Metabolic Plasticity and Combinatorial Radiosensitisation Strategies in Human Papillomavirus-Positive Squamous Cell Carcinoma of the Head and Neck Cell Lines.

BACKGROUND: A major objective in the management of human papillomavirus (HPV)-positive squamous cell carcinoma of the head and neck (SCCHN) is to reduce long-term functional ramifications while maintaining oncological outcomes. This study examined the metabolic profile of HPV-positive SCCHN and the potential role of anti-metabolic therapeutics to achieve radiosensitisation as a potential means to de-escalate radiation therapy. METHODS: Three established HPV-positive SCCHN cell lines were studied (UM-SCC-104, UPCI:SCC154, and VU-SCC-147), together with a typical TP53 mutant HPV-negative SCCHN cell line (UM-SCC-81B) for comparison. Metabolic profiling was performed using extracellular flux analysis during specifically designed mitochondrial and glycolytic stress tests. Sensitivity to ionising radiation (IR) was evaluated using clonogenic assays following no treatment, or treatment with: 25 mM 2-deoxy-D-glucose (glycolytic inhibitor) alone; 20 mM metformin (electron transport chain inhibitor) alone; or 25 mM 2-deoxy-D-glucose and 20 mM metformin combined. Expression levels of p53 and reporters of p53 function (MDM2, p53, Phospho-p53 [Ser15], TIGAR and p21 [CDKN1A]) were examined by western blotting. RESULTS: HPV-positive SCCHN cell lines exhibited a diverse metabolic phenotype, displaying robust mitochondrial and glycolytic reserve capacities. This metabolic profile, in turn, correlated with IR response following administration of anti-metabolic agents, in that both 2-deoxy-D-glucose and metformin were required to significantly potentiate the effects of IR in these cell lines. CONCLUSIONS: In contrast to our recently published data on HPV-negative SCCHN cells, which display relative glycolytic dependence, HPV-positive SCCHN cells can only be sensitised to IR using a complex anti-metabolic approach targeting both mitochondrial respiration and glycolysis, reflecting their metabolically diverse phenotype. Notionally, this may provide an attractive platform for treatment de-intensification in the clinical setting by facilitating IR dose reduction to minimise the impact of treatment on long-term function.

Elective management of regional nodal basins in cutaneous squamous cell carcinoma of the head and neck: Controversies and contemporary perspectives.

Non-melanoma skin cancer (NMSC) is among the most common cancers worldwide, with an incidence that continues to rise. Although cutaneous squamous cell carcinoma (cSCC) constitutes only approximately 20% of such cases, it represents the most common cause of NMSC mortality, owing largely to the propensity for development of regional lymph node metastases (LNM), which, when present, carry a dismal prognosis. Whilst overall rates of LNM are low, there are a number of patient and tumour factors that likely confer considerably higher risks, which has led several investigators to propose more proactive elective management of regional nodal basins in selected high-risk cases. Current international guidelines, however, do not recommend any elective treatment or sampling of regional nodal basins in the absence of clinically apparent disease. The purpose of this review is to explore in detail the fundamental issues underlying this controversy, focusing specifically on cSCC of the head and neck (cSCCHN). In particular the rationale for more a proactive elective approach to regional nodal basins, including the evidence-base underlying identification of potentially high-risk factors for development of LNM is discussed, along with oncological outcomes for those patients that do go onto suffer LNM. We also provide contemporary perspectives and evidence for approaches to electively managing regional nodal basins, and offer insight into how these may develop both in the clinical and research arenas.

Transoral laser microsurgery and radiotherapy for oropharyngeal squamous cell carcinoma: Equitable survival and enhanced function compared with contemporary standards of care.

INTRODUCTION: We describe the 5-year oncological and functional outcomes of transoral laser microsurgery, neck dissection (TLM + ND) and adjuvant radiotherapy (PORT) used to treat patients with oropharyngeal carcinoma. The effectiveness of external carotid artery (ECA) ligation in reducing post-operative bleeding, and fibrin glue following ND in reducing wound drainage and length of hospital stay is reported. MATERIALS AND METHODS: This retrospective case review of consecutive patients undergoing TLM between 2006 and 2017 used the Kaplan-Meier Estimator and Log-Rank Test for univariate, time-to-event analyses, and Cox-Proportionate Hazard modelling for multivariate analysis. RESULTS: 264 consecutive patients were included. Mean follow-up was 49.4 months. 219 (82.9%) patients received PORT. Five-year overall survival (OS), disease-free survival (DFS), and disease-specific survival (DSS) rates were 74.9%, 73.7%, and 86.2%, respectively. Five-year locoregional control was 89.4%. 65.5% of cases were Human papillomavirus associated (HPV+), for whom OS, DFS and DSS was 85.6%, 84.7% and 92.7%, respectively, and demonstrated significantly higher OS (hazard ratio (HR) 0.28, CI 0.16-0.49, p < 0.0001), DFS (HR 0.28, CI 0.17-0.47, p < 0.0001) and DSS (HR 0.2, CI 0.09-0.44, <0.001). Post-operative oropharyngeal bleeding occurred in 23 patients (8.7%), of which 5 were major/severe, in patients without ECA ligation. Fibrin glue significantly reduced neck drain output (p < 0.001), and length of hospital stay (p < 0.001). One-year gastrostomy dependence rate was 2.3%. CONCLUSIONS: TLM + ND + PORT results in favourable 5-year survival and locoregional control rates, and low feeding tube dependency rates. ECA ligation and fibrin glue appear to reduce major post-operative haemorrhage, wound drainage and length of hospital stay.

Outcomes and prognosticators in regionally recurrent cutaneous squamous cell carcinoma of the head and neck.

INTRODUCTION: Data regarding regionally metastatic cutaneous squamous cell carcinoma of the head and neck (cSCCHN) is limited and derived almost exclusively from Australian and United States (US) institutions. We report the first United Kingdom perspective, with the aims of benchmarking survival outcomes and identifying clinically relevant prognosticators. MATERIALS AND METHODS: Ninety-one patients with regionally recurrent cSCCHN treated with curative intent over a ten-year period (2009-2018) were studied retrospectively. Time-to-event analyses were used to estimate oncological outcomes, and log-rank statistics and Cox proportional hazards models used to examine potential prognosticators. Receiver operating characteristics were also used to analyse the influence of nodal disease burden. RESULTS: Parotid involvement (with or without neck involvement) was most common (79.2%), and time to recurrence in those with parotid disease alone significantly shorter than for any other disease distribution (p = 0.034). Respective five-year overall, disease-specific, and disease-free survival estimates were 43.8%, 63.8%, and 36.2%. Extracapsular spread (ECS) portended reduced DFS and DSS (p = 0.012 and p = 0.005 respectively). Increasing nodal burden (≥4 involved nodes) also reduced DSS (p = 0.020), while parotid disease alone predicted more favourable DSS (p = 0.008). ECS and isolated parotid involvement remained significant on multi-variate analysis (p = 0.014 and p = 0.028 respectively). CONCLUSIONS: Oncological outcomes were unfavourable but broadly consistent with previous reports, notionally lending support to a more proactive approach in managing the clinically node negative neck/parotid in selected high-risk cases. Our data also support distinct parotid classification and consideration of involved lymph node number in future staging systems.

The effect of fibrin sealant tissue glue in reducing post-operative collections following parotidectomy.

PURPOSE: Seroma/sialocele and haematoma formations following parotidectomy are common complications. Fibrin-sealant tissue glue (FSTG) applied to the surgical bed prior to closure has been used widely to reduce such complications at other surgical sites. We sought to evaluate a potential role in parotidectomy, examining outcomes before and after the use of FSTG was introduced in our department. METHODS: Outcomes were studied retrospectively for 1 year prior to the introduction of FSTG (group A, n = 31), and prospectively for 1 year subsequently (group B, n = 29). Primary outcome measures were seroma/sialocele and haematoma rates. Secondary outcome measures of interest included the use of a surgical drain and the duration of hospital stay. Chi-squared statistics and Mann-Whitney U tests were used to compare the outcomes between groups as appropriate. RESULTS: Seroma/sialocele rates were significantly lower in group B than in group A (n = 2 [6.9%] versus n = 8 [25.8%], p = 0.01) (Fig. 1), with an absolute risk reduction of 18.9%, a relative risk reduction of 26.7%, and a number needed to treat of 5.3. Haematoma rates were similar between groups (n = 0 [0%] versus n = 1 [3.2%], p = 0.36) (Fig. 2). In group A, a surgical drain was used in 24 cases (77.4%), while no cases in group B were drained.Fig. 1Seroma ratesFig. 2Haematoma rates CONCLUSION: The use of FSTG appears to significantly reduce the risk of post-parotidectomy seroma/sialocele formation and facilitates safe, drain-free daycase surgery. We hope this report will prompt other departments to consider using this technique and that our findings will help foster further appraisal in larger, prospective studies going forward.

TP53 mutations in head and neck cancer cells determine the Warburg phenotypic switch creating metabolic vulnerabilities and therapeutic opportunities for stratified therapies.

Patients with mutated TP53 have been identified as having comparatively poor outcomes compared to those retaining wild-type p53 in many cancers, including squamous cell carcinomas of the head and neck (SCCHN). We have examined the role of p53 in regulation of metabolism in SCCHN cells and find that loss of p53 function determines the Warburg effect in these cells. Moreover, this metabolic adaptation to loss of p53 function creates an Achilles' heel for tumour cells that can be exploited for potential therapeutic benefit. Specifically, cells lacking normal wild-type p53 function, whether through mutation or RNAi-mediated downregulation, display a lack of metabolic flexibility, becoming more dependent on glycolysis and losing the ability to increase energy production from oxidative phosphorylation. Thus, cells that have compromised p53 function can be sensitised to ionizing radiation by pre-treatment with a glycolytic inhibitor. These results demonstrate the deterministic role of p53 in regulating energy metabolism and provide proof of principle evidence for an opportunity for patient stratification based on p53 status that can be exploited therapeutically using current standard of care treatment with ionising radiation.

Innate and adaptive nasal mucosal immune responses following experimental human pneumococcal colonization.

Streptococcus pneumoniae (Spn) is a common cause of respiratory infection, but also frequently colonizes the nasopharynx in the absence of disease. We used mass cytometry to study immune cells from nasal biopsy samples collected following experimental human pneumococcal challenge in order to identify immunological mechanisms of control of Spn colonization. Using 37 markers, we characterized 293 nasal immune cell clusters, of which 7 were associated with Spn colonization. B cell and CD8+CD161+ T cell clusters were significantly lower in colonized than in non-colonized subjects. By following a second cohort before and after pneumococcal challenge we observed that B cells were depleted from the nasal mucosa upon Spn colonization. This associated with an expansion of Spn polysaccharide-specific and total plasmablasts in blood. Moreover, increased responses of blood mucosal associated invariant T (MAIT) cells against in vitro stimulation with pneumococcus prior to challenge associated with protection against establishment of Spn colonization and with increased mucosal MAIT cell populations. These results implicate MAIT cells in the protection against pneumococcal colonization and demonstrate that colonization affects mucosal and circulating B cell populations.

Defining the role of surgical drainage in paediatric deep neck space infections.

OBJECTIVES: Surgical drainage is the traditional mainstay of treatment of paediatric deep neck space infection (DNSI), but recently non-operative management in selected cases has been advocated. We sought to identify any characteristics predictive of requirement for surgical intervention. DESIGN: Retrospective cohort study using receiver operating characteristics analyses. SETTING: Tertiary referral paediatric hospital. PARTICIPANTS: Children (≤16 years) with a radiologically confirmed diagnosis of retro- or parapharyngeal abscess over a ten-year period. MAIN OUTCOME MEASURES: Predictive value of clinical and radiological variables in determining the requirement for surgical intervention. Length of hospital stay (LoS) was also examined. RESULTS: Ninety-three children were studied, 15 (16.1%) of whom underwent immediate surgery, 42 (45.2%) of whom underwent delayed surgery following an initial period of conservative management, and 36 (38.7%) of whom were managed conservatively. Age, WCC and CRP were not predictive of the need for surgical drainage. Radiological abscess diameter, however, was predictive of requirement surgery (AUC = 0.85 [95% CI ± 0.09] P = 0.02), with a cut-off value of 2.5 cm determined assuming equal weight to sensitivity and specificity. All DNSIs were successfully treated with no adverse outcomes, and there was no significant difference in LoS between groups. In those managed surgically, outcome and LoS did not depend on yield of pus. CONCLUSIONS: Selected paediatric DNSIs can be successfully managed conservatively, with abscess diameter >2.5 cm a significant predictor of need for surgical intervention. Any benefit of surgery does not appear to depend on intra-operative yield of pus.

Innate and adaptive nasal mucosal immune responses following experimental human pneumococcal colonization

Streptococcus pneumoniae (Spn) is a common cause of respiratory infection, but also frequently colonizes the nasopharynx in the absence of disease. We used mass cytometry to study immune cells from nasal biopsy samples collected following experimental human pneumococcal challenge in order to identify immunological mechanisms of control of Spn colonization. Using 37 markers, we characterized 293 nasal immune cell clusters, of which 7 were associated with Spn colonization. B cell and CD161+CD8+ T cell clusters were significantly lower in colonized than in noncolonized subjects. By following a second cohort before and after pneumococcal challenge we observed that B cells were depleted from the nasal mucosa upon Spn colonization. This associated with an expansion of Spn polysaccharide–specific and total plasmablasts in blood. Moreover, increased responses of blood mucosa-associated invariant T (MAIT) cells against in vitro stimulation with pneumococcus prior to challenge associated with protection against establishment of Spn colonization and with increased mucosal MAIT cell populations. These results implicate MAIT cells in the protection against pneumococcal colonization and demonstrate that colonization affects mucosal and circulating B cell populations.

Innate and adaptive nasal mucosal immune responses following experimental human pneumococcal colonization

Streptococcus pneumoniae (Spn) is a common cause of respiratory infection, but also frequently colonizes the nasopharynx in the absence of disease. We used mass cytometry to study immune cells from nasal biopsy samples collected following experimental human pneumococcal challenge in order to identify immunological mechanisms of control of Spn colonization. Using 37 markers, we characterized 293 nasal immune cell clusters, of which 7 were associated with Spn colonization. B cell and CD161+CD8+ T cell clusters were significantly lower in colonized than in noncolonized subjects. By following a second cohort before and after pneumococcal challenge we observed that B cells were depleted from the nasal mucosa upon Spn colonization. This associated with an expansion of Spn polysaccharide–specific and total plasmablasts in blood. Moreover, increased responses of blood mucosa-associated invariant T (MAIT) cells against in vitro stimulation with pneumococcus prior to challenge associated with protection against establishment of Spn colonization and with increased mucosal MAIT cell populations. These results implicate MAIT cells in the protection against pneumococcal colonization and demonstrate that colonization affects mucosal and circulating B cell populations.

Gaviscon® Advance alone versus co-prescription of Gaviscon® Advance and proton pump inhibitors in the treatment of laryngopharyngeal reflux.

OBJECTIVES: Management of laryngopharyngeal reflux (LPR) typically comprises alginates and proton pump inhibitors (PPIs) alone or in combination, yet evidence to support any particular treatment regimen is lacking. We sought to evaluate the efficacy of Gaviscon® Advance alone versus co-prescription with a PPI in treating LPR. METHODS: One hundred consecutive LPR patients with a reflux symptom index (RSI) score > 10 attending our joint voice clinic (JVC) were studied prospectively. All were treated with Gaviscon® Advance four times daily. If patients had been started on a PPI prior to their JVC attendance, this was optimised to a twice-daily dosing regimen and continued. RSI scores were recorded at first attendance and 3 months post-treatment via postal questionnaire. Scores were analysed using t tests and Levene's test for equality of variances. RESULTS: Follow-up RSI scores were returned by 72 patients, 39 of whom were treated with Gaviscon® Advance only (group A) and 33 with Gaviscon® Advance + PPI (group B). Mean pre-treatment RSI scores were similar between groups [group A: 19.2, 95% confidence interval (CI) ± 2.4; group B: 21.3, 95% CI ± 3.2 (p = 0.65)]. No significant differences were observed with respect to 3-month post-treatment RSI scores [group A: 9.9, 95% CI ± 2.8; group B: 12.6, 95% CI ± 4.2 (p = 0.82)] and change in RSI scores [group A: 9.3, 95% CI ± 3.0; group B: 8.7, 95% CI ± 2.9 [p = 0.75]). CONCLUSIONS: Gaviscon® Advance alone is effective in treating symptoms of LPR, while co-prescription with a high-dose PPI offers no additional benefit.

Metabolic signature of squamous cell carcinoma of the head and neck: Consequences of TP53 mutation and therapeutic perspectives.

There is a pressing need to identify ways of sensitising squamous cell carcinomas of the head and neck (SCCHN) to the effects of current treatments, both from oncological and functional perspectives. Alteration to cellular metabolism is now widely considered a hallmark of the cancer phenotype; presents a potentially attractive therapeutic target in this regard; and as such has received renewed research interest in recent years. However, whilst metabolic disruption may occur to some degree in all tumours, there is undoubtedly heterogeneity and detailed study of individual tumour types is paramount if effective therapeutic strategies targeting metabolism are to be developed and effectively deployed. In this review we outline current understanding of altered tumour metabolism and how these adaptations promote tumorigenesis generally. We relate this specifically to SCCHN by focusing on several recent key studies specific to SCCHN, and by discussing the role TP53 mutation may play in this metabolic switch, given the fundamental role of this oncogenic event in SCCHN tumorigenesis. Finally, we also offer insight into the potential therapeutic implications this may have in the clinical setting and make recommendations for future study.

Transoral laser microsurgery for oropharyngeal squamous cell carcinoma: A paradigm shift in therapeutic approach.

BACKGROUND: The contemporary treatment of oropharyngeal squamous cell carcinoma (SCC) is an area of debate. We report outcomes of a minimally invasive approach involving transoral laser microsurgery (TLM). METHODS: A consecutive series of patients (n = 153) undergoing primary TLM for oropharyngeal SCC from 2006 to 2013 was studied. Human papillomavirus (HPV) status was determined by p16 immunohistochemistry and high-risk HPV DNA in situ hybridization. Survival analyses were evaluated using Kaplan-Meier statistics. RESULTS: Tumor subsites included tonsil (n = 94; 61.5%), tongue base (n = 38; 24.8%), and soft palate (n = 21; 13.7%), with the majority being American Joint Committee on Cancer (AJCC) stage III/IVa (n = 124; 81.0%) and HPV-positive (n = 101; 66.0%). Three-year overall survival (OS), disease-specific survival (DSS), and disease-free survival (DFS) were 84.5%, 91.7%, and 78.2%, respectively. HPV-positivity portended favorable oncologic outcomes. One-year gastrostomy tube (G-tube) dependency was 1.3%. CONCLUSION: To the best of our knowledge, this is the largest single-center TLM oropharyngeal SCC series to date. Our data suggest that TLM +/- postoperative radiotherapy (PORT) results in at least as good oncologic outcomes as chemoradiotherapy (CRT), while conferring swallowing function advantages. © 2016 Wiley Periodicals, Inc. Head Neck , 2016 © 2016 Wiley Periodicals, Inc. Head Neck 38:1263-1270, 2016.

Relative expression of vascular endothelial growth factor isoforms in squamous cell carcinoma of the head and neck.

BACKGROUND: Alternative splicing of the vascular endothelial growth factor (VEGF) gene results in a family of antiangiogenic isoforms (VEGFxxx b), not yet investigated in squamous cell carcinoma of the head and neck (SCCHN). We examined, therefore, the prognostic value of the relative expression of VEGF isoforms in SCCHN. METHODS: A tissue microarray comprising 187 SCCHNs was studied by immunohistochemistry with total VEGF (panVEGF) and VEGFxxx b-specific antibodies, and scored by 2 assessors for intensity and proportion. Scores were combined and expression ratios calculated. RESULTS: No meaningful significant differences were observed between panVEGF, VEGFxxx b, or expression ratio, and presence of lymphatic metastasis, or overall survival. This held true when tumor subsites were analyzed independently and when human papillomavirus (HPV) was accounted for in the oropharyngeal subgroup. CONCLUSION: Differential VEGF isoform expression is not a reliable prognostic biomarker for either the clinically node negative/pathologically node-positive neck or overall survival in pharyngeal and laryngeal SCCHNs.

Stability and survival of bone-anchored hearing aid implant systems in post-irradiated patients.

Bone-anchored hearing aids (BAHAs) are based on the principle of osseointegration, which is fundamental to implant stability and survival. Previous exposure to ionising radiation may compromise this, as evidenced in relation to dental and craniofacial implants. There is a dearth of data, however, regarding BAHA implant systems in patients with previously irradiated implant sites. We sought, therefore, to investigate implant stability and survival in such patients. Patients were identified retrospectively from our electronic BAHA database. Hospital records were reviewed for demographics; operative technique; complications; and details regarding previous irradiation. Implant stability was assessed by resonance frequency analysis (RFA), generating a numerical value-implant stability quotient (ISQ). Extrapolating from dental studies, successfully loaded implants typically have ISQs of ≥60. Readings were, therefore, interpreted with respect to this. Seven patients were identified for inclusion. Mean time between irradiation and implant insertion was 33 months (range 16-72 months), and mean time from implant insertion to RFA measurement was 41 months (range 3-96 months). Operatively, all patients underwent single-stage procedures under local anaesthesia. One patient suffered a Holger's grade 2 skin reaction, while two suffered significant skin flap failure, requiring revision procedures. The implant survival rate was 100 %. All ISQ values were >60, with a mean of 66.9 (95 % confidence interval 63.1-70.6). Our data support sufficient osseointegration of BAHA implant systems in post-irradiated patients, but highlight issues with wound healing. Contemporary soft tissue preservation operative techniques will likely overcome this, facilitating safe and efficacious BAHA insertion in this ever-increasing group of patients.

Transoral laser microsurgery for early and moderately advanced laryngeal cancers: outcomes from a single centralised United Kingdom centre.

Transoral laser microsurgery (TLM) represents an important treatment for selected laryngeal cancers. Utilisation of TLM, however, is highly variable between United Kingdom (UK) centres, and published data relating to its use in the UK is scarce. We report outcomes from our tertiary referral centre, and highlight lessons learned. Patients undergoing primary TLM for laryngeal cancer with curative intent (2007-2011) were studied retrospectively. Survival analyses were evaluated using the Kaplan-Meier method and log-rank statistics used to examine the influence of several variables. Overall, 170 cases were included-153 glottic and 17 supraglottic. Median follow-up was 39 months (range 14-79 months). Respective 3-year local control (LC), overall survival (OS), disease-specific survival (DSS), and disease-free survival were 92, 92, 98, and 86 % for glottic carcinomas. Three-year LC and OS were both 88 % for supraglottic carcinomas. For glottic cases, a significant impact of pT stage on DSS was observed, and of age on OS. Median hospital stay was one and 19 days for glottic and supraglottic cases respectively, with respective 3-year laryngeal preservation rates of 97 and 94 %, and tracheostomy rates of 0 and 29 %. One patient in the glottic group and four in the supraglottic group failed to regain swallowing function post-operatively, remaining either PEG dependent or undergoing functional total laryngectomy. Our series confirms the oncological and functional efficacy of TLM, offering a unique large-scale UK perspective. Our experience indicates, however, that treatment of larger supraglottic tumours should be considered carefully, as functional outcomes may be compromised.