Developing and Validating a Multivariable Prognostic-Predictive Classifier for Treatment Escalation of Oropharyngeal Squamous Cell Carcinoma: The PREDICTR-OPC Study.

PURPOSE: While there are several prognostic classifiers, to date, there are no validated predictive models that inform treatment selection for oropharyngeal squamous cell carcinoma (OPSCC).Our aim was to develop clinical and/or biomarker predictive models for patient outcome and treatment escalation for OPSCC. EXPERIMENTAL DESIGN: We retrospectively collated clinical data and samples from a consecutive cohort of OPSCC cases treated with curative intent at ten secondary care centers in United Kingdom and Poland between 1999 and 2012. We constructed tissue microarrays, which were stained and scored for 10 biomarkers. We then undertook multivariable regression of eight clinical parameters and 10 biomarkers on a development cohort of 600 patients. Models were validated on an independent, retrospectively collected, 385-patient cohort. RESULTS: A total of 985 subjects (median follow-up 5.03 years, range: 4.73-5.21 years) were included. The final biomarker classifier, comprising p16 and survivin immunohistochemistry, high-risk human papillomavirus (HPV) DNA in situ hybridization, and tumor-infiltrating lymphocytes, predicted benefit from combined surgery + adjuvant chemo/radiotherapy over primary chemoradiotherapy in the high-risk group [3-year overall survival (OS) 63.1% vs. 41.1%, respectively, HR = 0.32; 95% confidence interval (CI), 0.16-0.65; P = 0.002], but not in the low-risk group (HR = 0.4; 95% CI, 0.14-1.24; P = 0.114). On further adjustment by propensity scores, the adjusted HR in the high-risk group was 0.34, 95% CI = 0.17-0.67, P = 0.002, and in the low-risk group HR was 0.5, 95% CI = 0.1-2.38, P = 0.384. The concordance index was 0.73. CONCLUSIONS: We have developed a prognostic classifier, which also appears to demonstrate moderate predictive ability. External validation in a prospective setting is now underway to confirm this and prepare for clinical adoption.

Determining the Effectiveness of Fibrin Sealants in Reducing Complications in Patients Undergoing Lateral Neck Dissection (DEFeND): A Randomised External Pilot Trial.

OBJECTIVES: High-quality randomised controlled trials (RCT) to support the use of Fibrin Sealants (FS) in neck dissection (ND) are lacking. The DEFeND trial assessed critical pilot/feasibility questions and signals from clinical outcomes to inform a future definitive trial. PATIENTS AND METHODS: The study design piloted was a blinded surgical RCT. All participants underwent unilateral ND for head and neck cancer. Interventional arm: ND with application of FS. CONTROL ARM: ND alone. Feasibility outcomes included recruitment, effectiveness of blinding, protocol adherence and evaluating administrative processes. Clinical outcomes included surgical complications (primary outcome), drainage volume, time to drain removal, length of hospital stay, pain and the Neck Dissection Impairment Index. RESULTS: Recruitment completed ahead of time. Fifty-three patients were recruited, and 48 were randomised at a rate of 5.3 patients/month. Blinding of patients, research nurses and outcome assessors was effective. Two protocol deviations occurred. Two patients were lost to follow-up. The mean (SD) Comprehensive Complication Index in the interventional arm was 6.5 (12.8), and it was 9.9 (14.2) in the control arm. The median (IQR) time to drain removal (days) was shorter in the interventional arm (2.67 (2.42, 3.58) vs. 3.40 (2.50, 4.27)). However, this did not translate to a clinically significant reduction in median (IQR) length of hospital stay in days (intervention: 3.48 (2.64, 4.54), control: 3.74 (3.11, 4.62)). CONCLUSION: The proposed trial design was effective, and a definitive surgical trial is feasible. Whilst there was a tendency for FS to improve clinical outcomes, the effect size did not reach clinical or statistical significance. (ISRCTN99181100).

ACTivity as medicine In Oncology for Head and Neck (ACTIOHN): Protocol for a feasibility study investigating a patient-centred approach to exercise for people with head and neck cancer.

BACKGROUND AND AIM: Attempts at personalisation of exercise programmes in head and neck cancer (HaNC) have been limited. The main aim of the present study is to investigate the feasibility and acceptability of introducing a remotely delivered, fully personalised, collaborative, and flexible approach to prescribing and delivering exercise programmes into the HaNC usual care pathway. METHODS: This is a single arm, feasibility study. Seventy patients diagnosed with HaNC will be recruited from two regional HaNC centres in the United Kingdom. Patients will undertake an 8-week exercise programme designed and delivered by cancer exercise specialists. The exercise programme will start any time between the time of diagnosis and up to 8 weeks after completing treatment, depending on patient preference. The content of the exercise programme will be primarily based on patient needs, preferences, and goals, but guided by current physical activity guidelines for people with cancer. The primary outcome measure is retention to the study. Secondary quantitative outcomes are uptake to the exercise programme, different measures of exercise adherence, pre- and post-intervention assessments of fatigue (Multidimensional Fatigue Symptom Inventory-Short Form), quality of life (SF-36), physical activity levels (International Physical Activity Questionnaire-Short Form), and various components of physical fitness. The outcomes of the nested qualitative study are acceptability and feasibility of the intervention evaluated via interviews with patients, health care professionals, and the cancer exercise specialists. Intervention and participant fidelity will be determined using checklists and scrutiny of each patient's logbook and the cancer exercise specialists' meeting notes. Analysis of quantitative data will be via standard summary statistics. Qualitative data will be analysed using thematic analysis. EXPECTED RESULTS: This feasibility study will inform the design and conduct of a future randomised controlled trial. Success will be defined according to a traffic light system for identifying the appropriateness of progression to a randomised controlled trial. TRIAL REGISTRATION: International Standard Randomised Controlled Trial Number registry (ISRCTN82505455).

Head and neck reconstruction in the vessel depleted neck using robot-assisted harvesting of the internal mammary vessels.

We report a novel technique of robot-assisted harvesting of the internal mammary vessels to provide effective recipient vessels in a patient with bilateral vessel depleted neck (VDN). A 44-year-old with a Notani grade III osteoradionecrosis (ORN) of the anterior mandible underwent robot-assisted (Da Vinci® Surgical System, Intuitive Surgical) harvesting of the left internal mammary vessels (LIMA, LIMV). Reconstruction of the mandibular defect was done with a virtually planned composite fibular free flap and microvascular anastomosis of the peroneal vessels to the LIMA and LIMV. Successful reconstruction of the anterior mandible was achieved with excellent recipient arterial diameter and length, devoid of any significant thoracic morbidities resulting from robot-assisted harvesting of the internal mammary vessels. Robot-assisted harvesting of internal mammary vessels is a viable alternative to an open approach. The advantages in tissue handling, vessel length, and favourable profile of complications may extend the indications for this otherwise 'niche' solution in the VDN.

Accuracy of preoperative clinical examination and imaging for mandibular resection in oral cancer: a systematic review of diagnostic test accuracy studies.

The aim of this systematic review is not only to analyse the accuracy of clinical examination and radiological preoperative assessment of mandibular invasion reported in isolation, but to highlight those reports that have combined them. A total of 1636 titles and abstracts published between 1995 - 2000 were screened following a literature search in PubMed. Keywords were "mandible" and "squamous cell carcinoma". A total of 90 full manuscripts were reviewed with 24 meeting defined inclusion/exclusion criteria and yielding the data reported. The most sensitive test was single photon emission tomography with eight out of the 10 studies reporting sensitivity higher than 95%. Magnetic resonance imaging (MRI) demonstrated superior sensitivity but was less specific than computed tomography (CT). A single report attempted to report the combined CT and MRI scans with a separate expert reporting but did not result in more reliable detection. Periosteal stripping was not reported, and there was insufficient data to establish the value of new technologies. This review confirms that, to our knowledge, there are no reliable data on the results of combining imaging techniques with or without clinical examination. It emphasises the lack of data for the combination of preoperative techniques to enhance safe oncological resection of the mandible. Based on the evidence gathered in this review an algorithm of assessment of possible mandibular invasion is proposed. With new technologies available and 3-dimensional models to help plan the mandibular resection and reconstruction, the potential of combining preoperative investigations should be fully realised through prospective research.

Genetic variants associated with mandibular osteoradionecrosis following radiotherapy for head and neck malignancy.

BACKGROUND/AIM: Utilising radiotherapy in the management of head and neck cancer (HNC) often results in long term toxicities. Mandibular osteoradionecrosis (ORN) represents a late toxicity associated with significant morbidity. We aim to identify a panel of common genetic variants which can predict ORN to aid development of personalised radiotherapy protocols. METHOD: Single nucleotide polymorphism (SNP) arrays were applied to DNA samples from patients who had prior HNC radiotherapy and minimum two years follow-up. A case cohort of mandibular ORN was compared to a control group of participants recruited to CRUK HOPON clinical trial. Relevant clinical parameters influencing ORN risk (e.g. smoking/alcohol) were collected. Significant associations from array data were internally validated using polymerase chain reaction (PCR) and pyrosequencing. RESULTS: Following inclusion of 141 patients in the analysis (52 cases, 89 controls), a model predictive for ORN was developed; after controlling for alcohol consumption, smoking, and age, 4053 SNPs were identified as significant. This was reduced to a representative model of 18 SNPs achieving 92% accuracy. Following internal technical validation, a six SNP model (rs34798038, rs6011731, rs2348569, rs530752, rs7477958, rs1415848) was retained within multivariate regression analysis (ROC AUC 0.859). Of these, four SNPs (rs34798038 (A/G) (p 0.006), rs6011731 (C/T) (p 0.018), rs530752 (A/G) (p 0.046) and rs2348569 (G/G) (p 0.005)) were significantly associated with the absence of ORN. CONCLUSION: This is the first genome wide association study in HNC using ORN as the endpoint and offers new insight into ORN pathogenesis. Subject to validation, these variants may guide patient selection for personalised radiotherapy strategies.

The relevance of surgical margins in clinically early oral squamous cell carcinoma.

OBJECTIVES: There is controversy regarding surgical margins in the management of early oral squamous cell carcinoma (OSCC). The main objectives of this study were to assess the: relevance of the margin independent of tumour variables; threshold for a safe margin; relevance of dysplasia at the margin. MATERIALS & METHODS: UK based retrospective multicenter cohort study of patients with previously untreated and clinically early OSCC between 1998 and 2016. All patients had surgery as the primary modality and had surgical staging of the neck. Minimum follow-up was 2 years. Margins were classified as: clear ≥5.0 mm; close 1.0-4.9 mm; involved not cut-through (INC-T) 0.1-0.9 mm; cut-through (C-T) 0 mm. RESULTS: 669 patients were included. After adjusting for tumour variables Cox multivariate regression analysis demonstrated that close margins had similar survival outcomes to clear margins (Hazard Ratio(HR) 0.99 (95%CI 0.50-1.95) for Local Recurrence Free Survival (LRFS); HR 1.08 (95%CI 0.7-1.66) for Disease Free Survival (DFS); HR 0.74 (95%CI 0.44-1.25) for Disease Specific Survival (DSS); HR 0.80 (95%CI 0.58-1.11) for Overall Survival (OS)). C-T margins had significantly worse LRFS (HR 5.01 (95%CI 2.02-12.39)) and DFS (HR 2.58 (95%CI 1.28-5.20)). INC-T margins had significantly worse DFS (HR 1.98 (95% CI 1.01-3.87)). Time dependent receiver operating characteristic curve analysis did not demonstrate a clear margin threshold for LRFS within 24 months (AUC = 0.53 (95%CI 0.41-0.64)). Dysplasia at the margin did not influence LRFS or DFS. CONCLUSION: Only resection margins <1 mm independently affected survival outcomes. This should be considered when making decisions regarding adjuvant treatment.

Determining the effectiveness of fibrin sealants in reducing complications in patients undergoing lateral neck dissection (DEFeND): study protocol for a randomised external pilot trial.

BACKGROUND: Complications after major surgery are a significant cause of morbidity and mortality. Neck dissection is one of the most commonly performed major operations in Head and Neck Surgical Oncology. Significant surgical complications occur in approximately 10-20% of all patients, increasing to 40% in patients who have had previous treatment to the area or have multiple co-morbidities and/or polypharmacy.Current evidence suggests that fibrin sealants (FS) may have potential clinical advantages in Head and Neck Surgery through the reduction of complications, volume of wound drainage and retention time of the drains. However, a paucity of high-quality trial-based evidence means that a surgical trial to determine the effectiveness of FS in reducing the rate and severity of complications in patients undergoing lateral neck dissection is warranted. The DEFeND randomised external pilot trial will address critical questions on how well key components of the proposed study design work together as well as the feasibility of a future phase III trial. METHODS: The study design that is being piloted is that of a two-arm, parallel group, superiority trial with block randomisation in a 1:1 allocation ratio. The interventional arm will constitute the application of FS (Artiss, Baxter Healthcare Ltd.) to the surgical wound following completion of a neck dissection procedure, in addition to standard of care (SOC). The control arm will constitute SOC alone. Eligible patients will include patients who require a lateral neck dissection with a minimum of three cervical nodal levels. Patients who require bilateral neck procedures or undergoing immediate reconstruction with free or regional flaps will be excluded. The outcomes being assessed will be recruitment rate, screened to randomisation rate, fidelity of blinding process using blinding indices, number of missing or incomplete data entries, number of protocol deviations and number of losses to follow-up. Suitability of the outcome measures proposed for the future phase III trial will also be assessed. DISCUSSION: The anticipated challenges for this study will be recruitment, complexity of the intervention and adherence to the protocol. The outcomes will inform the design, feasibility and conduct of a future phase III surgical trial. TRIAL REGISTRATION: First participant randomised: November 06, 2018; UKCRN Portfolio ID: 37896; ISRCTN99181100.

Essential characterisation of human papillomavirus positive head and neck cancer cell lines.

OBJECTIVES: The incidence of human papillomavirus (HPV)-positive head and neck cancer, particularly oropharyngeal, has been increasing rapidly. Understanding of this disease, and modelling of suitable therapeutics, requires sustainable cell cultures, yet they remain limited in number and of variable origin. A comprehensive understanding of these resources is therefore of great importance. MATERIALS AND METHODS: Viral gene expression assays and pathological testing methods were used in the six currently available HPV-positive cell lines derived from head and neck (H&N) subsites, two HPV-negative H&N and two cervical carcinoma cell lines. A 2D migration assay monitored cell movement, speed and pattern of migration. RESULTS: All six H&N and two cervical cell lines were confirmed HPV-positive by gold standard testing, yet variability between tests was apparent. Although migration was not significantly different between cell lines, each demonstrated unique migration patterns. CONCLUSION: Patient-derived cancer cells, arising as a consequence of natural oncogenic processes rather than in vitro manipulation, are essential for understanding cancer biology. We have characterised the available HPV-positive H&N cell lines and provided clear evidence of a persisting viral oncogenic driver in each, as such supporting their ongoing use as a model of HPV-positive H&N cancer. Importantly, we also highlight a need for caution to be exercised when translating future in vitro findings associated with these lines particularly in the context of oropharyngeal cancer given irregularities in tumour provenance (origin site and clinicopathological features).

Comparison of Molecular Assays for HPV Testing in Oropharyngeal Squamous Cell Carcinomas: A Population-Based Study in Northern Ireland.

BACKGROUND: Determination of human papillomavirus (HPV) status has become clinically relevant for patient stratification under UICC TNM8 staging. Within the United Kingdom, a combination of p16 IHC and HPV DNA-ISH is recommended for classifying HPV status. This study will assess a series of clinically applicable second-line molecular tests to run in combination with p16 IHC to optimally determine HPV status. METHODS: The ability of HPV RNA-ISH, HPV DNA-ISH, and HPV DNA-PCR to identify p16-positive/HPV-positive patients was investigated in a population-based oropharyngeal squamous cell carcinoma (OPSCC) cohort of patients diagnosed in Northern Ireland from 2000 to 2011. RESULTS: Only 41% of the Northern Irish OPSCC patient population was associated with HPV-driven carcinogenesis. Both ISH assays were more specific than the DNA-PCR assay (100% and 95% vs. 67%) and were less likely to be affected by preanalytic factors such as increasing block age. A pooled HPV genotype probe for RNA-ISH was found to be the most accurate molecular assay assessed (95% accuracy) when compared with p16 positivity. CONCLUSIONS: Our study demonstrates the advantage of tissue-based molecular assays when determining HPV status in retrospective samples. Specifically, we demonstrate the enhanced sensitivity and specificity of ISH techniques compared with PCR-based methodology when working with formalin-fixed paraffin-embedded tissue, and found HPV RNA-ISH to be the most effective assay for determining HPV status. IMPACT: As p16 IHC is a relatively inexpensive, accessible, and sensitive test for stratifying patients by HPV status, this study finds that more patients would benefit from first-line p16 IHC followed by specific HPV testing using HPV RNA-ISH to confirm HPV status.

Exploring the potential of BH3 mimetic therapy in squamous cell carcinoma of the head and neck.

Squamous cell carcinoma of the head and neck (SCCHN) is the sixth most common cancer worldwide, with overall survival of less than 50%. Current therapeutic strategies involving a combination of surgery, radiation, and/or chemotherapy are associated with debilitating side effects, highlighting the need for more specific and efficacious therapies. Inhibitors of BCL-2 family proteins (BH3 mimetics) are under investigation or in clinical practice for several hematological malignancies and show promise in solid tumors. In order to explore the therapeutic potential of BH3 mimetics in the treatment of SCCHN, we assessed the expression levels of BCL-2, BCL-XL, and MCL-1 via Western blots and immunohistochemistry, in cell lines, primary cells derived from SCCHN patients and in tissue microarrays containing tumor tissue from a cohort of 191 SCCHN patients. All preclinical models exhibited moderate to high levels of BCL-XL and MCL-1, with little or no BCL-2. Although expression levels of BCL-XL and MCL-1 did not correlate with patient outcome, a combination of BH3 mimetics to target these proteins resulted in decreased clonogenic potential and enhanced apoptosis in all preclinical models, including tumor tissue resected from patients, as well as a reduction of tumor volume in a zebrafish xenograft model of SCCHN. Our results show that SCCHN is dependent on both BCL-XL and MCL-1 for apoptosis evasion and combination therapy targeting both proteins may offer significant therapeutic benefits in this disease.

Recommendations for determining HPV status in patients with oropharyngeal cancers under TNM8 guidelines: a two-tier approach.

BACKGROUND: TNM8 staging for oropharyngeal squamous cell carcinomas (OPSCC) surrogates p16 immunohistochemistry for HPV testing. Patients with p16+ OPSCC may lack HPV aetiology. Here, we evaluate the suitability of TNM8 staging for guiding prognosis in such patients. METHODS: HPV status was ascertained using p16 immunohistochemistry and high-risk HPV RNA and DNA in situ hybridisation. Survival by stage in a cohort of OPSCC patients was evaluated using TNM7/TNM8 staging. Survival of p16+/HPV- patients was compared to p16 status. RESULTS: TNM8 staging was found to improve on TNM7 (log rank p = 0·0190 for TNM8 compared with p = 0·0530 for TNM7) in p16+ patients. Patients who tested p16+ but were HPV- (n = 20) had significantly reduced five-year survival (33%) compared to p16+ patients (77%) but not p16- patients (35%). Cancer stage was reduced in 95% of p16+/HPV- patients despite having a mortality rate twice (HR 2.66 [95% CI: 1.37-5.15]) that of p16+/HPV+ patients under new TNM8 staging criteria. CONCLUSION: Given the significantly poorer survival of p16+/HPV- OPSCCs, these data provide compelling evidence for use of an HPV-specific test for staging classification. This has particular relevance in light of potential treatment de-escalation that could expose these patients to inappropriately reduced treatment intensity as treatment algorithms evolve.

Head and neck reconstruction with free flaps based on the thoracodorsal system.

The advent or micro-vascular free tissue transfer has facilitated the reconstruction of increasingly complex head and neck defects. There are multiple donor sites available, each with its' own advantages and disadvantages. However, the subscapular system, including the thoracodorsal system, provides the widest array of soft tissue and osseous flaps, as well as chimeric options. Its advantages include a long pedicle, independently mobile tissue components, relative sparing from atherosclerosis, and minimal donor site morbidity. The soft tissue flaps available from the thoracodorsal system include the Latissimus Dorsi, and Thoracodorsal Artery Perforator flaps, while the Tip of Scapula provides the osseous component. This review paper outlines the anatomical basis for these flaps, as well as describing their utility in head and neck reconstruction.

Management of proliferative verrucous leukoplakia: Justification for a conservative approach.

BACKGROUND: Proliferative verrucous leukoplakia (PVL) is a progressive, multifocal, exophytic form of leukoplakia with high rates of malignant transformation. The purpose of this study was to evaluate a cohort of patients with PVL in a single tertiary referral clinic. METHOD: Cases meeting accepted diagnostic criteria were reviewed with regard to their pathology, demographic characteristics, management, and outcomes. Human papillomavirus (HPV) testing was undertaken on a subset. RESULTS: Almost half of the 48 patients with PVL (48%; n = 23) underwent malignant transformation after a median 23.4 months. The characteristics of this cohort were similar to those previously described, but management was notably more conservative. Conservative management of PVL was used in 92% of our patients, but the clinical outcomes seem comparable with previously described cohorts in which PVL was predominantly treated by surgical excision. All HPV testing was negative. CONCLUSION: Aggressive surgical intervention in the premalignant phase of PVL may not influence the rate of malignant transformation.

HPV-Related Oropharynx Cancer in the United Kingdom: An Evolution in the Understanding of Disease Etiology.

A rising incidence of oropharyngeal squamous cell carcinoma (OPSCC) incidence has occurred throughout the developed world, where it has been attributed to an increasing impact of human papillomavirus (HPV) on disease etiology. This report presents the findings of a multicenter cross-sectional retrospective study aimed at determining the proportion of HPV-positive and HPV-negative OPSCC within the United Kingdom. Archival tumor tissue blocks from 1,602 patients previously diagnosed with OPSCC (2002-2011) were collated from 11 centers. HPV status was determined with three validated commercial tests to provide valid data for 1,474 cases in total. Corresponding national incidence data from the same decade were obtained from UK Cancer registries. The overall proportion of HPV+ OPSCC between 2002 and 2011 was 51.8% [95% confidence interval (CI), 49.3-54.4], and this remained unchanged throughout the decade [unadjusted RR = 1.00 (95% CI, 0.99-1.02)]. However, over the same period, the incidence of OPSCC in the broader UK population underwent a 2-fold increase [age-standardized rate 2002: 2.1 (95% CI, 1.9-2.2); 2011: 4.1 (95% CI, 4.0-4.3)]. Although the number of OPSCCs diagnosed within the United Kingdom from 2002 to 2011 nearly doubled, the proportion of HPV+ cases remained static at approximately 50%. Our results argue that the rapidly increasing incidence of OPSCC in the United Kingdom cannot be solely attributable to the influence of HPV. The parallel increase in HPV+ and HPV- cases we documented warrants further investigation, so that appropriate future prevention strategies for both types of disease can be implemented. Cancer Res; 76(22); 6598-606. ©2016 AACR.

Squamous cell carcinoma of the head and neck outside the oropharynx is rarely human papillomavirus related.

OBJECTIVES/HYPOTHESIS: The incidence of human papillomavirus (HPV)-driven disease beyond the oropharynx varies greatly in the reported literature. STUDY DESIGN: Case series. METHODS: Two hundred twenty-one samples were strictly classified to the subsites of oral cavity, larynx, or hypopharynx at the time of primary surgery. Formalin-fixed paraffin-embedded samples were subjected to a validated, tiered, diagnostic algorithm of p16 immunohistochemistry, high-risk HPV in situ hybridization, and quantitative polymerase chain reaction for HPV E6 DNA. An additional 60 oropharyngeal cases acted as an internal biological control. RESULTS: An incidence of 4% of HPV-driven cases was observed across the subsites outside the oropharynx compared to 70% of tumors confined within it. CONCLUSIONS: This is the first reporting of a broad range of nonoropharyngeal HPV rates using this validated diagnostic algorithm. It remains unclear whether patients with HPV-driven disease originating outside the oropharynx enjoy the same survival advantage apparent in those patients with oropharyngeal squamous cell carcinomas. LEVEL OF EVIDENCE: 4 Laryngoscope, 124:2739-2744, 2014.

Evaluation of human papilloma virus diagnostic testing in oropharyngeal squamous cell carcinoma: sensitivity, specificity, and prognostic discrimination.

PURPOSE: Human papillomavirus-16 (HPV16) is the causative agent in a biologically distinct subset of oropharyngeal squamous cell carcinoma (OPSCC) with highly favorable prognosis. In clinical trials, HPV16 status is an essential inclusion or stratification parameter, highlighting the importance of accurate testing. EXPERIMENTAL DESIGN: Fixed and fresh-frozen tissue from 108 OPSCC cases were subject to eight possible assay/assay combinations: p16 immunohistochemistry (p16 IHC); in situ hybridization for high-risk HPV (HR HPV ISH); quantitative PCR (qPCR) for both viral E6 RNA (RNA qPCR) and DNA (DNA qPCR); and combinations of the above. RESULTS: HPV16-positive OPSCC presented in younger patients (mean 7.5 years younger, P = 0.003) who smoked less than HPV-negative patients (P = 0.007). The proportion of HPV16-positive cases increased from 15% to 57% (P = 0.001) between 1988 and 2009. A combination of p16 IHC/DNA qPCR showed acceptable sensitivity (97%) and specificity (94%) compared with the RNA qPCR "gold standard", as well as being the best discriminator of favorable outcome (overall survival P = 0.002). p16 IHC/HR HPV ISH also had acceptable specificity (90%) but the substantial reduction in its sensitivity (88%) impacted upon its prognostic value (P = 0.02). p16 IHC, HR HPV ISH, or DNA qPCR was not sufficiently specific to recommend in clinical trials when used in isolation. CONCLUSIONS: Caution must be exercised in applying HPV16 diagnostic tests because of significant disparities in accuracy and prognostic value in previously published techniques.