Human papillomavirus infection is rare in nonmalignant tonsil tissue in the UK: implications for tonsil cancer precursor lesions

Prevalence of Transcriptionally Active HPV Infection in Tumor-Free Oropharyngeal Tissue of OPSCC-Patients

Objectives

The natural history of HPV-related oropharyngeal squamous cell carcinoma (OPSCC) is still largely unknown. Since reports of second primary tumors (SPTs) in patients with HPV-related OPSCCs are increasing, a multifocal HPV infection, hinting a «virus-induced field effect», has been hypothesized. This study aimed to investigate the HPV-prevalence in normal appearing oropharyngeal tissue in patients with OPSCCs.

Materials and Methods

49 OPSCC patients undergoing panendoscopy were prospectively enrolled. Tumor specimens and biopsies of normal appearing oropharyngeal tissue adjacent to and distant from the index OPSCC underwent histopathological examination, p16INK4A immunohistochemical staining, HPV DNA and mRNA-detection. Patient characteristics and follow-up data on SPTs were obtained.

Results

26 of 49 (53%) OPSCC were positive for HPV DNA and p16INK4A. HPV mRNA was detected in 23 of 26 (88%) of these tumor samples. HPV DNA was detected in 36% adjacent mucosa and in 17% distant mucosa samples and only in patients with an HPV-related index OPSCC. HPV mRNA could not be detected in tumor-free distant and adjacent mucosa samples. No evidence of association between HPV detection in normal appearing mucosa and development of second primary tumors was found.

Conclusions

HPV was detectable but not transcriptionally active in adjacent/distant tumor-free oropharyngeal tissue. This suggests that a multifocal HPV infection, hinting a «virus-induced fielcd cancerization», may not be pertaining to HPV-related OPSCC.

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

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

Detection of human papillomavirus infection in oral cancers reported at dental facility: assessing the utility of FFPE tissues

Incidence of human papillomavirus (HPV)-associated oral cancers is on the rise. However, epidemiological data of this subset of cancers are limited. Dental hospital poses a unique advantage in detection of HPV-positive oral malignancies. We assessed the utility of formalin-fixed paraffin-embedded (FFPE) tissues, which are readily available, for evaluation of high-risk HPV infection in oral cancer. For protocol standardization, we used 20 prospectively collected paired FFPE and fresh tissues of histopathologically confirmed oral cancer cases reported in Oral Medicine department of a dental hospital for comparative study. Only short PCRs (~ 200 bp) of DNA isolated using a modified xylene-free method displayed a concordant HPV result. For HPV analysis, we used additional 30 retrospectively collected FFPE tissues. DNA isolated from these specimens showed an overall 23.4% (11/47) HPV positivity with detection of HPV18. Comparison of HPV positivity from dental hospital FFPE specimens with overall HPV positivity of freshly collected oral cancer specimens (n = 55) from three cancer care hospitals of the same region showed notable difference (12.7%; 7/55). Further, cancer hospital specimens showed HPV16 positivity and displayed a characteristic difference in reported sub-sites and patient spectrum. Overall, using a xylene-free FFPE DNA isolation method clubbed with short amplicon PCR, we showed detection of HPV-positive oral cancer in dental hospitals.

Genomic Instability and DNA Damage Repair Pathways Induced by Human Papillomaviruses

Human papillomaviruses (HPV) are the causative agents of cervical and other anogenital cancers as well as those of the oropharynx. HPV proteins activate host DNA damage repair factors to promote their viral life cycle in stratified epithelia. Activation of both the ATR pathway and the ATM pathway are essential for viral replication and differentiation-dependent genome amplification. These pathways are also important for maintaining host genomic integrity and their dysregulation or mutation is often seen in human cancers. The APOBEC3 family of cytidine deaminases are innate immune factors that are increased in HPV positive cells leading to the accumulation of TpC mutations in cellular DNAs that contribute to malignant progression. The activation of DNA damage repair factors may corelate with expression of APOBEC3 in HPV positive cells. These pathways may actively drive tumor development implicating/suggesting DNA damage repair factors and APOBEC3 as possible therapeutic targets.

Prevalence and characteristics of tonsillar human papillomavirus infection in tumor-free patients undergoing tonsillectomy

OBJECTIVE

This study evaluated the prevalence and characteristics of tonsillar human papillomavirus (HPV) infection in tumor-free patients undergoing tonsillectomy.

METHODS

We prospectively enrolled healthy patients who underwent tonsillectomy for tumor-free tonsillar disease. Their tonsillar HPV infections were evaluated using CLART HPV2, and subsequent p16 immunohistochemistry was performed in patients with positive HPV infection. Moreover, the results of tonsillar HPV infection were analyzed according to sex, age, and indication of tonsillectomy.

RESULTS

A total of 362 patients were included. HPV test was positive in 8 patients, with an overall prevalence of 2.2%. All detected HPV types were high-risk, including HPV 16 in six patients, HPV 52 in one patient, and HPV 58 in one patient. P16 was negative in all 8 patients with HPV infection. The prevalence of tonsillar HPV infection in males and females was 2.4% (6/246) and 1.7% (2/116), respectively (P > 0.999), and in pediatric and adult patients, 2.2% (5/228) and 2.2% (3/134), respectively (P > 0.999). The prevalence showed a bimodal peak at 1st and 6th decades, with the prevalence of 2.6% (5/194) and 7.9% (3/38), respectively. The prevalence of tonsillar HPV infection in tonsillitis and non-tonsillitis groups were 0.0% (0/104) and 3.1% (8/258), respectively (P = 0.111).

CONCLUSION

The prevalence of tonsillar HPV infection in tumor-free patients was low, but all detected HPV infections were high-risk types. Our results support using a 9-valent vaccine which covers all high-risk HPV types found in this study.

The Effect of Prophylactic HPV Vaccines on Oral and Oropharyngeal HPV Infection-A Systematic Review

Human papillomavirus (HPV) imposes an increased risk of developing cervical, anal and oropharyngeal cancer. In the Western world, HPV infection is currently the major cause of oropharyngeal cancer. The effectiveness of HPV vaccines for oral or oropharyngeal HPV infection is yet to be determined. This study conducted a systematic literature search in Pubmed and Embase. Studies investigating the impact of HPV vaccines on oral or oropharyngeal HPV infection were enrolled. This review reports the relative prevention percentage (RPP), including a risk of bias assessment as well as a quality assessment study. Nine studies were included (48,777 participants): five cross-sectional studies; one randomized community trial study (RCT); one longitudinal cohort study; and two case-control studies. A significant mean RPP of 83.9% (66.6–97.8%) was calculated from the cross-sectional studies, 82.4% in the included RCT and 83% in the longitudinal cohort study. Further, two case-control studies that measured antibody response in participants immunized with HPV vaccines were included. Respectively, 100% and 93.2% of participants developed HPV-16 Immunoglobulin G (IgG) antibodies in oral fluids post-vaccination. Analysis of the studies identified a significant decrease in vaccine-type oral or oropharyngeal HPV infections in study participants immunized with HPV vaccines across study designs and heterogenous populations. Further, a significant percentage of participants developed IgG antibodies in oral fluid post-vaccination.

HPV DNA/RNA detection in various oral and oropharyngeal biomaterials identifies active HPV infections also in non-neoplastic tonsils

Previous studies describe a correlation between HPV-positivity and non-smoking in TSCC; p16^INK4A-expression as surrogate-marker for HPV-DNA/RNA-positivity is discussed controversially. In the present study, these parameters are assessed prospectively. HPV-status of sputum and tonsillar-swabs was analyzed to determine their validity as surrogate-marker for tissue-HPV-status. TSCC- (n = 52) and non-neoplastic tonsillar tissue (n = 163) were analyzed. HPV-DNA- and HPV-RNA-status of total sputum, cellular fraction and supernatants, tonsillar-swabs and -tissue was determined by (RT)-PCR. Immunohistochemistry determined p16^INK4A-expression. 23/163 (14.2%) non-neoplastic tonsils were HPV-DNA-positive; five patients (3 HPV16, 2 HPV11) had active HPV-infections (HPV-RNA-positive), in all biomaterials. 140/163 (85.9%) patients were either HPV-DNA-positive or HPV-DNA-negative in all samples. 21/52 (40.4%) TSCC-tonsils were HPV-DNA-positive; 17 patients were HPV-RNA-positive (14 HPV16; 4 HPV18). 40/52 (76.9%) TSCC-patients were congruent in all biomaterials. p16^INK4A-expression alone would have misclassified the HPV-status of 14/52 (26.2%) TSCC-patients. This prospective study confirms the discrepancy between HPV-status and p16^INK4A-expression and the significant correlation between non-smoking and HPV-DNA-positivity. HPV-sputum- and/or swab-results do not consistently match tissue-results, possibly having (detrimental) consequences if those were used to assess tissue-HPV-status. In the 5 patients with active HPV infection in the non-neoplasitic tonsils, tonsillectomy likely prevented subsequent development of TSCC.

Periodontitis in tonsil cancer patients-A comparative study in accordance with tumour p16 status

OBJECTIVES

We assessed the periodontal situation radiologically according to tumour p16 status.

MATERIALS AND METHODS

Patients with a diagnosis of tonsillar cancer and availability of a digital panoramic radiograph (DPR) during a 5-year period were included in this retrospective study. The predictor variables were periodontal stability, marginal bone loss, marginal bone loss without periodontal stability and total number of teeth. Periodontal status was compared with p16 status, age, gender, smoking and alcohol use.

RESULTS

Among 115 patients included in the analyses (p16-negative, n = 24; p16-positive, n = 91), smoking (p < .0001), heavy alcohol use (p < .0001) and total number of teeth (p = .0001) were significantly associated with p16 status. Current smoking (OR = 7.3) and heavy alcohol use (OR = 10.1) increased the risk of p16-negative cancer.

CONCLUSIONS

Patients with p16-negative tonsillar carcinoma had less teeth than patients with p16-positive tumours. Other periodontal findings were common in both groups without statistical significance. Heavy alcohol use and smoking were the most important risk factors for p16-negative tonsillar carcinoma.

Modelling human papillomavirus biology in oropharyngeal keratinocytes

Most human papillomavirus (HPV) positive head and neck cancers arise in the tonsil crypts; deep invaginations at the tonsil surface that are lined with reticulated epithelium infiltrated by immune cells. As in cervical HPV infections, HPV16 is the most prevalent high-risk type in the oropharyngeal cancers, and a genital-oral route of infection is most likely. However, the natural history of HPV-driven oropharyngeal pathogenesis is an enigma, although there is evidence that it is different to that of cervical disease. It is not known if the virus establishes a productive or abortive infection in keratinocytes of the tonsil crypt, or if viral infections progress to cancer via a neoplastic phase, as in cervical HPV infection. The HPV DNA is more frequently found unintegrated in the cancers of the oropharynx compared to those that arise in the cervix, and may include novel HPV-human DNA hybrids episomes. Here, we review current understanding of HPV biology in the oropharynx and discuss the cell-based systems being used to model the HPV life cycle in tonsil keratinocytes and how they can be used to inform on HPV-driven neoplastic progression in the oropharynx.

This article is part of the theme issue ‘Silent cancer agents: multi-disciplinary modelling of human DNA oncoviruses’.

A global epidemic increase of an HPV-induced tonsil and tongue base cancer - potential benefit from a pan-gender use of HPV vaccine

In 2007, human papillomavirus (HPV) type 16 was finally recognized as a risk factor, besides smoking and alcohol, for oropharyngeal squamous cell carcinoma (OPSCC), including tonsillar squamous cell carcinoma (TSCC), by the International Agency for Research against Cancer. Just before, in 2006, the Food and Drug Administration had approved Gardasil, the first vaccine against HPV16, 18, 6 and 11, for preventive vaccination women against cervical cancer. Concurrently, some Western countries, where smoking was decreasing, disclosed an epidemic increase in the incidence of OPSCC, especially of TSCC and base of tongue cancer (BOTSCC), together accounting for 80-90% of all OPSCCs, and mainly affecting men. The epidemic was later revealed to be due to a rise in HPV-positive cases, and scientists in the field suggested HPV vaccination also of boys. Globally, there are roughly 96 000 incident OPSCC cases/year of which 20-24% are caused by HPV, thereby accounting for around 22 000 OPSCC cases annually. Of these cases, 80-90% are due to HPV16 infection and would be prevented with the presently registered HPV vaccines. In Western countries, such as Sweden (with almost 400 TSCC and BOTSCC cases per year) and the United States, HPV prevalence in OPSCC is higher and around 70%. HPV vaccination of girls has been initiated in many countries, and the vaccines have been efficient and their side effects limited. HPV vaccination of boys has, however, been the exception, but should definitely not be delayed any further. It would benefit both girls and boys directly, and result in better and more robust herd immunity. Today, we have the possibility to eliminate several high-risk HPV types in the younger generations and avoid more than 600 000 cancer cases annually worldwide, and this possibility should be embraced by offering global pan-gender HPV vaccination.

Differences in gene expression between high-grade dysplasia and invasive HPV+ and HPV- tonsillar and base of tongue cancer

BACKGROUND

Human papillomavirus (HPV) is a causative agent for tonsillar and base of tongue squamous cell carcinoma (TSCC/BOTSCC), as well as for cervical cancer. Premalignant stages in cervical cancer have been studied extensively, while little is known about premalignant stages in TSCC/BOTSCC and the role of HPV. Here we analyzed differences in gene and protein expression between high-grade dysplasia and invasive cancer in both HPV-positive (HPV+ ) and HPV-negative (HPV- ) TSCC/BOTSCC.

METHODS

High-grade dysplasia and invasive carcinoma were laser microdissected from HPV+ and HPV- TSCC/BOTSCC tumor sections. Differential gene expression was studied utilizing nanoString RNA-panels and genes of interest were validated on the protein level by immunohistochemistry.

RESULTS

Forty genes in the HPV+ tumors showed significantly different expression between high-grade dysplasia and invasive cancer and 33 genes in the HPV- tumors. Five out of the nine most significant pathways showed similar increased activity in invasive cancer as compared to high-grade dysplasia in both HPV+ and HPV- tumors. Lastly, significant differences in protein expression was confirmed for SPARC, psoriasin, type I collagen and galectin-1 in both HPV+ and HPV- tumors.

CONCLUSIONS

This is to our knowledge the first study disclosing differences and similarities in gene expression between dysplastic and invasive HPV+ and HPV- TSCC/BOTSCC.

Detection of high-risk human papillomavirus in the tonsils of galilee region adults and young adults undergoing tonsillectomy

INTRODUCTION

The presence of high-risk HPV in non-malignant tonsil tissues from patients who underwent tonsillectomy in the Galilee area might explain the low incidence of HPV-related oropharyngeal malignancy in the country. The aim of this retrospective study was to study the prevalence of human papillomavirus (HPV) in non-malignant tonsillectomy specimens of adults in the Galilee area.

MATERIALS AND METHODS

We conducted a retrospective analysis of all tonsil samples in our medical center. Tonsils from patients over 20 years of age who underwent tonsillectomy for the indication of recurrent tonsillitis and sleep apneas were eligible. Samples of formalin-fixed paraffin-embedded (FFPE) tonsillar tissue were tested for the presence of HPV DNA using polymerase chain reaction and by p16 immunohistochemistry.

RESULTS

Of the 71 tonsil samples, age range 20-65, none were positive for HPV DNA. Fifty-two FFPE specimens of tonsil with HPV-positive cancer tested positive by the same method served as positive controls.

CONCLUSIONS

HPV DNA is rare in non-malignant tonsil tissues of young adults and adults who underwent tonsillectomy in the Galilee area. Further research should be done in larger cohorts.

Mapping of human papilloma virus, p16, and epstein-barr virus in non-malignant tonsillar disease

Objectives

Due to their location in the entrance of the aero-digestive tract, tonsils are steadily exposed to viruses. Human papilloma virus (HPV) and Epstein-Barr virus (EBV) are two potentially oncogenic viruses that tonsils encounter. The incidence of HPV positive tonsillar cancer is on the rise and it is unknown when infection with HPV occurs.

Aim

To investigate if tonsils are infected with HPV and EBV, to study the co-expression of HPV and its surrogate marker p16, and to evaluate the number of EBV positive cells in benign tonsillar disease.

Materials and Methods

Tonsils from 40 patients in a university hospital were removed due to hypertrophy, chronic or recurrent infection. These were analyzed for presence of HPV, its surrogate marker p16, and EBV. HPV was studied using PapilloCheck (a PCR method), while p16 was identified in epithelial and lymphoid tissue with immunohistochemistry and EBV using EBER-ISH (Epstein-Barr encoding region-in situ hybridization).

Results

HPV was not detected, and p16 was present at low numbers in all epithelial samples as well as in 92.5% of the lymphoid tonsillar samples. At least one EBER-positive cell was seen in 65% of cases. Larger numbers of EBER-expressing cells were only seen in two cases.

Conclusion

These findings demonstrate that EBV and HPV infect tonsils independently, but further studies are warranted to confirm their infectious relationship.

Level of Evidence

Cross-sectional study.

Genomic characterization of clonal evolution during oropharyngeal carcinogenesis driven by human papillomavirus 16

Secondary prevention via earlier detection would afford the greatest chance for a cure in premalignant lesions. We investigated the exomic profiles of non-malignant and malignant changes in head and neck squamous cell carcinoma (HNSCC) and the genomic blueprint of human papillomavirus (HPV)-driven carcinogenesis in oropharyngeal squamous cell carcinoma (OPSCC). Whole-exome (WES) and whole-genome (WGS) sequencing were performed on peripheral blood and adjacent non-tumor and tumor specimens obtained from eight Korean HNSCC patients from 2013 to 2015. Next-generation sequencing yielded an average coverage of 94.3× for WES and 35.3× for WGS. In comparative genomic analysis of non-tumor and tumor tissue pairs, we were unable to identify common cancer-associated early mutations and copy number alterations (CNA) except in one pair. Interestingly, in this case, we observed that non-tumor tonsillar crypts adjacent to HPV-positive OPSCC appeared normal under a microscope; however, this tissue also showed weak p16 expression. WGS revealed the infection and integration of high-risk type HPV16 in this tissue as well as in the matched tumor. Furthermore, WES identified shared and tumor-specific genomic alterations for this pair. Clonal analysis enabled us to infer the process by which this transitional crypt epithelium (TrCE) evolved into a tumor; this evolution was accompanied by the subsequent accumulation of genomic alterations, including an ERBB3 mutation and large-scale CNAs, such as 3q27-qter amplification and 9p deletion. We suggest that HPV16-driven OPSCC carcinogenesis is a stepwise evolutionary process that is consistent with a multistep carcinogenesis model. Our results highlight the carcinogenic changes driven by HPV16 infection and provide a basis for the secondary prevention of OPSCC.

Human papillomavirus in tonsillectomy specimen from China and Pakistan - Prevalence and genotype distribution

BACKGROUND

The expected corresponding increase in tonsillar human papillomavirus (HPV) infection associated with increasing incidence of oropharyngeal squamous cell carcinoma (OPSCC) substantiate the evaluation of normal tonsillar tissue in different population. The epidemiology of HPV in tonsillar tissue varies geographically. This study evaluated samples from two countries to determine the prevalence in respective samples.

OBJECTIVE

To characterize HPV infection in non-malignant tonsillar tissue from Shaanxi, China (herein after referred to as China) and Punjab, Pakistan (herein after referred to as Pakistan).

METHODOLOGY

The DNA extracted from formalin-fixed, paraffin-embedded tumor free tonsillar tissue was evaluated using polymerase chain reaction (PCR). A total of 367 cases from China and 139 cases from Pakistan were screened for HPV DNA using GP5+/GP6+ consensus primer. Genotype of the positive cases was determined for common HPV types (6, 11, 16, 18, 52, 58) simultaneously by type-specific PCR.

RESULTS

The mean age of cohorts in China was 13.42 (Median age 7, Range 2-72 years) while in Pakistan it was 10.77 (Median age 8, Range 3-42 years) the gender distribution was 61.6% male in China and in Pakistan they were 56.8%, rest were females. The overall prevalence of HPV in China was 2.45% and 2.16% in Pakistan. High risk human papillomavirus was 1.63% in China with 5 cases positive for HPV 16 and HPV 58 in 1 case. In Pakistan, 2 cases (1.43%) of HPV 16 were detected. Low-risk types include HPV 11 present in 2 cases from China, while HPV 6 was detected in 1 case each from both the countries.

CONCLUSION

A low prevalence of HPV was found in China and Pakistan; high-risk and low-risk HPV were detectable in tonsillar tissue from both countries. Age stratification (< 5 years, 5-14 years, 15-25 years, > 25 years) suggest that sexual and non-sexual transmission of the virus can occur. The difference in the genotype distribution geographically within China and with Pakistan was observed in the case of HPV 58. The most common type in both the countries was HPV 16.

The molecular landscape of head and neck cancer

Head and neck squamous cell carcinomas (HNSCCs) arise in the mucosal linings of the upper aerodigestive tract and are unexpectedly heterogeneous in nature. Classical risk factors are smoking and excessive alcohol consumption, and in recent years, the role of human papillomavirus (HPV) has emerged, particularly in oropharyngeal tumours. HPV-induced oropharyngeal tumours are considered a separate disease entity, which recently has manifested in an adapted prognostic staging system while the results of de-intensified treatment trials are awaited. Carcinogenesis caused by HPV in the mucosal linings of the upper aerodigestive tract remains an enigma, but with some recent observations, a model can be proposed. In 2015, The Cancer Genome Atlas (TCGA) consortium published a comprehensive molecular catalogue on HNSCC. Frequent mutations of novel druggable oncogenes were not demonstrated, but the existence of a subgroup of genetically distinct HPV-negative head and neck tumours with favourable prognoses was confirmed. Tumours can be further subclassified based on genomic profiling. However, the amount of molecular data is currently overwhelming and requires detailed biological interpretation. It also became apparent that HNSCC is a disease characterized by frequent mutations that create neoantigens, indicating that immunotherapies might be effective. In 2016, the first results of immunotherapy trials with immune checkpoint inhibitors were published, and these may be considered as a paradigm shift in head and neck oncology.

Prevalence of High-Risk Human Papillomavirus in Tonsil Tissue in Healthy Adults and Colocalization in Biofilm of Tonsillar Crypts

IMPORTANCE

The pathogenesis of human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma is currently an important topic of elucidation. The presence of latent HPV infection in tonsil tissue of healthy adults may provide an explanation for a component of this process and contribute to the understanding of HPV-associated squamous cell carcinoma oncogenesis of the oropharynx.

OBJECTIVE

To determine the prevalence of oropharyngeal HPV and to determine the spatial relationship between the virus and crypt biofilm in tonsil tissue.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective, cross-sectional study was carried out using samples obtained from tonsils that were archived at a university hospital following elective nononcologic tonsillectomy from 2012 to 2015. Samples consisted of formalin-fixed paraffin embedded samples of tumor-free tonsil tissue from 102 adults between the ages of 20 and 39 years.

EXPOSURES

Human papillomavirus status was assessed by polymerase chain reaction, and high-risk subtypes 16 and 18 were assessed with quantitative polymerase chain reaction assay. Samples that demonstrated presence of HPV were then analyzed by in situ hybridization to localize the viral capsid protein. These samples were then stained with concanavalin A to establish biofilm presence and morphology. These samples were also stained with diamidino-phenylindole (DAPI) to visualize location of the virus in relation to cell nuclei. These data were then assembled for aggregate analysis to colocalize HPV in the biofilm of the tonsillar crypts.

MAIN OUTCOMES AND MEASURES

Outcome measurements were determined prior to data collection and include prevalence of high-risk HPV types 16 and 18 in tonsil tissue of otherwise healthy adults, as well as demonstration with immunohistochemistry of HPV in tonsillar crypt biofilm.

RESULTS

In 102 otherwise healthy adults (55 [53.9%] female; age range, 20-39 years), the overall prevalence of HPV in tonsils was 4.9% (n = 5); and high-risk type 16 or 18, 3.9% (n = 4). In this sample population, in situ hybridization colocalized HPV virus to the biofilm of the tonsillar crypts.

CONCLUSIONS AND RELEVANCE

Biofilm is present in the tonsillar crypts in a considerable proportion of tonsil tissues and may be reproducibly identified. Human papillomavirus is demonstrated to colocalize to the crypt biofilm. This has important implications with respect to the determination of HPV prevalence rates in the oropharynx. It may also play a role in the pathogenesis of HPV-related oropharyngeal carcinoma.

The Intersection of HPV Epidemiology, Genomics and Mechanistic Studies of HPV-Mediated Carcinogenesis

Of the ~60 human papillomavirus (HPV) genotypes that infect the cervicovaginal epithelium, only 12–13 “high-risk” types are well-established as causing cervical cancer, with HPV16 accounting for over half of all cases worldwide. While HPV16 is the most important carcinogenic type, variants of HPV16 can differ in their carcinogenicity by 10-fold or more in epidemiologic studies. Strong genotype-phenotype associations embedded in the small 8-kb HPV16 genome motivate molecular studies to understand the underlying molecular mechanisms. Understanding the mechanisms of HPV genomic findings is complicated by the linkage of HPV genome variants. A panel of experts in various disciplines gathered on 21 November 2016 to discuss the interdisciplinary science of HPV oncogenesis. Here, we summarize the discussion of the complexity of the viral–host interaction and highlight important next steps for selected applied basic laboratory studies guided by epidemiological genomic findings.

The prevalence of human papillomavirus in pediatric tonsils: a systematic review of the literature

BACKGROUND

HPV-related head and neck cancer rates have been increasing in recent years, with the tonsils being the most commonly affected site. However, the current rate of HPV infection in the pediatric population remains poorly defined. The objective of this study was to systematically review and evaluate the prevalence and distribution of HPV in the tonsils of pediatric patients undergoing routine tonsillectomy.

METHODS AND RESULTS

The literature was searched using PubMed, EMBASE, Scopus, CINAHL, Cochrane Library, and ProQuest Dissertations & Theses Global databases (inception to December 2017) by two independent review authors. Inclusion criteria included articles which evaluated the prevalence of HPV in a pediatric cohort without known warts or recurrent respiratory papillomatosis, those which used tonsil biopsy specimens for analysis, and those with six or more subjects and clear outcomes reported. Eleven studies met the inclusion criteria. Using the Oxford Clinical Evidence-based Medicine (OCEBM) guidelines, two reviewers appraised the level of evidence of each study, extracted data, and resolved discrepancies by consensus. The systematic review identified 11 articles (n = 2520). Seven studies detected HPV in the subject population, with prevalence values ranging from 0 to 21%. The level of evidence for all included studies was OCEBM Level 3.

CONCLUSIONS

HPV may be present in pediatric tonsillectomy specimens; however, the largest included study demonstrated a prevalence of 0%. Future testing should be performed using methods with high sensitivities and specificities, such as reverse transcript real-time PCR or digital droplet PCR.

Prevalence of high-risk human papillomavirus infection and cancer gene mutations in nonmalignant tonsils

OBJECTIVES

To analyze the prevalence of high-risk HPV (human papillomavirus) and genetic alterations in nonmalignant tonsils.

METHODS

We collected benign fresh tonsillar tissue specimens from 477 patients undergoing tonsillectomy because of chronic tonsillitis or tonsillar hypertrophy in 2012 (Group A, n=237) and in 2015 (Group B, n=240). Luminex xMAP technique served to detect E6/E7 DNA from 16 different high-risk HPV types. Tonsillar DNA and peripheral blood leukocyte DNA from the infected individuals were analyzed using Nimblegen SeqCap EZ Comprehensive Cancer Design panel. The panel targets 578 different genes that are relevant in carcinogenesis. HPV negative tonsillar specimens from age- and gender matched individuals were used as controls. All specimens harboring high-risk HPV were analyzed using fluorescence in situ hybridization (FISH).

RESULTS

Five of 477 (1.0%) patients tested positive for the following HPV types: HPV16 (two cases), HPV52 (one case), HPV66 (one case), HPV52 and HPV68 (coinfection, one case). FISH analyses showed that the appearance of HPV in specimens infected with HPV 16 was episomal. Benign tonsils infected with high-risk HPV harbored mutations in EP300, NF1, PIK3CA, and RB1 which are considered relevant in the development of HPV-associated head and neck squamous cell carcinoma (SCC).

CONCLUSIONS

The prevalence of high-risk HPV in nonmalignant tonsils is low. High-risk HPV positive tonsils harbored mutations in genes that are commonly altered in HPV-associated head and neck SCC. The role of these mutations in tonsillar carcinogenesis is an interesting target for future research.

SLPI and AnxA2 expression in neoplasm-free palatine tonsils is associated with smoking habit of individuals

In order to confirm the inverse correlation between secretory leucocyte protease inhibitor (SLPI) expression, and human papillomavirus (HPV) infection previously observed in head and neck squamous-cell carcinoma, the present study retrospectively investigated the association between SLPI and Annexin A2 (AnxA2) expression, and HPV status in non-neoplastic chronic tonsillitis (n=118), and tonsillar hyperplasia (n=96) tissue. We hypothesised that smoking induces the upregulation of SLPI, resulting in reduced binding of HPV to AnxA2, a known modulator of HPV entry into the cell. SLPI and cyclin-dependent kinase inhibitor 2A (p16^INK4A) protein expression was measured using immunohistochemistry in 214 specimens; SLPI and AnxA2 gene expression was measured using reverse transcription-quantitative polymerase chain reaction in 213 cases; and DNA was isolated from all the specimens to determine HPV status. The association between the results of the aforementioned analyses and the smoking habits of patients was analysed. The samples were HPV-negative. p16^INK4A expression demonstrated moderate and strong staining in 38, and 0 cases, respectively. SLPI expression presented negative, weak and moderate signals in 163, 45, and 6 cases, respectively. A positive correlation was identified between smoking and SLPI (P=0.0001). Gene expression analysis (n=213) revealed that smoking (n=48) resulted in a significant increase in SLPI and AnxA2 expression. A significant positive correlation between AnxA2 and SLPI, indicating a surplus of AnxA2 in relation to SLPI, was exclusively identified in non-smokers. The data demonstrated that smoking results in increased SLPI and AnxA2 expression also in non-neoplastic tonsillar tissue. The observed surplus of AnxA2 in relation to SLPI identified exclusively in the tonsillar tissue of non-smokers indicates a higher possibility of a successful HPV infection of the tonsillar tissue of non-smokers, given the properties of AnxA2 to function as an infection modulator.

Primary, secondary and tertiary prevention of human papillomavirus-driven head and neck cancers

Human papillomavirus (HPV)-driven oropharyngeal cancers (OPCs) represent an increasing proportion of head and neck cancers that could become, in the next few decades, a public health problem in certain western countries. This significant epidemiological change strongly calls for preventive measures. Prophylactic HPV vaccination and screening programmes for early identification and treatment of premalignant lesions are currently being used to reduce the incidence of uterine cervical cancer, which is the paradigm of HPV-driven malignancy. These strategies have proven to be efficient as the incidence of cervical cancer has dramatically dropped since the 1960s in most countries where they are properly applied. The success of cervical cancer prevention encourages the development of similar approaches to prevent HPV-driven OPCs. However, a number of important limitations impede their application to HPV-driven OPCs, and the development of innovative and specific strategies dedicated to this disease are urgently needed. This article provides an overview on primary, secondary and tertiary prevention of HPV-driven OPC and discusses some directions for future research.

Human papillomavirus prevalence in mouthwashes of patients undergoing tonsillectomy shows dominance of HPV69, without the corresponding finding in the tonsils

BACKGROUND

The role of human papillomavirus (HPV) in tonsillar squamous cell carcinomas (TSCC) is of interest, since a considerable proportion of TSCC in Sweden and other Western countries is HPV positive. Nevertheless, the natural history of HPV in normal tonsils, and the progression from localized infection to pre-malignant lesion to cancer are poorly understood. The aim of this study was to investigate whether HPV types found in mouthwash samples correlated to those in tonsillar tissue from the same individuals undergoing tonsillectomy.

METHODS

Mouthwash samples from 232 patients, aged 3-56 years, undergoing tonsillectomy, the majority with chronic tonsillitis, were collected at the time of surgery and analysed for the presence of 27 HPV types by a bead based multiplex assay.

RESULTS

An HPV prevalence of 10.3% (24/232) was observed in mouthwash samples, with HPV 69 being the dominant type (10/24). Ten patients were positive for high risk HPV (HPV 16, 33, 35, 45, 56, 59). None of the tonsils resected from patients with HPV-positive mouthwash samples were positive for HPV.

CONCLUSIONS

Despite an oral HPV prevalence of 10.3% in mouthwash samples from tonsillectomized patients, with dominance of HPV 69, none of the corresponding tonsillar samples exhibited the presence of HPV.

Prevalence of human papillomavirus in tonsil brushings and gargles in cancer-free patients: The SPLIT study

OBJECTIVE

To evaluate human papillomavirus (HPV) prevalence in the tonsil using extensive ex vivo brushing and gargling in a large age-stratified sample of cancer-free patients.

MATERIALS AND METHODS

From 2012 to 2016, consecutive patients undergoing tonsillectomy for benign indications in 19 French University Hospitals were invited to participate in the SPLIT study. Immediately after resection, half-tonsils were extensively brushed at the pathology laboratories on the surface epithelium and in tonsil crypts to collect exfoliated cells. In 11 centers, patients aged 15 and over (adults) were also asked to provide gargle samples before surgery. HPV-DNA detection used a very sensitive Luminex technology to evaluate 21 HPV types.

RESULTS

Tonsil brushings from 692 patients aged 1-70 years and gargles from 268 adults were tested for HPV. Among adults, overall HPV prevalence was 3.6% in tonsil brushings and 13.1% in gargles and HPV16 prevalence was 2.2% and 4.1%, respectively. Among 139 children, tonsil brushings were positive in two girls (1.4%). Percent agreement in HPV detection in paired tonsil brushings and gargles in adults was 85.8% and positive agreement 9.5%. HPV prevalence in gargles significantly varied by sex (prevalence ratio in men vs women=2.1; 95% confidence interval; 1.1-4.1) and tonsillectomy indication (non-infectious vs. infectious=4.9; 1.4-17.0).

CONCLUSION

HPV infection is infrequent in tonsil brushings of cancer-free children and adults. In contrast, HPV infection in gargles in adults is rather common. Low agreement in paired tonsil brushings and gargles suggests that gargle is not representative of HPV prevalence in the tonsil.

Sensitivity of tumor surface brushings to detect human papilloma virus DNA in head and neck cancer

OBJECTIVE

Human papilloma virus (HPV) induced head and neck squamous cell carcinoma (HNSCC) represents a distinct tumor subset. We questioned how accurately a brushing from the tumor surface detects HPV in patients with HNSCC.

MATERIALS AND METHODS

Brushings from the tumor surface were compared with HPV DNA isolation from formalin-fixed and paraffin-embedded (FFPE) tumor biopsies, which served as the reference standard. In both matrices, HPV DNA was detected using a commercially available test kit. In addition, p16 was assessed in tumor biopsies by immunohistochemistry (IHC). The tumors were considered p16 positive if 70% or more of cancer cells expressed p16.

RESULTS

93 patients with HNSCC were included. Sensitivity and specificity of the brush test were 83% (95%CI: 67-92%) and 85% (95%CI: 72-93%). Results of p16 IHC were concordant with FFPE samples DNA determinations in 73/93 patients. In 53 patients (57%) the tumor was located in the oropharynx and in 40 patients (43%) the tumor was located in the non-oropharynx region. Sensitivity and specificity of the brush test in patients with oropharyngeal cancer was higher with 86% (95%CI: 70-95%) and 89% (95%CI: 65-99%).

CONCLUSION

Superficial brushes from the tumor surface may be used to identify HPV positive HNSCC.

Carcinogenic human papillomavirus infection

Infections with human papillomavirus (HPV) are common and transmitted by direct contact. Although the great majority of infections resolve within 2 years, 13 phylogenetically related, sexually transmitted HPV genotypes, notably HPV16, cause - if not controlled immunologically or by screening - virtually all cervical cancers worldwide, a large fraction of other anogenital cancers and an increasing proportion of oropharyngeal cancers. The carcinogenicity of these HPV types results primarily from the activity of the oncoproteins E6 and E7, which impair growth regulatory pathways. Persistent high-risk HPVs can transition from a productive (virion-producing) to an abortive or transforming infection, after which cancer can result after typically slow accumulation of host genetic mutations. However, which precancerous lesions progress and which do not is unclear; the majority of screening-detected precancers are treated, leading to overtreatment. The discovery of HPV as a carcinogen led to the development of effective preventive vaccines and sensitive HPV DNA and RNA tests. Together, vaccination programmes (the ultimate long-term preventive strategy) and screening using HPV tests could dramatically alter the landscape of HPV-related cancers. HPV testing will probably replace cytology-based cervical screening owing to greater reassurance when the test is negative. However, the effective implementation of HPV vaccination and screening globally remains a challenge.

Detection of high-risk human papillomavirus infection in tonsillar specimens using 2 commercially available assays

THE OBJECTIVE OF THE STUDY IS TO DETERMINE THE PREVALENCE OF HIGH-RISK HUMAN PAPILLOMAVIRUS (HRHPV) INFECTION IN TONSILLAR SWABS AND TISSUE: Patients undergoing tonsillectomy for nonmalignant causes were enrolled. A flocked swab and fresh tissue were collected from the left and right tonsil of each patient. Specimens were tested for hrHPV DNA using the Roche cobas test and for the presence of E6/E7 messenger RNA using the Hologic Aptima hrHPV test. Of the 193 patients enrolled, 129 were in the pediatric group (ages 1-12years; median, 5years), and 64 were in the adult group (ages 13-55; median, 22years). All swab and tissue specimens were negative for hrHPV by both methods. Positive, negative, and internal controls performed as expected. We found a 0% rate of infection indicating that detectable hrHPV infection in tonsillar tissue appears to be uncommon in the children and adults in the population sampled.

Oral Human Papillomavirus Infection in Men Who Have Sex with Men: A Systematic Review and Meta-Analysis

BACKGROUND

The epidemiology of oral human papillomavirus (HPV) infection in men who have sex with men (MSM) differs from anogenital HPV infection. The impact of HPV vaccination has, to date, largely focussed on anogenital outcomes. Vaccination of MSM in the UK has been recommended and, if implemented, baseline estimates of oral HPV prevalence will be useful.

METHODS

We searched Medline, Embase and psycINFO databases for studies reporting prevalence, incidence, and clearance of oral HPV infection in MSM. We performed a random-effects meta-analysis and meta-regression on prevalence estimates and summarised within-study risk factors for oral HPV DNA detection and incidence/clearance rates. We also performed a meta-analysis of the effect of MSM on oral HPV prevalence compared to heterosexual men.

RESULTS

26 publications were identified. The pooled prevalence of oral HPV16 from twelve estimates was 3.0% (95%CI 0.5-5.5) in HIV-negative and 4.7% (95%CI 2.1-7.3) in HIV-positive MSM. Median age of study participants explained 38% of heterogeneity (p<0.01) in HPV prevalence estimates (pooled = 17% and 29% in HIV-negative and HIV-positive, respectively; 22 estimates). Nine studies compared MSM to heterosexual men and found no difference in oral HPV prevalence (pooled OR 1.07 (95%CI 0.65-1.74)). The clearance rate was higher than incidence within studies. Type-specific concordance between oral and anogenital sites was rare.

CONCLUSION

There was substantial heterogeneity between estimates of oral HPV prevalence in MSM populations that was partly explained by HIV status and median age.

Deep brush-based cytology in tonsils resected for benign diseases

A fraction of oropharyngeal cancer (OPC), especially in the tonsil, is caused by human papillomavirus (HPV), mainly HPV16. Noninvasive diagnostic methods to detect precancerous lesions in the tonsil would be useful, e.g., liquid-based cytology (LBC). However, ill-characterized precancerous lesions may be hidden in the depth of the tonsillar crypts. We therefore conducted a study on HPV and tonsillar precancerous lesions to evaluate, among other things, the utility of LBC obtained by deep brushing of the resected tonsils. Two hundred non-paediatric patients (mean age: 30.3 years) who underwent tonsillectomy for infection-related conditions (69%) or other conditions (mainly obstructive sleep apnoea, 31%) were included. An ultra-sensitive Luminex bead-based platform was used to test for the DNA of 21 mucosal HPV types; 56% of slides were unsatisfactory due to low number of squamous epithelial cells or the masking effect of a large number of lymphocytes. Three patients (1.5%; 95% CI: 0.5-4.3) showed suspicious cytological findings (atypical squamous cells-cannot exclude high-grade squamous intraepithelial lesion, ASC-H) while 3 others were HPV-positive (2 for HPV16 and 1 for HPV39). None of the ASC-H patients and HPV-positive patients showed dysplasia at histological examination. The rarity of HPV infection in the tonsil conflicts with the relatively frequent detection of the virus in the mouth. In conclusion, aggressive deep brushing of tonsils, while hardly applicable in vivo, is unlikely to be a reliable method to detect precancerous lesions. The absence of OPC screening modalities places the priority on multi-purpose primary prevention strategies, i.e., HPV vaccination and reduction of smoking and drinking.

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

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

Role of Prophylactic Bilateral Tonsillectomy as a Cancer Preventive Strategy

The rate of vaccination against human papillomavirus (HPV) among adolescent girls and boys over the past few years has been stagnant in spite of the increase in incidence of HPV-positive oropharyngeal (OPX) squamous cell carcinoma (SCC). The indirect relationship between HPV cancer incidence and preventive vaccination poses a public health concern and has caused clinicians to search for other methods toward eradicating the ongoing oropharyngeal carcinoma epidemic. This alarming increase in OPX is motivating a search for therapeutic prevention strategies, including biomarker discovery, risk assessment, therapeutic vaccines, immunotherapy, and surgery. The current Danish Cancer Registry study by Fakhry and colleagues (in this issue) is the first to investigate the impact of prior tonsillectomy on the development of HPV OPX. They report that remote tonsillectomy resulted in a decreased incidence of tonsillar SCC. While thought-provoking, this study has a small sample size. Also, tonsillectomy does not address all anatomic sites at risk; there is lack of well-defined precancerous lesions or biomarkers to identify high-risk patients, and cost and morbidity make it impractical to justify prophylactic tonsillectomy as a cancer preventive strategy at present. The provocative clinical signal reported in this study supports further research and strategies that employ surgery when the technology and epidemiology can reliably be used to identify high-risk subjects.