Validation of NRG Oncology's prognostic nomograms for oropharyngeal cancer in the Veterans Affairs database

BACKGROUND

To test whether nomograms developed by NRG Oncology for oropharyngeal squamous cell carcinoma (OPSCC) patients could be validated in an independent population-based sample.

METHODS

The authors tested nomograms for estimating progression-free survival (PFS) and overall survival (OS) in patients from the Veterans Health Administration with previously untreated locoregionally advanced OPSCC, diagnosed between 2008 and 2017, managed with definitive radiotherapy with or without adjuvant systemic therapy. Covariates were age, performance status, p16 status, T/N category, smoking history, education history, weight loss, marital status, and anemia. We used multiple imputation to handle missing data and performed sensitivity analyses on complete cases. Validation was assessed via Cox proportional hazards models, log-rank tests, and c-indexes.

RESULTS

A total of 4007 patients met inclusion criteria (658 patients had complete data). Median follow-up time was 3.20 years, with 967 progression events and 471 noncancer deaths. Each risk score was associated with poorer outcomes per unit increase (PFS score, hazard ratio [HR], 1.42 [1.37-1.47]; OS score, HR, 1.40 [1.34-1.45]). By risk score quartile, 2-year PFS estimates were 89.2%, 78.5%, 65.8%, and 48.3%; OS estimates were 92.6%, 83.6%, 73.9%, and 51.3%, respectively (P < .01 for all comparisons). C-indices for models of PFS and OS were 0.65 and 0.67, for all patients, respectively (0.69 and 0.73 for complete cases). The nomograms slightly overestimated PFS and OS in the overall cohort but exhibited high agreement in complete cases.

CONCLUSIONS

NRG nomograms were effective for predicting PFS and OS for patients with OPSCC, supporting their broader applicability in the OPSCC population undergoing definitive radiotherapy.

Outcomes After Oral Cavity and Oropharyngeal Salvage Surgery

OBJECTIVES

Investigate outcomes following oral cavity and oropharyngeal salvage surgery.

METHODS

Adult patients who underwent salvage surgery for recurrent squamous cell carcinoma of the oral cavity and oropharynx from 1996 to 2018 were analyzed using multivariable Cox proportional hazards regression. Disease-free survival (DFS), overall survival (OS), associated factors, and basic quality measures were analyzed.

RESULTS

One hundred and eight patients (72% oral cavity, 28% oropharynx) were followed for a median of 17.9 months. Median DFS and OS were 9.9 and 21 months, respectively. Surgery with adjuvant chemoradiotherapy compared to surgery alone (hazard ratio [HR] = 0.15, 95% confidence interval [CI]: 0.03-0.78) and negative margins (HR = 0.36, 95% CI: 0.14-0.90) were associated with better DFS, while lymphovascular space invasion (LVSI) (HR = 2.66, 95% CI: 1.14-6.19) and higher stage (III vs. I-II, HR = 3.94, 95% CI: 1.22-12.71) were associated with worse DFS. Higher stage was associated with worse OS (HR = 3.79, 95% CI: 1.09-13.19). Patients were hospitalized for a median of 8 days with 24% readmitted within 30 days. A total of 72% and 38% of patients, respectively, underwent placement of a feeding tube or tracheostomy.

CONCLUSIONS

After oral cavity and oropharyngeal salvage surgery, adjuvant chemoradiotherapy, negative margins, negative LVSI, and lower stage were associated with a lower risk of recurrence. Only lower-stage disease was associated with improved survival. The majority of patients had feeding tubes, half underwent free tissue transfer, a third required tracheostomy, and a quarter was readmitted.

LEVEL OF EVIDENCE

3 Laryngoscope, 2022.

Development of second primary malignancies after transoral surgery in human papilloma virus-positive oropharyngeal squamous cell carcinoma

BACKGROUND

Little data exists regarding the incidence of oropharyngeal and upper aerodigestive tract (UADT) second primary malignancies (SPM) among human papilloma virus (HPV)-positive oropharyngeal squamous cell carcinoma (OPSCC). Here we evaluate SPM rates among patients with HPV-related OPSCC.

METHODS

A retrospective cohort study of 412 patients with HPV-related OPSCC who underwent transoral resection +/- adjuvant therapy at a single center between 1996 and 2018.

RESULTS

Twenty patients (4.9%) developed SPM of the UADT, nine (2.2%) occurring in the oropharynx. Median time to diagnosis was 59.5 months (0-173 months). Risk of SPM was lower for patients receiving adjuvant radiation (aHR: 0.25, 95%CI: 0.08-0.78). There was no difference in overall or disease-free survival between those with and without SPM.

CONCLUSION

The rate of SPM among patients with HPV-positive OPSCC is lower than reported rates among HPV-negative OPSCC. To date, this is the largest study evaluating SPM in patients with surgically treated HPV-positive OPSCC.

Effects of oral screen exercise on orofacial and pharyngeal activity: An exploratory study using videofluoroscopy and surface electromyography in healthy adults

Objective

The oral screen is a device commonly used for treatment of orofacial disorders. The objective of this exploratory study was to examine the effect of oral screen exercise on the muscle activity in the lips, submental complex, masseter muscle, and kinematic activity of the tongue base, soft palate, pharynx, and larynx in healthy adults. This was compared with the kinematic activity during a dry swallow. It was hypothesized that not only the lip musculature but also other structures in the oral and pharyngeal cavities are activated while using an oral screen device.

Method

Ten healthy subjects used an oral screen during examination with videofluoroscopy and surface electromyography (EMG). Three different instructions for oral screen application and a dry swallow were examined.

Results

The lip muscles showed the highest activity during oral screen exercise. The other muscle groups were activated to a lesser degree. The pattern of activation differed between individuals. Compared with a dry swallow, the range of motion of the tongue base, posterior pharyngeal wall, and the larynx was significantly smaller during oral screen activation. No major differences were found between three different instructions.

Conclusion

This study indicates that the lips and submental complex and, to a lesser degree, oral, pharyngeal, and laryngeal structures are activated with the oral screen, but the pattern of activation varied between individuals. In comparison to the activity during a dry swallow, range of motion during oral screen exercise is small.

The role of saliva PCR assay in the diagnosis of COVID-19

INTRODUCTION

The introduction of a self-collection sampling method with less discomfort would be of great benefit in reducing the risk of medical provider's contamination and patient's acceptance. The aim of the present study was to investigate saliva samples' diagnostic performance for the COVID-19 RT-PCR test compared to pharyngeal swabs.

METHODOLOGY

From individuals referred to a medical center with presentations compatible with COVID-19 who were eligible for molecular diagnostic tests, 80 cases were selected. Nasopharyngeal and oropharyngeal swabs (placed into the same transport tube) along with self-collected saliva sample were taken from each participant for COVID-19 RT-PCR assay. The results of pharyngeal swabs and saliva sample were compared.

RESULTS

Sixty-two (78%) infected cases were detected, of whom 31 (39%) cases tested positive for both pharyngeal swab and saliva samples. 24 (30%) and 7 (9%) cases tested positive only for pharyngeal or saliva samples, respectively. The overall percentage of agreement between pharyngeal swab and saliva sample was 61%, with a kappa value of 0.24 (p-value = 0.019, 95% CI: 0.04-0.44), showing a fair level of agreement. The diagnostic sensitivity of pharyngeal swabs was 88.71% (95% CI: 78.11-95.34), and the diagnostic sensitivity of saliva samples was 61.29% (95% CI: 48.07-73.40). Compared to pharyngeal swabs (oropharyngeal and nasopharyngeal swabs in the same collection tube), an important observation was that seven more positive cases were detected among saliva samples.

CONCLUSIONS

The findings of the present study indicated that self-collected saliva samples cannot replace pharyngeal swabs. Still, saliva samples significantly increased the case detection rate and can be used along with pharyngeal swabs.

Complete Response to Nivolumab in Recurrent/Metastatic HPV-Positive Head and Neck Squamous Cell Carcinoma Patient After Progressive Multifocal Leukoencephalopathy: A Case Report

In an immune-competent context nivolumab showed long-term benefit in overall survival in recurrent/metastatic head and neck squamous cell carcinoma (HNSCC); however, in special cancer population such as these patients with immunodeficiency and viral infections, data on checkpoint inhibitors (ICI) activity are scant. Herein, we report a patient with a Human papilloma virus (HPV)-related oropharyngeal cancer (OPC) and CD4 lymphocytopenia. After a first-line treatment complete remission, the patient experienced Human Polyomavirus (JCV) infection in the brain. Consequently, to the recovery from progressive multifocal leukoencephalopathy (PML) the patient metastasized and was enrolled in a single-arm trial with nivolumab (EudraCT number: 2017-000562-30). A complete and durable response (more 3 years) was observed after 10 nivolumab injections Q2wks, interrupted for persistent drug related G2 diarrhea and a syndrome of inappropriate antidiuretic hormone secretion. We describe the circulating immune profile (before-, during-, and after nivolumab), consistent with the clinical history. Moreover, during nivolumab treatment, brain MRI evidenced the presence of small punctuate areas of contrast enhancement, reflecting a mild immune response in perivascular spaces. By cytofluorimetry, we observed that during JCV infection the CD4/CD8 ratio of the patient was under the normal values. After JCV infection recovery and before nivolumab treatment, CD4/CD8 ratio reached the normality threshold, even if the CD4⁺ T cell count remained largely under the normal values. During ICI, gene expression xCell analyses of circulating immune cells of the patient, showed a progressive normalization of the total immune profile, with significant boost in CD4⁺ and CD8⁺ T cells and a reduction in NK T, comparable to the circulating immune profile of reference tumor-free HNSCC patients. The present case supports the activity of ICI in a population of special cancer patients; whether JCV and HPV infections (alone or together) might have a possible role as immune booster(s), require further investigations.

Analysis of the results of radiotherapy and chemoradiotherapy on the background of immunotherapy of patients with cancer of the oral cavity and oropharynx

BACKGROUND

Advances in medicine, especially in the field of immunology in oncology, contribute to the development of new ways and methods of treating cancer of the oral cavity and oropharynx. Preclinical and clinical studies of cytokine and dendritic cell therapy, blockade of immune checkpoints, T cell uptake, treatment with monoclonal antibodies and peptide vac-cines are performed. Some of these immunotherapeutic drugs are introduced into medical practice. Changes in the immune system of patients with cancer of the oral cavity and oropharynx justify the feasibility of further targeted research of new immunotherapeutic effects on malignant tumors.

MATERIALS AND METHODS

The article represents the data of the analysis of antitumor immunity in 61 patients with cancer of the oral cavity and oropharynx who re-ceived (chemo) radiotherapy against the background of immunotherapy with the immune agent containing alpha/beta-defensins, and compares laboratory indices with clinical observation of tumor regression in patients. The influence of the immune agent containing alpha/beta-defensins was determined by analyzing the changes in the absolute and relative numbers of lymphocytes, the number of CD3+ T cells, natural killers (NK) and natural killer T cells (NKT cells).

RESULTS

The preparation containing alpha/beta-defensins has been found to enhance cytostatic antitumor effect of (chemo) radiotherapy, having a dose-dependent and cytoprotective effects considering NK cells, so the immune response to the tumor development is enhanced with the use of this agent. The data of laboratory examination of immune status correspond to the direct results of tumor regression in patients with cancer of the oral cavity and oropharynx. Clinically higher regression indices are in patients receiving radiotherapy with immunotherapy at doses of 40 and 60mg.

CONCLUSION

We confirmed the antitumor efficacy of the immunomodulatory agent containing alpha/beta-defensins in the treatment of patients with squamous cell carcinoma of the oral cavity and oropharynx and the reasonability of its use  on the clinic.

Primary pharyngeal synovial sarcoma in a pediatric patient: A case report

RATIONALE

Synovial sarcoma is a rare malignant tumor that typically originates from the soft tissue of the extremities. The occurrence of primary pharyngeal synovial sarcoma is even rarer, and few studies have reported its radiological features. Here, we report a case of pediatric primary pharyngeal synovial sarcoma and describe the conventional and advanced magnetic resonance imaging (MRI) findings with pathologic correlation.

PATIENT CONCERNS

An 11-year-old girl presented to the otolaryngologic clinic with dysphagia.

DIAGNOSIS

Laryngoscopy revealed a large mass in the oropharynx. MRI revealed a well-defined soft tissue mass with a maximal diameter of approximately 5 cm originating from the submucosal space of the oropharynx. The mass was primarily solid and showed homogeneous contrast-enhancement. The mass was hypointense on T1-weighted images and hyperintense on T2-weighted images. The mass showed a homogeneously low apparent diffusion coefficient value on diffusion-weighted imaging, which indicated high tumor cellularity. Dynamic contrast-enhanced MRI revealed a hypovascular tumor with low values of the volume transfer constant between the extracellular extravascular space and blood plasma and blood plasma volume per unit tissue volume. Amide proton transfer-weighted MRI revealed a relatively high amide proton transfer signal in the tumor, indicating a high protein/peptide component. The patient underwent partial surgical resection of the tumor, and the diagnosis of biphasic synovial sarcoma was confirmed on postoperative pathological examination.

INTERVENTION

The patient was started on chemotherapy with vincristine, ifosfamide, doxorubicin, and etoposide.

OUTCOMES

The tumor did not respond to the 3 cycles of the chemotherapy. Thus, the patient underwent second surgery and subsequent radiation therapy. The patient is now under ifosfamide/carboplatin/etoposide chemotherapy.

LESSON

Synovial sarcoma should be considered in the differential diagnosis of pediatric oropharyngeal submucosal tumors. Multimodal MRI may aid diagnosis, although the final diagnosis should be based on the postoperative pathological examination findings.

[Microbiocenosis-regulating therapy of inflammatory pathology of the oropharynx]

Inflammatory pathology of the oropharynx, which does not lose its relevance, is a problem that is of interest to doctors of various specialties. As one of the main causes of inflammatory diseases of the pharynx, the influence of microorganisms, primarily viruses, on the mucous membrane of the upper respiratory tract is indicated. The authors of the article emphasize the importance of preserving the indigenous microbiota, which provides a barrier function and prevents the adhesion and colonization of pathogenic microorganisms. In this regard, the most effective and safe is local microbiocenosis-regulatory therapy using lysozyme, a natural peptide that has antiseptic, anti-inflammatory and immunoregulatory effects. As such a drug, the authors recommend the combined drug Lorolizin, which can be used in the treatment of acute pharyngitis, acute tonsillitis, and adenoiditis.

Salivary HPV Persistence Following Treatment of Oropharyngeal Squamous Cell Carcinoma

OBJECTIVE

To determine the persistence of human papillomavirus (HPV) infection following treatment of HPV-positive oropharyngeal squamous cell carcinoma (HPV + OPSCC).

METHODS

A cross-sectional study was undertaken at The Ottawa Hospital (Ottawa, ON, Canada), a tertiary academic hospital and regional cancer center. Adult patients who were diagnosed with HPV + OPSCC between the years of 2014 and 2016 and treated with curative intent, and who were alive and willing to consent were eligible for inclusion. A saliva assay was used to test for the presence of HPV DNA in a random sample of patients. qPCR was used to amplify DNA from saliva samples.

RESULTS

Saliva samples were obtained from 69 patients previously treated with HPV + OPSCC. All patients had a minimum of 2 years of follow-up. 5 patients tested positive for HPV: 2 were positive for HPV-16, 2 for HPV-18, and 1 "other" HPV type. No patient in our study cohort had suffered recurrence post-treatment.

CONCLUSIONS

This study is the first to demonstrate the prevalence of persistent oncogenic HPV DNA in saliva following treatment for HPV + OPSCC. This prevalence appears to be low, despite the fact that persistent HPV infection is a precursor for the development of HPV + OPSCC. This finding raises questions about what factors influence the clearance or persistence of HPV DNA in saliva after treatment for HPV + OPSCC, and may add to our understanding about the longitudinal effects of HPV infection in these cancers.

Current Therapeutic Strategies in Patients with Oropharyngeal Squamous Cell Carcinoma: Impact of the Tumor HPV Status

Simple Summary

Contrary to other head and neck subsites, oropharyngeal squamous cell carcinoma (OPSCC) has shown a considerable increase in incidence over the past 20 years. This growing incidence is largely due to the increasing place of human papillomavirus (HPV)-related tumors. HPV-positive and HPV-negative OPSCC are two distinct entities with considerable differences in terms of treatment response and prognosis. However, there are no specific recommendations yet in the therapeutic management of OPSCC patients according to their tumor HPV-status. The aim of this review is therefore to discuss the therapeutic management of patients with OPSCC and the impact of HPV status on treatment selection.

Abstract

Since there is no published randomized study comparing surgical and non-surgical therapeutic strategies in patients with oropharyngeal squamous cell carcinoma (OPSCC), the therapeutic management of these patients remains highly controversial. While human papillomavirus (HPV)-positive and HPV-negative OPSCC are now recognized as two distinct diseases with different epidemiological, biological, and clinical characteristics, the impact of HPV status on the management of OPSCC patients is still unclear. In this review, we analyze the current therapeutic options in patients with OPSCC, highlighting the most recent advances in surgical and non-surgical therapies, and we discuss the impact of HPV status on the therapeutic strategy.

A FOUR PROBIOTIC PREPARATION FOR VENTILATOR-ASSOCIATED PNEUMONIA IN MULTI-TRAUMA PATIENTS: RESULTS OF A RANDOMIZED CLINICAL TRIAL

The role of probiotics for the prevention of ventilator-associated pneumonia remains inconclusive. Our aim was to assess the efficacy of a probiotics regimen for VAP prophylaxis in mechanically ventilated multi-trauma patients, intubated immediately after the injurious insult. In a randomized, placebo-controlled study enrolling multi-trauma patients, anticipated to require mechanical ventilation for more than 10 days were randomly assigned to receive prophylaxis either with a probiotic formula [n=59] or placebo [n=53]. The probiotic formula was a preparation of Lactobacillus acidophilus LA-5 (1.75 × 10⁹ cfu), L. plantarum (0.5 × 10⁹ cfu), B. lactis BB-12 (1.75 × 10⁹ cfu) and S. boulardii (1.5 × 10⁹ cfu) per sachet. Each patient received two sachets twice daily for 15 days; one through the nasogastric tube; and another spread on the oropharynx. The incidence of VAP was the primary endpoint. The incidence of other infections and sepsis and the duration of hospital stay were the secondary endpoints. Probiotics administration reduced notably the incidence of VAP [11.9% vs 28.3%, odds ratio 0.34, 95%CIs 0.13-0.92, p=0.034] and of sepsis [6.8% vs 24.5%, OR 0.22, 95% CIs 0.07-0.74, p=0.016]. Furthermore, probiotics prophylaxis decreases the time of stay in the intensive care unit (ICU) and of hospital stay. The prophylactic use of probiotics as a combination of enteral and topical application to oropharynx exerted a positive effect on the incidence of VAP and sepsis as well as on the ICU and total hospital stay in patients under protracted mechanical ventilation.

Longitudinal Morphological Changes in the Adenoids and Tonsils in Japanese School Children

The adenoid (Ad) and tonsil (Ts), located in the upper airway, play an important role in immunological protection. These lymphoid tissues grow rapidly, reach a peak of growth at the age of 6-8 years, and decrease in their size thereafter. However, little information is available on the longitudinal growth patterns of Ad and Ts in the general population. This study aimed to evaluate the individual growth of Ad and Ts during childhood using lateral cephalograms taken longitudinally from the same individuals at the ages of 8-12 years. Our results showed that the cross-sectional areas of the Ad, nasopharynx (Np), and oropharynx (Op) significantly increased with age while small changes in the size of Ts were present throughout the study period. In addition, the values of Ad/Np and Ts/Op decreased significantly with age in the elementary school. Furthermore, there was a strong and significant correlation between the Ad/Np ratio and upper airway resistance, indicating the narrowest distance in the upper airway. In conclusion, the airway occupation in Np and Op increased with age due to the increase in the sizes of Np and Op but not the decrease in the sizes of Ad and Ts.

Opioid Usage and Pain Control in Benign Oropharyngeal Surgery: An Observational Prospective Study

OBJECTIVES

Little data is available on opioid usage in the adult population for benign oropharyngeal surgery. The objective here is to evaluate opioid prescribing patterns, opioid consumption, and patient pain patterns following benign oropharyngeal surgery, specifically tonsillectomy and adenoidectomy, tonsillectomy alone, and expansion sphincter pharyngoplasty.

METHODS

Patients aged ≥18 years old and received a tonsillectomy, tonsillectomy and adenoidectomy, or expansion sphincter pharyngoplasty between November 2019 and August 2020 were included. Patients were provided a survey which included a visual analog scale for recording their pain postoperatively and the amount of opioid they had remaining.

RESULTS

About 103 patients completed the post-operative questionnaire. Patients were prescribed 38 837 morphine milligram equivalents and used 28 644: approximately 26% went unused, which is the equivalent of 1346 5 mg oxycodone pills. Opioid consumption correlated with the initial dosage: patients consumed 12% more narcotic on average as the initial prescription went upwards by 50 morphine milligram equivalents. Obstructive sleep apnea, history of smoking, and being female predicted increased opioid usage in this cohort. Pain was reported the highest on postoperative day 1. A prescription of approximately 225 morphine milligram equivalents (150 mg oxycodone) was associated with decreased opioid use in this cohort. Larger initial prescriptions did not result in fewer requests for refills.

CONCLUSION

A significant amount of opioid medication went unused in this study. A prescription of 225 morphine milligram equivalents (or 150 mg oxycodone) provided appropriate analgesia for the majority of patients. Larger prescriptions may result in increased opioid consumption and may not reduce the amount of refills. More study is needed to confirm these findings.

Mycoplasma bovis May Travel Along the Eustachian Tube to Cause Meningitis in Japanese Black Cattle

Mycoplasma bovis (M. bovis) is a common inhabitant of the upper and lower respiratory tracts of cattle and is considered to be the main aetiological agent of otitis media in calves. The eustachian tube appears to be the most common portal for pathogens to enter the middle ear. We investigated the transmission route of M. bovis causing otitis media that progressed to meningitis or meningoencephalitis in Japanese Black cattle. M. bovis was detected in 10 cases by a loop-mediated isothermal amplification method or by immunohistochemistry. One case of caseonecrotic granulomatous meningoencephalitis, one case of caseonecrotic granulomatous meningitis, one case of suppurative meningoencephalitis, eight cases of eustachitis, nine cases of tonsillitis and six cases of suppurative bronchopneumonia were identified by histopathological examination. M. bovis antigen was detected in the eustachian tubes of eight cases. In nine cases, M. bovis was also detected in tonsillar epithelial crypts and lumina, in intraluminal inflammatory cells and in the epithelial cells of minor salivary glands located around the eustachian tubes and tonsils. The results suggest that M. bovis can infect and colonize the tonsils and enter the eustachian tubes, causing otitis media, which, in cases of chronic infection, can progress to meningitis.

Assessing the impact of magnetic resonance treatment simulation (MRSIM) on target volume delineation and dose to organs at risk for oropharyngeal radiotherapy

Introduction

Assessing the use of a radiation therapy (RT) planning MRI performed in the treatment position (pMRI) on target volume delineation and effect on organ at risk dose for oropharyngeal cancer patients planned with diagnostic MRI (dMRI) and CT scan.

Methods

Diagnostic MRI scans were acquired for 26 patients in a neutral patient position using a 3T scanner (dMRI). Subsequent pMRI scans were acquired on the same scanner with a flat couch top and the patient in their immobilisation mask. Each series was rigidly registered to the patients planning CT scan and volumes were first completed with the CT/dMRI. The pMRI was then made available for volume modification. For the group with revised volumes, two IMRT plans were developed to demonstrate the impact of the modification. Image and registration quality was also evaluated.

Results

The pMRI registration led to the modification of target volumes for 19 of 26 participants. The pMRI target volumes were larger in absolute volume resulting in reduced capacity for organ sparing. Predominantly, modifications occurred for the primary gross tumour volume (GTVp) with a mean Dice Similarity Coefficient (DSC) of 0.7 and the resulting high risk planning target volume, a mean DSC of 0.89. Both MRIs scored similarly for image quality, with the pMRI demonstrating improved registration quality and efficiency.

Conclusions

A pMRI provides improvement in registration efficiency, quality and a higher degree of oncologist confidence in target delineation. These results have led to a practice change within our department, where a pMRI is acquired for all eligible oropharyngeal cancer patients.

The conundrum of pharyngeal teeth origin: the role of germ layers, pouches, and gill slits

There are several competing hypotheses on tooth origins, with discussions eventually settling in favour of an 'outside-in' scenario, in which internal odontodes (teeth) derived from external odontodes (skin denticles) in jawless vertebrates. The evolution of oral teeth from skin denticles can be intuitively understood from their location at the mouth entrance. However, the basal condition for jawed vertebrates is arguably to possess teeth distributed throughout the oropharynx (i.e. oral and pharyngeal teeth). As skin denticle development requires the presence of ectoderm-derived epithelium and of mesenchyme, it remains to be answered how odontode-forming skin epithelium, or its competence, were 'transferred' deep into the endoderm-covered oropharynx. The 'modified outside-in' hypothesis for tooth origins proposed that this transfer was accomplished through displacement of odontogenic epithelium, that is ectoderm, not only through the mouth, but also via any opening (e.g. gill slits) that connects the ectoderm to the epithelial lining of the pharynx (endoderm). This review explores from an evolutionary and from a developmental perspective whether ectoderm plays a role in (pharyngeal) tooth and denticle formation. Historic and recent studies on tooth development show that the odontogenic epithelium (enamel organ) of oral or pharyngeal teeth can be of ectodermal, endodermal, or of mixed ecto-endodermal origin. Comprehensive data are, however, only available for a few taxa. Interestingly, in these taxa, the enamel organ always develops from the basal layer of a stratified epithelium that is at least bilayered. In zebrafish, a miniaturised teleost that only retains pharyngeal teeth, an epithelial surface layer with ectoderm-like characters is required to initiate the formation of an enamel organ from the basal, endodermal epithelium. In urodele amphibians, the bilayered epithelium is endodermal, but the surface layer acquires ectodermal characters, here termed 'epidermalised endoderm'. Furthermore, ectoderm-endoderm contacts at pouch-cleft boundaries (i.e. the prospective gill slits) are important for pharyngeal tooth initiation, even if the influx of ectoderm via these routes is limited. A balance between sonic hedgehog and retinoic acid signalling could operate to assign tooth-initiating competence to the endoderm at the level of any particular pouch. In summary, three characters are identified as being required for pharyngeal tooth formation: (i) pouch-cleft contact, (ii) a stratified epithelium, of which (iii) the apical layer adopts ectodermal features. These characters delimit the area in which teeth can form, yet cannot alone explain the distribution of teeth over the different pharyngeal arches. The review concludes with a hypothetical evolutionary scenario regarding the persisting influence of ectoderm on pharyngeal tooth formation. Studies on basal osteichthyans with less-specialised types of early embryonic development will provide a crucial test for the potential role of ectoderm in pharyngeal tooth formation and for the 'modified outside-in' hypothesis of tooth origins.

Therapeutic strategies: Surgery for human papillomavirus-associated oropharyngeal carcinoma

Treatment of oropharyngeal cancer (OPC) has undergone considerable evolution since the discovery of human papillomavirus (HPV)-associated OPC. It is widely understood that HPV OPC affects a younger population and standard treatment offers improved oncologic outcomes compared with non-HPV OPC but can cause significant toxicities and long-term side effects. Surgery for treatment de-escalation is an active area of research. The purpose of this review is to explore surgery as it relates to the treatment of HPV OPC with a focus on the evolution of treatment, rationale for surgery, surgical techniques, outcomes, and the role of surgery in de-escalation of treatment.

A retrospective analysis of surgery in prestyloid parapharyngeal tumors: Lateral approaches vs transoral robotic surgery

OBJECTIVE

Surgery is the standard treatment for most tumors in the prestyloid parapharyngeal space (PPS) but it can be a challenging procedure because of the anatomical complexity of the area. Prestyloid surgery can be performed with various lateral approaches or with a medial approach using transoral robotic surgery (TORS)-either alone or in combination with a transcervical incision. We have retrospectively compared our center's results with lateral and medial approaches.

METHODS

Between 2015 and 2020, 28 patients with prestyloid PPS tumors underwent surgery at our center: 14 with lateral approaches, including transcervical, transcervical-parotid, and transcervical-mandibular, and 14 with medial approaches (12 with TORS and two with TORS plus a transcervical incision). We compared surgical time, postsurgical complications, length of hospital stay, need for feeding tube, and relapse-free survival in the two patient groups.

RESULTS

Pleomorphic adenoma was the most frequent tumor and 60.7% of the tumors were benign. Tumor volume and maximum length were similar in the two groups of patients. Intraoperative image guidance and ultrasound were used in 33% of TORS. TORS was associated with less surgical time, fewer complications, and shorter hospital stays. Recurrence rates were similar in the two groups.

CONCLUSION

The medial approach by TORS offers superior results in prestyloid tumors than the open lateral approach and can be refined by intraoperative guidance. Level of Evidence: 4.

Tumor detection with transoral use of flexible endoscopy for unknown primary head and neck cancer

OBJECTIVES

With the advent of new optical technologies, early pharyngolaryngeal cancerous lesions can be better visualized. Although the conventional transnasal approach offers great views of the hypopharynx and larynx, the visualization of the oropharynx and palatine tonsils is limited. Through the transoral insertion of a flexible video-laryngoscope, direct views of the oropharynx and oral cavity can be obtained. Thus, transoral examination may contribute to primary detection of cancers of unknown primary (CUP).

METHODS

Eighty-five CUP patients from Tokai University were included retrospectively in this study, from 2006 to 2017. Starting in 2010, we employed the transoral examination in addition to our conventional method. The primary detection rates were compared before and after 2010. Oropharyngeal primaries were further analyzed for tumor subsite and p16 status.

RESULTS

The overall primary detection rate did not improve with the addition of transoral examination. However, greater numbers of oropharyngeal primaries were detected. The oropharyngeal lesions detected by transoral examination were mainly p16 positive, located on the palatine tonsil.

CONCLUSION

Transoral examination is a noninvasive, easy method to adopt in an outpatient setting, and a promising technique to improve tumor detection in this era of human papillomavirus-associated head and neck cancers.

LEVEL OF EVIDENCE

3.

The "oral" history of COVID-19: Primary infection, salivary transmission, and post-acute implications

Severe acute respiratorysyndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19, has led to more than 3.25 million recorded deaths worldwide as of May 2021. COVID-19 is known to be clinically heterogeneous, and whether the reported oral signs and symptoms in COVID-19 are related to the direct infection of oral tissues has remained unknown. Here, we review and summarize the evidence for the primary infection of the glands, oral mucosae, and saliva by SARS-CoV-2. Not only were the entry factors for SARS-CoV-2 found in all oral tissues, but these were also sites of SARS-CoV-2 infection and replication. Furthermore, saliva from asymptomatic individuals contained free virus and SARS-CoV-2-infected oral epithelial cells, both of which were found to transmit the virus. Collectively, these studies support an active role of the oral cavity in the spread and transmission of SARS-CoV-2 infection. In addition to maintaining the appropriate use of personal protective equipment and regimens to limit microbial spread via aerosol or droplet generation, the dental community will also be involved in co-managing COVID-19 "long haulers"-now termed Post-Acute COVID-19 Syndrome. Consequently, we propose that, as SARS-CoV-2 continues to spread and as new clinical challenges related to COVID-19 are documented, oral symptoms should be included in diagnostic and prognostic classifications as well as plans for multidisciplinary care.

Increased PD-L1 and p16 expression are common in oropharyngeal squamous cell carcinoma

Overexpression of p16 is closely related to human papillomavirus (HPV)-associated oropharyngeal squamous cell carcinoma (SCC) and pertains a prognostic relevance. Programmed cell death 1-ligand 1 (PD-L1) is another important marker, as anti-PD-L1 immunotherapy is available. Retrospective analysis of 57 cases of the SCC involving oropharynx (27 cases), hypopharynx (5 cases), larynx (11 cases), and oral cavity (14 cases) was performed. Each case was scrutinized for the basaloid morphology, p16, and PD-L1 expression. Basaloid morphology was identified in 47% of total cases. The majority of basaloid SCC variants were located in the oropharynx (89%). High expression of p16 was mostly observed in the oropharynx. High PD-L1 expression was seen predominantly in oropharyngeal and hypopharyngeal locations. Further studies in a larger cohort are necessary to correlate PD-L1 and p16 expression with survival.

An Updated Review on Head and Neck Cancer Treatment with Radiation Therapy

The complexity of head and neck cancers (HNC) mandates a multidisciplinary approach and radiation therapy (RT) plays a critical role in the optimal management of patients with HNC, either as frontline or adjuvant treatment postoperatively. The advent of both definitive and post-operative RT has significantly improved the outcomes of patients with HNC. Herein, we discuss the role of postoperative RT in different subtypes of HNC, its side effects, and the importance of surveillance. The treatment regions discussed in this paper are the oral cavity, nasopharynx, paranasal sinus cavity, oropharynx, larynx and hypopharynx. Multiple studies that demonstrate the importance of definitive and/or postoperative RT, which led to an improved outlook of survival for HNC patients will be discussed.

The effect of short radiation treatment breaks on chemo-radiotherapy for oropharyngeal cancers

BACKGROUND

Numerous studies and guidelines suggest an outcome detriment from radiation treatment breaks (rTBs) and the need for compensatory dosing in patients with head and neck cancer.

METHODS

In a consecutive cohort of 521 patients with oropharyngeal squamous cell carcinoma (OPSCC), we investigated the impact of rTBs and prolongation of overall treatment time (OTT) on OS, DFS, LRC, and cancer recurrence using competing risk and multivariate analyses.

RESULTS

Neither OTT prolongation by ≤2 days nor rTBs of ≤3 days were associated with detriments to clinical outcomes. Consecutive breaks of ≥3 days were also not significantly associated with detriment to clinical outcomes. There was significantly increased competing mortality in those with longer breaks.

CONCLUSIONS

In OPSCC patients treated with definitive concurrent chemoradiotherapy, there is no significant association between disease failure and total rTBs of ≤3 consecutive or scattered days. Further investigation is needed for longer breaks.