Hypocalcemia Following Thyroidectomy in a Patient With COVID-19: A Case Report and Literature Review.

COVID-19 can lead to various complications, including severe respiratory symptoms. Both viral infections and total thyroidectomy are known to cause hypocalcemia, making a history of thyroidectomy a potential risk factor for hypocalcemia in COVID-19 patients. We present the case of a 34-year-old woman with Graves' disease who developed hypocalcemia due to COVID-19 following a total thyroidectomy. The patient underwent an uneventful total thyroidectomy, with preservation of at least three of the four parathyroid glands. Postoperatively, her parathyroid hormone (PTH) levels were normal, and she was discharged without tetany. However, on postoperative day 90, she experienced mild hypocalcemia during a COVID-19 infection, although it was asymptomatic. By postoperative day 127, she presented with severe tetany and general malaise. Testing confirmed a reinfection with SARS-CoV-2 and hypocalcemia, while PTH levels remained normal. Treatment with intravenous calcium gluconate, oral calcium lactate, and alfacalcidol effectively resolved the hypocalcemia and tetany. The patient was subsequently discharged without tetany and has since been monitored without the need for calcium or vitamin D supplementation. This case highlights that the COVID-19 infection following a total thyroidectomy can cause hypocalcemia. Postoperative hypocalcemia is a common issue in head and neck surgery, and viral infections like COVID-19 should be considered in the differential diagnosis of hypocalcemia.

Hypoxia-Targeted Immunotherapy with PD-1 Blockade in Head and Neck Cancer.

Intratumoral hypoxia is associated with tumor progression, aggressiveness, and therapeutic resistance in several cancers. Hypoxia causes cancer cells to experience replication stress, thereby activating DNA damage and repair pathways. MutT homologue-1 (MTH1, also known as NUDT1), a member of the Nudix family, maintains the genomic integrity and viability of tumor cells in the hypoxic tumor microenvironment. Although hypoxia is associated with poor prognosis and can cause therapeutic resistance by regulating the microenvironment, it has not been considered a treatable target in cancer. This study aimed to investigate whether hypoxia-induced MTH1 is a useful target for immunotherapy and whether hypoxic conditions influence the antitumor activity of immune cells. Our results showed that MTH1 expression was elevated under hypoxic conditions in head and neck cancer cell lines. Furthermore, we identified a novel MTH1-targeting epitope peptide that can activate peptide-specific CD4+ helper T cells with cytotoxic activity. The proliferation and cytotoxic activity of T cells were maintained under hypoxic conditions, and PD-1 blockade further augmented the cytotoxicity. These results indicate that MTH1-targeted immunotherapy combined with checkpoint blockade can be an effective strategy for the treatment of hypoxic tumors.

Prognostic Value of the 18F-FDG PET/CT and Haematological Parameters in Head and Neck Cancer.

INTRODUCTION: Fluorine 18-fluoro-glucose positron emission tomography/computed tomography (18F-FDG PET/CT) is commonly used for the staging of head and neck cancer. This study aimed to evaluate the correlation between 18F-FDG PET/CT, haematological parameters and prognosis in patients with advanced head and neck cancer. METHODS: This was a single-institutional retrospective study of 83 patients with advanced head and neck squamous cell carcinoma (HNSCC) who underwent 18F-FDG PET/CT imaging before initial treatment between 2014 and 2018. 18F-FDG PET/CT after treatment was performed in 57 patients. The prognostic parameters of the pre- and post-treatment maximum standardised uptake value (SUVmax), metabolic tumour volume (MTV), total lesion glycolysis (TLG) of primary tumours and haematological parameters were analysed to evaluate the association between overall survival (OS) and progression-free survival (PFS). RESULTS: Pre-MTV, pre-TLG and post-SUVmax were significantly associated with poor OS and PFS (p < 0.05). Haematological parameters, including pretreatment neutrophil/lymphocyte ratio and C-reactive protein/albumin ratio, were associated with 18F-FDG PET/CT parameters. In multivariate analysis, post-SUVmax was an independent prognostic factor for OS and PFS. CONCLUSION: A correlation between PET/CT metabolic and haematological parameters was observed. The volume and intensity of 18F-FDG uptake region, in addition to haematological parameters, are feasible markers for predicting the progression of HNSCC in daily practice. Further, post-SUVmax could be an independent parameter for predicting poor survival.

Guidance of clinical management for patients with tonsillar focal disease.

Tonsillar focal diseases (TFDs) are defined as "diseases caused by organic and/or functional damage in organs distant from tonsil, and the disease outcome is improved by tonsillectomy." Although several reports and reviews have shown the efficacy of tonsillectomy for TFDs, no guidelines for the clinical management of the diagnosis and treatment of TFDs have been reported. Therefore, the Society of Stomato-pharyngology established a committee to guide the clinical management of patients with TFDs, and the original guide was published in May 2023. This article summarizes the English version of the manuscript. We hope that the concept of TFDs will spread worldwide, and that one as many patients with TFDs will benefit from tonsillectomy.

A comparison of the clinical efficacy of tonsillectomy with steroid pulse therapy and tonsillectomy therapy alone for patients with immunoglobulin A nephropathy: a retrospective observational study.

BACKGROUND: Tonsillectomy with steroid pulse therapy (TSP) and tonsillectomy monotherapy (T) have improved the prognosis of patients with immunoglobulin A nephropathy (IgAN). However, a consensus has not been reached on the best treatment for these patients. This study aimed to compare the efficacies of TSP and T. METHODS: Data of patients with IgAN who received TSP or T were retrospectively analyzed. The exclusion criterion was a serum creatinine level > 1.5 mg/dL. The clinical remission and renal survival rates were compared. RESULTS: Patients were divided into groups based on the treatment method: the TSP (n = 82) and T groups (n = 41). No significant differences were observed in patient characteristics, except for the observation period (TSP: 60 months, T: 113 months). The log-rank test revealed that the clinical remission rate was significantly higher in the TSP group than in the T group (p < 0.05). The superiority of TSP was also observed in the urinary protein excretion (> / = or < 1 g/day) of the two subgroups. According to the Cox proportional-hazards model, the treatment method and daily urinary protein extraction were independent factors affecting clinical remission. The 10-year renal survival rates in the TSP and T groups were 100% and 92.5%, respectively. The log-rank test revealed a tendency for a higher renal survival rate in the TSP group than in the T group (p = 0.09). CONCLUSION: The clinical remission rate was significantly higher with TSP than with T, regardless of urinary protein levels. TSP tended to have a better renal survival rate than T.

A case of hyalinizing trabecular tumor of the thyroid: diagnostic significance of PAX8-GLIS3 fusion.

BACKGROUND: Hyalinizing trabecular tumor (HTT) is an uncommon follicular cell-derived thyroid tumor classified as a low-risk neoplasm by the World Health Organization Classification of Tumors of Endocrine Organs, 5th edition. The PAX8-GLIS3 gene fusion is reportedly a pathognomonic genetic alteration of HTT. CASE PRESENTATION: A 43-year-old Japanese female was incidentally discovered to have an 8-mm, well-defined, hypoechoic mass in the left lobe of the thyroid gland by ultrasound examination. Contrast-enhanced computed tomography scan revealed a solid mass exhibiting slight homogeneous enhancement in the lower pole of the thyroid gland. The mass was diagnosed as atypia of undetermined significance by fine-needle aspiration cytology. The patient underwent left hemithyroidectomy with routine central compartment dissection. Histologic findings revealed tumor cells with elongated nuclei and intranuclear pseudoinclusions arranged with trabeculae architecture or small nests in hyalinized stroma. Weak membranous and cytoplasmic staining was found by MIB1 (Ki-67) immunostaining. The final diagnosis was HTT of the thyroid gland. Next-generation sequencing genetic analysis of a surgical specimen revealed no pathologic mutations, including BRAF, H/K/NRAS, or RET-PTC fusions. The PAX8-GLIS3 fusion was detected by RT-PCR. CONCLUSIONS: A rare case of HTT was demonstrated through imaging, cytologic, histologic and molecular investigations. PAX8-GLIS3 fusion detected by RT-PCR and Sanger sequencing was confirmed to be a genetic hallmark of HTT.

Common Characteristics of Sinonasal Inflammation Associated with IgG4-Related Disease and Other Chronic Inflammatory Diseases: A Retrospective Observational Study.

INTRODUCTION: Immunoglobulin G4-related disease (IgG4-RD) is a systemic inflammatory disease characterized by elevated serum IgG4, tissue infiltration of IgG4-positive cells, and fibrosis. Although a number of IgG4-RD patients show sinonasal involvement, there is little known about sinonasal inflammation associated with IgG4-RD. This study aimed to describe the clinicopathological features of sinonasal inflammation associated with IgG4-RD and to compare with other inflammatory diseases, such as eosinophilic chronic rhinosinusitis (ECRS) and granulomatosis with polyangiitis (GPA). METHODS: A retrospective analysis of clinicopathological features of patients with sinonasal lesions and high serum IgG4 was performed. Patient data were reviewed to determine whether they fulfilled the diagnostic criteria for other inflammatory diseases. RESULTS: Six of 7 patients were diagnosed with IgG4-RD, while 1 patient was diagnosed with GPA. In the 6 patients with IgG4-RD, intranasal findings showed nasal polyps in 3 patients (50%) and nasal crusting in the 3 patients (50%). Computed tomography showed ethmoid sinus involvement in 5 patients (83%). Five of the 6 patients (83%) were diagnosed with IgG4-RD based on nasal biopsy, whereas 1 patient (17%) was diagnosed based on lacrimal gland biopsy. Four patients fulfilled the Japanese epidemiological survey of refractory ECRS (JESREC) criteria. However, none of the patients showed eosinophil infiltration. Although the patient with GPA showed high levels of serum IgG4 and tissue infiltration of IgG4-positive cells in the nasal biopsy, the patient showed common clinical features of GPA. CONCLUSION: Patients with sinonasal inflammation associated with IgG4-RD had similar clinical characteristics with ECRS and GPA. Histopathological findings of the nasal biopsy from clinically diagnosed GPA was consistent with that of IgG4-RD. Sinonasal inflammation associated with IgG4-RD should be diagnosed based not only on tissue infiltration of IgG4-positive cells but in conjunction with clinical findings such as local nasal characteristics, involvement of other organs, and serum antineutrophil cytoplasmic antibody levels. IgG4-RD should be ruled out in patients with eosinophilia without histopathological eosinophil infiltration.

Combined approach for predicting the efficacy of nivolumab in head and neck carcinoma by tissue and soluble expressions of PD-L1 and PD-L2.

BACKGROUND: Predictive biomarkers for nivolumab in recurrent or metastatic head and neck squamous cell carcinoma (RMHNSCC) have not yet been established. METHODS: The tumor proportion score (TPS), combined positive score (CPS), and soluble forms of programmed cell death ligand-1 (PD-L1) and programmed cell death ligand-2 (PD-L2) were retrospectively analyzed in patients with RMHNSCC treated with nivolumab. RESULTS: The positivity rates for TPS (PD-L1), CPS (PD-L1), TPS (PD-L2), and CPS (PD-L2) were 73.8%, 78.2%, 56.4%, and 78.2%, respectively. Patients with high TPS (PD-L1), CPS (PD-L1), or CPS (PD-L1 and PD-L2) showed significantly prolonged progression-free survival. Favorable overall survival was associated with high CPS (PD-L1 and PD-L2) and low soluble PD-L1 and PD-L2 levels. The expressions of tissue and soluble PD-L1/2 were not correlated. CONCLUSIONS: Our study revealed that compared to PD-L1 expression alone, dual expression of PD-L1 and PD-L2 in tissue or soluble form could be feasible biomarkers in patients with RMHNSCC who received nivolumab.

Lipoma Arising in the Eustachian Tube.

Lipomas are among the most common soft tissue tumors. Surgical removal of lipoma is considered if the patient has symptoms or cosmetic challenges. Lipomas that develop from any fat tissue in the body and involve the eustachian tube are extremely rare. Herein, we report the case of a patient with a lipoma arising in the eustachian tube. We also summarized the literature on tumors originating from the eustachian tubes. A 62-year-old female presented to our department with a five-year history of left nasal congestion. Nasal endoscopy revealed a tumor in the left eustachian tube. The tumor was considered a lipoma on computed tomography (CT) and magnetic resonance imaging (MRI) and was removed using a transnasal endoscopic approach. Nasal endoscopy and radiologic imaging can be used to detect tumors in the nasopharynx, including the eustachian tubes. Magnetic resonance imaging is particularly useful for the diagnosis of lipomas. A lipoma in the eustachian tube can cause nasal congestion and aural fullness, and the transnasal endoscopic approach is useful for tumor removal.

Exploring Immunological Effects and Novel Immune Adjuvants in Immunotherapy for Salivary Gland Cancers.

Salivary gland cancer (SGC) is rare and comprises over 20 histological subtypes. Recently, clinical experience regarding immunotherapies for SGCs has been accumulating, yet their efficacy remains controversial. Understanding the tumor microenvironment (TME), including the expression of immune checkpoint molecules in SGC, is crucial to optimizing immunotherapy. In this review, we demonstrate that high-grade mucoepidermoid carcinoma and salivary duct carcinoma generally exhibit immune-hot TME with high immune cell infiltration, frequent genetic mutations, and robust immune checkpoint molecule expression. In contrast, adenoid cystic carcinomas exhibit an immune-cold TME. While the reported efficacy of immune checkpoint inhibitors (ICIs) for SGCs is generally poor, several studies showed promising clinical efficacy of ICIs, with an objective response rate ranging from 20.0-33.3%, indicating that ICIs might be beneficial for a specific population of SGC. Molecule-targeted therapies including anti-human epidermal growth factor receptor 2 and anti-androgen receptor therapies have shown promising clinical efficacy against SGC. Recent evidence indicates that these molecules could be targets for antigen-specific immunotherapies including chimeric antigen receptor-T therapy and cancer vaccines. This review discusses the current understanding and future directions of immunotherapies for SGCs, including ongoing clinical trials.

Immunotherapy targeting tumor-associated antigen in a mouse model of head and neck cancer.

BACKGROUND: The identification of epitope peptides from tumor-associated antigens (TAAs) is informative for developing tumor-specific immunotherapy. However, only a few epitopes have been detected in mouse TAAs of head and neck cancer (HNSCC). METHODS: Novel mouse c-Met-derived T-cell epitopes were predicted by computer-based algorithms. Mouse HNSCC cell line-bearing mice were treated with a c-Met peptide vaccine. The effects of CD8 and/or CD4 T-cell depletion, and vaccine combination with immune checkpoint inhibitors (ICIs) were evaluated. Tumor re-inoculation was performed to assess T-cell memory. RESULTS: We identified c-Met-derived short and long epitopes that elicited c-Met-reactive antitumor CD8 and/or CD4 T-cell responses. Vaccination using these peptides showed remarkable antitumor responses via T cells in which ICIs were not required. The c-Met peptide-vaccinated mice rejected the re-inoculated tumors. CONCLUSIONS: We demonstrated that novel c-Met peptide vaccines can induce antitumor T-cell response, and could be a potent immunotherapy in a syngeneic mouse HNSCC model.

Soluble CD27 as a predictive biomarker for intra-tumoral CD70/CD27 interaction in nasopharyngeal carcinoma.

In CD70-expressing tumors, the interaction of CD70 on tumor cells with its lymphocyte receptor, CD27, is thought to play a role in immunosuppression in the tumor microenvironment and elevated serum levels of soluble CD27 (sCD27). Previous studies showed that CD70 is expressed in nasopharyngeal carcinoma (NPC), an Epstein-Barr virus (EBV)-related malignancy. However, the association between intratumoral CD70/CD27 expression and serum levels of sCD27 in NPC remains unclear. In the present study, we show that CD70 is primarily expressed by tumor cells in NPC and that CD27-positive lymphocytes infiltrate around tumor cells. NPC patients with CD27-positive lymphocytes had significantly better prognosis than patients lacking these cells. In addition, high CD70 expression by tumor cells tended to be correlated with shorter survival in NPC patients with CD27-positive lymphocytes. Serum sCD27 levels were significantly increased in patients with NPC and provided good diagnostic accuracy for discriminating patients from healthy individuals. The concentration of serum sCD27 in patients with CD70-positive NPC with CD27-positive lymphocytes was significantly higher than in patients with tumors negative for CD70 and/or CD27, indicating that the intratumoral CD70/CD27 interaction boosts the release of sCD27. Furthermore, positive expression of CD70 by NPC cells was significantly correlated with EBV infection. Our results suggest that CD70/CD27-targeted immunotherapies may be promising treatment options and that sCD27 may become an essential tool for evaluating the applicability of these therapies by predicting the intratumoral CD70/CD27 interaction in NPC.

Efficacy of Cetuximab Combined with Paclitaxel in Patients with Recurrent Salivary Gland Carcinoma: A Retrospective Observational Study.

INTRODUCTION: Due to the rarity and various histological types, a standard chemotherapy regimen for recurrent or metastatic salivary gland carcinoma (SGC) has not been established. Molecular-targeted therapy is a novel cancer therapy based on the expression of target molecules. However, few molecular-targeted therapy types have shown satisfactory efficacy for patients with SGC. Our study described promising results of epidermal growth factor receptor (EGFR)-targeting therapy with paclitaxel in patients with SGC. METHODS: The medical records of patients with recurrent SGC treated with weekly cetuximab combined with paclitaxel (Cmab-PTX) between December 2017 and December 2022 at our institutions were retrospectively analyzed. RESULTS: Seven patients with SGC received Cmab-PTX therapy. The median age was 76 years. All patients were high-grade histological types, and EGFR expression was positive in all examined patients. Cmab-PTX was administered for a median period of 20 months (range of 2-36 months). The overall responses were three with complete response, two with partial response, one with stable disease (>24 weeks), and one with progressive disease. The objective response and disease control rates were 71.4% and 85.7%, respectively. Progression-free survival ranged between 2 and 36 months (median 12 months), whereas overall survival ranged between 4 and 111 months (median 36 months). One patient experienced a grade 4 adverse event (neutropenia), which was conservatively manageable. CONCLUSION: Although the treatment sensitivity of SGC with high-grade histological types is usually poor, Cmab-PTX could be a promising treatment regimen for recurrent SGC. Due to the rarity and various histological types, a standard chemotherapy regimen for recurrent or metastatic salivary gland carcinoma (SGC) has not been established. Molecular-targeted therapy is a novel cancer therapy based on the expression of target molecules. However, few molecular-targeted therapy types have shown satisfactory efficacy in patients with SGC. Our study described promising results of cetuximab (Cmab), epidermal growth factor receptor (EGFR)-targeting therapy with paclitaxel (PTX) in patients with SGC. Seven patients with SGC received Cmab-PTX therapy. The median age was 76 years. All patients were high-grade histological types, and EGFR expression was positive in all examined patients. Cmab-PTX was administered for a median period of 20 months. The overall responses were three with complete response, two with partial response, one with stable disease (>24 weeks), and one with progressive disease. The objective response rate was 71.4%. Progression-free survival ranged between 2 and 36 months (median 12 months), whereas overall survival ranged between 4 and 111 months (median 36 months). One patient experienced a grade 4 adverse event (neutropenia), which was conservatively manageable. Our study revealed a preferable objective response rate of Cmab-PTX for patients with high-grade SGC. Although the treatment sensitivity of SGC with high-grade histological types is usually poor, Cmab-PTX could be a promising treatment regimen for recurrent SGC.

Hypopharyngeal Diffuse Large B-Cell Lymphoma in a 74-Year-Old Man Presenting with Dysphagia: A Case Report.

BACKGROUND Malignant lymphomas can occur at various sites. Hypopharyngeal tumors are at risk for airway obstruction and require rapid diagnosis and treatment. Most hypopharyngeal malignancies are squamous cell carcinomas; other tumors are rare. To date, only a few cases of malignant hypopharyngeal lymphoma have been reported, and its specific characteristics are unknown. Herein, we report a case of right hypopharyngeal diffuse large B-cell lymphoma (DLBCL) in a 74-year-old man with dysphagia. CASE REPORT A 74-year-old man presented to our hospital with dysphagia. He had no relevant medical history. Endoscopic examination revealed a right hypopharyngeal tumor. The surface of the tumor was smooth, with no evidence of hemorrhage. Computed tomography revealed a 40-mm mass located in the hypopharynx. We performed a tracheotomy and biopsy of the tumor. Histopathological examination revealed a diffuse proliferation of large atypical B cells with negative staining for Epstein-Barr virus by in situ hybridization. Immunohistochemical staining was positive for CD20 but negative for CD3 and CD10. The patient was administered chemotherapy. The tumor reduced in size, and the patient recovered completely. During the two-year follow up, no recurrence of cancer was observed. CONCLUSIONS Although most hypopharyngeal tumors are squamous cell carcinomas (SCCs), the possibility of other types of tumors should also be considered. Malignant lymphoma of the hypopharynx is rare, and more cases need to be studied and reported in the future.

Cerebral Infarction as a Rare Adverse Event of Immune Checkpoint Inhibitors in Patients With Head and Neck Squamous Cell Carcinoma: A Case Series.

Immune checkpoint inhibitors (ICIs) are a novel treatment option for treating head and neck squamous cell carcinoma (HNSCC). Among the immune-related adverse effects, cerebral infarction (CI) is a rare but fatal complication, and it has been reported in various cancers, except HNSCC. Herein, we describe three cases of patients diagnosed with HNSCC who experienced CI following ICI treatment. In addition, we conducted a comprehensive literature review on ICI-related thrombosis. Three patients with recurrent HNSCC were treated with nivolumab. Two patients had a history of CI, or heart disease, and were concurrently prescribed antithrombotic medications during nivolumab treatment. The number of nivolumab administrations varied from 1-25 before the onset of CI. All patients experienced worsening of neurological symptoms due to CI, irrespective of antithrombotic treatment, and they ultimately succumbed to the disease within 16-222 days following their initial ICI administration. ICIs may cause thromboembolisms, leading to CI. Based on our review of the literature, a history of thromboembolism or heart disease could be a risk factor for ICI-related thrombosis.

An Otogenic Variant of Lemierre's Syndrome Caused by Trueperella bernardiae: A Case Report and Literature Review.

Upper airway infections caused by anaerobic bacteria, including pharyngitis and tonsillitis, are a common cause of septic thrombosis (Lemierre's syndrome). Although otitis media rarely progresses to systemic infection, an abscess surrounding the middle ear can affect the central nervous system. Trueperella bernardiae was originally considered a non-pathogenic aerobic bacterium but has subsequently been reported to cause bacteremia and brain abscesses. Here, we report a case of otitis media caused by T. bernardiae complicated by meningitis, subdural empyema, and septic pulmonary emboli in an immunocompetent patient.

Treatment outcomes of alternating chemoradiotherapy for nasopharyngeal carcinoma: a single-center safety and efficacy study

Abstract Objective To evaluate the efficacy and safety of Alternating Chemoradiotherapy (ACRT) using cisplatin and 5-Fluorouracil (5-FU) in patients with nasopharyngeal carcinoma. Methods This was a retrospective study in which patients' clinical records were reviewed to identify patients with a new diagnosis of nasopharyngeal carcinoma at our institution between January 2005 and January 2019. Thirty-seven eligible patients were identified; of these, the clinical details of 27 patients treated with ACRT were evaluated. Patient outcomes, including overall survival and progression-free survival, and adverse events were assessed. Results Of these initial 37 patients, 1, 10, 13, 10, and 3 were staged as I, II, III, IVA, and IVB, respectively, as defined by the 8th edition of the TNM classification system. Twenty-seven patients received ACRT comprising sequential administration of chemotherapy, radiotherapy (wide field), chemotherapy, radiotherapy (shrinking field), and chemotherapy. The 5-year overall survival and progression-free survival rates were 83.7% and 88.9%, respectively. Treatment compliance was 93%, which is comparable to that of previous reports. Conclusion ACRT using cisplating and 5-fluorouracil was well tolerated with acceptable efficacy. Level of Evidence IVa

Brachyury-targeted immunotherapy combined with gemcitabine against head and neck cancer.

Brachyury is a transcription factor belonging to the T-box gene family and is involved in the posterior formation of the mesoderm and differentiation of chordates. As the overexpression of Brachyury is a poor prognostic factor in a variety of cancers, the establishment of Brachyury-targeted therapy would be beneficial for the treatment of aggressive tumors. Because transcription factors are difficult to treat with a therapeutic antibody, peptide vaccines are a feasible approach for targeting Brachyury. In this study, we identified Brachyury-derived epitopes that elicit antigen-specific and tumor-reactive CD4+ T cells that directly kill tumors. T cells recognizing Brachyury epitopes were present in patients with head and neck squamous cell carcinoma. Next, we focused on gemcitabine (GEM) as an immunoadjuvant to augment the efficacy of antitumor responses by T cells. Interestingly, GEM upregulated HLA class I and HLA-DR expression in tumor, followed by the upregulation of anti-tumor T cell responses. As tumoral PD-L1 expression was also augmented by GEM, PD-1/PD-L1 blockade and GEM synergistically enhanced the tumor-reactivity of Brachyury-reactive T cells. The synergy between the PD-1/PD-L1 blockade and GEM was also confirmed in a mouse model of head and neck squamous cell carcinoma. These results suggest that the combined treatment of Brachyury peptide with GEM and immune checkpoint blockade could be a promising immunotherapy against head and neck cancer.