Beta-defensin index: A functional biomarker for oral cancer detection.

There is an unmet clinical need for a non-invasive and cost-effective test for oral squamous cell carcinoma (OSCC) that informs clinicians when a biopsy is warranted. Human beta-defensin 3 (hBD-3), an epithelial cell-derived anti-microbial peptide, is pro-tumorigenic and overexpressed in early-stage OSCC compared to hBD-2. We validate this expression dichotomy in carcinoma in situ and OSCC lesions using immunofluorescence microscopy and flow cytometry. The proportion of hBD-3/hBD-2 levels in non-invasively collected lesional cells compared to contralateral normal cells, obtained by ELISA, generates the beta-defensin index (BDI). Proof-of-principle and blinded discovery studies demonstrate that BDI discriminates OSCC from benign lesions. A multi-center validation study shows sensitivity and specificity values of 98.2% (95% confidence interval [CI] 90.3-99.9) and 82.6% (95% CI 68.6-92.2), respectively. A proof-of-principle study shows that BDI is adaptable to a point-of-care assay using microfluidics. We propose that BDI may fulfill a major unmet need in low-socioeconomic countries where pathology services are lacking.

The effect of transfusion on survival in head and neck cancer after free tissue reconstruction.

Objective: To examine if perioperative blood transfusion affects overall survival (OS) and recurrence-free survival (RFS) in head and neck cancer patients who undergo free tissue reconstruction. Design: Retrospective cohort study. Methods: The medical records of free tissue flaps between 2007 and 2010 were reviewed. Differences in demographics and clinical factors based on the level of transfused packed red blood cells (PRBC) were examined using chi-squared tests, Kruskal-Wallis tests, and/or ANOVA tests. Survival time was compared using a Cox proportional hazard model. Results: Data were available for 183 patients. Patients who had PRBC transfusion significantly differed from the non-transfused group by flap type, flap with bone, Charlson Comorbidity Index (CCI), and hemoglobin and hematocrit. When stratified into three groups based on units of PRBC; flap type, flap with bone, CCI, preoperative hemoglobin, and hematocrit were found to differ significantly. The 2-year Kaplan-Meier plot demonstrated improved OS for those who did not receive any PRBC transfusion. The use of more than 3 units of blood decreased 2-year OS significantly when compared to the non-transfused group. Finally, after adjusting for CCI using a Cox proportional hazard model, survival was significantly affected by CCI. Conclusion: After controlling for patient age, oncologic stage, cancer subsite, histology, type of free flap, vascularized bone-containing flap, recurrence type, CCI, and preoperative hemoglobin and hematocrit, patients who received 3 or more units of PRBC in the perioperative period had significantly decreased OS. RFS did not differ between the transfused versus non-transfused groups. Level of Evidence: Level 4.

Free Flap Donor Sites in Head and Neck Reconstruction.

Microvascular free tissue transfer, also referred to as free flaps surgery, is a reconstructive technique that has become a foundational component of complex head and neck reconstruction. There have been considerable advancements in the field over the last 30 years including the number and variety of free flaps. Each of these free flaps has unique characteristics that must be considered for the defect when selecting a donor site. Here, the authors focus on the most common free flaps used in head and neck reconstruction.

Single cell transcriptomic analysis of HPV16-infected epithelium identifies a keratinocyte subpopulation implicated in cancer.

Persistent HPV16 infection is a major cause of the global cancer burden. The viral life cycle is dependent on the differentiation program of stratified squamous epithelium, but the landscape of keratinocyte subpopulations which support distinct phases of the viral life cycle has yet to be elucidated. Here, single cell RNA sequencing of HPV16 infected compared to uninfected organoids identifies twelve distinct keratinocyte populations, with a subset mapped to reconstruct their respective 3D geography in stratified squamous epithelium. Instead of conventional terminally differentiated cells, an HPV-reprogrammed keratinocyte subpopulation (HIDDEN cells) forms the surface compartment and requires overexpression of the ELF3/ESE-1 transcription factor. HIDDEN cells are detected throughout stages of human carcinogenesis including primary human cervical intraepithelial neoplasias and HPV positive head and neck cancers, and a possible role in promoting viral carcinogenesis is supported by TCGA analyses. Single cell transcriptome information on HPV-infected versus uninfected epithelium will enable broader studies of the role of individual keratinocyte subpopulations in tumor virus infection and cancer evolution.

Managing Oromandibular Hardware Failure after Free Flap Surgery.

Hardware failure after oromandibular reconstruction using free tissue transfer can delay additional therapies directed at cancer treatment and prevent patients from returning to normal oral function. Understanding and strict adherence to principles of rigid fixation is critical in preventing complications. Early surgical intervention for hardware exposure as well as utilization of locoregional flaps may prevent the need for more extensive revision surgery.

Association of Neoadjuvant Pembrolizumab for Oral Cavity Squamous Cell Carcinoma With Adverse Events After Surgery in Treatment-Naive Patients.

Importance: Pembrolizumab, a monoclonal antibody targeting programmed cell death 1, is currently approved by the US Food and Drug Administration for recurrent or metastatic head and neck squamous cell carcinoma (HNSCC). The potential neoadjuvant role of programmed cell death 1 inhibitors in primary surgical management of HNSCC and effects on surgical outcomes are poorly understood. Objective: To evaluate the incidence of postoperative adverse events in treatment-naive patients with advanced oral cavity cancer receiving neoadjuvant pembrolizumab when compared with matched controls, as part of a window-of-opportunity multi-institutional clinical trial assessing neoadjuvant pembrolizumab for locally advanced HNSCC. Design, Setting, and Participants: This retrospective cohort study at a single tertiary academic institution included treatment-naive patients with local regionally advanced oral cavity squamous cell carcinoma (OCSCC) who were undergoing surgical resection. Exposures: Patients with local regionally advanced resectable OCSCC who received neoadjuvant pembrolizumab were retrospectively reviewed for postoperative adverse events. Controls were matched by age, race, smoking status, and overall cancer stage based on historical data at the same institution. Matched-cohort analysis was performed using a McNemar test to assess differences between the groups. Main Outcomes and Measures: Incidence of adverse events following surgical resection of advanced OCSCC within 30 days of surgery and on continued follow-up. Results: A total of 64 patients (32 as part of the prospective clinical trial and 32 as controls; mean [SD] age, 59.6 [10.3] years; 28 [44%] women) were included in the analysis. Postoperative adverse events in the 32 patients receiving pembrolizumab included lymphedema (n = 20 [63%]), trismus (n = 7 [22%]), return to operating room (n = 7 [22%]), wound infection (n = 7 [22%]), fistula (n = 6 [19%]), wound dehiscence (n = 4 [13%]), flap failure (n = 3 [9%]), and hematoma (n = 2 [6%]). The matched control group demonstrated similar complication rates without considerable differences, except for trismus (n = 16 [50%]), which was greater by a difference of 28.1% (95% CI, 5.6%-50.6%) in the control group. Conclusions and Relevance: This cohort study examined surgical complications among patients with local regionally advanced OCSCC treated with neoadjuvant pembrolizumab and found that serious adverse events were similar to those in patients who underwent standard-of-care treatment. This suggests that there is no increased perioperative morbidity in the use of preoperative treatment with immunotherapy. Further prospective studies are needed to validate these findings for oral cavity cancer and other subsites of the head and neck.

Phase II Trial of Adjuvant Nivolumab Following Salvage Resection in Patients with Recurrent Squamous Cell Carcinoma of the Head and Neck.

PURPOSE: Locoregional relapse in patients with head and neck squamous cell carcinoma (HNSCC) is common, approaching 50% for some subsites despite multimodality therapy. Salvage surgery is the standard of care, but able to achieve durable control in only a minority of patients. While adjuvant radiotherapy or chemo-radiotherapy is offered to select patients, this approach can be prohibitively toxic. Given the activity and tolerability of programmed death-1 inhibitors in metastatic HNSCC, we investigated the safety and efficacy of adjuvant nivolumab after salvage surgical resection. PATIENTS AND METHODS: This was an open-label, multi-institutional phase II clinical trial (NCT03355560). Patients with recurrent, resectable HNSCC were enrolled within 6 weeks of salvage surgery. Six 28-day cycles of adjuvant nivolumab were planned. The primary endpoint was 2-year disease-free survival (DFS) more than 58%, based on an institutional historical control group of 71 patients with recurrent HNSCC who underwent salvage surgery. RESULTS: Between February 2018 and February 2020, 39 patients were enrolled. At a median follow-up of 22.1 months, 2-year DFS was 71.4% [95% confidence interval (CI), 57.8-88.1] and the 2-year overall survival (OS) was 73% (95% CI, 58-91.8). Three of 39 (8%) patients experienced grade 3 treatment-related adverse events and 3 of 39 (8%) discontinued treatment due to side effects. Ten of 39 had locoregional recurrence, while 2 of 10 also had synchronous metastatic disease. There was no difference in DFS between PD ligand-1 (PD-L1)-positive and PD-L1-negative patients. There was a nonsignificant trend toward improved DFS in patients with high tumor mutational burden (P = 0.083). CONCLUSIONS: Adjuvant nivolumab after salvage surgery in locally recurrent HNSCC is well tolerated and showed improved DFS compared with historical controls.

Phase II Clinical Trial of Neoadjuvant and Adjuvant Pembrolizumab in Resectable Local-Regionally Advanced Head and Neck Squamous Cell Carcinoma.

PURPOSE: Patients with resected, local-regionally advanced, head and neck squamous cell carcinoma (HNSCC) have a one-year disease-free survival (DFS) rate of 65%-69% despite adjuvant (chemo)radiotherapy. Neoadjuvant PD-1 immune-checkpoint blockade (ICB) has demonstrated clinical activity, but biomarkers of response and effect on survival remain unclear. PATIENTS AND METHODS: Eligible patients had resectable squamous cell carcinoma of the oral cavity, larynx, hypopharynx, or oropharynx (p16-negative) and clinical stage T3-T4 and/or two or more nodal metastases or clinical extracapsular nodal extension (ENE). Patients received neoadjuvant pembrolizumab 200 mg 1-3 weeks prior to surgery, were stratified by absence (intermediate-risk) or presence (high-risk) of positive margins and/or ENE, and received adjuvant radiotherapy (60-66 Gy) and concurrent pembrolizumab (every 3 weeks × 6 doses). Patients with high-risk HNSCC also received weekly, concurrent cisplatin (40 mg/m2). Primary outcome was one-year DFS. Secondary endpoints were one-year overall survival (OS) and pathologic response (PR). Safety was evaluated with CTCAE v5.0. RESULTS: From February 2016 to October 2020, 92 patients enrolled. The median age was 59 years (range, 27-80), 30% were female, 86% had stage T3-T4, and 69% had ≥N2. At a median follow-up of 28 months, one-year DFS was 97% (95% CI, 71%-90%) in the intermediate-risk group and 66% (95% CI, 55%-84%) in the high-risk group. Patients with a PR had significantly improved one-year DFS relative to patients without response (93% vs. 72%, hazard ratio 0.29; 95% CI, 11%-77%). No new safety signals were identified. CONCLUSIONS: Neoadjuvant and adjuvant pembrolizumab increased one-year DFS rate in intermediate-risk, but not high-risk, HNSCC relative to historical control. PR to neoadjuvant ICB is a promising surrogate for DFS.

Multi-Institutional Study Validates Safety of Intraoperative Cesium-131 Brachytherapy for Treatment of Recurrent Head and Neck Cancer.

INTRODUCTION: Surgery is the primary treatment for resectable, non-metastatic recurrent head and neck squamous cell carcinoma (HNSCC). We explore the safety and oncologic benefit of intraoperative Cesium-131 (Cs-131) brachytherapy combined with salvage local and/or regional surgical resection. METHODS AND MATERIALS: Findings were reported from a single arm multi-institutional prospective phase 1/2 trial involving surgery plus Cs-131 (surgery + Cs-131) treatment. The results of two retrospective cohorts-surgery alone and surgery plus intensity modulated radiation therapy (surgery + ReIMRT)-were also described. Included patients had recurrent HNSCC and radiation history. Safety, tumor re-occurrence, and survival were evaluated. RESULTS: Forty-nine patients were enrolled in the surgery + Cs-131 prospective study. Grade 1 to 3 adverse events (AEs) occurred in 18 patients (37%), and grade 4 AEs occurred in 2 patients. Postoperative percutaneous endoscopic gastrostomy (PEG) tubes were needed in 10 surgery + Cs-131 patients (20%), and wound and vascular complications were observed in 12 patients (24%). No cases of osteoradionecrosis were reported in the surgery + Cs-131 cohort. We found a 49% 2-year disease-free survival at the site of treatment with a substantial number of patients (31%) developing metastatic disease, which led to a 31% overall survival at 5 years. CONCLUSIONS: Among patients with local/regional recurrent HNSCC status-post radiation, surgery + Cs-131 demonstrated acceptable safety with compelling oncologic outcomes, as compared to historic control cohorts. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, identifiers NCT02794675 and NCT02467738.

Trends in Number of Women Speakers at the American Head and Neck Society Meetings, 2007-2019.

Importance: The number of female speakers at American Head and Neck Society (AHNS) conferences should ideally be consistent with the number of women entering head and neck surgery fellowships to ensure gender equity in the field. Yet the presence of women speakers at the annual AHNS meetings, which is specific to the field of head and neck cancer, endocrine and microvascular reconstructive surgery, has yet to be studied. Objective: To determine whether the proportion of female speakers at the AHNS has increased in a manner consistent with the numbers of women entering fellowships since 2007. Design, Setting, and Participants: This qualitative study assessed 13 final meeting programs from AHNS national/international conferences from 2007 to 2019. The number of male and female participants in different roles throughout the meeting were retrospectively tracked. Participants were male and female speakers at AHNS national/international conferences who took part in the roles of scientific session presenter, scientific session moderator, expert panelist, miscellaneous moderator, and named lecturers/keynote speaker. Gender of the speaker was determined by searching names on the internet and using available published pronouns. Main Outcomes and Measures: Number of speaking opportunities for men and women in different roles from 2007 to 2019 as well as number of men and women entering AHNS fellowships since 2007 and new active AHNS members since 2012. Results: In this qualitative study, from 2007 to 2019, 4059 speakers were identified. Of these speakers, 902 (22%) were women and 3157 (78%) were men. Overall, there was a strong correlation between increasing years and number of women speakers from 2007 to 2019 (ρ = 0.75; 95% CI, 0.72-0.78). There were 2096 invited speaking roles that excluded research presentations, of which 400 were offered to female participants (19.1%) across the study period. There were 131 different women that made up all 400 of the opportunities that were offered to women in the years surveyed. There was a strong correlation in the proportion of women as presenters for oral abstracts, expert panelists, and miscellaneous moderators between the years but no correlation in scientific session moderators and named lecturers/keynote speakers. Of the 45 named lecturers/keynote speakers in the programs tracked, only 2 were women. Conclusions and Relevance: In this study, from 2007 to 2019, the presence of women at ANHS has increased overall, reflecting the changing demographic characteristics of those entering in head and neck oncology and microvascular surgery fellowships. However, a strong disparity continues to exist for preeminent speaking opportunities.

Permanent Interstitial Cesium-131 Brachytherapy in Treating High-Risk Recurrent Head and Neck Cancer: A Prospective Pilot Study.

PURPOSE/OBJECTIVES: To establish the feasibility and safety of intraoperative placement of cesium-131 (Cs-131) seeds for re-irradiation in recurrent head and neck cancer (HNC). METHODS: Patients with resectable recurrent HNC who were deemed to have a high risk of second recurrence were eligible. Immediately after tumor extirpation, seeds were implanted in the surgical bed based on the preoperative treatment plan with intraoperative adjustment. The surgical bed and the seeds were covered with a regional flap or microvascular free flap. A CT of the neck was obtained on postoperative day 1 for evaluation of the postoperative dose distribution. Patients were followed 1 and 3 months after surgery, then every 3 months in the first 2 years. RESULTS: From November 2016 to September 2018, 15 patients were recruited and 12 patients received treatment per protocol. For the patients who had implants, the sites of initial recurrence included 10 neck alone, 1 neck and larynx, and 1 neck/peristomal. The median follow-up was 21.4 months. After surgery, patients remained hospitalized for a median of 6 days. There were no high-grade toxicities except two patients with wound complications requiring wound care. Eight patients had recurrences, three locoregional alone, three distant alone, and two with both locoregional and distant recurrences. Only one patient had an in-field failure. Five patients died, with 1- and 2-year overall survival of 75 and 58%. CONCLUSIONS: Cs-131 implant after surgical resection in recurrent HNC is feasible and safe. There were no unexpected severe toxicities. Most failures were out-of-field or distant. CLINICAL TRIAL REGISTRATION: ClinicalTrials.gov, identifier NCT02794675.

Modified Head and Neck Swallow Scale: Using EORTC-QLQ-H&N35 to Predict Overall Survival.

OBJECTIVES/HYPOTHESIS: Dysphagia is a treatment-related complication of head and neck cancer (HNCA). We demonstrate the predictive value of a modified head and neck swallow scale (m-HNSW) adapted from the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire-Head and Neck 35 (EORTC-QLQ-H&N35). STUDY DESIGN: Retrospective Cohort Study. METHODS: Retrospective, single-center cohort study utilizing a prospectively collected database of HNCA patients in a high-volume tertiary referral center. 736 HNCA patients more than 2 years from completion of treatment were identified. EORTC-QLQ-H&N35 data collected from at least one of three defined episodes of care were used. The m-HNSW uses three questions to form a 9-point dysphagia scale. A Cox proportional hazards model was used to determine the effect of the m-HNSW while controlling for demographics, tumor staging, site, and treatment. RESULTS: Using data from 3, 6, 12 months from treatment, we analyzed a subset that included 328 patients. Three months after the completion of therapy, the m-HNSW score had a significant association with 1 (HR = 1.24, P = .0005) and 5 year survival (HR = 1.19, P = .0002) after accounting for body mass index. Six (HR = 1.14, P = .014) and 12 month (hazard ratio (HR) = 1.33, P < .0001) scores post completion of therapy predict 5-year survival. An increase of the m-HNSW score by 1 point was associated with an increase in death by 24%, and 19% at 1 and 5 years following therapy. CONCLUSIONS: The m-HNSW is a simple assessment of dysphagia using previously validated EORTC-QLC-H&N35 data that when taken at 3, 6, and 12 months after completion of therapy is predictive of overall survival. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:2478-2482, 2021.

Heparin-mediated antibiotic delivery from an electrochemically-aligned collagen sheet.

BACKGROUND: Implantable medical devices and hardware are prolific in medicine, but hardware associated infections remain a major issue. OBJECTIVE: To develop and evaluate a novel, biologic antimicrobial coating for medical implants. METHODS: Electrochemically compacted collagen sheets with and without crosslinked heparin were synthesized per a protocol developed by our group. Sheets were incubated in antibiotic solution (gentamicin or moxifloxacin) overnight, and in vitro activity was assessed with five-day diffusion assays against Pseudomonas aeruginosa. Antibiotic release over time from gentamicin-infused sheets was determined using in vitro elution and high performance liquid chromatography (HPLC). RESULTS: Collagen-heparin-antibiotic sheets demonstrated larger growth inhibition zones against P. aeruginosa compared to collagen-antibiotic alone sheets. This activity persisted for five days and was not impacted by rinsing sheets prior to evaluation. Rinsed collagen-antibiotic sheets did not produce any inhibition zones. Elution of gentamicin from collagen-heparin-gentamicin sheets was gradual and remained above the minimal inhibitory concentration for gentamicin-sensitive organisms for 29 days. Conversely, collagen-gentamicin sheets eluted their antibiotic load within 24 hours. Overall, heparin-associated sheets demonstrated larger inhibition zones against P. aeruginosa and prolonged elution profile via HPLC. CONCLUSION: We developed a novel, local antibiotic delivery system that could be used to coat medical implants/hardware in the future and reduce post-operative infections.

Head and neck surgery global outreach: Ethics, planning, and impact.

BACKGROUND: Head and neck surgical oncology and reconstruction are uniquely suited to address burdens of disease in underserved areas. Since these efforts are not well known in our specialty, we sought to understand global outreach throughout our society of surgeons. METHODS: Survey distributed to members of the American Head and Neck Surgery involved in international humanitarian head and neck surgical outreach trips. RESULTS: Thirty surgeons reported an average of seven trips to over 70 destinations. Identification of candidates, finances, on-site patient care, complications, long-term post-surgical care, ethics, and educational goals are reported. We report a success rate of 90% on 125 free flaps performed in these settings. CONCLUSIONS: The effort to answer the call for alleviating the global burden of surgical disease is strong within our specialty. There is a shared focus on humanitarian effort and teaching. Ethics of high resource surgeries such as free flap reconstruction remains controversial.

Cancellous Tibial Bone Graft for Malunion after Mandibular Reconstruction in Head and Neck Cancer.

OBJECTIVES/HYPOTHESIS: While nonunion after mandibular reconstruction for head and neck surgery is rare, literature exploring management is scarce. Our primary objective was to determine success rates of tibial bone graft (TBG) in achieving mandibular union. Secondary objectives include determining factors that contribute to failure of TBG. STUDY DESIGN: Retrospective Chart Review. METHODS: Retrospective chart review between January 1, 2008 and December 31, 2018. Patients who underwent a mandibulotomy or mandibulectomy with osteocutaneous free flap reconstruction were identified. Patients who were pursuing dental rehabilitation, subsequently diagnosed with mandibular nonunion and received a cancellous TBG were assessed. RESULTS: The 15 patients meeting inclusion criteria were mostly male (67%), white (87%), and nonsmokers (67%) with a median age of 64 (IQR = 60-73). Successful union occurred in 13 of 18 (72%) TBGs and the majority (63%) had a partial union documented at the time of surgery. Five patients (83%) who initially had a mandibulotomy achieved union compared to 78% of those with osteocutaneous reconstruction (P = 1.0). Postoperative radiation did not affect rates of union: 80% for both (P = 1.0). Patients with osteoradionecrosis (ORN) achieved union in 67% of cases compared to 75% of cases who did not have ORN (P = .86). There were similar rates of union for those who required perioperative antibiotics for infection and those without infection (67% vs. 75%, P = .86). Dental rehabilitation was achieved in 55% of patients, most commonly dentures. CONCLUSIONS: This study shows that TBG can be used to achieve union for patients with malunion after head and neck cancer reconstruction. We show its successful use within the reconstructive algorithm for patients regardless of postoperative radiation for very small defects. LEVEL OF EVIDENCE: 3 Laryngoscope, 131:1291-1296, 2021.

Absent Posterior Belly of Digastric Muscle.

OBJECTIVE: Report a unique case of absent posterior belly of digastric muscle, with a literature review and discussion of its clinical importance. METHODS: Present a case report and review the current literature including PUBMED search terms; "absent posterior digastric", "digastric muscle", "posterior belly". RESULTS: While there were multiple reports of accessory anterior and posterior bellies and absence of anterior belly, there is a paucity of literature on absence of posterior belly of digastric muscle. CONCLUSION: To our knowledge, this is the first report of an absent posterior belly of the digastric muscle. The posterior belly of the digastric muscle is an important landmark in neck dissection, and its absence makes knowledge of other anatomic landmarks critically important. Laryngoscope, 131:1501-1502, 2021.

Surgical Techniques for Head and Neck Reconstruction in the Vessel-Depleted Neck.

The vessel-depleted neck presents a unique and challenging scenario for reconstructive surgery of the head and neck. Prior surgery and radiation often result in significant scarring and damage to the neck vasculature, making identification of suitable recipient vessels for microvascular free tissue transfer exceedingly difficult. Therefore, alternative reconstructive techniques and/or vessel options must be considered to obtain a successful reconstructive outcome for a patient. In this article, we discuss our experience and approach to the management of the vessel-depleted neck, emphasizing the importance of preoperative planning and having multiple backup options prior to surgery. The various preoperative imaging modalities and available options for recipient arteries and veins are presented in detail. Additionally, we discuss modifications of select free flaps to maximize their utility in successful reconstruction. Together with thoughtful preoperative planning, these techniques can help aid the reconstructive surgeon in addressing the complex decisions associated with the vessel-depleted neck.

CD8+ CD73+ T cells in the tumor microenvironment of head and neck cancer patients are linked to diminished T cell infiltration and activation in tumor tissue.

Recent studies have implicated a role for adenosine-dependent immunosuppression in head and neck tumor microenvironments. We describe expression of CD73, an enzyme critical to the generation of adenosine from extracellular AMP, in T cells and other cell types within human head and neck tumors. Flow cytometric analyses of tumor-infiltrating cells indicate that CD3+ cells are the predominant source of CD73 among immune infiltrating cells and that CD73 expression, especially among CD8+ T cells, is inversely related to indices of T cell infiltration and T cell activation in the microenvironment of head and neck tumors. We provide evidence that CD73 expression on peripheral T cells and levels of soluble CD73 in circulation are correlated with CD73 expression on CD8+ T cells in tumors. Moreover, fluorescent microscopy studies reveal that CD8+ CD73+ cells are observed in close proximity to tumor cells as well as in surrounding tissue. In vitro studies with peripheral blood T cells indicate that anti-CD3-stimulation causes loss of CD73 expression, especially among cells that undergo proliferation and that exogenous AMP can impair T cell proliferation, while sustaining CD73 expression. These data suggest that CD8+ CD73+ T cells may be especially important mediators of immunosuppression in human head and neck cancer.

Safety Recommendations for Evaluation and Surgery of the Head and Neck During the COVID-19 Pandemic.

Importance: The rapidly expanding novel coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2, has challenged the medical community to an unprecedented degree. Physicians and health care workers are at added risk of exposure and infection during the course of patient care. Because of the rapid spread of this disease through respiratory droplets, health care workers who come in close contact with the upper aerodigestive tract during diagnostic and therapeutic procedures, such as otolaryngologists-head and neck surgeons, are particularly at risk. A set of safety recommendations was created based on a review of the literature and communications with physicians with firsthand knowledge of safety procedures during the COVID-19 pandemic. Observations: A high number of health care workers were infected during the first phase of the pandemic in the city of Wuhan, China. Subsequently, by adopting strict safety precautions, other regions were able to achieve high levels of safety for health care workers without jeopardizing the care of patients. The most common procedures related to the examination and treatment of upper aerodigestive tract diseases were reviewed. Each category was reviewed based on the potential risk imposed to health care workers. Specific recommendations were made based on the literature, when available, or consensus best practices. Specific safety recommendations were made for performing tracheostomy in patients with COVID-19. Conclusions and Relevance: Preserving a highly skilled health care workforce is a top priority for any community and health care system. Based on the experience of health care systems in Asia and Europe, by following strict safety guidelines, the risk of exposure and infection of health care workers could be greatly reduced while providing high levels of care. The provided recommendations, which may evolve over time, could be used as broad guidance for all health care workers who are involved in the care of patients with COVID-19.