Global prevalence of human papillomavirus-related oral and oropharyngeal squamous cell carcinomas: a systematic review and meta-analysis

OBJECTIVE

To conduct a systematic review to determine the global prevalence of HPV in oral squamous cell carcinoma (OSCC) and oropharyngeal squamous cell carcinoma (OPSCC).

MATERIALS AND METHODS

Literature was searched through October 2022 in main databases to address the question "What is the global prevalence of Human Papillomavirus in oral and oropharyngeal cancer?" Studies had to identify HPV by PCR, ISH, or p16 immunohistochemistry to be eligible. Quality was assessed using the JBI checklist for prevalence studies. Meta-analyses were performed, and reporting followed PRISMA guidelines.

RESULTS

Sixty-five studies were included, and most of them had methodological limitations related to sampling and the HPV detection tool. The pooled prevalence of HPV-positivity was 10% (event rate = 0.1; 95% CI: 0.07, 0.13; P < 0.01; I2 = 88%) in the oral cavity and 42% (event rate = 0.42; 95% CI: 0.36, 0.49; P = 0.02; I2 = 97%) in oropharynx. The highest HPV prevalence in OSCC was reached by Japan, meanwhile, in OPSCC, Finland and Sweden were the most prevalent. HPV16 is the genotype most frequent with 69% in OSCC and 89% in OPSCC, being the tonsils the intraoral location more affected by HPV (63%, p < 0.01, I2 76%).

CONCLUSION

The evidence points to an apparent burden in HPV-related OPSCC, mostly in North America, Northern Europe, and Oceania, especially due to the HPV16 infection suggesting different trends across continents.

CLINICAL RELEVANCE

This updated systematic review and meta-analysis provide sufficient evidence about the global HPV prevalence in OSCC and OPSCC and the most frequent HPV subtype worldwide.

Dysregulated microRNA Expression Relevant to TERT Promoter Mutations in Tonsil Cancer-A Pilot Study

Tonsillar squamous cell carcinomas (TSCCs) exhibit high rates of human papillomavirus (HPV) positivity. The expression profiles of microRNA (miRNA), which are small RNA molecules that play pivotal roles in biological processes, in TSCC in relation to the HPV status and cancer-related genetic mutations are not well investigated. Herein, we expanded our previous research, which was focused on established clinicopathological and genetic mutational data, to profile miRNA expression in TSCC, aiming to identify clinically relevant targets for early diagnosis and therapeutic intervention. The miRNA profiles were analyzed using the nCounter Nanostring miRNA Expression assay in 22 surgically resected TSCC tissues and their contralateral normal tonsil tissues. The TERT promoter (TERTp) gene was the only relevant candidate gene associated with differentially expressed miRNAs in TSCC. Hierarchical clustering analysis revealed high expression levels of hsa-miR-1285-5p, hsa-miR-1203, hsa-miR-663a, hsa-miR-1303, hsa-miR-33a-5p, and hsa-miR-3615 coupled with low expression levels of hsa-miR-3182, hsa-miR-219a-2-3p, and hsa-miR-767-3p, which were associated with HPV-positive TSCC (p = 0.009). Functional enrichment analysis revealed that these dysregulated miRNAs tended to be involved in protein binding (molecular function) and cellular components (biological processes). Therefore, hsa-miR-1285-5p and hsa-miR-663a may be associated with HPV-positive TERTp-mutated tumors and may serve as potential treatment targets and biomarkers for early detection.

Assessment of the Mutation Profile of Tonsillar Squamous Cell Carcinomas Using Targeted Next-Generation Sequencing

Data regarding driver mutation profiles in tonsillar squamous cell carcinomas (TSCCs) remain scarce, limiting the understanding of its pathogenesis and unexpected behavior in the updated staging system. We investigated the incidence of clinically relevant mutations and their contribution in the prognosis of the condition, and their association with human papillomavirus (HPV) infection and adjuvant therapy. We subjected 43 surgically resected TSCC samples to targeted next-generation sequencing, determined their HPV status using polymerase chain reaction, and performed The Cancer Genomic Atlas and Gene Set Enrichment analyses. Thirty-five TSCC samples (81.4%) showed at least one oncogenic/likely oncogenic mutation among twenty-nine cancer-related genes. The top five mutated genes were TP53 (46.5%), PIK3CA (25.6%), PTEN (18.6%), EGFR (16.3%), and SMAD4 (14.0%). The EGFR pathway was the most frequently affected (51.2%), followed by the p53 (48.8%), PI3K (39.5%), and RTK (34.9%) pathways. The gene set enrichment analysis confirmed that the genes involved in signal transduction, such as growth factor receptors and second messengers, EGFR tyrosine kinase inhibitors, and PI3K signaling pathways, were mostly related with TSCCs. TP53 mutation was an independent prognostic factor predicting worse overall survival in the adjuvant therapy group. RTK mutations were related to survival in all patients and in the HPV-positive group, but multivariate analyses showed no significance. In conclusion, oncogenic/likely oncogenic mutations were relatively high in TSCCs, and TP53 and RTK mutations may be candidate predictors for poor prognosis in the adjuvant therapy and HPV-positive groups, respectively, under the updated staging system.

It Takes Two to Tango: A Review of Oncogenic Virus and Host Microbiome Associated Inflammation in Head and Neck Cancer

Simple Summary

Certain viruses, specifically, human papillomavirus (HPV) and Epstein–Barr virus (EBV), have been linked with the development of head and neck cancer. In this study, we review the mechanisms by which (these) viruses lead to cellular transformation and a chronic inflammatory state. Given that the head and neck host a rich microbiome (which itself is intrinsically linked to inflammation), we scrutinize the literature to highlight the interplay between viruses, cellular transformation, inflammation, and the local host microbiome in head and neck cancer.

Abstract

While the two primary risk factors for head and neck squamous cell carcinoma (HNSCC) are alcohol and tobacco, viruses account for an important and significant upward trend in HNSCC incidence. Human papillomavirus (HPV) is the causative agent for a subset of oropharyngeal squamous cell carcinoma (OPSCC)—a cancer that is impacting a rapidly growing group of typically middle-aged non-smoking white males. While HPV is a ubiquitously present (with about 1% of the population having high-risk oral HPV infection at any one time), less than 1% of those infected with high-risk strains develop OPSCC—suggesting that additional cofactors or coinfections may be required. Epstein–Barr virus (EBV) is a similarly ubiquitous virus that is strongly linked to nasopharyngeal carcinoma (NPC). Both of these viruses cause cellular transformation and chronic inflammation. While dysbiosis of the human microbiome has been associated with similar chronic inflammation and the pathogenesis of mucosal diseases (including OPSCC and NPC), a significant knowledge gap remains in understanding the role of bacterial-viral interactions in the initiation, development, and progression of head and neck cancers. In this review, we utilize the known associations of HPV with OPSCC and EBV with NPC to investigate these interactions. We thoroughly review the literature and highlight how perturbations of the pharyngeal microbiome may impact host-microbiome-tumor-viral interactions—leading to tumor growth.

Negative Prognostic Implication of TERT Promoter Mutations in Human Papillomavirus-Negative Tonsillar Squamous Cell Carcinoma Under the New 8th AJCC Staging System

Telomerase reverse transcriptase gene promoter (TERTp) mutation is a potential candidate for pathogenesis and therapeutic target of tonsillar squamous cell carcinomas (TSCCs) in association with human papillomavirus (HPV). Their clinical relevance has not been validated under the new 8th American Joint Committee on Cancer (AJCC) staging system. We analyzed real-time peptide nucleic acid–mediated PCR and sequencing methods (TERTp mutation) and real-time PCR-based assay (HPV) in 80 surgically resected TSCCs. The 8th edition staging system improved the stratification of the early and advanced stages and between T or N categories for overall survival over the 7th edition. TERTp mutation was found in 7.5%, and HPV in 80.0% of the patients. The majority (83.3%) of TERTp mutation cases were HPV-positive TSCCs. Applying the 8th edition staging system, TERTp mutation was an independent factor of poor prognosis for disease-free survival (DFS) in TSCC patients, supporting the clinical significance of TERTp mutation in tonsil cancer. TERTp mutations were also negatively correlated with overall survival and DFS in HPV-negative TSCCs. Conclusively, TERTp mutation provides negative prognostic impact on survival of surgically managed tonsil cancers staged with the AJCC 8th edition.

Relationship Between p16 Expression and Prognosis in Patients with Oropharyngeal Cancer Undergoing Surgery

BACKGROUND/AIM

Prognostic impact of p16 expression in patients with oropharyngeal squamous cell carcinoma (OSCC) undergoing surgery is not fully examined. The aim of this study was to clarify these issues.

PATIENTS AND METHODS

Sixty-four OSCC subjects were analyzed. Immuno-histochemical staining of p16, a surrogate marker for human papillomavirus (HPV), was performed histopathologically. Data were retrospectively analyzed according to p16 positivity and factors linked to prognosis were also analyzed.

RESULTS

No significant difference was observed in the prognosis between the p16-positive group (n=28) and the p16-negative group (n=36). In patients undergoing post-operative radiation, the p16-positive group (n=18) had a significantly better prognosis than the p16-negative group (n=6). On multivariate analysis, transoral surgery was a significant predictor of overall survival (p=0.0173).

CONCLUSION

Prognostic impact of p16 can be emphasized in a subgroup of OSCC patients undergoing surgery. Surgery with sufficient surgical margin may be chosen as the first treatment for HPV-negative OSCC in some cases.

Survival outcome of tonsillar squamous cell carcinoma (TSCC) in the context of human papillomavirus (HPV): A systematic review and meta-analysis

OBJECTIVE

The objective of our study was to assess whether HPV-positive TSCC had better survival and prognosis rates, when compared to HPV-negative TSCC.

METHOD

A systematic review and meta-analysis was performed comparing HPV status in TSCC patients. TSCC was confirmed with histopathology and HPV status was confirmed with PCR, immunohistochemistry and/or in-situ-hybridisation. The primary endpoints were overall survival (OS) and disease free survival (DFS).

RESULTS

Twenty-four studies were identified, involving 1921 TSCC cases, of which 56.2% (1079) were HPV positive. OS was significantly higher in patients with HPV-positive compared to HPV-negative TSCC in years 1-5 (OR 2.54, P < 0.01; OR 2.93 P < 0.01; OR 2.74 P < 0.01; OR 2.20 P < 0.01, and OR 2.14 P < 0.01 respectively). Similarly, DFS was also significantly higher in patients with HPV-positive compared to HPV-negative TSCC in years 1-3 (OR 2.86, P < 0.01; OR 2.60 P < 0.02; and OR 2.60 P < 0.01 respectively), which was attenuated in years 4 and 5 (OR 1.83, P = 0.10 and OR 1.50, P = 0.12).

CONCLUSION

This is the largest meta-analysis with 1921 patients, comparing non-HPV induced TSCC and HPV induced TSCC, looking at outcome and survival. HPV-positive had better OS and DFS.

HPV-Positive Oropharyngeal Carcinoma

Objective

Human papillomavirus-positive (HPV+) head and neck squamous cell carcinoma is increasing in incidence and appears to exhibit improved response to treatment and better survival than that of HPV– head and neck squamous cell carcinoma. The purpose of this systematic review was to examine the current literature regarding treatment and prognosis of HPV+ oropharyngeal squamous cell carcinoma (OPSCC) and identify whether type of treatment (primarily surgery vs primarily radiation) significantly affects survival rates.

Data Sources

PubMed and Cochrane Library databases.

Review Methods

A computerized search of the PubMed and Cochrane Library databases was performed to identify English-language articles published between January 1, 2000, and October 21, 2014. Studies were included only if they were prospective or retrospective observational series of OPSCC patients that reported HPV status, treatment regimen, and survival outcomes. Outcomes were determined for HPV+ and HPV– OPSCC patients, with subanalyses according to the type of treatment received.

Results

Fifty-six articles were eligible for this review. In the HPV+ analysis, the unadjusted hazard rate ratio (HR) for surgery vs radiation treatment was 1.33 ( P = .114). Nine confounders were considered, and HRs were adjusted for each covariate. While HRs were almost all >1 for all covariates, none of the HRs was statistically significant at P < .05. The HR for HPV– OPSCC was higher for radiation than surgery.

Conclusions

HPV+ OPSCC has an improved prognosis and lower rates of adverse events when compared with HPV– OPSCC. HPV– OPSCC had significantly worse outcomes when treated with primary radiation as compared with primary surgery. There was no statistically significant difference in HRs for HPV+ OPSCC with primary radiation vs primary surgery treatment.

Prevalence of tonsillar human papillomavirus infections in Denmark

The incidence of tonsillar carcinomas associated with Human Papillomavirus (HPV) infection has increased dramatically over the last three decades. In fact, currently in Scandinavia, HPV-associated cases account for over 80 % of tonsillar carcinoma cases. Yet, the epidemiology and natural history of tonsillar HPV infections remains poorly characterized. Our aim was to characterize such infections in the Danish population in tumor-free tonsillar tissue. Unlike previous studies, we considered both palatine tonsils. We examined both tonsils from 80 patients with peritonsillar abscess (n = 25) or chronic tonsillar disease (n = 55). HPV was detected by nested PCR with PGMY 09/11 and GP5+/GP6+L1 consensus primers, and typed by sequencing. Samples were also analyzed using a higher-throughput method, the CLART HPV 2 Clinical Array Assay. The overall prevalence of HPV tonsillar infection was 1.25 % (1/80, 95 % CI 0.03-6.77 %) by nested PCR, and 0 % by CLART HPV2 Clinical Array. The HPV-positive patient was a 16-year-old female with recurrent tonsillitis and tonsillar hypertrophy. The type detected was HPV6. HPV was not detected in the contralateral tonsil of this patient. Compared to cervical HPV infections in Denmark, tonsillar HPV infections are 10- to 15-fold less frequent. In the HPV-positive patient in this study, HPV was detected in only one of the tonsils. This raises the possibility that prior studies may underestimate the prevalence of HPV infections, as they do not consider both palatine tonsils.

Chromogenic in situ hybridization and p16/Ki67 dual staining on formalin-fixed paraffin-embedded cervical specimens: correlation with HPV-DNA test, E6/E7 mRNA test, and potential clinical applications

Although HPV-DNA test and E6/E7 mRNA analyses remain the current standard for the confirmation of human papillomavirus (HPV) infections in cytological specimens, no universally adopted techniques exist for the detection of HPV in formalin-fixed paraffin-embedded samples. Particularly, in routine laboratories, molecular assays are still time-consuming and would require a high level of expertise. In this study, we investigated the possible use of a novel HPV tyramide-based chromogenic in situ hybridization (CISH) technology to locate HPV on tissue specimens. Then, we evaluate the potential usefulness of p16^INK4a/Ki-67 double stain on histological samples, to identify cervical cells expressing HPV E6/E7 oncogenes. In our series, CISH showed a clear signal in 95.2% of the specimens and reached a sensitivity of 86.5%. CISH positivity always matched with HPV-DNA positivity, while 100% of cases with punctated signal joined with cervical intraepithelial neoplasia grade 2 or worse (CIN2+). p16/Ki67 immunohistochemistry gave an interpretable result in 100% of the cases. The use of dual stain significantly increased the agreement between pathologists, which reached 100%. Concordance between dual stain and E6/E7 mRNA test was 89%. In our series, both CISH and p16^INK4a/Ki67 dual stain demonstrated high grade of performances. In particular, CISH would help to distinguish episomal from integrated HPV, in order to allow conclusions regarding the prognosis of the lesion, while p16^INK4a/Ki67 dual stain approach would confer a high level of standardization to the diagnostic procedure.

Improved survival of Japanese patients with human papillomavirus-positive oropharyngeal squamous cell carcinoma

BACKGROUND

The prevalence of oropharyngeal carcinoma is rising in western Europe and the United States, where there appears to be a strong association between human papillomavirus (HPV) and oropharyngeal squamous cell carcinoma (OPSCC). However, such a correlation has not yet been fully evaluated in Japan.

METHODS

We performed a retrospective analysis of the association between tumour HPV status and the demographic and clinicopathological parameters of 71 patients with OPSCC at Hokkaido University Hospital, Japan, between 1998 and 2009. The parameters included age, gender, survival, tumour subsite, tumour-node-metastasis (TNM) stage, smoking history, second primary tumour status, recurrence/residual disease at the primary site, and overall survival. HPV status was established by multiplex polymerase chain reaction (PCR) analysis.

RESULTS

Of the 71 oropharyngeal cancers, 20 were positive for HPV-16, two for HPV-18, and one for HPV-58. Kaplan-Meier survival analysis showed improved overall survival rates in patients with HPV-positive tumours (p = 0.0038) compared with HPV-negative tumours. Of the 45 patients who received chemoradiotherapy, HPV-positive patients experienced better overall survival than HPV-negative patients (p = 0.0032). In a multivariate analysis, the survival benefit of HPV-positive patients was independent of age and T and N classification.

CONCLUSIONS

HPV status is a significantly favourable prognostic factor in oropharyngeal cancer and could be used as a marker to optimize the treatment of patients with this type of cancer in Japan.

A 20-year retrospective study of tonsil cancer incidence and survival trends in South East England: 1987-2006

BACKGROUND

There has been an increasing incidence of tonsil cancer worldwide. Documenting these changes is crucial to cancer prevention and control measures, resource allocation and understanding disease aetiology.

OBJECTIVE

To analyse the changing epidemiology of tonsil cancer in South East England over a 20-year period between 1987 and 2006.

DESIGN

A retrospective, quantitative study using secondary anonymised data obtained from the Thames Cancer Registry, London. Data were analysed using spss v.17 and survival analyses with Kaplan-Meier and Cox regression.

SETTING

This study was conducted in South East of England comprising London, Kent, Surrey and Sussex counties with an average population of 12 million. This population increased from 10.7 to 11.8 million (a 10% increase) between 1987 and 2006.

PARTICIPANTS

All patients with tonsil cancer in South East England registered with the Thames Cancer Registry (ICD-10 code C09) between 1987 and 2006. A total of 1794 patients' data were analysed. Ethical Considerations: Ethical approval was granted by the Kent Research Ethics Committee.

MAIN OUTCOME MEASURES

Data were analysed for demographic trends including gender, age at diagnosis, yearly incidence and survival.

RESULTS

Tonsil cancer incidence has increased significantly from 0.60 to 1.45 per 100,000 in the 20 years (P < 0.001). This increase is mainly amongst men and age groups 40-59 years with a significant reduction in age at diagnosis by 2 years from 61.6 years in the first decade to 59.6 years in the second decade (P < 0.001). Survival was worse in men, older age groups and in the presence of synchronous tumours (P < 0.001). There has been a statistically significant increase in median survival times from tonsil cancer by about 3 years from 2.7 years in the first decade to 5.7 years in the second decade of this study (P < 0.001).

CONCLUSIONS

Tonsil cancer incidence has increased in the 20 years of this study in South East England, especially amongst men and age groups 40-59 years. There has also been significant reduction in the mean age at diagnosis and an increase in median survival times for tonsil cancer. Further studies are needed to explain these trends.

Discrimination of 'driver' and 'passenger' HPV in tonsillar carcinomas by the polymerase chain reaction, chromogenic in situ hybridization, and p16(INK4a) immunohistochemistry

Human papillomavirus (HPV) positive tonsillar squamous cell carcinoma (TSCC) is associated with a favorable clinical outcome. However, the HPV detected in a given tumor may be causal (driver HPV) or an incidental bystander (passenger HPV). There is a need to discriminate these forms of HPV in TSCCs to understand their impact on HPV as a biomarker for use in TSCC patient management. This study has compared the polymerase chain reaction (PCR), chromogenic in situ hybridization (CISH), and p16(INK4a) immunohistochemistry in the assessment of HPV status in TSCC. Archival specimens of TSCC from thirty patients were investigated. HPV was detected by PCR in 25/30 (83.3%) tumors; HPV16 (70.0%) and HPV52 (6.7%) were the most common types. HPV was corroborated by CISH in 22/25 (88.0%) specimens; integrated HPV was implicated by the presence of punctate signals in each of these cases. p16(INK4a) staining was found in 20/22 (90.9%) HPV PCR positive samples; two PCR/CISH HPV positive cases were p16(INK4a) negative and two HPV negative samples were p16(INK4a) positive. These data suggest that a minority of HPV positive TSCCs are positive for passenger HPV and that two or more assays may be required for diagnosing driver HPV status. Further studies are required to exam whether oropharyngeal tumors positive for passenger HPV have a less favorable prognosis than tumors that are driver HPV positive. The clinical significance of TSCCs that test HPV negative/p16(INK4a) positive, PCR and CISH HPV positive/p16 (INK4a) negative, or PCR HPV positive/p16 (INK4a) and CISH negative, also requires further investigation.

John M. Tonsillar Squamous Cell Carcinoma

Objective. To analyze outcomes in patients with squamous cell carcinoma (SCCA) of the tonsil from the years 1998 to 2006. To assess factors that may affect disease-specific survival, such as patient characteristics and/or treatment modality.

Study Design and Setting. National Cancer Institute’s Surveillance Epidemiology and End Results (SEER) program.

Subjects and Methods. The SEER database was used to perform a population-based cohort analysis for patients diagnosed with SCCA of the tonsil from 1998 to 2006. Disease-specific survival was correlated with sex, age, ethnicity, year of diagnosis, and treatment modality in a univariate Cox proportional hazards analysis and a multiple Cox-regression model with and without interaction effect.

Results. Applied inclusion criteria resulted in 8378 patients. Of this patient cohort, 80% were male and 85% were white. The mean patient age at diagnosis was 58.1 years. On univariate and multivariate analyses, ethnicities other than white carried a significantly higher rate of disease-specific death (hazard ratio = 1.71, P < .001). Each additional year of age at the time of diagnosis carried approximately a 4% increase in likelihood of disease-specific death. With each passing year of time at diagnosis, patients carried a decreased risk of disease-specific death ( P < .001); this value was significant in all 3 statistical models. Patients who underwent external-beam radiation had a higher likelihood of disease-specific survival with each passing year at time of diagnosis.

Conclusion. Population analysis based on the SEER database reveals increased disease-specific survival from tonsillar SCCA in more recent years. This may be because of earlier diagnosis, an increase in less aggressive subtypes of SCCA, and more effective treatment modalities.

The role of high-risk human papillomavirus infection in oral and oropharyngeal squamous cell carcinoma in non-smoking and non-drinking patients: a clinicopathological and molecular study of 46 cases

The aim of the study was to investigate the role of high-risk human papillomavirus (HR-HPV) infection in the etiopathogenesis of oral (OSCC) and oropharyngeal (OPSCC) squamous cell carcinoma in non-smoking and non-drinking patients (NSNDP). Twenty-four OSCCs and 22 OPSCCs were analyzed by immunohistochemistry for p16(INK4a) protein (p16) expression and by chromogene in situ hybridization (CISH) and polymerase chain reaction (PCR) for HR-HPV DNA presence. The series included 23 males and 23 females aged 35-93 years. p16 expression was seen in 7 out of 24 (29%) OSCCs and in 22 out of 22 (100%) OPSCCs. Using CISH, HR-HPV DNA was observed in 6 out of 24 (25%) OSCCs and in 21 out of 22 (95%) OPSCCs. HPV DNA was found in 3 out of 24 (13%) OSCCs and in 18 out of 22 (82%) OPSCCs using PCR. HPV 16 and 33 were detected in 16 and in two cases, respectively. Compared with OSCCs, OPSCCs more frequently showed basaloid morphology (p < 0.0001), lymph node involvement (p = 0.0063), diffuse p16 expression (p < 0.0001), HR-HPV DNA presence using both CISH and PCR (p < 0.0001; p < 0.0001), and better outcome. The sensitivity and specificity of p16 expression for HR-HPV DNA presence detected by CISH were 0.89 and 0.95, respectively, and 0.95 and 0.85 for PCR detected HPV DNA. The sensitivity and specificity of CISH for PCR detected presence of HPV DNA were 1.00 and 0.73, respectively. Our study is the first larger study analyzing OSCC and OPSCC in NSNDP. Our results indicate that unlike OSCC, a vast majority of OPSCCs may be associated with HR-HPV infection.

The increasing clinical relevance of human papillomavirus type 16 (HPV-16) infection in oropharyngeal cancer

Human papillomavirus type 16 (HPV-16) has been established beyond doubt as a causative agent in oropharyngeal squamous cell carcinoma (SCC). The incidence of oropharyngeal cancer has risen in recent decades, as has the proportion of patients who have a biologically relevant HPV-16 infection. Combined data from 14 recently published studies (2006-2010) show that 57% of 1316 reported cases of oropharyngeal SCC were HPV-16 positive. They had significantly better prognosis (hazard ratio (HR) for 5-year overall survival range 0.05-0.64), although smoking and higher T stage often appear as confounding factors to this favourable prognostic benefit. HPV-16 therefore has increasing importance as a clinically useful prognostic biomarker, but a benefit in survival has been seen in the use of surgery, radiotherapy, and chemotherapy, so specific changes in the preferred methods of treatment are hard to justify. Future trials that include oropharyngeal SCC will consider HPV-16 routinely as a stratification factor, and its use as a predictive biomarker awaits the development of effective targeted treatments. The undeniable and impressive prognostic significance of HPV-16 should hasten its addition to standard pathological reporting of oropharyngeal SCC, and ultimately to its inclusion in TNM staging systems of the American Joint Committee on Cancer (AJCC) and the International Union against Cancer (UICC).

The role of human papillomavirus in head and neck cancer

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