Detection of CSF1 gene derangement in 'sclerosing mucoepidermoid carcinoma with eosinophilia' of the parotid gland masquerading as Langerhans cell histiocytosis.

Key Clinical Message: When faced with a slowly enlarging firm mass in the parotid gland accompanied by a histological picture of unusual sclerosis with abundant Langerhans cells and eosinophilic infiltrates, sclerosing mucoepidermoid carcinoma with eosinophilia should be considered as one of the differential diagnoses. Further studies are warranted for accurate diagnosis and appropriate treatment. Abstract: Sclerosing mucoepidermoid carcinoma of the salivary gland with eosinophilia is a rare tumor mostly negative for the MAML2 rearrangement commonly seen in salivary mucoepidermoid carcinoma. It was not listed as an entity in the 2022 WHO Classification of Head and Neck Tumors. We presented one case initially diagnosed as Langerhans cell histiocytosis and recurred as a frankly invasive carcinoma. Molecular studies showed CSF1 gene derangement and provided new understanding concerning the Langerhans cell and eosinophilic reaction. Further molecular studies on this entity would throw light on its oncogenesis and refine its nomenclature.

Mitochondrial DHODH regulates hypoxia-inducible factor 1 expression in OTSCC.

Oral tongue squamous cell carcinoma (OTSCC) was one of the most hypoxic tumors with unfavorable outcomes. Hypoxia-inducible factor-1 (HIF-1) signaling was associated with cancer proliferation, lymph node metastasis, angiogenesis and poor prognosis of OTSCC. Dihydroorotate dehydrogenase (DHODH) catalyzed the rate-limiting step in the de novo pyrimidine biosynthesis. The aim of the study was to explore the biological function of DHODH and investigate whether DHODH regulated HIF-1 signaling in OTSCC. Proliferation, migration and anoikis resistance were used to determine the function of DHODH. Western blot and luciferase activity assays were used to determine the regulatory role of DHODH on HIF-1. We found that increased DHODH expression was associated with advanced tumor stage and poorly differentiated tumor in head and neck cancer patients in The Cancer Genome Atlas (TCGA). DHODH enhanced the proliferation and aggressiveness of OTSCC. Moreover, DHODH prompted tumor growth and metastasis in vivo. DHODH promoted transcription, protein stability, and transactivation activity of HIF1A. DHODH-induced HIF1A upregulation in OTSCC can be reversed by reactive oxygen species (ROS) scavenger, indicating that DHODH enhanced HIF1A expression via ROS production. DHODH inhibitor suppressed DHODH-mediated ROS generation and HIF1A upregulation. Targeting DHODH using clinically available inhibitor, atovaquone, might provide a new strategy to treat OTSCC.

Manuscript title: the maxillary swing approach - the first Scandinavian experience.

BACKGROUND: The maxillary swing approach was introduced three decades ago in the head and neck field providing optimal surgical exposure for tumors in the nasopharyngeal and/or the retromaxillary space. OBJECTIVES: To report the clinical experience, patient surgical morbidity and survival outcomes following the introduction of the maxillary swing approach in Denmark. MATERIAL AND METHODS: A retrospective study including patients who underwent the maxillary swing approach from January 2012 - January 2020. Baseline and perioperative data, pathology, postoperative morbidity and survival outcomes were registered. RESULTS: Sixteen patients were included of which 15 had a malignant tumor with different histology, while one patient had a benign tumor. Most commonly reported short-term morbidity were trismus, cheek hypoesthesia, nasopalatal fistula, lacrimation and nasal stenosis (<3 months postoperatively) improving markedly at 12 months follow-up. For patients with malignant tumors, the 5-year overall survival and recurrence-free survival rates were 60% and 66.7%, respectively. CONCLUSIONS AND SIGNIFICANCE: The maxillary swing approach was safely implemented by a multidisciplinary team at a high-volume centralized head and neck cancer center in Denmark. The procedure may be considered for salvage surgery of recurrent nasopharyngeal carcinomas and selected malignant and benign tumors located in the nasopharynx and/or retromaxillary space inaccessible by other surgical modalities.

Novel approach to reduce SARS-CoV-2 transmission during trans-oral robotic surgery.

This study describes a novel approach in the reduction of SARS-CoV-2 transmission during trans-oral robotic surgery (TORS). Eight patients underwent TORS between 01 February 2020 and 07 September 2020. A sterile plastic sheet draped over sterile supports with water-tight seal around each cannula was used to create a sterile working space within which the robotic arms could freely move during operation. This set-up acts as an additional physical barrier against droplet and aerosol transmission. Operative diagnosis; droplet count and distribution on plastic sheet and face shields of console and assistant surgeons, and scrub nurse were documented. TORS tumour excision was performed for patients with suspected tonsillar tumour (n = 3) and tongue base tumour (n = 2). TORS tonsillectomy and tongue base mucosectomy was performed for cervical nodal metastatic carcinoma of unknown origin (n = 3). Droplet contamination was noted on all plastic drapes (n = 8). Droplet contamination was most severe over the central surface at 97.2% (91.7-100.0%), with the highest droplet count along the centre-most column where it overlies the site of operation in the oral cavity 33.3% (n = 31). Droplet count decreased towards the periphery. Contamination rate was 2.8% (0.0-8.3%) over the right lateral surface. There was no droplet contamination over the vertex and left lateral surface of plastic drapes. No droplet contamination was noted on face shields of all parties. The use of sterile plastic drapes with water-tight seal around each robotic cannula can help reduce viral transmission to healthcare providers during TORS.

Extracranial/Intracranial Vascular Bypass in the Treatment of Head and Neck Cancer - Related Carotid Blowout Syndrome.

OBJECTIVE/HYPOTHESIS: To investigate the endovascular intervention or extracranial/intracranial (EC/IC) vascular bypass in the management of patients with head and neck cancer-related carotid blowout syndrome (CBS). STUDY DESIGN: Retrospective case series. METHODS: Retrospective analysis of clinical data of patients with head and neck cancer-related CBS treated by endovascular intervention and/or EC/IC vascular bypass, analysis of its bleeding control, neurological complications, and survival results. RESULTS: Thrity-seven patients were included. Twenty-five were associated with external carotid artery (ECA); twelve were associated with internal or common carotid artery (ICA/CCA). All patients with ECA hemorrhage were treated with endovascular embolization. Of the 12 patients with ICA/CCA hemorrhage, 9 underwent EC/IC bypass, 1 underwent endovascular embolization, and 3 underwent endovascular stenting. For patients with ECA-related CBS, the median survival was 6 months, and the 90-day, 1-year, and 2-year survival rates were 67.1%, 44.7%, and 33.6%, respectively; the estimated rebleeding risk at 1-month, 6-month, and 2-year was 7.1%, 20.0%, and 31.6%, respectively. For patients with ICA/CCA-related CBS, the median survival was 22.5 months, and the 90-day, 1-year, and 2-year survival rates were 92.3%, 71.8%, and 41.0%, respectively; the estimated rebleeding risk at 1 month, 6 months, and 2 years is 7.7%,15.4%, and 15.4%, respectively. ICA/CCA-related CBS patients have significantly longer survival time and lower risk of rebleeding, which may be related to the more use of EC/IC vascular bypass as a definite treatment. CONCLUSIONS: For patients with ICA/CCA-related CBS, if there is more stable hemodynamics, longer expected survival, EC/IC vascular bypass is preferred. LEVEL OF EVIDENCE: 4 Laryngoscope, 131:1548-1556, 2021.

Robot-assisted real-time sentinel lymph node mapping in oral cavity cancer: preliminary experience.

This study aims to assess the feasibility of using indocyanine green and robotic near infra-red fluorescent imaging (Firefly®) for sentinel lymph node biopsy in cN0 oral cavity cancer. Ten patients with early squamous cell carcinoma of the tongue (n = 8) and buccal mucosa (n = 2) were included. Peritumoral injection of 10 mg indocyanine green and real-time mapping of sentinel lymph nodes in the neck was performed using Firefly® via a retro-auricular trans-hairline incision. Sentinel lymph node was detected in all patients at 1.2 sentinel lymph node per person. Majority were situated in level II (91.7%). Mean time to detection of sentinel lymph node was 171.0 (68.0-312.0)s. Mean signal-to-background ratio was 5.62 (3.51-7.91). Frozen section of one sentinel lymph node was positive for malignancy, paraffin section of which confirmed the presence of metastatic disease. Modified radical neck dissection was performed for that particular patient, paraffin section of which did not show any tumor deposit. Frozen section and paraffin section of all other sentinel lymph nodes (n = 11) and neck dissection specimens yielded no malignancy. All resection margins were clear. Three patients completed adjuvant radiotherapy for pT2N0 (n = 2) and pT2N1 (n = 1) carcinoma of the tongue. Mean follow-up was 12.0 (4.0-18.0) months. All patients were alive at last follow-up with no disease recurrence. There were no adverse outcomes associated with the use of indocyanine green and robot-assisted neck dissection. Indocyanine green and Firefly® for sentinel lymph node biopsy in cN0 oral cavity cancer is feasible with no adverse effects.

CD38 triggers inflammasome-mediated pyroptotic cell death in head and neck squamous cell carcinoma.

BACKGROUND: Pyroptosis is a form of inflammatory cell death. Although it is recognized that NLRP3 (nucleotide-binding domain, leucine-rich repeat-containing family, pyrin domain-containing 3) inflammasome is involved in pyroptosis activation, the mechanism by which head and neck squamous cell carcinoma (HNSCC) inhibits pyroptotic cell death remains undefined. This study aims to delineate the role of calcium regulator CD38 in NLRP3 inflammasome-dependent pyroptosis in HNSCC. METHODS: CD38 overexpressing HNSCC cell lines (SAS, CAL27, SNU899) were generated using lentiviral vectors. NLRP3 and gasdermin D (GSDMD) quantity were detected using Western blot. Caspase-1 activity changes were measured using the Caspase-Glo® 1 inflammasome assay. Cell death proportion was determined by flow cytometry analysis. Proliferation assay was performed using xCELLigence RTCA system. Mouse xenotransplantation was performed to evaluate the potential oncogenic or tumor-suppressive function of CD38. ChIP assay was conducted to verify whether transcription factor NFAT1-mediated NLRP3 expression. RESULTS: Exogenous calcium treatment can lead to a significant increase in caspase-1 activity in HNSCC. This feature was also observed in HNSCC cells with stable CD38 overexpression. CD38-overexpressing cell lines showed a significant reduction in proliferation. Further, expression of NLRP3 protein level was significantly increased in CD38-overexpressing cell lines. The N-terminal effector domain of GSDMD was remarkably increased in the CD38-overexpressing HNSCC. ChIP assay indicated that calcium-sensitive transcription factor NFAT1 was possibly involved in the transcriptional upregulation of NLRP3 observed in CD38-overexpressing HNSCC. The pre-clinical xenograft model revealed that CD38 expression had an inhibiting function on HNSCC progression. CONCLUSION: In conclusion, our results suggested that activation of pyroptosis in HNSCC is a calcium-dependent process. Reduced expression of calcium ion regulator CD38 functions could prevent inflammasome-induced pyroptosis in HNSCC. CD38 may function as a tumor suppressor in HNSCC progression.

NADPH oxidase 5α promotes the formation of CD271 tumor-initiating cells in oral cancer.

Oral tongue squamous cell carcinoma (OTSCC) has a distinctive cell sub-population known as tumor-initiating cells (TICs). CD271 is a functional TIC receptor in head and neck cancers. The molecular mechanisms governing CD271 up-regulation remains unclear. Oxidative stress is a contributing factor in TIC development. Here, we explored the potential role of NADPH oxidase 5 (NOX5) and its regulatory mechanism on the development of CD271-expressing OTSCC. Our results showed that the splice variant NOX5α is the most prevalent form expressed in head and neck cancers. NOX5α enhanced OTSCC proliferation, migration, and invasion. Overexpression of NOX5α increased the size of OTSCC xenograft significantly in vivo. The tumor-promoting functions of NOX5α were mediated through the reactive oxygen species (ROS)-generating property. NOX5α activated ERK singling and increased CD271 expression at the transcription level. Also, NOX5α reduces the sensitivity of OTSCC to cisplatin and natural killer cells. The findings indicate that NOX5α plays an important part in the development of TIC in OTSCC.

Recommendations for surgical management of recurrent nasopharyngeal carcinoma during COVID-19 pandemic.

Nasopharyngeal carcinoma is endemic in southern parts of China including Hong Kong. Primary treatment entails radiotherapy ± chemotherapy depending on disease stage at presentation. Surgery is offered as a means of salvage for persistent and recurrent disease. Comprehensive preoperative work-up, careful patient selection, attention to details perioperation and multidisciplinary approach is essential in ensuring optimal outcomes after salvage surgery for recurrent nasopharyngeal carcinoma patients. Since the COVID-19 outbreak, we are faced with unprecedented challenges with priorities of care and resources being shifted to combat the virus. These include patient selection and timing of treatment, while preventing disease transmission to heath care providers. Practices and recommendations made in this document are intended to support safe clinical practice and efficient use of resources during this challenging time.

Tracheostomy during COVID-19 pandemic-Novel approach.

BACKGROUND: This study describes a novel approach in reducing SARS-CoV-2 transmission during tracheostomy. METHODS: Five patients underwent tracheostomy between April 1, 2020 and April 17, 2020. A clear and sterile plastic drape was used as an additional physical barrier against droplets and aerosols. Operative diagnosis; droplet count and distribution on plastic sheet and face shields were documented. RESULTS: Tracheostomy was performed for patients with carcinoma of tonsil (n = 2) and nasopharynx (n = 1), and aspiration pneumonia (n = 2). Droplet contamination was noted on all plastic sheets (n = 5). Droplet contamination was most severe over the central surface at 91.5% (86.7%-100.0%) followed by the left and right lateral surfaces at 5.2% (6.7%-10.0%) and 3.3% (6.7%-10.0%), respectively. No droplet contamination was noted on all face shields. CONCLUSION: Plastic drapes can help reduce viral transmission to health care providers during tracheostomy. Face shields may be spared which in turn helps to conserve resources during the novel coronavirus disease 2019 pandemic.

Conservation of personal protective equipment for head and neck cancer surgery during COVID-19 pandemic.

BACKGROUND: COVID-19 pandemic has led to a global shortage of personal protective equipment (PPE). This study aims to stratify face shield needs when performing head and neck cancer surgery. METHODS: Fifteen patients underwent surgery between March 1, 2020 and April 9, 2020. Operative diagnosis and procedure; droplet count and distribution on face shields were documented. RESULTS: Forty-five surgical procedures were performed for neck nodal metastatic carcinoma of unknown origin (n = 3); carcinoma of tonsil (n = 2), tongue (n = 2), nasopharynx (n = 3), maxilla (n = 1), and laryngopharynx (n = 4). Droplet contamination was 57.8%, 59.5%, 8.0%, and 0% for operating, first and second assistant surgeons, and scrub nurse respectively. Droplet count was highest and most widespread during osteotomies. No droplet splash was noted for transoral robotic surgery. CONCLUSION: Face shield is not a mandatory adjunctive PPE for all head and neck surgical procedures and health care providers. Judicious use helps to conserve resources during such difficult times.

Curcumin enhances cisplatin sensitivity by suppressing NADPH oxidase 5 expression in human epithelial cancer.

Cisplatin-based chemotherapy regimens serve a pivotal role in human cancer treatment. Nevertheless, treatment failure may occur if the cancer is inherently resistant to cisplatin or acquires a resistant phenotype during the course of treatment. Although cisplatin resistance can hinder the efficacy of cisplatin treatment for human cancer, the underlying mechanism remains poorly understood. The current study established a cisplatin-resistant human epithelial cancer cell line. Notably, differential upregulation of NADPH oxidase 5 (NOX5) was identified in this resistant cell line. Furthermore, cisplatin treatment induced cancer cells to express NOX5 and cells that overexpressed NOX5 exhibited greater resistance to cisplatin via the activation of Akt. Treatment with curcumin may suppress NOX5 expression in cancer cells and enhance sensitivity to cisplatin treatment. In a xenograft model, a combined regimen of cisplatin with low-dose curcumin significantly reduced malignant tumor growth. These data demonstrate that curcumin has a chemosensitizing effect on cisplatin-resistant epithelial cancer types. Therefore, the use of curcumin in addition to a cisplatin-based treatment regimen may improve treatment outcomes in human patients with epithelial cancer.

Surgical Treatment of Advanced Staged Hypopharyngeal Cancer.

It is not uncommon for patients with hypopharyngeal cancer to present at an advanced stage of disease. Surgical treatment provides a cure for the tumour with immediate relief from obstruction to the airway and the swallowing passage. Careful planning of surgery is important to ensure good outcome of treatment and prevent complications, some of which may be fatal. The shape of the hypopharynx resembles that of a funnel, with a wide circumference above in continuity with the oropharynx, and a small circumference below where it joins with the cervical oesophagus. As a result, while small tumours require the partial removal of the hypopharynx, large tumours, especially those involving the post-cricoid region, warrant a complete, circumferential pharyngectomy. For tumours that invade the cervical esophagus, transcervical approach is still feasible, and this is facilitated by the removal of the manubrium, allowing access to the tumour and resection with clear margins. In the presence of synchronous tumours lower down in the esophagus, pharyngo-laryngo-esophagectomy is indicated. Successful reconstruction of defects after tumour extirpation allows proper wound healing and early delivery of adjuvant radiotherapy. It is also important to ensure quick recovery of the long-term swallowing function. It ranges from the use of the soft tissue flap with skin island that is sutured as a patch to the remnants of the pharyngeal mucosa, to the use of a visceral flap, such as the free jejunal flap, to repair the circumferential pharyngectomy defects. The treatment protocol is personalized according to the extent of the tumour and the characteristics of the patients.

Surgical salvage of recurrent T3 nasopharyngeal carcinoma: Prognostic significance of clivus, maxillary, temporal and sphenoid bone invasion.

BACKGROUND: To study the efficacy of surgery for recurrent T3 nasopharyngeal carcinoma (NPC) and to determine the prognostic significance of various skull base bone invasion. METHOD: Retrospective view of the surgical outcome for recurrent T3 NPC. Kaplan Meier and log rank tests were used to determine the 5-year overall and disease specific survival. Multivariate analysis was used to identify significant independent prognostic factors that affect the surgical outcome. RESULTS: Between 1990 and 2017, 208 patients with recurrent T3 NPC were recruited. Salvage surgery was performed via the endoscopic endonasal approach (n = 22, 10.6%), endoscopic transpterygoid approach (n = 63, 30.3%) and the maxillary swing approach (n = 123, 59.1%). Thirty-eight (18.3%) patients required vascular bypass. The skull base bone involved by the tumours included: maxillary sinus (n = 13), clivus (n = 36), pterygoid process (n = 61), sphenoid sinus (n = 30), petrous part of the temporal bone (n = 42) and a combination of the above (n = 26). The mean follow-up duration was 41.7 months. Multivariate analysis identified tumours involving with both cortexes of the clivus and the lateral wall of the sphenoid sinus, as well as positive bone resection margins as the significant independent prognostic factors for surgical outcome. CONCLUSION: Outcome of surgical salvage is significantly worse for tumours that involve multiple bones at the skull base, particularly when both cortexes of the clivus and the lateral wall of the sphenoid sinus are invaded. Indication of aggressive surgery in such circumstances is controversial.

Detection of Epstein-Barr virus (EBV)-encoded microRNAs in plasma of patients with nasopharyngeal carcinoma.

BACKGROUND: Nasopharyngeal carcinoma (NPC) latently infected by Epstein-Barr virus (EBV) expresses 40 EBV BART microRNAs (miRNAs). Difference in diagnostic efficacy of these miRNAs on NPC detection was observed. Here, we performed a comprehensive evaluation on the efficacy of these miRNAs. METHODS: Quantitative polymerase chain reaction was performed on plasma nucleic acid isolated from patients with NPC and noncancer donors. RESULTS: For primary NPC, BART2-5P, BART6-3P, BART7-3P, BART7-5P, BART9-5P, BART11-3P, BART17-5P, and BART19-5P were significantly elevated. For recurrent NPC, plasma levels of BART2-3P, BART2-5P, BART5-3P, BART5-5P, BART6-3P, BART8-3P, BART9-5P, BART17-5P, BART19-3P, and BART20-3P were significantly increased. Area under curve (AUC) analysis showed that BART19-5P had the best performance to identify NPC which was serologically EBV DNA undetectable. For recurrent NPC, BART8-3P and BART10-3P had highest AUC value for identifying cancer in EBV DNA undetectable plasma. CONCLUSION: Our data supported the use of circulating EBV miRNAs in NPC and recurrent NPC detection.

Establishment and characterization of new tumor xenografts and cancer cell lines from EBV-positive nasopharyngeal carcinoma.

The lack of representative nasopharyngeal carcinoma (NPC) models has seriously hampered research on EBV carcinogenesis and preclinical studies in NPC. Here we report the successful growth of five NPC patient-derived xenografts (PDXs) from fifty-eight attempts of transplantation of NPC specimens into NOD/SCID mice. The take rates for primary and recurrent NPC are 4.9% and 17.6%, respectively. Successful establishment of a new EBV-positive NPC cell line, NPC43, is achieved directly from patient NPC tissues by including Rho-associated coiled-coil containing kinases inhibitor (Y-27632) in culture medium. Spontaneous lytic reactivation of EBV can be observed in NPC43 upon withdrawal of Y-27632. Whole-exome sequencing (WES) reveals a close similarity in mutational profiles of these NPC PDXs with their corresponding patient NPC. Whole-genome sequencing (WGS) further delineates the genomic landscape and sequences of EBV genomes in these newly established NPC models, which supports their potential use in future studies of NPC.

Application of three-dimensional printing technology in orbital floor fracture reconstruction.

IMPORTANCE: Orbital floor fracture is common among patients suffering from facial trauma. Open reduction and reconstruction of the orbital floor with Medpor is the treatment of choice in our centre to correct diplopia and enophthalmos. OBJECTIVE: Application of locally available 3D printing service in perioperative planning of orbital floor reconstruction with porous polyethylene. DESIGN: We present two patients who suffered from orbital floor fracture complicated by diplopia. Open reduction and orbital floor reconstruction with Medpor was performed with the guidance of a 3D printed customized model of the orbital floor defect. PARTICIPANTS: Both patients were admitted through the Emergency Department to surgical ward after facial trauma. CT scan of the face showed orbital floor fracture with entrapment of inferior rectus muscle. Clinically patients also suffered from diplopia on extreme gaze. RESULTS: With the aid of 3D printed model, it shortened operative time and duration of anaesthesia. Defect-specific Medpor could be trimmed and molded easily from the model and thus reduced fatigue of the material. Furthermore, the model was helpful in patient education and explanation of the surgical procedure. CONCLUSIONS AND RELEVANCE: Application of 3D printing in medical specialties is rapidly developing in the past few years. In orbital floor fracture reconstruction, 3D printed model provides a customized solution, decreases operative time and duration of anaesthesia.

Epstein-Barr virus-encoded microRNA BART7 downregulates major histocompatibility complex class I chain-related peptide A and reduces the cytotoxicity of natural killer cells to nasopharyngeal carcinoma.

Evasion from natural killer (NK) cell surveillance enables cancer to proliferate and spread at the early stages. NK cells mediate specific cytolysis by activation of the triggering receptors on their cell surface, of which the communication between natural killer group 2, member D (NKG2D) and major histocompatibility complex class I chain-related peptide A (MICA) is a key regulatory axis. It has been indicated that cancer cells can reduce the surface expression of MICA, which thereby reduces the cytotoxicity of NK cells. In nasopharyngeal carcinoma (NPC), however, the underlying mechanism remains unclear. The present study indicated that MICA expression in NPC was regulated by TGFß1. Furthermore, the human MICA gene was demonstrated to contain the c-Myc binding site in the promoter region. Notably, the results suggested that TGFß1 upregulated MICA expression by promoting c-Myc expression. Additionally, the findings demosntrated that TGFß1 expression in NPC was negatively controlled by Epstein-Barr virus-encoded microRNA BART7 (ebv-miR-BART7). In ebv-miR-BART7-expressing NPC, the TGFß1/c-Myc/MICA regulatory axis was significantly inhibited. Notably, functional analysis indicated that NPC cells expressing ebv-miR-BART7 were less sensitive to the cytolysis mediated by NK cells. In conclusion, the present results revealed that ebv-miR-BART7-expressing NPC may impair NK cells recognition and activity, which suggests that targeting ebv-miR-BART7 may be a useful therapeutic strategy in NPC immunotherapy.