Next Article in Journal
Epigenetic Activation of Wnt/β-Catenin Signaling in NAFLD-Associated Hepatocarcinogenesis
Next Article in Special Issue
Current Technologies and Recent Developments for Screening of HPV-Associated Cervical and Oropharyngeal Cancers
Previous Article in Journal
The Role of the C-Clamp in Wnt-Related Colorectal Cancers
Previous Article in Special Issue
Human Papillomavirus Genotype Distribution in Invasive Cervical Cancer in Pakistan
Open AccessReview

HPV Associated Head and Neck Cancer

Department of Radiation Oncology, Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 2M9, Canada
Department of Medical Biophysics, University of Toronto, Toronto, ON M5G 1L7, Canada
Department of Radiation Oncology, University of Toronto, Toronto, ON M5T 1P5, Canada
Author to whom correspondence should be addressed.
Academic Editor: David Wong
Cancers 2016, 8(8), 75;
Received: 29 June 2016 / Revised: 26 July 2016 / Accepted: 2 August 2016 / Published: 5 August 2016
(This article belongs to the Special Issue HPV Associated Cancers)


Head and neck cancers (HNCs) are a highly heterogeneous group of tumours that are associated with diverse clinical outcomes. Recent evidence has demonstrated that human papillomavirus (HPV) is involved in up to 25% of HNCs; particularly in the oropharyngeal carcinoma (OPC) subtype where it can account for up to 60% of such cases. HPVs are double-stranded DNA viruses that infect epithelial cells; numerous HPV subtypes, including 16, 18, 31, 33, and 35, drive epithelial cell transformation and tumourigenesis. HPV positive (HPV+) HNC represents a distinct molecular and clinical entity from HPV negative (HPV−) disease; the biological basis for which remains to be fully elucidated. HPV positivity is strongly correlated with a significantly superior outcome; indicating that such tumours should have a distinct management approach. This review focuses on the recent scientific and clinical investigation of HPV+ HNC. In particular, we discuss the importance of molecular and clinical evidence for defining the role of HPV in HNC, and the clinical impact of HPV status as a biomarker for HNC.
Keywords: biomarker; head and neck cancer; head and neck squamous cell carcinoma; human papillomavirus; (HPV+); HPV negative (HPV−); microRNA; oropharyngeal carcinoma; prognosis biomarker; head and neck cancer; head and neck squamous cell carcinoma; human papillomavirus; (HPV+); HPV negative (HPV−); microRNA; oropharyngeal carcinoma; prognosis

1. Introduction

Head and neck cancer (HNC) comprises a diverse group of tumours, with an incidence of over 500,000 cases annually worldwide [1]. The most common type of HNC is head and neck squamous cell carcinoma (HNSCC), the sixth most common cancer worldwide [2], which can arise from the oral cavity, nasal cavity, larynx, hypopharynx, and oropharynx. HNSCC pathogenesis has historically been associated with tobacco and alcohol use [3], but not all cases of HNSCC are associated with these high risk behaviours. The causative association between human papillomavirus (HPV) and cancer, a Nobel Prize winning discovery, was first recognized in the 1970s by Professor Harald zur Hausen, who identified the presence of HPV in cervical cancer [4]. Then, in 1983, evidence of HPV infection was identified in a subset of oropharyngeal carcinomas (OPC) [5]. Since that time, HPV has been clearly implicated as the causative agent in a subset of HNC [6]. Over the past 15 years, there has been a significant increase in the incidence of HPV positive (HPV+) HNC [7,8], particularly in tumours arising in the oropharynx (i.e., OPC), comprising approximately 60% of all cases [9,10,11]. This review summarizes the role of HPV in HNC, as well as the molecular, clinical, and demographic distinctions between HPV+ and HPV negative (HPV−) HNC. Furthermore, we discuss the importance of assessing HPV status as a clinically relevant biomarker, and therapeutic implications for the appropriate management of HPV+ HNC as a distinct diagnostic entity.

2. HPV and HNC

HPV is a non-enveloped, double-stranded DNA virus encoding a total of 8–9 proteins in approximately 8000 base pairs [12], with the ability to infect cutaneous or mucosal tissues [13]. There are approximately 179 distinct HPV genotypes [14], which can be divided into low risk and high risk groups based on their capacity to drive malignant transformation. The “high risk” HPV subtypes most clearly implicated in cancer are HPV16, 18, 31, 33, 35, 45, 51, 52, and 56, which are capable of causing cancers of the cervix, head and neck, anus, vagina, vulva, and penis [6]. The most commonly implicated subtype in HNSCC is HPV16, accounting for over 80% of HPV+ HNSCC [14,15]. Recently, our group examined HPV infection in 515 HNSCCs via RNA-sequencing data from The Cancer Genome Atlas (TCGA) [14]. Therein, we identified the presence of HPV transcripts in 73 (14%) of the HNSCCs, of which 61 (84%) were HPV16, and the other 12 (16%) were other subtypes (8 HPV33, 3 HPV35, 1 HPV56) [14]. Interestingly, HPV18, which is responsible for approximately 5% of cervical cancers [16], and which has been shown to contribute to approximately 2.5% of HNCs worldwide [15], was not identified in this cohort. Goodman et al. also recently reported the incidence of HPV subtypes in a cohort of 529 OPC samples, identifying HPV16 in 322 (61%) of the OPCs, and other high risk HPV subtypes in 56 (11%) of the OPCs, including: 31 HPV33, 14 HPV18, 11 HPV35, 4 HPV31, 4 HPV52, 3 HPV39, and 2 HPV45 [17].
The HPV capsid proteins L1 and L2 are responsible for tissue-specific infection. Replication is controlled by the E1 and E2 proteins, which regulate transcription of other viral genes [18]. A depiction of the HPV16 genome structure is shown in Figure 1. In HPV positive tumours, three viral proteins are responsible for oncogenesis; E5, E6, and E7 (reviewed in detail in [19]). The E6 and E7 proteins cooperatively inhibit apoptosis, promote uncontrolled cell proliferation, and induce genetic instability [20,21]. E6 activates the ubiquitin ligase E6AP, resulting in degradation of p53 [22], while E7 targets the retinoblastoma 1 protein (pRb) [23], causing de-repression of E2F, leading to overexpression of p16 and increased cell proliferation [24]. The function of E5 has yet to be fully elucidated; however, it is known to act together with E6 and E7 to promote transformation, and plays an important role in immune evasion [21,25].

3. Clinical and Demographic Features of HPV+ HNC

HPV+ HNC represents a distinct disease from HPV− tumours. Patients with HPV+ tumours present at a younger age (median = 57 vs. 64 years for HPV+ vs. HPV− OPC) [11], and are less likely to partake in excess alcohol consumption or heavy tobacco use [26]. A retrospective analysis of the annual trends in HNC from 1973–2003 demonstrated that although the annual incidence in smoking-related HNSCC has declined significantly over the recent decades at a rate of 1.85% annually, HPV-associated HNSCC has increased in incidence significantly, at a rate of 0.8% annually [27]. Additionally, HPV-related tumours more frequently arise in the oropharynx, whereas smoking-related tumours arise more commonly in the oral cavity, larynx, or hypopharynx [28]. HPV+ tumours are more likely to be smaller and poorly differentiated (with basaloid features), with a higher incidence of advanced lymph node (LN) metastases in comparison to HPV− tumours [29,30,31,32].
Despite a more aggressive clinical presentation, HPV status is the best independent predictor of survival in these patients [31,33,34]. An analysis of 493 HNSCC patients with LN metastases identified that HPV+ LN were larger and more likely to be cystic, yet they exhibited improved loco-regional control, whereby they regressed more quickly and were more likely to resolve following treatment in comparison to the LNs of HPV− patients [35]. HPV+ OPCs have a significant survival advantage over HPV− tumours, with a 58% reduction in mortality risk [34]. Additionally, HPV+ HNC patients with a history of tobacco use appear to fare worse than non-tobacco users with HPV+ HNC, indicating the prognostic importance of tobacco as a modulating factor in HNC [36,37]. Interestingly, the rate of distant metastasis (DM) is similar between HPV+ and HPV− OPC patients, and tumours of patients with HPV+ disease that develop DM appear to have a more aggressively disseminating phenotype [34,38]. However, the mechanism of DM development in HPV+ and HPV− patients has yet to be elucidated. Given the excellent loco-regional control of HPV+ patients, DM therefore remains as the major cause of death in these patients [11,38]. Methods to predict the risk of developing DM in HNC patients would enable refined risk stratification and inform appropriate treatment design for these patients.

4. Molecular Alterations in HPV+ vs. HPV− HNC

In both HPV+ and HPV− HNC, the p53 and pRb pathways are frequently altered; however, the mechanism of inactivation is distinct. As described above, the E6 and E7 viral proteins functionally inactivate p53 and pRb in HPV+ HNC. However, the majority of HPV− tumours have p53 mutations, widespread copy-number loss, and promoter hyper-methylation and mutation of CDKN2A, leading to a loss of p16 expression [39,40]. Furthermore, genomic studies have identified distinct molecular differences between HPV+ and HPV− HNC, including divergent gene expression patterns, mutations, amplifications, and deletions [41,42,43]. HPV+ OPC frequently exhibit TRAF3 loss, PIK3CA activating mutations, and E2F1 amplification; while HPV− HNSCC commonly harbour 11q amplifications, and mutations in CASP8 and HRAS [9]. However, despite these differences, HPV+ and HPV− tumours share frequent focal amplifications in 3q26/28, a region encoding the transcription factors TP63 and SOX2, and the PIK3CA oncogene [9]. In addition, tumours harbouring integrated HPV exhibit differential patterns of DNA methylation, mutations, and gene expression as compared to episomal HPV+ tumours [39]. Transcripts expressed from an integrated virus are known to be more stable, and HPV integration is associated with a proliferative advantage [19], as well as increased genomic instability [44].

5. Determination of HPV Status and HPV as a Biomarker

HPV testing has recently been included in the American Joint Committee on Cancer (AJCC)/Union for International Cancer Control (UICC) guidelines as a standard pathological assessment for OPC [45]. However, guidelines for HPV detection have not been clearly defined, and methods for determining HPV status often vary between studies [46]. HPV detection by polymerase chain reaction (PCR) amplification of viral RNA from fresh or frozen tissues is widely accepted as the gold-standard method for determining HPV status [47]. To validate this and other detection methods in formalin-fixed paraffin-embedded (FFPE) tissues, our group examined three methods to determine HPV status: p16 immunohistochemistry (IHC), HPV16 (in situ hybridization; ISH), and quantitative real-time PCR (qRT-PCR) for HPV16 E6 mRNA. Though all three methods reliably detected HPV positive tissues, p16 IHC was more sensitive than HPV16 ISH, and is technically easier to perform than HPV16 E6 mRNA quantification by qRT-PCR [10]. We have now used this method extensively at the Princess Margaret Cancer Centre to confirm HPV positivity as a diagnostic marker, and facilitated the implementation of p16 IHC testing for OPC patients across multiple cancer centers in Canada [11,36]. However, it is important to note that although p16 is a reliable surrogate for determining HPV positivity, it cannot distinguish between HPV16 and other HPV subtypes. Methods for determining HPV status and distinguishing HPV subtypes in tumour tissues are summarized in Table 1.

5.1. MicroRNAs as Biomarkers for HPV+ HNC

MicroRNAs (miRNA) are small endogenous non-coding RNAs that are approximately 22 nucleotides in length [49]. Dysregulated miRNAs have established roles as both oncogenes and tumour suppressors [50], and act primarily through binding and direct repression of mRNA targets, thereby regulating gene expression [49]. MiRNAs have been proposed as useful tumour-specific biomarkers in cancer [51,52]. As such, a number of studies have examined the association between miRNAs and HNC prognosis. MiRNA signatures have been associated with HPV/p16 status, disease free and overall survival, and the risk of developing DM. Table 2 summarizes miRNAs implicated as putative biomarkers in HNC.
MiRNAs also hold potential as biomarkers for predicting treatment response in HNC, as a number of reports have shown the association between specific miRNAs with development of DM and survival (Table 2). Numerous studies have functionally characterized causal links between miRNAs and tumour development or progression in a subset of non-HPV related HNC (reviewed in [56]), which further highlights the utility of miRNAs as accurate tumour biomarkers. However, miRNA signatures have not been incorporated into clinical practice to date. Large-scale validation of existing prognostic and predictive miRNA signatures will be essential for their application as clinically informative biomarkers in HNC.

5.2. Circulating Biomarkers for HPV+ HNC

Circulating biomarkers indicative of HNC prognosis or treatment response would enable a non-invasive method of monitoring disease status and for improved treatment stratification. Few studies have identified circulating biomarkers for HNC; however, this important field of research is rapidly growing. Tinhofer et al. examined the persistence of circulating tumour cells (CTC) isolated from peripheral blood following treatment with adjuvant chemotherapy for locally advanced HNSCC. Interestingly, in the subset of OPCs within this dataset, CTCs were not predictive of disease free survival (DFS) or overall survival (OS). However, in non-OPCs, CTC were an independent prognostic marker of poorer DFS and OS [57]. Therefore, upon further validation, CTC quantification could prove to be a useful tool to identify patients who could benefit from treatment intensification.
Though outcome for HPV+ HNC patients is generally superior to HPV− patients, a subset of HPV+ patients have a poor prognosis, associated with the development of DM [11,58]. The ability to pre-identify the HPV+ patients with aggressive disease would facilitate optimal management of these patients in the clinic. A recent study examined the use of circulating neutrophil count (CNC), circulating monocyte count (CMC), and circulating lymphocyte count (CLC) as prognostic markers for HPV+ and HPV− OPC. The authors identified that high pretreatment CNC and CMC independently predicted for poor survival, and high CLC predicted for superior survival in HPV+ patients, whereas these trends did not correlate with survival in HPV− OPC [59]. This study therefore suggests the possible utility of pretreatment CNC, CMC, and CLC counts as early prognostic indicators for HPV+ OPC. Similarly, Wansom et al. examined the correlation between the level of circulating adaptive immune cells and outcome in HPV16+ OPC, finding that elevated pretreatment levels of CD8 T cells were associated with better response to induction chemotherapy, complete tumour response post chemoradiation treatment, and significantly improved survival [60]. Therefore, quantification of pretreatment CD8 T cell levels could provide valuable insight into the response to treatment for patients with HPV16+ OPC. Another study examined the level of HPV DNA isolated from the plasma of patients with HPV+ OPC. Pretreatment, HPV DNA was detectable in 65% of patients, and dropped rapidly to undetectable levels following radiation treatment [61]. In a subset of patients, HPV DNA increased to quantifiable levels at the time of DM development, highlighting the potential for this tool in detecting recurrence for patients with HPV+ OPC.

6. Therapeutic Perspectives: Treatment of HPV+ HNC as a Distinct Entity

Due to the distinct clinical and demographic features of HPV+ HNC as compared to HPV− HNC, HPV status has now been established as a reliable prognostic biomarker for this disease [36]. As such, patients with HPV+ HNC would likely benefit from unique disease management approaches [11,58]. Factors related to the inherent biological differences between HPV+ and HPV− tumours may influence the radiosensitive phenotype of HPV+ tumours. Studies have demonstrated that HPV+ tumour cells are intrinsically more radiosensitive than HPV− tumour cells, due to radiation-induced sustained cell cycle arrest [62,63]. This finding may be attributed to multiple factors, including decreased degradation of p53 by E6, resulting in re-activation of canonical p53 mediated cell cycle arrest and increased apoptosis [62], as well as impaired p16-mediated homologous recombination repair of double-stranded breaks [63]. Moreover, HPV+ tumours appear to be generally less hypoxic than HPV− tumours [64], resulting in a more radiosensitive phenotype, although there is conflicting evidence in this domain [65,66].
Smoking is well-implicated as a causative agent in HPV− HNC, and a history of heavy tobacco use is correlated with poor prognosis [28]. Smoking is also an important risk factor in HPV+ HNC [67]. Patients with HPV+ OPC with a history of smoking for more than 20 pack-years (PY) had a 2-year OS rate of 80%, as compared with an OS rate of 95% for HPV+ patients with a history of fewer than 20 PYs, though survival rates were still superior to HPV− OPC with over 20 PYs, with an OS rate of 63% [31]. Thus, tobacco exposure is a key prognostic indicator in both HPV+ and HPV− disease, and it is important to include smoking history within the criteria for disease risk stratification.
Immune modulation also appears to play a significant role in HPV+ HNC, which exhibit higher levels of immune infiltration than HPV− tumours [68]; these increased levels of immune infiltration in HPV+ tumours correlate with a significantly better outcome [69]. Furthermore, HPV16+ HNC patients have significantly higher levels of circulating T cells specific for HPV16 E7 protein, highlighting the essential role of immune modulation in HNC biology, as well as identifying a potential novel biomarker [70,71].
Current treatment regimens for HNC are aggressive and have significant treatment-associated toxicities, as a result of surgery, chemotherapy, and/or radiation treatment. These include both acute toxicities, such as mucositis, nausea, pain, hematologic changes, and stomatitis, among numerous other acute side effects, and late toxicities, such as chronic xerostomia, fibrosis, edema, trismus, and dysphagia [67]. Low risk HPV+ patients that are known to have significantly better survival rates would benefit from treatment de-intensification in order to minimize short and long-term treatment sequelae [72], while maintaining high rates of loco-regional control [73]. As such, a recent publication by our group described the need to refine the current recursive partitioning analysis (RPA) based TMN stage and prognostic groups for classification of HPV+ OPC, as defined by the AJCC/UICC classification system. The proposed criteria include patient age and smoking PY as well as the current RPA stage into four prognostic groups, yielding a significantly better prognostic performance than the current RPA classification [36]. Refining these disease risk classifications to identify low, medium, and high risk patients will undoubtedly improve HPV-associated OPC management, and allow for informed clinical trial design and appropriate selection of patients for treatment de-intensification trials. Chera et al. reported results of a Phase II chemoradiation therapy de-escalation trial for 43 patients with favourable risk, HPV+, and non-smoking associated OPC, with the primary endpoint of improved pathologic complete response (pCR). Encouragingly, patients experienced improved rates of pCR and decreased toxicity compared to standard therapies (NCT01530997, [74]). However, this study did not assess longer-term progression free survival (PFS), DFS rates, or late toxicities. The ECOG 1308 (NCT01084083) Phase II de-intensification trial examined PFS and OS of 62 HPV+ OPC patients who received low dose intensity-modulated radiation therapy (IMRT) with cetuximab following complete response to induction chemotherapy, as compared with 15 patients with partial response or stable disease who received standard dose IMRT with cetuximab. Preliminary findings of this trial report 1-year PFS rates of 91% and 87% for low dose and standard-dose groups, respectively [75]. Importantly, sub-group analysis of patients treated with low dose IMRT that had high risk features, including advanced tumour stage, nodal stage, and smoking history of over 10 PY, identified promising efficacy, with 1-year PFS rates of 86%, 88%, and 84%, respectively. Once long-term follow-up data is available for this trial, conclusions may be drawn regarding the effect of reduced IMRT dose on OS and late toxicities in HPV+ OPC patients. Another de-escalation trial was recently established by NRG Oncology and the National Cancer Institute (NCI)-US for patients with p16 positive, non-smoking associated OPC, to examine whether reduced IMRT doses with or without cisplatin treatment maintain PFS rates observed in patients treated at higher doses, while reducing treatment-associated toxicities (NCT02254278). Results from treatment de-escalation trials such as these will be essential to establish whether the current DFS and OS rates will be maintained following de-intensification of treatment for low risk HPV+ OPC.

HPV Subtype Specific Treatment Considerations

As discussed previously, HPV16 is the most prevalent HPV subtype in HNC, contributing to over 80% of HNSCC [14,15]. Interestingly, patients with HPV16+ tumours appear to present at a slightly younger age than other HPV subtypes, with a median age at diagnosis of 56–57.5 years for HPV16+ vs. 59.5 years for other HPV subtypes [14,17], though the clinical importance of this difference remains unclear. Importantly, the OS rate for patients with tumours harbouring high risk HPV subtypes other than HPV16 is significantly lower than HPV16+ HNSCCs. Our group identified a 3-year OS rate of 88% for patients with HPV16+ HNSCC, while the 3-year OS was reduced to 49% for patients with the other HPV subtypes [14]. Similarly, Goodman et al. identified a 5-year OS rate of 65% for HPV16+ OPC, and a significantly worse OS rate of 46% for patients with other high risk HPV+ tumours, though HPV− patients fared worse, with a 5-year OS rate of only 28% [17]. These findings underscore an essential clinical distinction between HPV subtypes, and suggest that treatment de-intensification strategies might not be appropriate for all HPV+ subtypes.

7. Conclusions

In summary, HPV has become a recognized oncogenic driver in HNC, and the incidence of HPV+ HNC, particularly HPV+ OPC, is on the rise. HPV associated HNC is a distinct clinical entity, with significantly improved treatment response and survival rates in comparison to HPV− HNC. Clinical management of low risk HPV+ HNC may therefore require unique treatment approaches focused on de-intensification of current standard of care therapies. Results of new and ongoing treatment de-escalation trials in these low risk patients will be crucial for establishing whether the current rates of DFS and OS are maintained while treatment-associated toxicities are reduced.
HPV16 is the subtype most frequently associated with HNC, and current clinically relevant detection methods focus on identifying the presence of HPV16 by PCR or ISH, or detection of p16 protein expression in tumour samples by IHC. However, HPV+ tumours involving other HPV subtypes generally exhibit reduced survival rates, though these rates may be somewhat superior to HPV− disease. Thus, a subset of HPV+ tumours may not benefit from treatment de-intensification strategies, highlighting the importance of informed clinical trial design. Additionally, diagnostic and prognostic biomarkers, including HPV-associated miRNAs and circulating monocytes or lymphocytes, may prove to yield strong clinical utility, and warrant further investigation and clinical validation.


This review is funded by the Canadian Institutes for Health Research, the Mariano Elia Chair in Head & Neck Cancer Research, the Campbell Family Institute for Cancer Research, the Ministry of Health and Long-Term Care, and the Princess Margaret Cancer Centre Head & Neck Translational Program, with philanthropic funds from the Wharton Family, Joe’s Team, and Gordon Tozer.

Author Contributions

Tara Spence, Jeff Bruce, Kenneth W. Yip, and Fei-Fei Liu all contributed to the writing of this manuscript.

Conflicts of Interest

The authors declare no conflict of interest.


The following abbreviations are used in this manuscript:
American Joint Committee on Cancer/Union for International Cancer Control
circulating lymphocyte count
circulating monocyte count
circulating neutrophil count
circulating tumour cell
disease free survival
distant metastases
formalin-fixed paraffin-embedded
head and neck cancer
head and neck squamous cell carcinoma
human papillomavirus
human papillomavirus positive
human papillomavirus negative
intensity-modulated radiation therapy
in situ hybridization
lymph node
National Cancer Institute
oropharyngeal carcinoma
overall survival
oral squamous cell carcinoma
polymerase chain reaction
pathologic complete response
progression free survival
pack years
retinoblastoma protein
quantitative real-time polymerase chain reaction
recursive partitioning analysis
The Cancer Genome Atlas


  1. Jemal, A.; Bray, F.; Center, M.M.; Ferlay, J.; Ward, E.; Forman, D. Global cancer statistics. CA Cancer J. Clin. 2011, 61, 69–90. [Google Scholar] [CrossRef] [PubMed]
  2. Kamangar, F.; Dores, G.M.; Anderson, W.F. Patterns of cancer incidence, mortality, and prevalence across five continents: defining priorities to reduce cancer disparities in different geographic regions of the world. J. Clin. Oncol. 2006, 24, 2137–2150. [Google Scholar] [CrossRef] [PubMed]
  3. Mashberg, A.; Boffetta, P.; Winkelman, R.; Garfinkel, L. Tobacco smoking, alcohol drinking, and cancer of the oral cavity and oropharynx among U.S. veterans. Cancer 1993, 72, 1369–1375. [Google Scholar] [CrossRef]
  4. The Nobel Prize in Physiology or Medicine 2008. Available online: (accessed on 20 May 2016).
  5. Syrjanen, K.J.; Pyrhonen, S.; Syrjanen, S.M.; Lamberg, M.A. Immunohistochemical demonstration of human papilloma virus (HPV) antigens in oral squamous cell lesions. Br. J. Oral Surg. 1983, 21, 147–153. [Google Scholar] [CrossRef]
  6. IARC. Human Papillomaviruses. IARC Monogr. Eval. Carcinog. Risks Hum. 1995, 64, 1–428. [Google Scholar]
  7. Pytynia, K.B.; Dahlstrom, K.R.; Sturgis, E.M. Epidemiology of HPV-associated oropharyngeal cancer. Oral Oncol. 2014, 50, 380–386. [Google Scholar] [CrossRef] [PubMed]
  8. Chaturvedi, A.K.; Engels, E.A.; Pfeiffer, R.M.; Hernandez, B.Y.; Xiao, W.; Kim, E.; Jiang, B.; Goodman, M.T.; Sibug-Saber, M.; Cozen, W.; et al. Human papillomavirus and rising oropharyngeal cancer incidence in the United States. J. Clin. Oncol. 2011, 29, 4294–4301. [Google Scholar] [CrossRef] [PubMed]
  9. Cancer Genome Atlas Network. Comprehensive genomic characterization of head and neck squamous cell carcinomas. Nature 2015, 517, 576–582. [Google Scholar]
  10. Shi, W.; Kato, H.; Perez-Ordonez, B.; Pintilie, M.; Huang, S.; Hui, A.; O'Sullivan, B.; Waldron, J.; Cummings, B.; Kim, J.; et al. Comparative prognostic value of HPV16 E6 mRNA compared with in situ hybridization for human oropharyngeal squamous carcinoma. J. Clin. Oncol. 2009, 27, 6213–6221. [Google Scholar] [CrossRef] [PubMed]
  11. O’Sullivan, B.; Huang, S.H.; Siu, L.L.; Waldron, J.; Zhao, H.; Perez-Ordonez, B.; Weinreb, I.; Kim, J.; Ringash, J.; Bayley, A.; et al. Deintensification candidate subgroups in human papillomavirus-related oropharyngeal cancer according to minimal risk of distant metastasis. J. Clin. Oncol. 2013, 31, 543–550. [Google Scholar]
  12. NIAID. Papillomavirus Episteme Kowledge Source: HPV16. National Institute of Allergy and Infectious Disease, National Institutes of Health. Available online: (accessed on 10 June 2016).
  13. Suzich, J.A.; Ghim, S.J.; Palmer-Hill, F.J.; White, W.I.; Tamura, J.K.; Bell, J.A.; Newsome, J.A.; Jenson, A.B.; Schlegel, R. Systemic immunization with papillomavirus L1 protein completely prevents the development of viral mucosal papillomas. Proc. Natl. Acad. Sci. USA 1995, 92, 11553–11557. [Google Scholar] [CrossRef] [PubMed]
  14. Bratman, S.V.; Bruce, J.P.; O’Sullivan, B.; Pugh, T.J.; Xu, W.; Yip, K.W.; Liu, F.F. Human papillomavirus genotype association with survival in head and neck squamous cell carcinoma. JAMA Oncol. 2016, 2, 823–826. [Google Scholar] [CrossRef] [PubMed]
  15. Ndiaye, C.; Mena, M.; Alemany, L.; Arbyn, M.; Castellsague, X.; Laporte, L.; Bosch, F.X.; de Sanjose, S.; Trottier, H. HPV DNA, E6/E7 mRNA, and p16INK4a detection in head and neck cancers: A systematic review and meta-analysis. Lancet. Oncol. 2014, 15, 1319–1331. [Google Scholar] [CrossRef]
  16. Anderson, L.A.; O’Rorke, M.A.; Wilson, R.; Jamison, J.; Gavin, A.T.; Northern Ireland HPV Working Group. HPV prevalence and type-distribution in cervical cancer and premalignant lesions of the cervix: A population-based study from Northern Ireland. J. Med. Virol. 2016, 88, 1262–1270. [Google Scholar] [CrossRef] [PubMed]
  17. Goodman, M.T.; Saraiya, M.; Thompson, T.D.; Steinau, M.; Hernandez, B.Y.; Lynch, C.F.; Lyu, C.W.; Wilkinson, E.J.; Tucker, T.; Copeland, G.; et al. Human papillomavirus genotype and oropharynx cancer survival in the United States of America. Eur. J. Cancer 2015, 51, 2759–2767. [Google Scholar] [CrossRef] [PubMed]
  18. Hebner, C.M.; Laimins, L.A. Human papillomaviruses: Basic mechanisms of pathogenesis and oncogenicity. Rev. Med. Virol. 2006, 16, 83–97. [Google Scholar] [CrossRef] [PubMed]
  19. Moody, C.A.; Laimins, L.A. Human papillomavirus oncoproteins: Pathways to transformation. Nat. Rev. Cancer 2010, 10, 550–560. [Google Scholar] [CrossRef] [PubMed]
  20. Duensing, S.; Lee, L.Y.; Duensing, A.; Basile, J.; Piboonniyom, S.; Gonzalez, S.; Crum, C.P.; Munger, K. The human papillomavirus type 16 E6 and E7 oncoproteins cooperate to induce mitotic defects and genomic instability by uncoupling centrosome duplication from the cell division cycle. Proc. Natl. Acad. Sci. USA 2000, 97, 10002–10007. [Google Scholar] [CrossRef] [PubMed]
  21. DiMaio, D.; Mattoon, D. Mechanisms of cell transformation by papillomavirus E5 proteins. Oncogene 2001, 20, 7866–7873. [Google Scholar] [CrossRef] [PubMed]
  22. Scheffner, M.; Werness, B.A.; Huibregtse, J.M.; Levine, A.J.; Howley, P.M. The E6 oncoprotein encoded by human papillomavirus types 16 and 18 promotes the degradation of p53. Cell 1990, 63, 1129–1136. [Google Scholar] [CrossRef]
  23. Munger, K.; Werness, B.A.; Dyson, N.; Phelps, W.C.; Harlow, E.; Howley, P.M. Complex formation of human papillomavirus E7 proteins with the retinoblastoma tumor suppressor gene product. EMBO J. 1989, 8, 4099–4105. [Google Scholar] [PubMed]
  24. Song, S.; Liem, A.; Miller, J.A.; Lambert, P.F. Human papillomavirus types 16 E6 and E7 contribute differently to carcinogenesis. Virology 2000, 267, 141–150. [Google Scholar] [CrossRef] [PubMed]
  25. DiMaio, D.; Petti, L.M. The E5 proteins. Virology 2013, 445, 99–114. [Google Scholar] [CrossRef] [PubMed]
  26. Goon, P.K.; Stanley, M.A.; Ebmeyer, J.; Steinstrasser, L.; Upile, T.; Jerjes, W.; Bernal-Sprekelsen, M.; Gorner, M.; Sudhoff, H.H. HPV & head and neck cancer: A descriptive update. Head Neck Oncol. 2009. [Google Scholar] [CrossRef][Green Version]
  27. Chaturvedi, A.K.; Engels, E.A.; Anderson, W.F.; Gillison, M.L. Incidence trends for human papillomavirus-related and -unrelated oral squamous cell carcinomas in the United States. J. Clin. Oncol. 2008, 26, 612–619. [Google Scholar] [CrossRef] [PubMed]
  28. Sturgis, E.M.; Cinciripini, P.M. Trends in head and neck cancer incidence in relation to smoking prevalence: An emerging epidemic of human papillomavirus-associated cancers? Cancer 2007, 110, 1429–1435. [Google Scholar] [CrossRef] [PubMed]
  29. Rischin, D.; Young, R.J.; Fisher, R.; Fox, S.B.; Le, Q.T.; Peters, L.J.; Solomon, B.; Choi, J.; O’Sullivan, B.; Kenny, L.M.; et al. Prognostic significance of p16INK4A and human papillomavirus in patients with oropharyngeal cancer treated on TROG 02.02 phase III trial. J. Clin. Oncol. 2010, 28, 4142–4148. [Google Scholar] [CrossRef] [PubMed]
  30. Gillison, M.L.; Koch, W.M.; Capone, R.B.; Spafford, M.; Westra, W.H.; Wu, L.; Zahurak, M.L.; Daniel, R.W.; Viglione, M.; Symer, D.E.; et al. Evidence for a causal association between human papillomavirus and a subset of head and neck cancers. J. Natl. Cancer Inst. 2000, 92, 709–720. [Google Scholar] [CrossRef] [PubMed]
  31. Fakhry, C.; Westra, W.H.; Li, S.; Cmelak, A.; Ridge, J.A.; Pinto, H.; Forastiere, A.; Gillison, M.L. Improved survival of patients with human papillomavirus-positive head and neck squamous cell carcinoma in a prospective clinical trial. J. Natl. Cancer Inst. 2008, 100, 261–269. [Google Scholar] [CrossRef] [PubMed]
  32. Posner, M.R.; Lorch, J.H.; Goloubeva, O.; Tan, M.; Schumaker, L.M.; Sarlis, N.J.; Haddad, R.I.; Cullen, K.J. Survival and human papillomavirus in oropharynx cancer in TAX 324: A subset analysis from an international phase III trial. Ann. Oncol. 2011, 22, 1071–1077. [Google Scholar] [CrossRef] [PubMed]
  33. O’Rorke, M.A.; Ellison, M.V.; Murray, L.J.; Moran, M.; James, J.; Anderson, L.A. Human papillomavirus related head and neck cancer survival: A systematic review and meta-analysis. Oral Oncol. 2012, 48, 1191–1201. [Google Scholar] [CrossRef] [PubMed]
  34. Ang, K.K.; Harris, J.; Wheeler, R.; Weber, R.; Rosenthal, D.I.; Nguyen-Tan, P.F.; Westra, W.H.; Chung, C.H.; Jordan, R.C.; Lu, C.; et al. Human papillomavirus and survival of patients with oropharyngeal cancer. N. Engl. J. Med. 2010, 363, 24–35. [Google Scholar] [CrossRef] [PubMed]
  35. Huang, S.H.; O’Sullivan, B.; Xu, W.; Zhao, H.; Chen, D.D.; Ringash, J.; Hope, A.; Razak, A.; Gilbert, R.; Irish, J.; et al. Temporal nodal regression and regional control after primary radiation therapy for N2–N3 head-and-neck cancer stratified by HPV status. Int. J. Radiat. Oncol. Biol. Phys. 2013, 87, 1078–1085. [Google Scholar] [CrossRef] [PubMed]
  36. Huang, S.H.; Xu, W.; Waldron, J.; Siu, L.; Shen, X.; Tong, L.; Ringash, J.; Bayley, A.; Kim, J.; Hope, A.; et al. Refining American Joint Committee on Cancer/Union for International Cancer Control TNM stage and prognostic groups for human papillomavirus-related oropharyngeal carcinomas. J. Clin. Oncol. 2015, 33, 836–845. [Google Scholar] [CrossRef] [PubMed]
  37. Smith, E.M.; Rubenstein, L.M.; Haugen, T.H.; Pawlita, M.; Turek, L.P. Complex etiology underlies risk and survival in head and neck cancer human papillomavirus, tobacco, and alcohol: A case for multifactor disease. J. Oncol. 2012. [Google Scholar] [CrossRef] [PubMed]
  38. O’Sullivan, B.; Huang, S.H.; Perez-Ordonez, B.; Massey, C.; Siu, L.L.; Weinreb, I.; Hope, A.; Kim, J.; Bayley, A.J.; Cummings, B.; et al. Outcomes of HPV-related oropharyngeal cancer patients treated by radiotherapy alone using altered fractionation. Radiother. Oncol. 2012, 103, 49–56. [Google Scholar] [CrossRef] [PubMed]
  39. Parfenov, M.; Pedamallu, C.S.; Gehlenborg, N.; Freeman, S.S.; Danilova, L.; Bristow, C.A.; Lee, S.; Hadjipanayis, A.G.; Ivanova, E.V.; Wilkerson, M.D.; et al. Characterization of HPV and host genome interactions in primary head and neck cancers. Proc. Natl. Acad. Sci. USA 2014, 111, 15544–15549. [Google Scholar] [CrossRef] [PubMed]
  40. Sepiashvili, L.; Bruce, J.P.; Huang, S.H.; O’Sullivan, B.; Liu, F.F.; Kislinger, T. Novel insights into head and neck cancer using next-generation “omic” technologies. Cancer Res. 2015, 75, 480–486. [Google Scholar] [CrossRef] [PubMed]
  41. Walter, V.; Yin, X.; Wilkerson, M.D.; Cabanski, C.R.; Zhao, N.; Du, Y.; Ang, M.K.; Hayward, M.C.; Salazar, A.H.; Hoadley, K.A.; et al. Molecular subtypes in head and neck cancer exhibit distinct patterns of chromosomal gain and loss of canonical cancer genes. PLoS ONE 2013, 8, e56823. [Google Scholar] [CrossRef]
  42. Lechner, M.; Frampton, G.M.; Fenton, T.; Feber, A.; Palmer, G.; Jay, A.; Pillay, N.; Forster, M.; Cronin, M.T.; Lipson, D.; et al. Targeted next-generation sequencing of head and neck squamous cell carcinoma identifies novel genetic alterations in HPV+ and HPV− tumors. Genome Med. 2013. [Google Scholar] [CrossRef] [PubMed]
  43. Stransky, N.; Egloff, A.M.; Tward, A.D.; Kostic, A.D.; Cibulskis, K.; Sivachenko, A.; Kryukov, G.V.; Lawrence, M.S.; Sougnez, C.; McKenna, A.; et al. The mutational landscape of head and neck squamous cell carcinoma. Science 2011, 333, 1157–1160. [Google Scholar] [CrossRef] [PubMed][Green Version]
  44. Korzeniewski, N.; Spardy, N.; Duensing, A.; Duensing, S. Genomic instability and cancer: Lessons learned from human papillomaviruses. Cancer Lett. 2011, 305, 113–122. [Google Scholar] [CrossRef] [PubMed]
  45. Seethala, R.R.; Weinreb, I.; Carlson, D.L.; McHugh, J.B.; Harrison, L.B.; Richardson, M.S.; Sahah, J.; Ferris, R.L.; Wenig, B.M.; Thompson, L.D.R. Protocol for the examination of specimens from patients with carcinomas of the larynx. College of American Pathologists. Available online: (accessed on 25 May 2016).
  46. Westra, W.H. Detection of human papillomavirus (HPV) in clinical samples: Evolving methods and strategies for the accurate determination of HPV status of head and neck carcinomas. Oral Oncol. 2014, 50, 771–779. [Google Scholar] [CrossRef] [PubMed]
  47. Kosel, S.; Burggraf, S.; Engelhardt, W.; Olgemoller, B. Increased levels of HPV16 E6*I transcripts in high-grade cervical cytology and histology (CIN II+) detected by rapid real-time RT-PCR amplification. Cytopathology 2007, 18, 290–299. [Google Scholar] [CrossRef] [PubMed]
  48. Giuliani, L.; Coletti, A.; Syrjanen, K.; Favalli, C.; Ciotti, M. Comparison of DNA sequencing and Roche Linear array in human papillomavirus (HPV) genotyping. Anticancer Res. 2006, 26, 3939–3941. [Google Scholar] [PubMed]
  49. Bartel, D.P. MicroRNAs: Genomics, biogenesis, mechanism, and function. Cell 2004, 116, 281–297. [Google Scholar] [CrossRef]
  50. Xue, W.Q.; Qin, H.D.; Ruan, H.L.; Shugart, Y.Y.; Jia, W.H. Quantitative association of tobacco smoking with the risk of nasopharyngeal carcinoma: A comprehensive meta-analysis of studies conducted between 1979 and 2011. Am. J. Epidemiol. 2013, 178, 325–338. [Google Scholar] [CrossRef] [PubMed]
  51. Bertoli, G.; Cava, C.; Castiglioni, I. MicroRNAs: New biomarkers for diagnosis, prognosis, therapy prediction and therapeutic tools for breast cancer. Theranostics 2015, 5, 1122–1143. [Google Scholar] [CrossRef] [PubMed]
  52. He, Y.; Lin, J.; Kong, D.; Huang, M.; Xu, C.; Kim, T.K.; Etheridge, A.; Luo, Y.; Ding, Y.; Wang, K. Current state of circulating microRNAs as cancer biomarkers. Clin. Chem. 2015, 61, 1138–1155. [Google Scholar] [CrossRef] [PubMed]
  53. Hui, A.B.; Lin, A.; Xu, W.; Waldron, L.; Perez-Ordonez, B.; Weinreb, I.; Shi, W.; Bruce, J.; Huang, S.H.; O’Sullivan, B.; et al. Potentially prognostic miRNAs in HPV-associated oropharyngeal carcinoma. Clin. Cancer Res. 2013, 19, 2154–2162. [Google Scholar] [CrossRef] [PubMed]
  54. Childs, G.; Fazzari, M.; Kung, G.; Kawachi, N.; Brandwein-Gensler, M.; McLemore, M.; Chen, Q.; Burk, R.D.; Smith, R.V.; Prystowsky, M.B.; et al. Low-level expression of microRNAs let-7d and miR-205 are prognostic markers of head and neck squamous cell carcinoma. Am. J. Pathol. 2009, 174, 736–745. [Google Scholar] [CrossRef] [PubMed]
  55. Gee, H.E.; Camps, C.; Buffa, F.M.; Patiar, S.; Winter, S.C.; Betts, G.; Homer, J.; Corbridge, R.; Cox, G.; West, C.M.; et al. hsa-mir-210 is a marker of tumor hypoxia and a prognostic factor in head and neck cancer. Cancer 2010, 116, 2148–2158. [Google Scholar] [CrossRef] [PubMed]
  56. Spence, T.; Bruce, J.; Yip, K.W.; Liu, F.F. MicroRNAs in nasopharyngeal carcinoma. Chin. Clin. Oncol. 2016. [Google Scholar] [CrossRef] [PubMed]
  57. Tinhofer, I.; Konschak, R.; Stromberger, C.; Raguse, J.D.; Dreyer, J.H.; Johrens, K.; Keilholz, U.; Budach, V. Detection of circulating tumor cells for prediction of recurrence after adjuvant chemoradiation in locally advanced squamous cell carcinoma of the head and neck. Ann. Oncol. 2014, 25, 2042–2047. [Google Scholar] [CrossRef] [PubMed]
  58. Huang, S.H.; Perez-Ordonez, B.; Weinreb, I.; Hope, A.; Massey, C.; Waldron, J.N.; Kim, J.; Bayley, A.J.; Cummings, B.; Cho, B.C.; et al. Natural course of distant metastases following radiotherapy or chemoradiotherapy in HPV-related oropharyngeal cancer. Oral Oncol. 2013, 49, 79–85. [Google Scholar] [CrossRef] [PubMed]
  59. Huang, S.H.; Waldron, J.N.; Milosevic, M.; Shen, X.; Ringash, J.; Su, J.; Tong, L.; Perez-Ordonez, B.; Weinreb, I.; Bayley, A.J.; et al. Prognostic value of pretreatment circulating neutrophils, monocytes, and lymphocytes in oropharyngeal cancer stratified by human papillomavirus status. Cancer 2015, 121, 545–555. [Google Scholar] [CrossRef] [PubMed]
  60. Wansom, D.; Light, E.; Worden, F.; Prince, M.; Urba, S.; Chepeha, D.B.; Cordell, K.; Eisbruch, A.; Taylor, J.; D'Silva, N.; et al. Correlation of cellular immunity with human papillomavirus 16 status and outcome in patients with advanced oropharyngeal cancer. Arch. Otolaryngol. Head Neck Surg. 2010, 136, 1267–1273. [Google Scholar] [CrossRef] [PubMed]
  61. Cao, H.; Banh, A.; Kwok, S.; Shi, X.; Wu, S.; Krakow, T.; Khong, B.; Bavan, B.; Bala, R.; Pinsky, B.A.; et al. Quantitation of human papillomavirus DNA in plasma of oropharyngeal carcinoma patients. Int. J. Radiat. Oncol. Biol. Phys. 2012, 82, e351–e358. [Google Scholar] [CrossRef] [PubMed]
  62. Kimple, R.J.; Smith, M.A.; Blitzer, G.C.; Torres, A.D.; Martin, J.A.; Yang, R.Z.; Peet, C.R.; Lorenz, L.D.; Nickel, K.P.; Klingelhutz, A.J.; et al. Enhanced radiation sensitivity in HPV-positive head and neck cancer. Cancer Res. 2013, 73, 4791–4800. [Google Scholar] [CrossRef] [PubMed]
  63. Dok, R.; Kalev, P.; van Limbergen, E.J.; Asbagh, L.A.; Vazquez, I.; Hauben, E.; Sablina, A.; Nuyts, S. p16INK4a impairs homologous recombination-mediated DNA repair in human papillomavirus-positive head and neck tumors. Cancer Res. 2014, 74, 1739–1751. [Google Scholar] [CrossRef] [PubMed]
  64. Overgaard, J.; Eriksen, J.G.; Nordsmark, M.; Alsner, J.; Horsman, M.R.; the Danish Head and Neck Cancer Study Group. Plasma osteopontin, hypoxia, and response to the hypoxia sensitiser nimorazole in radiotherapy of head and neck cancer: Results from the DAHANCA 5 randomised double-blind placebo-controlled trial. Lancet. Oncol. 2005, 6, 757–764. [Google Scholar] [CrossRef]
  65. Mortensen, L.S.; Johansen, J.; Kallehauge, J.; Primdahl, H.; Busk, M.; Lassen, P.; Alsner, J.; Sorensen, B.S.; Toustrup, K.; Jakobsen, S.; et al. FAZA PET/CT hypoxia imaging in patients with squamous cell carcinoma of the head and neck treated with radiotherapy: Results from the DAHANCA 24 trial. Radiother. Oncol. 2012, 105, 14–20. [Google Scholar] [CrossRef] [PubMed]
  66. Sorensen, B.S.; Busk, M.; Olthof, N.; Speel, E.J.; Horsman, M.R.; Alsner, J.; Overgaard, J. Radiosensitivity and effect of hypoxia in HPV positive head and neck cancer cells. Radiother. Oncol. 2013, 108, 500–505. [Google Scholar] [CrossRef] [PubMed]
  67. Marur, S.; D’Souza, G.; Westra, W.H.; Forastiere, A.A. HPV-associated head and neck cancer: A virus-related cancer epidemic. Lancet Oncol. 2010, 11, 781–789. [Google Scholar] [CrossRef]
  68. Heusinkveld, M.; Goedemans, R.; Briet, R.J.; Gelderblom, H.; Nortier, J.W.; Gorter, A.; Smit, V.T.; Langeveld, A.P.; Jansen, J.C.; van der Burg, S.H. Systemic and local human papillomavirus 16-specific T-cell immunity in patients with head and neck cancer. Int. J. Cancer 2012, 131, E74–E85. [Google Scholar] [CrossRef] [PubMed]
  69. Ward, M.J.; Thirdborough, S.M.; Mellows, T.; Riley, C.; Harris, S.; Suchak, K.; Webb, A.; Hampton, C.; Patel, N.N.; Randall, C.J.; et al. Tumour-infiltrating lymphocytes predict for outcome in HPV-positive oropharyngeal cancer. Br. J. Cancer 2014, 110, 489–500. [Google Scholar] [CrossRef] [PubMed]
  70. Hoffmann, T.K.; Arsov, C.; Schirlau, K.; Bas, M.; Friebe-Hoffmann, U.; Klussmann, J.P.; Scheckenbach, K.; Balz, V.; Bier, H.; Whiteside, T.L. T cells specific for HPV16 E7 epitopes in patients with squamous cell carcinoma of the oropharynx. Int. J. Cancer 2006, 118, 1984–1991. [Google Scholar] [CrossRef] [PubMed]
  71. Albers, A.; Abe, K.; Hunt, J.; Wang, J.; Lopez-Albaitero, A.; Schaefer, C.; Gooding, W.; Whiteside, T.L.; Ferrone, S.; DeLeo, A.; et al. Antitumor activity of human papillomavirus type 16 E7-specific T cells against virally infected squamous cell carcinoma of the head and neck. Cancer Res. 2005, 65, 11146–11155. [Google Scholar] [CrossRef] [PubMed]
  72. Deboni, A.L.; Giordani, A.J.; Lopes, N.N.; Dias, R.S.; Segreto, R.A.; Jensen, S.B.; Segreto, H.R. Long-term oral effects in patients treated with radiochemotherapy for head and neck cancer. Support. Care Cancer 2012, 20, 2903–2911. [Google Scholar] [CrossRef] [PubMed]
  73. Corry, J.; Peters, L.J.; Rischin, D. Optimising the therapeutic ratio in head and neck cancer. Lancet. Oncol. 2010, 11, 287–291. [Google Scholar] [CrossRef]
  74. Chera, B.S.; Amdur, R.J.; Tepper, J.; Qaqish, B.; Green, R.; Aumer, S.L.; Hayes, N.; Weiss, J.; Grilley-Olson, J.; Zanation, A.; et al. Phase 2 Trial of de-intensified chemoradiation therapy for favorable-risk human papillomavirus-associated oropharyngeal squamous cell carcinoma. Int. J. Radiat. Oncol. Biol. Phys. 2015, 93, 976–985. [Google Scholar] [CrossRef] [PubMed]
  75. Marur, S.; Li, S.; Cmelak, A.; Gillison, M.; Ferris, R.L.; Bauman, J.; Zhao, W.; W., W.; Chung, C.H.; Wagner, L.; et al. E 1308: A phase II trial of induction chemotherapy (IC) followed by cetuximab with low dose versus standard dose IMRT in patients with human papilloma virus (HPV)-associated resectable squamous cell carcinoma of the oropharynx (OPSCC). J. Clin. Oncol. 2013, 31. abstr 6005. [Google Scholar]
Figure 1. Structure of the HPV16 Genome (adapted from, [12]). Coding regions and spliced transcripts encoded by the HPV16 genome are depicted. The early (E) genes encode the non-structural proteins that are produced early in the infectious cycle, while the late (L) genes encode structural capsid proteins that are produced late during viral infection.
Figure 1. Structure of the HPV16 Genome (adapted from, [12]). Coding regions and spliced transcripts encoded by the HPV16 genome are depicted. The early (E) genes encode the non-structural proteins that are produced early in the infectious cycle, while the late (L) genes encode structural capsid proteins that are produced late during viral infection.
Cancers 08 00075 g001
Table 1. Methods for determination of HPV status and HPV subtype.
Table 1. Methods for determination of HPV status and HPV subtype.
HPV16 E1 PCRHPV16, the most common HPV subtype implicated in HNC, is quantified by qRT-PCR in DNA extracted from bulk tumour tissueHighly sensitiveFalse positives may occur; technically more difficult to perform than IHC/ISH; detects only HPV16[10]
p16 IHCp16 is upregulated indirectly via repression of pRb by E7; loss of p16 is common in HPV- HNCTechnically easy to perform and clinically feasible; comparatively low costIndirect method of HPV detection; does not distinguish between HPV subtypes[10]
HPV16 ISHHPV16, the most common HPV subtype implicated in HNC, is quantified and directly visualized in tumour cellsTechnically easier to perform and clinically feasible; comparatively low cost; allows direct visualization of HPV in tumour nucleiDetects only HPV16[10]
RNA-SeqSpecific HPV viral transcripts can be detected by sequencing RNA transcriptsAccurate method for detecting HPV positivity and HPV subtypeHigh cost; technically difficult, requiring specialized resources; limited clinical feasibility at present[14]
DNA SequencingHPV can be detected by DNA sequencing Accurate method for detecting HPV positivity and HPV subtypeHigh cost; technically difficult, requiring specialized resources; limited clinical feasibility at present[48]
Roche Linear ArrayDetection of HPV by PCR amplification of DNA using HPV subtype specific primersAccurate method for detecting HPV positivity and HPV subtype; most accurate method for resolving the presence of multiple HPV subtypes in one sampleRequires specialized resources; limited clinical feasibility at present[48]
Abbreviations: head and neck cancer (HNC), human papillomavirus (HPV), immunohistochemistry (IHC), in situ hybridization (ISH), polymerase chain reaction (PCR), quantitative real-time polymerase chain reaction (qRT-PCR).
Table 2. MicroRNAs implicated as biomarkers in HPV+ HNC.
Table 2. MicroRNAs implicated as biomarkers in HPV+ HNC.
MicroRNAsHNC SubtypeExpression in HNC ¥Role as BiomarkersRef
miR-20b, miR-9, miR-9*OPCmiR-9, miR-9* (up)Associated with HPV/p16-status[53]
miR-20b (down)
miR-107, miR-151, miR-492OPCmiR-107, miR-151(up) Correlated with overall survival[53]
miR-492 (down)
miR-20b, miR-107, miR-151, miR-182, miR-361OPCmiR-107, miR-151, miR-182, miR-361 (up)Correlated with disease free survival[53]
miR-20b (down)
miR-151, miR-152, miR-324-5p, miR-361, miR-492OPCmiR-151, miR-324-5p, miR-361 (up) Correlated with distant metastases[53]
miR-152, miR-492 (down)
let-7d, miR-205HNSCCdownAssociated with disease free and overall survival[54]
miR-210HNC overalldownAssociated with hypoxia; correlate with reduced overall and disease free survival[55]
Abbreviations: head and neck cancer (HNC), head and neck squamous cell carcinoma (HNSCC), human papillomavirus (HPV), microRNA (miR), oropharyngeal carcinoma (OPC). ¥ Expression normalized relative to normal adjacent tissue [53], contralateral healthy mucosa [54], or histologically normal tonsil tissue from tonsillectomy patients [55].
Back to TopTop