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Background: The current diagnostic standard for detection of high‐risk human papillomavirus (HPV) in oropharyngeal squamous cell carcinoma is via a two‐stage algorithm, namely p16 immunohistochemistry followed by HPV DNA in situ hybridization in p16 positive cases. This study evaluated the feasibility of automated RNA in situ hybridization on a clinical platform as a single‐step alternative to the two‐stage algorithm within a routine diagnostic histopathology setting. Methods: Thirty‐eight cases positive for both p16 and DNA in situ hybridization, 42 p16 negative cases and 20 cases positive for p16 but negative for DNA in situ hybridization were randomly selected. High‐risk HPV RNA in situ hybridization was undertaken on all cases on an automated clinical platform. Manufacturer‐recommended and on‐slide additional p16/HPV positive and negative controls were used. Test quality assurance and diagnostic RNA in situ hybridization were independently assessed by two observers. A consensus diagnosis was reached in the presence of a third observer on discordant cases. All RNA in situ hybridization results were then correlated against p16 and DNA ISH status. Results: Inter‐slide RNA in situ hybridization staining variation was observed in control sections. RNA in situ hybridization demonstrated a high inter‐observer agreement rate (κ =.897, P <.001). Following consensus review, there was full concordance between RNA in situ hybridization and the current standard. Conclusion: Human papillomavirus testing by standalone automated RNA in situ hybridization on a clinical diagnostic platform currently available in routine diagnostic histopathology laboratories is a feasible alternative to the two‐step algorithm of p16 and DNA in situ hybridization. Control tissue staining procedures need to be adapted to achieve the most accurate results. [ABSTRACT FROM AUTHOR]

Background: Hypoxia imaging is a promising tool for targeted therapy but the links between imaging features and underlying molecular characteristics of the tumour have not been investigated. The aim of this study was to compare hypoxia biomarkers and gene expression in oropharyngeal squamous cell carcinoma (OPSCC) diagnostic biopsies with hypoxia imaged with 64Cu-ATSM PET/CT.Methods: 64Cu-ATSM imaging, molecular and clinical data were obtained for 15 patients. Primary tumour SUVmax, tumour to muscle ratio (TMR) and hypoxic volume were tested for association with reported hypoxia gene signatures in diagnostic biopsies. A putative gene signature for hypoxia in OPSCCs (hypoxic volume-associated gene signature (HVS)) was derived.Results: Hypoxic volume was significantly associated with a reported hypoxia gene signature (rho=0.57, P=0.045), but SUVmax and TMR were not. Immunohistochemical staining with the hypoxia marker carbonic anhydrase 9 (CA9) was associated with a gene expression hypoxia response (rho=0.63, P=0.01). Sixteen genes were positively and five genes negatively associated with hypoxic volume (adjusted P<0.1; eight genes had adjusted P<0.05; HVS). This signature was associated with inferior 3-year progression-free survival (HR=1.5 (1.0-2.2), P=0.047) in an independent patient cohort.Conclusions: 64Cu-ATSM-defined hypoxic volume was associated with underlying hypoxia gene expression response. A 21-gene signature derived from hypoxic volume from patients with OPSCCs in our study may be linked to progression-free survival. [ABSTRACT FROM AUTHOR]

• Frequently mutated genes in OSCC: TP53 (64%), FAT1 (27%), CDKN2A , CASP8 and DNAH7. • Tumor somatic mutations of OSCC can be detected in saliva DNA at high sensitivity. • The mutation detection is independent of primary site of the tumor or tumor stage. The incidence of head and neck squamous cell carcinoma (HNSCC) continues to increase and although advances have been made in treatment, it still has a poor overall survival with local relapse being common. Conventional imaging methods are not efficient at detecting recurrence at an early stage when still potentially curable. The aim of this study was to test the feasibility of using saliva to detect the presence of oral squamous cell carcinoma (OSCC) and to provide additional evidence for the potential of this approach. Fresh tumor, whole blood and saliva were collected from patients with OSCC before treatment. Whole exome sequencing (WES) or gene panel sequencing of tumor DNA was performed to identify somatic mutations in tumors and to select genes for performing gene panel sequencing on saliva samples. The most commonly mutated genes identified in primary tumors by DNA sequencing were TP53 and FAT1. Gene panel sequencing of paired saliva samples detected tumor derived mutations in 9 of 11 (82%) patients. The mean variant allele frequency for the mutations detected in saliva was 0.025 (range 0.004 – 0.061). Somatic tumor mutations can be detected in saliva with high frequency in OSCC irrespective of site or stage of disease using a limited panel of genes. This work provides additional evidence for the suitability of using saliva as liquid biopsy in OSCC and has the potential to improve early detection of recurrence in OSCC. Trials are currently underway comparing this approach to standard imaging techniques. [ABSTRACT FROM AUTHOR]

Objectives: Dental rehabilitation post‐radiotherapy often requires the consideration of dental implants. However, these are tentatively prescribed due to the concern of hypovascularisation and possible osteoradionecrosis. Hence, the current study assessed the microvasculature of the dento‐alveolar bone at implant sites taking into consideration the exact radiotherapy dose received to the region. Materials and methods: Bone cores were taken from nine patients during implant treatment and compared to nine control patients. Specimens were stained using CD31 and digitalised using a high‐resolution scanner for qualitative and quantitative assessment of the microvasculature. Monaco® treatment planning system was used to volume the implant site providing mean dose (Dmean) and maximum dose (Dmax). Results: A total of 23 bone cores were retrieved for analysis. The cohort had a Dmean of 38.4 Gy (59.6‐24.3 Gy). Qualitative analysis identified a clear reduction in the miniscule terminal capillaries and high incidence of obliterated lumens with increasing radiotherapy. Microvasculature density of irradiated patients was markedly reduced (P =.0034) compared to the control group with an inverse correlation to RT doses (P <.0001). Specifically, doses up to 30 Gy appear to preserve sufficient vascularisation (~77% in comparison with control) and tissue architecture. By contrast, exposure to higher doses 40%‐61% of the micro‐vessels were lost. Conclusion: Intensity‐modulated radiotherapy doses above 30 Gy identified reduction in microvasculature which is a lower threshold than previously accepted. In pharyngeal cancer patients' doses to the jaw bones often exceed this threshold. Coupled with favourable survival in certain oropharyngeal and nasopharyngeal cancer, dental rehabilitation via implants provides a significant clinical challenge. [ABSTRACT FROM AUTHOR]

Summary: Objectives: Patients with human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC) have a reduced risk of developing second primary upper aerodigestive tract (UADT) tumours compared to patients with HPV-negative primary tumours at the same site. To determine whether this finding might be explained by a lack of viral-induced field cancerisation or multifocal infection, we investigated whether there was epithelial dysplasia and/or evidence of HPV infection at other pharyngeal mucosal sites in patients presenting with the disease. Materials and methods: Sixty-three patients with primary tonsil SCC and 108 pharyngeal endoscopic biopsies, representing at least one pharyngeal subsite from each patient, were included in this study. Tissue samples were tested using HPV PCR (GP5+/6+), p16 immunohistochemistry (IHC) and high risk HPV DNA in situ hybridisation (ISH). Results: There were 46 patients with HPV-related SCC and 17 patients with HPV-negative disease. PCR detected HPV DNA in a fifth of pharyngeal endoscopic biopsies and was equally likely to be from a patient with HPV-related SCC as from a patient with HPV negative disease. All PCR positive cases were tested using p16 IHC and high risk HPV ISH and only three biopsies were positive. Significantly, these three biopsies all showed evidence of epithelial dysplasia and were from patients with an HPV positive index tumour. Conclusion: Our data suggest that virus-induced field cancerisation and/or multifocal oncogenic HPV infection of the pharynx is uncommon in OPSCC and supports the concept that these patients have a lower risk of developing second primary tumours of the UADT. [Copyright &y& Elsevier]