Macroscopic and multiple metastases in sentinel lymph node biopsy are respectively associated with poor prognosis in early oral cancer.

BACKGROUND: A multicenter, randomized controlled phase III trial was conducted on sentinel lymph node biopsy (SLNB) and elective neck dissection for T1 (depth of invasion ≥ 4 mm)-T2N0M0 oral cavity squamous cell carcinoma. This study identified factors associated with poor prognosis in patients who underwent SLNB based on a subgroup analysis of this trial. METHODS: We analyzed 418 sentinel lymph nodes (SLNs) from 132 patients who underwent SLNB. The metastatic SLNs were classified into three categories based on size-isolated tumor cells: < 0.2 mm, micrometastasis: ≥ 0.2 mm and < 2 mm, and macrometastasis: ≥ 2 mm. Three groups were formed based on the number of metastatic SLNs: no metastasis, 1 metastatic node, and ≥ 2 metastatic nodes. The size and number of metastatic SLNs on survival were evaluated using Cox proportional hazard models. RESULTS: Patients with macrometastasis and ≥ 2 metastatic SLNs had worse overall survival (OS) and disease-free survival (DFS) after adjustment for potential confounders (HR for OS: macrometastasis, 4.85; 95% CI 1.34-17.60; ≥ 2 metastatic SLN, 3.63; 95% CI 1.02-12.89; HR for DFS: macrometastasis, 2.94; 95% CI 1.16-7.44; ≥ 2 metastatic SLN, 2.97; 95% CI 1.18-7.51). CONCLUSIONS: In patients who underwent SLNB, a poorer prognosis was associated with macrometastasis or having ≥ 2 metastatic SLNs.

Circulating naïve and effector memory T cells correlate with prognosis in head and neck squamous cell carcinoma.

T-cell memory is an important mechanism for long-term protection against diverse pathogens. Generation and persistence of memory T cells are vital components of anti-tumor immunity, given their ability to persist for prolonged durations, as well as activate and migrate rapidly. In the present study, we investigated the clinical and prognostic significance of T-cell subsets in the peripheral circulation of patients with head and neck squamous cell carcinoma (HNSCC). Moreover, we calculated the enrichment scores of T-cell subsets in primary tumor tissues and compared their clinical characteristics using a public database. Multivariate survival analyses of circulating T-cell parameters revealed that clinical parameters, except M factor, were not independent prognostic factors, whereas proportions of CD8+ T cells, naïve T cells (TN s), effector memory T cells (TEM s), and CD38+ CD8+ T cells were independent prognostic factors, suggesting the importance of these peripheral T-cell parameters as independent prognostic biomarkers. Consistent with these results, the T-cell enrichment analysis indicated that enrichment of CD8+ TN s in the tumor microenvironment was an independent prognostic factor. Moreover, an ex vivo experiment demonstrated significantly less cytotoxic activity in CD38+ T cells than in CD38- T cells. These findings suggest that T-cell memory-related parameters in both systemic immunity and the tumor microenvironment could be used as prognostic biomarkers regardless of clinical characteristics. Further characterization of circulating T cells would lead to the development of novel biomarkers for patients with HNSCC.

Dynamic alterations of circulating T lymphocytes and the clinical response in patients with head and neck squamous cell carcinoma treated with nivolumab.

Cancer immunotherapy using immune checkpoint inhibitors (ICIs) has been recognized as a novel therapeutic option for head and neck squamous cell carcinoma (HNSCC). However, only approximately 20-30% of patients with recurrent/metastatic (R/M) HNSCC benefit. Moreover, the mechanisms underlying the response to ICIs remain unclear. We investigated the proportion, activation status, and expression level of immune checkpoint molecules in circulating T cell subsets in R/M HNSCC patients treated with nivolumab using flow cytometry and mass cytometry, and then determined whether treatment response was associated with these values. We also assessed the changes in the frequency of tumor-associated antigens, MAGE-A4 and p53, -specific T cells prior to and after nivolumab treatment using the IFN-γ ELISPOT assay. The proportion of activated CD4+ and CD8+ TEMRA cells significantly increased in the disease-controlled patients but not in disease-progressed patients. As expected, the expression of PD-1 in T cells markedly decreased regardless of the therapeutic response. Meanwhile, T cell immunoglobulin mucin-3 expression on CD8+ T cells was significantly higher in patients with disease progression than in disease-controlled patients after treatment. The frequency of the tumor-associated antigens, MAGE-A4- and p53-specific T cells, was not correlated with clinical responses; however, in the disease-controlled patients, the frequency of MAGE-A4-specific T cells was significantly augmented. We concluded that in R/M HNSCC patients treated with nivolumab, circulating T cells show dynamic alterations depending on treatment efficacy. An analysis of the immunokinetics of circulating T cells could thus provide new insights into rational therapeutic strategies in cancer immunotherapy for HNSCC.

AKT3 is a key regulator of head and neck squamous cell carcinoma.

The phosphatidylinositol 3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) pathway plays a vital role in cell proliferation, apoptosis, metabolism, and angiogenesis in various human cancers, including head and neck squamous cell carcinoma (HNSCC). In the present study, we aimed to clarify the role of AKT, which is a major downstream effector of the PI3K-AKT-mTOR pathway, in HNSCC. We first investigated the mRNA expression of AKT isoforms using RNA-sequencing data from The Cancer Genome Atlas database. We observed a specific elevation of AKT3 expression in HNSCC tissues when compared with that in normal tissues. Furthermore, AKT3 expression correlated with genes related to the immunosuppressive microenvironment more than the other AKT isoforms and PIK3CA. Accordingly, we focused on AKT3 and performed a knockdown approach using an HNSCC cell line. AKT3 knockdown cells exhibited impaired proliferation, a shift in the cell cycle from G2/M to G1/G0 phase, an increase in apoptotic cells, and downregulation of gene expression related to immunosuppression, as well as the knockdown of its upstream regulator PIK3CA. We also performed immunohistochemistry for both AKT3 and PIK3CA using surgical specimens from 72 patients with HNSCC. AKT3 expression in tumor cells correlated with immune cell infiltration and unfavorable prognosis when compared with PIK3CA. These findings suggested that AKT3 expression is a potential biomarker for predicting the immunoreactivity and prognosis of HNSCC. Furthermore, the isoform-specific inhibition of AKT3 could be developed as a novel cancer therapy that efficiently suppresses the PI3K-AKT-mTOR pathway.

Immunological features of circulating monocyte subsets in patients with squamous cell carcinoma of the head and neck.

BACKGROUND: Circulating monocytes are classified into three subsets according to their CD14 and CD16 expressions. Here we investigated all three subsets in patients with squamous cell carcinoma of the head and neck (SCCHN). METHODS: Peripheral blood from 54 patients with SCCHN and 24 healthy donors (HDs) was tested for flowcytometry. Immunohistochemical staining of the primary tumor was performed. SCCHN cells were co-cultured with human monocytes in vitro. RESULTS: The level of intermediate monocytes was significantly lower in SCCHN than in HDs. The expression levels of HLA-G, PD-L1, and CD51 on intermediate monocytes was evidently greater in patients with SCCHN. In vitro co-culturing of SCCHN cells with monocytes revealed a significant increase in CD51 expression levels on monocytes. The decrease in expression levels of the maturation markers CX3CR1 and CD68 was significantly correlated to poor clinical outcomes. CONCLUSION: The level of intermediate monocytes was decreased in cancer patients in favor of immature and expressed immunosuppressive molecules.

In vitro assessment of antitumor immune responses using tumor antigen proteins produced by transgenic silkworms.

The evaluation of antitumor immune responses is essential for immune monitoring to predict clinical outcomes as well as treatment efficacies in cancer patients. In this study, we produced two tumor antigen (TA) proteins, melanoma antigen family A4 and wild type p53, using TG silkworm systems and evaluated anti-TA-specific immune responses by enzyme-linked immunosorbent spot assays in patients with head and neck cancer. Eleven (61.1%) of 18 patients showed significant IFN-γ production in response to at least one TA; however, the presence of TA-specific immune responses did not significantly contribute to better prognosis (overall survival, p = 0.1768; progression-free survival, p = 0.4507). Further studies will need to be performed on a larger scale to better assess the clinical significance of these systems. The production of multiple TA proteins may provide new avenues for the development of immunotherapeutic strategies to stimulate a potent and specific immune response against tumor cells as well as precise assessment of antitumor immune responses in cancer patients.

Rapid Effect of Benralizumab for Hypereosinophilia in a Case of Severe Asthma with Eosinophilic Chronic Rhinosinusitis.

A 56-year-old man with severe asthma underwent bronchial thermoplasty (BT). However, his asthma exacerbated and hypereosinophilia developed 2 months later, thus necessitating oral corticosteroid (OCS) therapy. Six months after BT, a diagnosis of severe asthma with eosinophilic chronic rhinosinusitis (ECRS) was made and benralizumab treatment was initiated; the blood eosinophil count subsequently decreased and lung function improved, thereby permitting OCS dose tapering. Surprisingly, benralizumab both reduced nasal polyps and ameliorated ECRS. Thus, benralizumab may be a useful drug for the rapid treatment of severe asthma with ECRS, especially in patients with hypereosinophilia.

Prospective observational study of carbon-ion radiotherapy for non-squamous cell carcinoma of the head and neck.

To evaluate the efficacy and safety of carbon-ion radiotherapy for non-squamous cell carcinoma of the head and neck, 35 patients were enrolled in this prospective study. The primary end-point was the 3-year local control rate, and the secondary end-points included the 3-year overall survival rate and adverse events. Acute and late adverse events were evaluated according to the Common Terminology Criteria for Adverse Events, version 4.0. The median follow-up time for all patients was 39 months. Thirty-two and three patients received 64.0 Gy (relative biological effectiveness) and 57.6 Gy (relative biological effectiveness) in 16 fractions, respectively. Adenoid cystic carcinoma was dominant (60%). Four patients had local recurrence and five patients died. The 3-year local control and overall survival rates were 93% and 88%, respectively. Acute grade 2-3 radiation mucositis (65%) and dermatitis (31%) was common, which improved immediately with conservative therapy. Late mucositis of grade 2, grade 3, and grade 4 were observed in 11, one, and no patients, respectively. There were no adverse events of grade 5. Carbon-ion radiotherapy achieved excellent local control and overall survival rates for non-squamous cell carcinoma. However, the late mucosal adverse events were not rare, and meticulous treatment planning is required. Trial registration no. UMIN000007886.

[A Case Report of Acute Angioedema that Showed Dramatic Response to Administration of a C1-inactivator].

Angioedema is characterized by rapid and severe swelling of the subcutaneous and submucosal tissues. Angioedema involving the upper airway can lead to life-threatening airway obstruction, and needs prompt diagnosis and treatment. Herein, we report a case of acute angioedema which was suspected as having been caused by estrogen imbalance. A 32-year-old woman who was taking a fertility drug for infertility treatment, presented with sudden swelling of the face and neck region and breathing difficulty. Her symptoms continued to progress despite antibiotic and corticosteroid administration. We suspected hereditary angioedema (HAE), and administered a C1-inactivator, which led to immediate and dramatic resolution of the symptoms. Since the C4 and C1-inhibitor levels were normal, the possibility of HAE type III was considered. However, another possibility was that her complicated hormonal condition, including oral intake of a fertility drug, menstruation, and mental stress may have led to estrogen imbalance causing angioedema. Currently, a variety of hormone therapies is widely used ; therefore, caution is needed against the development of estrogen-dependent angioedema.

Relationship between tumor-associated macrophage subsets and CD47 expression in squamous cell carcinoma of the head and neck in the tumor microenvironment.

Tumor-associated macrophages (TAM) have been classified into an immunostimulatory M1 subset against microbes and malignancies, and an immunoregulatory M2 subset that secretes immunosuppressive cytokines in order to repair tissues damaged by malignancies. The infiltration of M2 in the tumor microenvironment is known to facilitate immunosuppression and tumor-promoting properties. In the present study, we investigated the phagocytic potential of these macrophage subsets in oral squamous cell carcinoma (OSCC) in relation to the expression of CD47, the 'don't eat me' signal against macrophages. The macrophage subsets M1 (induced by GM-CSF and IFN-γ) and M2 (induced by M-CSF and IL-10) were derived from the CD14(+) cells of healthy donors. Phagocytosis of the CFSE-labeled CD47(+) cell line HSC-3 by M1/M2 was assessed using flow cytometry and suppressed by an anti-CD47 neutralizing antibody or CD47 siRNA. Furthermore, CD68(+) and CD163(+) macrophage subset counts infiltrating tumor tissue and the expression of CD47 on cancer cells were examined immunohistochemically in 74 cases of OSCC, and their relationships with clinicopathological parameters or prognoses were determined. The phagocytic potential of M1 was similar to that of M2 in vitro. Phagocytosis by M1 increased in a CD47-dependent manner by the neutralizing antibody and siRNA, but did not in M2. An immunohistochemical (IHC) analysis revealed that the expression of CD47 did not correlate with macrophage subsets in peritumoral tissue or with any clinicopathological parameters; however, the stronger expression of CD47 by cancer cells and larger number of total macrophages/M2 were independently related to shorter survivals. Our results suggest that the expression of CD47 by cancer cells is related to evasion from phagocytosis, particularly that by M1 in vitro. IHC results indicate that various mechanisms are involved in the engulfing potential of TAM subsets in vivo.

Dynamic changes in immune cell profile in head and neck squamous cell carcinoma: Immunomodulatory effects of chemotherapy.

Tumor cells have evolved sophisticated means of escape from the host immune system. To date, several important immunological phenomena have been revealed in peripheral blood as well as within tumors. In the present study, we first investigated the proportion and activation status of peripheral immune regulatory cells and CD8(+) T-cell subsets in patients with head and neck squamous cell carcinoma (HNSCC) using a multicolor flow cytometer, and then evaluated how therapy with docetaxel, cisplatin, and 5-fluorouracil modulated the immune cell profile in peripheral blood. The proportion of naïve T cells was lower and that of effector memory T cells (TEM ) was higher in HNSCC patients than in healthy donors. Moreover, the proportions of activated TEM cells and effector T cells (TEFF ) were dramatically increased in patients with advanced stage disease. The proportion of regulatory T cells and CD14(+) HLA-DR(-) myeloid-derived suppressor cells was elevated in HNSCC patients. Of note, after therapy, in addition to the transient reduction in immune regulatory cells, decreases in central memory T cells and increases in TEFF cells were observed among CD8(+) T-cell subsets, suggesting differentiation from central memory T cells into TEFF cells. Our results suggested that, despite the immunosuppressive status in HNSCC patients, tumor-specific immune responses mediated by CD8(+) T cells might be induced and maintained. Moreover, chemotherapy can trigger not only a transient reduction in immune regulatory cells but also further activation of CD8(+) T cells.

Nivolumab-induced hypophysitis in a patient with advanced malignant melanoma.

The anti-programmed cell death-1 monoclonal antibody (mab), nivolumab has recently been approved for the treatment of unresectable or metastatic malignant melanoma and non-small-cell lung cancers in Japan. Ipilimumab, an anti-cytotoxic T lymphocyte antigen-4 mab for malignant melanoma that was approved earlier than nivolumab in Western countries, is known to frequently cause endocrine immune-related adverse events such as hypophysitis and thyroid dysfunction. We herein report a patient with advanced melanoma who appeared to develop hypophysitis as a consequence of the inhibition of PD-1 by nivolumab. One week after the 6th administration of nivolumab, the patient developed progressive fatigue and appetite loss. Laboratory data on admission for the 7th administration of nivolumab showed eosinophilia and hyponatremia. Since ACTH and cortisol levels were low, nivolumab was discontinued and a large dose of hydrocortisone (100 mg/d) was promptly administered intravenously. A magnetic resonance imaging scan revealed the mild enlargement of the anterior pituitary gland and thickening of the stalk with homogenous contrast. A detailed assessment of anterior pituitary functions with hypothalamic hormone challenges showed that hormonal secretions other than ACTH and TSH were normal. With a replacement dose of hydrocortisone (20 mg/d), the 7th administration of nivolumab was completed without exacerbating the patient's general condition. The present report provides the first detailed endocrinological presentation of nivolumab-induced hypophysitis showing the enlargement of the pituitary gland and stalk in a malignant melanoma patient in Japan. Oncologists and endocrinologists need to be familiar with potentially life-threatening hypophysitis induced by immune-checkpoint inhibitors.

A Case of Maxillary Arteriovenous Fistula Rupture Treated by Vascular Interventional Radiology.

A 64-year-old woman with neurofibromatosis type 1 was admitted because of a sudden hematoma in her right neck and throat. To prevent an airway obstruction, tracheostomy was performed, but bleeding into the trachea persisted and was difficult to stop. Bleeding arose from a vessel lesion in the right parapharyngeal space, passed through the paratracheal space, and finally reached the tracheostomy wound. An arteriovenous fistula (AVF) in the maxillary artery was revealed by angiography. We diagnosed rupture of the varix resulting from venous high pressure caused by the AVF. The patient was treated by vascular interventional radiology (IVR). A large number of platinum coils were inserted and N-butyl-2-cyanoacrylate (NBCA) was embolized in the AVF and varix. Although innovative vascular IVR was better than surgery to treat AVF of the head and neck lesion, some problems were encountered. The cost for the provided medical services was high, and NBCA was not approved by the pharmaceutical affairs law in Japan.

[Sequential Chemoradiotherapy for Advanced Head and Neck Cancer: A Clinical Study with 33 Cases].

A total of 33 patients with advanced head and neck cancer (AHNC) treated with sequential chemoradiotherapy (SCRT) were retrospectively evaluated at Gunma University Hospital between 2009 and 2011. The regimen of SCRT was docetaxel, cisplatin, and fluorouracil (TPF)-based induction chemotherapy (ICT), accompanied by docetaxel and cisplatin-based concurrent chemoradiotherapy (CCRT), and oral administration of TS-1 after that. The response rate was 61%, the 3-year overall survival rate was 42%, the non-tumor-bearing survival rate was 27%, and the tumor-bearing survival rate was 15%. Fourteen of 33 patients were tumor-free, and their 3-year overall survival rate was surprisingly 86%. On the other hand, 3-year overall survival rate in the remaining 19 patients was significantly low. To select good response cases for ICT was important. In such cases, TPF should be applied repeatedly, which achieved a 61% response rate even in AHNC. A long-term TS-1 oral medication suppressed cancer regrowth and contributed to long-term survival.

Immunological significance of the accumulation of autophagy components in oral squamous cell carcinoma.

The immunological significance of autophagy in the tumor microenvironment remains unclear. To explore the relationship between autophagy and anti-tumor immune responses, we investigated the expression of autophagy-related proteins and infiltration of immune cells using immunohistochemistry (IHC). The expression of three representative autophagy components, LC3, Beclin-1 and p62/SQSTM1, as well as the number of dendritic cells (DC), T cells and NK cells were examined by IHC in 74 patients with oral squamous cell carcinoma (OSCC). The relationship between the expression of autophagy-associated molecules and various clinicopathological parameters was also evaluated. The expression of both LC3 and p62/SQSTM1 in the peripheral site significantly correlated with an increase in the infiltration of T cells. Furthermore, the expression of p62/SQSTM1 and Beclin-1 correlated with that of HLA class I and class II in tumor cells, respectively. In addition, several unfavorable clinicopathological parameters correlated with an increase in the expression of LC3 in the peripheral site. The correlation observed between LC3 or p62/SQSTM1 and the infiltration of T cells suggests that autophagy may actively mobilize immune cells toward the cancer bed. Meanwhile, the three autophagy-associated proteins examined were linked to malignant potential and an unfavorable prognosis.

Immunosuppressive activity of cancer-associated fibroblasts in head and neck squamous cell carcinoma.

Cancer-associated fibroblasts (CAFs) have been shown to play an important role in angiogenesis, invasion, and metastasis. In the present study, we determined whether CAFs within the tumor microenvironment (TME) in head and neck squamous cell carcinoma (HNSCC) contributed to promoting immunosuppression and evasion from immune surveillance. Six pairs of CAFs and normal fibroblasts (NFs) were established from the resected tumor tissues of patients with HNSCC. The effects of CAFs and NFs on the functions of T cells were comparatively analyzed. CAFs expressed the co-regulatory molecules, B7H1 and B7DC, whereas NFs did not. The expression levels of cytokine genes, including those for IL6, CXCL8, TNF, TGFB1, and VEGFA, were higher in CAFs. T cell proliferation was suppressed more by CAFs or their supernatants than by NFs. Moreover, PBMCs co-cultured with the supernatants of CAFs preferentially induced T cell apoptosis and regulatory T cells over those co-cultured with the supernatants of NFs. A microarray analysis revealed that the level of genes related to the leukocyte extravasation and paxillin signaling pathways was higher in CAFs than in NFs. These results demonstrated that CAFs collaborated with tumor cells in the TME to establish an immunosuppressive network that facilitated tumor evasion from immunological destruction.

[Prediction of Post-operative Lymph Node Metastasis with a Molecular Biological Test in Head and Neck Cancer].

We assessed herein the post-operative lymph node metastasis in head and neck cancer, using the One-step nucleotide amplification (OSNA) method targeting matrix metalloproteinase 7 (MMP-7). Compared with the pathological test, the molecular biological test revealed more lymph node metastasis, resulting in poor prognosis. Six cases, of which the number of lymph node metastasis was the same between pathological and molecular biological test, survived. On the other hand, three of four cases, in which number of lymph node metastasis in the molecular biological test were larger than the pathological test, died from metastasis. We concluded that the pathological test underestimated metastasis, and OSNA with MMP-7 was useful for the prediction of post-operative lymph node metastasis.

Enhancement of Tumor Antigen-specific T-cell Responses by Immune Checkpoint Blockade in Human Papillomavirus-related Head and Neck Squamous Cell Carcinoma.

BACKGROUND/AIM: Human papillomavirus (HPV)-positive head and neck squamous cell carcinoma (HNSCC) is clinically and immunologically distinct from HPV-negative HNSCC. Herein, we investigated the presence of tumor antigens HPV E6/E7 and wild-type p53-specific T-cell responses, and the impact of immune checkpoint blockade in patients with HPV-positive HNSCC. MATERIALS AND METHODS: Peripheral blood mononuclear cells (PBMCs) from patients with HPV-positive HNSCC were stimulated with HPV E6/E7 or wild-type p53-derived peptide mixture and evaluated using the interferon-γ enzyme-linked immunosorbent spot assay. Flow cytometry was performed to analyze the proportion of T-cell subsets and T cells expressing immune checkpoint molecules. RESULTS: HPV E6/E7-specific T cells were detected in 22 (95.7%) of 23 patients, whereas wild-type p53-specific T cells were detected in 3 (15.0%) of 20 patients. Seven (43.8%) of 16 patients exhibited wild-type p53-specific T-cell responses, as determined using whole proteins instead of peptides. Immune checkpoint blockade enhanced wild-type p53-specific T-cell responses in 9 (45.0%) of 20 patients. Flow cytometric analysis of PBMCs revealed that responders exhibiting enhanced wild-type p53-specific T-cell responses following immune checkpoint blockade had a significantly higher proportion of Ki-67+CD4+ T cells, Ki-67+CD8+ T cells, regulatory T cells, PD-1+CD4+ T cells, and TIM-3+CD4+ T cells than non-responders. CONCLUSION: Our findings indicate that tumor antigen-specific T cells are present in the peripheral blood of patients with HPV-positive HNSCC. Blockade of checkpoint pathways can enhance T-cell responses in certain patients, probably via activated T cells, Tregs, and/or exhausted CD4+ T cells.

Alteration of cancer stem cell-like phenotype by histone deacetylase inhibitors in squamous cell carcinoma of the head and neck.

Recent progression in the understanding of stem cell biology has greatly facilitated the identification and characterization of cancer stem cells (CSCs). Moreover, evidence has accumulated indicating that conventional cancer treatments are potentially ineffective against CSCs. Histone deacetylase inhibitors (HDACi) have multiple biologic effects consequent to alterations in the patterns of acetylation of histones and are a promising new group of anticancer agents. In this study, we investigated the effects of two HDACi, suberoylanilide hydroxamic acid (SAHA) and trichostatin A (TSA), on two CD44+ cancer stem-like cell lines from squamous cell carcinoma of the head and neck (SCCHN) cultured in serum-free medium containing epidermal growth factor and basic fibroblast growth factor. Histone deacetylase inhibitors inhibited the growth of SCCHN cell lines in a dose-dependent manner as measured by MTS assays. Moreover, HDACi induced cell cycle arrest and apoptosis in these SCCHN cell lines. Interestingly, the expression of cancer stem cell markers, CD44 and ABCG2, on SCCHN cell lines was decreased by HDACi treatment. In addition, HDACi decreased mRNA expression levels of stemness-related genes and suppressed the epithelial-mesencymal transition phenotype of CSCs. As expected, the combination of HDACi and chemotherapeutic agents, including cisplatin and docetaxel, had a synergistic effect on SCCHN cell lines. Taken together, our data indicate that HDACi not only inhibit the growth of SCCHN cell lines by inducing apoptosis and cell cycle arrest, but also alter the cancer stem cell phenotype in SCCHN, raising the possibility that HDACi may have therapeutic potential for cancer stem cells of SCCHN.

Subglottic Schwannoma: a report of a rare case that was treated with medial thyrotomy.

We present a rare case of primary subglottic schwannoma in a 51-year-old man. He presented with subacute dyspnea and progressively worsening stridor. Videoendoscopy revealed the presence of a submucosal mass in the subglottic area, which measured 2 cm in diameter and had occluded approximately 80% of the lumen. Computed tomography (CT) and magnetic resonance imaging (MRI) showed a tumor arising from the left posterior wall of the subglottis and extending from the level of the cricoid cartilage to the first tracheal ring. After tracheostomy for airway management, subglottic schwannoma was diagnosed via fiberscopy-assisted punch biopsy. We removed the tumor via a medial thyrotomy (laryngofissure), and the post-excisional raw surface of the cricoid and tracheal cartilage was covered with a free buccal mucosal flap, which was attached using absorbable sutures and fibrin glue. No complications including recurrent nerve palsy developed after the procedure, and early postoperative ambulation was successfully performed. The patient is currently well, and the subglottic wound is clear. Although long-term follow-up is required, medial thyrotomy and coverage of the exposed cartilage with a free buccal mucosal flap is more effective for large subglottic schwannomas than laryngeal or tracheal resection with permanent tracheal tunnel formation from the viewpoint of phonation disability and the risk of complications.