The Role of the p16 and p53 Tumor Suppressor Proteins and Viral HPV16 E6 and E7 Oncoproteins in the Assessment of Survival in Patients with Head and Neck Cancers Associated with Human Papillomavirus Infections

The role of HPV in the survival prognosis of patients with head and neck squamous cell carcinoma, especially patients with laryngeal squamous cell carcinoma (LSCC) and hypopharyngeal squamous cell carcinoma (HPSCC), is still somewhat ambiguous. The present study aimed to explore the significance of tumor suppressor proteins and HPV16 E6 and E7 oncoproteins in the assessment of survival in patients with oropharyngeal squamous cell carcinoma (OPSCC), LSCC, and HPSCC associated with high-risk (HR-) and low-risk (LR-) HPV infections. By utilizing molecular and immunohistochemical investigations of HNSCC samples and patient data, univariate and multivariate survival analyses were conducted. The presence of HPV DNA (LR- and HR-HPV) was associated with a better 5-year OS and DSS for OPSCC and LSCC. The IHC overexpression of HPV16 E6 protein and p16 protein was associated with better survival in the univariate (for OPSCC) and multivariate (OPSCC and HPSCC) survival analyses. The overexpression of p53 was associated with better survival in OPSCC. HPV infection plays a significant role in the tumorigenesis of HNSCC, and the immunohistochemical assessment of HPV16 E6 protein expression should be interpreted as a useful prognostic marker for OPSCC and HPSCC.

Treatment de-escalation for HPV+ oropharyngeal cancer: A systematic review and meta-analysis

Human Papillomavirus (HPV) related oropharyngeal carcinoma (OPC) carries a better prognosis compared with HPV-counterparts, thereby pushing the adoption of de-intensification treatment approaches as new strategies to preserve superior oncologic outcomes while minimizing toxicity. We evaluated the effect of treatment de-intensification in terms of overall survival (OS), progression-free survival (PFS), locoregional and distant control (LRC and DM) by selecting prospective or retrospective studies, providing outcome data with reduced intensification versus standard curative treatment in HPV+ OPC patients, with a systematic analysis till September 2020. The primary outcome of interest was OS. Secondary endpoints were PFS, LRC, and DM expressed as HR. A total of 55 studies (from 1393 screened references) were employed for quantitative synthesis for 38 929 patients. Among n = 48 studies with data available, de-intensified treatments reduced OS in HPV+ OPCs (HR = 1.33, 95% CI 1.17-1.52; p < 0.01). In de-escalated treatments, PFS was also decreased (HR = 2.11, 95% CI 1.65-2.69; p < 0.01). Compared with standard treatments, reduced intensity approaches were associated with reduced locoregional and distant disease control (HR = 2.51, 95% CI 1.75-3.59; p < 0.01; and HR = 1.9, 95% CI 1.25-2.9; p < 0.01). Chemoradiation improved survival in a definitive curative setting compared with radiotherapy alone (HR = 1.42, 95% CI 1.16-1.75; p < 0.01). When adjuvant treatments were compared, standard and de-escalation strategies provided similar OS. In conclusion, in patients with HPV+ OPC, de-escalation treatments should not be widely and agnostically adopted in clinical practice, as therein lies a concrete risk of offering a sub-optimal treatment to patients.

Is p16-positive oropharyngeal squamous cell carcinoma associated with favorable prognosis? A systematic review and meta-analysis

The purpose of this systematic review and meta-analysis was to compare the prognosis of patients with p16 expressing oropharyngeal squamous cell cancers to patients with p16 non-expressing cancers. Clinical outcomes that were evaluated included overall survival, local recurrence, disease-free survival, disease-specific survival, and event-free survival. The following electronic databases were searched: Cochrane Library, MEDLINE (via Pubmed), and Web of Science. Publications were restricted to English language. Studies were limited to controlled clinical trials on the survival rates of patients with oropharyngeal tumors that were p16 expressing, compared to patients with p16 non-expressing tumors, and at least one clinical endpoint reported by trial authors (hazard ratios). Specific ascertainment criteria were applied for inclusion and exclusion of eligible studies. Data was independently extracted in duplicate. This systematic review adhered to the Preferred Reporting Items for Systematic Reviews and Meta-analysis PRISMA checklist. Risk of bias was assessed for all included studies, and disagreements between review authors were discussed until an agreement was reached. Eighteen studies were included for final review and meta-analysis. The subgroup meta-analyses, which included survival and recurrence data, showed significantly favorable outcomes for patients with p16 expressing tumors. There is strong evidence to support that patients with p16 expressing oropharyngeal squamous cell cancers have favorable clinical outcomes and prognosis.

Human Papilloma Virus as a Biomarker for Personalized Head and Neck Cancer Radiotherapy

A dramatic increase in the incidence of HPV-related oropharyngeal cancer has been reported in some parts of the western world over the past 30 years. They constitute a clinically distinct subgroup of cancers in terms of molecular biology, patient characteristics, and treatment outcome. This chapter describes the molecular characteristics, epidemiology, and demographics of the HPV-related head and neck cancers and discuss available methods to detect HPV-related tumours. The impact of HPV-related biomarkers in clinical studies on radiotherapy only, altered fractionation, modulation of hypoxia, and concurrent chemo- or bio-radiotherapy are reviewed as well as the perspectives of de-escalation and immune-modulation are discussed.

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.

A model for predicting clinical outcome in patients with human papillomavirus-positive tonsillar and base of tongue cancer

AIM

To combine clinical and molecular markers into an algorithm for predicting outcome for individual patients with human papillomavirus (HPV) DNA/p16(INK4a) positive tonsillar and base of tongue squamous cell carcinoma (TSCC and BOTSCC).

BACKGROUND

Head-neck cancer treatment has become more intensified, comprising not only surgery and radiotherapy, but also induction/concomitant chemotherapy and targeted therapy. With less treatment, 3-year disease free survival (DFS) is 80% for HPV-positive TSCC and BOTSCC. An 85-100% 3-year DFS is observed for HPV(+) TSCC and BOTSCC with absence of HLA class I, or CD44 expression, or high CD8(+) tumour-infiltrating lymphocyte (TIL) counts suggesting that therapy could be tapered for many if patients could be identified individually.

PATIENTS AND METHODS

Patients treated curatively, with HPV DNA/p16(INK4a) positive tumours examined for HLA class I and II, CD44 and CD8(+)TILs, were included. An L1-regularised logistic regression was used to evaluate the effect of the biomarker data, age, stage, diagnosis, smoking and treatment on 3-year risk of death or relapse on a training cohort of 197 patients diagnosed 2000-2007 and validated on a cohort of 118 patients diagnosed 2008-2011.

RESULTS

The variables finally included in the model were HLA class I, CD8(+) TILs, age, stage and diagnosis (TSCC or BOTSCC). The model showed acceptable discrimination and calibration. The discriminative ability of the model did not diminish after validation (AUC=0.77).

CONCLUSION

To our knowledge, this is the first model to utilise information from several markers to predict an individual probability of clinical outcome for patients with HPV DNA/p16(INK4a) positive tumours.

Reduced Expression of the Antigen Processing Machinery Components TAP2, LMP2, and LMP7 in Tonsillar and Base of Tongue Cancer and Implications for Clinical Outcome

OBJECTIVES: Patients with human papillomavirus (HPV)–positive tonsillar squamous cell carcinoma (TSCC) and base of tongue squamous cell carcinoma (BOTSCC) have a better clinical outcome than those with corresponding HPV-negative tumors. Moreover, there is a strong positive correlation between absent/low as opposed to strong HLA class I expression and favorable clinical outcome for HPV-positive tumors, while the reverse applies to HPV-negative tumors. The expression of the antigen processing machinery (APM) components TAP1, TAP2, LMP2, and LMP7 in these tumors in relation to HPV status, HLA class I expression, each other, and clinical outcome was therefore investigated. MATERIAL AND METHODS: Formalin-fixed paraffin-embedded TSCC and BOTSCC, derived from 151 patients and previously analyzed for HPV DNA, HLA class I, and LMP10 expression were stained by immunohistochemistry for TAP1, TAP2, LMP2, and LMP7. RESULTS: Absent/low TAP2, LMP2, and LMP7 expression, similar to HLA class I and LMP10, was common in TSCC and BOTSCC, irrespective of HPV status. Expression of TAP1 and TAP2 was correlated, as was LMP2 to LMP7. LMP2 and LMP7 expression was also associated to HLA class I expression. Moreover, absence of LMP7 was linked to increased disease-free survival in both HPV-positive and HPV-negative cases. CONCLUSION: Reduced expression of TAP2, LMP2, and LMP7 was frequent in TSCC and BOTSCC and their expression as well as that of TAP1 was often interrelated. Furthermore, low LMP7 expression correlated to better clinical outcome and may, together with HPV status, potentially be used for prediction of treatment response.

Prevalence and risk factors for oral HPV infection in young Australians

The prevalence of human papillomavirus (HPV)–associated head and neck cancers is increasing, but the prevalence of oral HPV infection in the wider community remains unknown. We sought to determine the prevalence of, and identify risk factors for, oral HPV infection in a sample of young, healthy Australians. For this study, we recruited 307 Australian university students (18–35 years). Participants reported anonymously about basic characteristics, sexual behaviour, and alcohol, tobacco and illicit drugs use. We collected oral rinse samples from all participants for HPV testing and typing. Seven of 307 (2.3%) students tested positive for oral HPV infection (3 HPV-18, one each of HPV-16, -67, -69, -90), and six of them were males (p = 0.008). Compared to HPV negative students, those with oral HPV infection were more likely to have received oral sex from more partners in their lifetime (p = 0.0004) and in the last year (p = 0.008). We found no statistically significant associations with alcohol consumption, smoking or numbers of partners for passionate kissing or sexual intercourse. In conclusion, oral HPV infection was associated with male gender and receiving oral sex in our sample of young Australians.

Human papillomavirus prevalence is high in oral samples of patients with tonsillar and base of tongue cancer

MATERIAL AND METHODS

Presence of HPV DNA was analyzed in mouthwash and tonsillar swab samples, if indicative of HPV-positive tonsillar or base of tongue cancer in 76 patients, with suspected head neck cancer, undergoing diagnostic endoscopy at Karolinska University Hospital. The diagnosis and tumor HPV status was later obtained from patients' records. As controls, 37 tumor-free dental visitors were included.

RESULTS

Of the 76 patients, 22/29 (76%) and 16/18 (89%) had an HPV-positive tonsillar and base of tongue cancer respectively, with 18/22 (82%) and 8/16 (50%) respectively having tumor concordant HPV-type positive oral samples. Two other HPV-positive oral samples in the base of tongue cancer group did not correlate to the tumor HPV status. Among the remaining patients, 19 with other head neck cancer and 10 with benign conditions, 4/29 (14%) had HPV-positive oral samples. Consequently, of the HPV-positive oral samples, dominated by HPV16 and high signals, 27/32 (84%) were derived from 26 patients with concordant HPV-type positive tonsillar or base of tongue cancer and one patient with an unknown primary head and neck cancer. The other five HPV-positive oral samples, with mainly low signals were derived from two patients with non-concordant HPV-type positive tumor biopsies, two patients with HPV-negative tumor biopsies and a patient with a benign condition. Of the dental patients, 3/37 (8%) had HPV-positive tonsillar swabs with weak signals.

CONCLUSION

In patients with suspected head neck cancer, HPV-positive oral samples, especially HPV16 with high signals, could be indicative of HPV-positive tonsillar or base of tongue cancer.

Human papillomavirus and p53 expression in cancer of unknown primary in the head and neck region in relation to clinical outcome

Patients with cancer of unknown primary (CUP) in the head neck region are generally treated with neck dissection followed by radiotherapy at times combined with chemotherapy, a treatment associated with considerable side effects. Some of these tumors may originate as human papillomavirus (HPV)-positive oropharyngeal squamous cell carcinoma (OSCC), with better clinical outcome than head neck squamous cell cancer (HNSCC) in general, and could potentially do well with less treatment. Here, we therefore investigated whether HPV status and p53-expression correlated to clinical outcome in patients with CUP in the head neck region. Fifty metastases were analyzed for presence of HPV DNA, and expression of p16^INK4A and p53 and the data were correlated to clinical outcome. Patients with HPV DNA-positive (HPV_DNA+) metastases had significantly better 5-year overall survival (OS) compared to those with HPV_DNA− metastases (80.0% vs. 36.7%, respectively; P = 0.004), with a similar tendency for disease-free survival (DFS). These survival rates showed excellent concordance with those of HPV_DNA+ and HPV_DNA− OSCC in Sweden during the same time period, strengthening the hypothesis that HPV_DNA+ head and neck CUP may originate from HPV_DNA+ OSCC. In addition, having absent/intermediary-low as compared to high expression of p53 correlated to a better prognosis with a 69% as compared to 14% 5-year OS, respectively (P < 0.001), and for DFS the tendency was analogous. In conclusion, both HPV status and p53 expression are valuable prognostic factors in patients with CUP in the head and neck region and should be further explored for clinical use.

Human papilloma virus positive oropharyngeal squamous cell carcinoma: a growing epidemic

The incidence of oropharyngeal squamous cell carcinoma (OPSCC) is increasing despite a decrease in tobacco use. Almost 20-30% of patients with OPSCC do not have the traditional risk factors of smoking and alcohol use and in a vast majority of these patients, the human papilloma virus (HPV) appears to drive the malignant transformation. HPV induced malignant transformation is attributed to two viral oncogenes and their non-structural protein products (E6 and E7). These two proteins appear to affect carcinogenesis by their inhibitory effects on p53 and retinoblastoma proteins (Rb). Patients with HPV mediated OPSCC seem to have a better prognosis compared to their non-HPV counterparts. However, in the absence of strong evidence, standard of care at this time for OPSCC does not differ based on HPV status. Current research is focused on the role of de-escalation of treatment and elucidation of prognostic markers in this unique population. This review focuses on the pathogenesis of HPV mediated OPSCC and details the current evidence in the management of these patients.

Prognostic markers in stage I oral cavity squamous cell carcinoma

OBJECTIVES/HYPOTHESIS

Early-stage oral squamous cell carcinoma (OSCC) treatment is based on anatomic location, clinical TNM staging, and histological grade. It is a heterogeneous disease group. Classification of patients with OSCC by immunohistochemical analysis of established oncoproteins and evaluate disease course was our primary objective. Characterization of stage I OSCC patients in Southwest Finland was our secondary objective.

STUDY DESIGN

Immunohistochemical analysis of tumor specimens and retrospective analysis of patient data of the patient treated in Turku University Hospital for T1N0M0 OSCC during the years 2000-2004.

METHODS

Paraffin-embedded tumor specimens from 35 OSCC patients were collected and analyzed for HIF-1α, CD44, p16, Ki67, and podoplanin by immunohistochemistry and correlated with clinical findings.

RESULTS

Tumoral CD44 and HIF1-α expression levels, in combination, predicted 5-year disease-free survival. Reduced expression of CD44 and elevated expression of HIF1-α is associated with the lowest probability of disease-free survival compared to the population as a whole (P < .001 in Kaplan-Meier analysis). Patients with grade I tumors demonstrated improved disease-specific survival compared to those with grade II tumors (P = .027). No association was seen between p16 expression, Ki67 labeling index, or podoplanin expression and prognosis in our 35 specimens.

CONCLUSIONS

HIF-1α and CD44 immunohistochemical detection could potentially serve as a prognostic tool in therapy selection for early-stage OSCC.

LEVEL OF EVIDENCE

2b.

Cetuximab: its unique place in head and neck cancer treatment

Head and neck cancer is the sixth most common cancer worldwide. At present, globally about 650,000 new cases of squamous cell carcinoma of the head and neck (SCCHN) are diagnosed each year. The epidermal growth factor receptor (EGFR) is almost invariably expressed in SCCHN. Overexpression of the EGFR is a strong and independent unfavorable prognostic factor in SCCHN. Cetuximab is a chimeric monoclonal antibody, which binds with high affinity to the extracellular domain of the human EGFR, blocking ligand binding, resulting in inhibition of the receptor function. It also targets cytotoxic immune effector cells towards EGFR-expressing tumor cells (antibody dependent cell-mediated cytotoxicity). The addition of cetuximab to radiotherapy (RT) improves locoregional control and survival when compared to RT alone. The addition of cetuximab to platinum-based chemoradiation (CRT) is feasible but does not lead to an improved outcome. Cetuximab plus RT has never been compared prospectively to CRT, which therefore remains the standard treatment for patients with locoregionally advanced SCCHN for whom surgery is not considered the optimal treatment, provided they can tolerate CRT. The addition of cetuximab to platinum-based chemotherapy prolongs survival in patients with recurrent or metastatic SCCHN. The combination of a platinum-based regimen and cetuximab should be considered as the standard first line regimen for patients who can tolerate this treatment.

Tumor infiltrating CD8+ and Foxp3+ lymphocytes correlate to clinical outcome and human papillomavirus (HPV) status in tonsillar cancer

Background

Human papillomavirus (HPV) is a causative factor for tonsillar squamous cell carcinoma (TSCC) and patients with HPV positive (HPV⁺) TSCC have a better clinical outcome than those with HPV negative (HPV⁻) TSCC. However, since not all patients with HPV⁺TSCC respond to treatment, additional biomarkers are needed together with HPV status to better predict response to therapy and to individualize treatment. For this purpose, we examined whether the number of tumor infiltrating cytotoxic and regulatory T-cells in TSCC correlated to HPV status and to clinical outcome.

Methods

Formalin fixed paraffin embedded TSCC, previously analysed for HPV DNA, derived from 83 patients, were divided into four groups depending on the HPV status of the tumor and clinical outcome. Tumors were stained by immunohistochemistry and evaluated for the number of infiltrating cytotoxic (CD8⁺) and regulatory (Foxp3⁺) T-cells.

Results

A high CD8⁺ T-cell infiltration was significantly positively correlated to a good clinical outcome in both patients with HPV⁺ and HPV^- TSCC patients. Similarly, a high CD8⁺/Foxp3⁺ TIL ratio was correlated to a 3-year disease free survival. Furthermore, HPV⁺TSCC had in comparison to HPV⁻TSCC, higher numbers of infiltrating CD8⁺ and Foxp3⁺ T-cells.

Conclusions

In conclusion, a positive correlation between a high number of infiltrating CD8⁺ cells and clinical outcome indicates that CD8⁺ cells may contribute to a beneficial clinical outcome in TSCC patients, and may potentially serve as a biomarker. Likewise, the CD8⁺/Foxp3⁺cell ratio can potentially be used for the same purpose.

Human papillomavirus (HPV) 16 E6 variants in tonsillar cancer in comparison to those in cervical cancer in Stockholm, Sweden

Background

Human papillomavirus (HPV), especially HPV16, is associated with the development of both cervical and tonsillar cancer and intratype variants in the amino acid sequence of the HPV16 E6 oncoprotein have been demonstrated to be associated with viral persistence and cancer lesions. For this reason the presence of HPV16 E6 variants in tonsillar squamous cell carcinoma (TSCC) in cervical cancer (CC), as well as in cervical samples (CS), were explored.

Methods

HPV16 E6 was sequenced in 108 TSCC and 52 CC samples from patients diagnosed 2000–2008 in the County of Stockholm, and in 51 CS from young women attending a youth health center in Stockholm.

Results

The rare E6 variant R10G was relatively frequent (19%) in TSCC, absent in CC and infrequent (4%) in CS, while the well-known L83V variant was common in TSCC (40%), CC (31%), and CS (29%). The difference for R10G was significant between TSCC and CC (p = 0.0003), as well as between TSCC and CS (p = 0.009). The HPV16 European phylogenetic lineage and its derivatives dominated in all samples (>90%).

Conclusion

The relatively high frequency of the R10G variant in TSCC, as compared to what has been found in CC both in the present study as well as in several other studies in different countries, may indicate a difference between TSCC and CC with regard to tumor induction and development. Alternatively, there could be differences with regard to the oral and cervical prevalence of this variant that need to be explored further.