chain reaction protocol. Serum antibodies against HPV 16, 18, and 31 viral capsids were detected using an immunoassay technique. Logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CI) of oral cancer according to HPV exposure variables. HPV DNA was detected in 19% of cases (14 out of 72), and 5% of controls (six out of 129). Among tonsil-related cancers (palatine tonsil and base of tongue) viral DNA was detected in 43% of cases (nine out of 21). The OR for tonsil-related cancers for high-risk HPV types was 19.32 (95%CI: 2.3-159.5), after adjustment for socio-demographic characteristics, tobacco, and alcohol consumption. The equivalent OR for HPV 16 seropositivity was 31.51 (95%CI: 4.5-219.7). The ORs of non-tonsillar oral cancers for high risk HPV DNA in oral cells and for seropositivity were 2.14 (95%CI: 0.4-13.0) and 3.16 (95%CI: 0.8-13.0), respectively. These results provide evidence supporting a strong causal association between HPV infection and tonsil-related cancers. The evidence for an etiologic link is less clear for non-tonsillar oral cancers.

Correlation between serological immune response analyzed by a new ELISA for HPV-16/18 E7 oncoprotein and clinical characteristics of cervical cancer patients

Human papillomaviruses (HPVs), particularly HPV-16/18, are linked to cervical cancer development. Full-length, recombinant HPV-16/18 E7 oncoproteins were used in a new streptavidin-biotin capture ELISA method to investigate anti-HPV E7 antibody prevalence in serum. Sera from 99 healthy women, 70 cervical cancer patients, and 30 patients with cervical pre-invasive neoplasia were analyzed. Anti-HPV-16/18 E7 positivity was found in 53% of cervical cancer patients, in 40% with cervical pre-invasive neoplasia, and in 8% of healthy women. Serum samples from 12 cervical cancer patients were obtained at different time intervals during the treatment. Eleven out of 12 showed a correspondence between HPV-E7 antibody levels (decreasing versus increasing) and the type of response (clinically complete or partial response versus progression or stable disease) at each serological evaluation. Five patients with recurrent HPV-16/18-positive cervical carcinoma were analyzed before and after vaccination with HPV-16/18 E7-pulsed autologous dendritic cells; anti-HPV-16/18 E7 positivity was found in 3 out of 5 women. In conclusion, this assay could potentially be used as an adjunctive tool to monitor the type of response to treatment and possibly to detect antibody induction in cervical cancer patients after vaccination, as a potential marker to evaluate its efficacy.

Oral cancer; the evidence for sexual transmission

The incidence of oral cancer amongst young adults is increasing in many European and high incidence countries. Most oral cancer is aetiologically linked to the use of tobacco and/or alcohol but nearly two decades ago, we produced the first evidence for the presence of viral nucleic acids in oral squamous cell carcinoma (OSCC) tissues, hypothesising that there may be a viral involvement in at least some OSCC. Subsequently, human papillomaviruses (HPV) in particular have been implicated in OSCC. Antibody responses to HPV are seen and HPV-DNA detected in tumours by us and many others, the virus being mainly HPV-16, the genotype associated with ano-genital cancer. Recent studies have indicated that HPV may be aetiologically important particularly in some types of oropharyngeal cancer, at least in tonsillar carcinogenesis, and may represent an alternative pathway in carcinogenesis to the established factors of tobacco and alcohol. Studies of patients with OSCC have suggested possible sexual transmission of HPV.

Human papillomavirus type 16 in head and neck carcinogenesis

The aetiology of squamous cell carcinomas of the head and neck (HNSCC) is multifactorial. Oncogenic human papillomaviruses (HPVs), a causative agent in uterine cervical cancer, have also been repeatedly detected in HNSCC, especially in squamous cell carcinomas of tonsils. Approximately half the HPV DNA-positive HNSCC contain detectable E6/E7 transcripts with wild-type p53, reduced pRb and overexpressed p16 in the tumours. HPV-16 is the predominant type and exists in episomal, integrated, or mixed forms. Tonsillar carcinomas have a remarkably higher viral load than carcinomas at other sites of the head and neck region. HPV-16 DNA has also been detected in tumour-free tonsils. Infection by oncogenic HPVs is a necessary but not a sufficient cause of cancers. Studies on the molecular mechanisms underlying HPV-associated carcinogenesis are difficult, because HPV is not easy to propagate in vitro. HPV-immortalised human tonsillar epithelial cell lines may provide an in vitro model to study co-factors for the HPV-associated tonsillar cancers and to test the effects of anti-viral and anti-tumour agents.

Human papillomavirus-associated head and neck cancer is a distinct epidemiologic, clinical, and molecular entity

There is currently sufficient evidence to conclude that human papillomavirus (HPV) plays a role in the pathogenesis of a distinct subset of head and neck squamous cell cancers (HNSCC), particularly tonsillar cancers. There is a strong and consistent association between high-risk HPV types, specifically HPV16, a known human carcinogen, and these distinctive oropharyngeal cancers with molecular characteristics indicative of viral oncogene function. Risk for HPV-HNSCC is increased by certain sexual behaviors after consideration of alcohol and tobacco exposure, consistent with an extensive literature that has established HPV infection as a sexually transmitted disease. Furthermore, exposure to HPV16 has been associated with increased risk for subsequent development of oropharyngeal cancer. Prophylactic and therapeutic vaccines targeted against the viral capsid components and oncoproteins will provide the ultimate evidence for a role for HPV in HNSCC, if demonstrated to be effective in the prevention or therapy of this disease. It is time for clinician scientists to translate knowledge of this newly recognized disease entity into potential applications for the prevention, detection, and treatment of HPV-HNSCC.

The role of human papillomavirus in oral carcinogenesis

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