Association between salivary inflammatory mediators and oral mucositis in patients with cancer undergoing chemotherapy.

PURPOSE: Oral mucositis is a severe adverse event in patients undergoing chemotherapy and radiotherapy that may lead to the termination of cancer treatment. This study aimed to elucidate the relationship between salivary inflammatory mediators and oral mucositis in patients undergoing chemotherapy. METHODS: This prospective cohort study included 167 patients who underwent chemotherapy at our institution between June 2020 and November 2023. We evaluated the association between chemotherapy-induced oral mucositis and salivary inflammatory mediators using multiple comparison tests and logistic regression analyses. RESULTS: Of the 167 patients, 67 (40.1%) had oral mucositis. Dunn's multiple comparison test revealed that interleukin-6 was significantly higher in oral mucositis of grades 2 and ≥ 3 (P < 0.01) and tumor necrosis factor (TNF)-α was significantly higher in oral mucositis of grades 3-4 (P < 0.01). Logistic regression analysis showed that the risk of oral mucositis was significantly higher for tumor necrosis factor (TNF)-α > 4.4 pg/mL than for TNF-α ≤ 4.4 pg/mL (adjusted odds ratio, 2.4; 95% confidence interval, 1.1-5.3; P = 0.03). CONCLUSION: Saliva is useful in evaluating inflammation in patients with chemotherapy-induced oral mucositis. Furthermore, TNF-α may be a predictive marker for the severity of oral mucositis in patients undergoing chemotherapy.

Dysregulation of Amphiregulin stimulates the pathogenesis of cystic lymphangioma.

Along with blood vessels, lymphatic vessels play an important role in the circulation of body fluid and recruitment of immune cells. Postnatal lymphangiogenesis commonly occurs from preexisting lymphatic vessels by sprouting, which is induced by lymphangiogenic factors such as vascular endothelial growth factor C (VEGF-C). However, the key signals and cell types that stimulate pathological lymphangiogenesis, such as human cystic lymphangioma, are less well known. Here, we found that mouse dermal fibroblasts that infiltrate to sponges subcutaneously implanted express VEGF-D and sushi, Von Willebrand factor type A, EGF, and pentraxin domain containing 1 (SVEP1) in response to PDGFRß signal. In vitro, Pdgfrb knockout (ß-KO) fibroblasts had reduced expression of VEGF-D and SVEP1 and overproduced Amphiregulin. Dysregulation of these three factors was involved in the cyst-like and uneven distribution of lymphatic vessels observed in the ß-KO mice. Similarly, in human cystic lymphangioma, which is one of the intractable diseases and mostly occurs in childhood, fibroblasts surrounding cystic lymphatics highly expressed Amphiregulin. Moreover, fibroblast-derived Amphiregulin could induce the expression of Amphiregulin in lymphatic endothelial cells. The dual source of Amphiregulin activated EGFR expressed on the lymphatic endothelial cells. This exacerbation cascade induced proliferation of lymphatic endothelial cells to form cystic lymphangioma. Ultimately, excessive Amphiregulin produced by fibroblasts surrounding lymphatics and by lymphatic endothelial cells per se results in pathogenesis of cystic lymphangioma and will be a fascinating therapeutic target of cystic lymphangioma.

Presurgical imaging of the subscapular artery with three-dimensional-computed tomography angiography: Application to harvesting subscapular system free-flaps.

A subscapular system free-flap is extremely useful for maxillofacial reconstruction since it facilitates the simultaneous harvesting of multiple flaps using one subscapular artery (SSA) alone. However, cases of aberrations in the SSAs have been reported. Therefore, the morphology of SSA needs to be confirmed preoperatively before harvesting the flaps. Recent developments in imaging, such as three-dimensional (3D) computed tomography angiography (3D CTA), facilitate obtain high-quality images of blood vessel images. Therefore, we examined the utility of 3D CTA in navigating the course of the SSA before harvesting subscapular system free-flaps. We examined the morphology and aberrations of the SSA using 39 sides of the 3D CTA data and 22 sides of Japanese cadavers. SSAs can be classified into types S, I, P, and A. Type S SSAs are significantly long (mean length = 44.8 mm). Types I and P SSAs have short mean lengths, measuring ≤2 cm in approximately 50% of cases. In type A, the SSA is absent. The frequency of types S, I, P, and A SSAs were 28.2%, 7.7%, 51.3%, and 12.8%, respectively. Type S can be advantageous for harvesting the SSA in subscapular system free-flaps, because it is significantly longer. In contrast, types I and P might be dangerous because their mean lengths are shorter. In type A, caution is needed not to injure the axillary artery because the SSA is absent. When surgeons need to harvest the SSA, presurgical 3D CTA is recommended.

Targeting CD36-Mediated Lipid Metabolism by Selective Inhibitor-Augmented Antitumor Immune Responses in Oral Cancer.

The fatty acid receptor CD36 is expressed on various malignant cells and is suggested to contribute to tumor progression. CD36 is also expressed by several immune cells and involved in immune responses and may be a potential target in cancer immunotherapy. In this study, we investigated whether the selective inhibition of CD36 can inhibit tumor progression and facilitate an antitumor immune response in oral squamous carcinoma cells (OSCCs). We assessed the effects of sulfosuccinimidyl oleate sodium (SSO), a CD36 inhibitor, on the proliferation apoptosis and alteration in tumor cell surface expression levels of immune accessory molecules in vitro. We also assessed whether SSO-treated OSCCs could promote a T cell response via a Mixed Lymphocyte Reaction (MLR) assay. We also investigated the direct antitumor effects and immunomodulatory effects of SSO using a mouse oral cancer OSCC model. SSO treatment significantly inhibited OSCC proliferation, increased apoptotic cell death, and upregulated the cell surface expression of several immune accessory molecules, including CD83, MHC-Class II, and PD-L1. SSO-treated OSCCs augmented T cell proliferation following MLR. In vivo SSO administration significantly attenuated mouse tumor growth with an increased proportion of immune cells, including CD4+ T, CD8+ T, and dendritic cells; it also decreased the proportion of immune suppressive cells, such as myeloid-derived suppressor and regulatory T cells. These results suggest that the selective inhibition of CD36 can induce direct and indirect antitumor effects by facilitating host antitumor immune responses in OSCCs.

Hospital pharmacist interventions for the management of oral mucositis in patients with head and neck cancer receiving chemoradiotherapy: a multicenter, prospective cohort study.

PURPOSE: Oral mucositis is a severe adverse event in patients with head and neck cancer (HNC) receiving chemotherapy and radiotherapy that may cause the termination of cancer treatment. In this study, we aimed to reveal the benefits of pharmacist interventions in oral health care for patients with HNC receiving concurrent chemoradiotherapy (CCRT). METHODS: We conducted a multicenter, prospective cohort study on 173 patients from September 2019 to August 2022. We evaluated the association between the occurrence of oral mucositis during CCRT and various factors in the absence or presence of direct medication instructions from hospital pharmacists. RESULTS: Sixty-eight patients received medication instructions from pharmacists (the pharmacist intervention group), whereas 105 patients did not receive instructions (the control group). Logistic regression analysis showed that grade 2 (Gr 2) oral mucositis was significantly lower in patients receiving pharmacist interventions than in patients in the control group (adjusted odds ratio [aOR], 0.42; 95% confidence interval [CI], 0.18-0.96; P = 0.04). The time to onset of Gr 2 oral mucositis was significantly longer in the pharmacist intervention group than in the control group (hazard ratio, 0.53; 95% CI, 0.29-0.97; P = 0.04). CONCLUSION: Direct intervention, especially when provided by hospital pharmacists, can have a real effect in supporting patients with HNC experiencing severe side effects of treatments. Moreover, the integration of pharmacists into the oral healthcare team is becoming even more essential to reduce the severity of side effects.

Clinical Application of Hyperdry Amniotic Membrane in Cleft Palate Repair.

OBJECTIVE: To examine the safety and efficacy of hyperdry amniotic membrane (HDAM) for wound closure after palatoplasty in cleft palate patients. METHODS: HDAMs were prepared by washing and drying under infrared rays and microwaves at temperatures less than 60°C using a hyperdrying device. A total of 16 cleft palate patients (8 males, 8 females), aged 1 to 3 years (mean age 1 year 9 months), received one-stage pushback palatoplasty. The remaining raw wound after surgery was covered by an HDAM and a plastic cover plate. The cover plate was removed 1 week after surgery and parameters including temperature, feeding, allergic reactions, postoperative bleeding, re-epithelialization, wound dehiscence, and infection were monitored during the follow-up period of 31.2 months. RESULTS: All patients could adequately ingest at 5 days postoperation and after removal of the cover plate. None of the patients had a persistent fever or allergic reactions. Ingestion was feasible immediately in all patients, and no postoperative bleeding was observed during ingestion. No secondary hemorrhages were observed during follow-up. No postoperative wound dehiscence on the midline of the palate was observed. No infections were observed after the removal of the cover plate. No patients suffered from severe scar formation or contracture of the wound in the follow-up period. Hemorrhage, undue epithelialization, and scar contracture did not occur in any patient. The mean evaluation score was 7.75 points. CONCLUSION: HDAM can be used safely and effectively for wound closure following palatoplasty in cleft palate infants. Future studies testing the safety of patient's own amnion for palatoplasty, are required.

RSK-Mediated Non-canonical Activation of EphA2 by Tamoxifen.

The long-term administration of tamoxifen to estrogen receptor α (ERα)-positive breast cancer patients is an established treatment that reduces mortality and recurrence. However, resistance to tamoxifen and an increased risk of endometrial cancer may occur; therefore, the mechanisms by which tamoxifen causes these adverse effects warrant further study. Tamoxifen has been shown to activate mitogen-activated protein kinase (MAPK) in an ERα-independent manner; therefore, we investigated its effects on the MAPK-mediated non-canonical activation of EphA2, a critical event regulating cell migration. Tamoxifen at slightly higher concentrations induced the rapid phosphorylation of EphA2 at Ser-897 via the MAPK/extracellular signal-regulated kinase (ERK) kinase (MEK)-ERK-ribosomal S6 kinases (RSK) pathway in HeLa cells. In addition, tamoxifen significantly enhanced the migration ability of ERα-negative MDA-MB-231 breast cancer cells in RSK- and EphA2-dependent manners. Phosphorylated EphA2 was internalized and re-localized to the plasma membrane, including lamellipodia, in an RSK-dependent manner. Collectively, the present results provide novel insights into the tumor-promoting activity of tamoxifen.

Multicenter retrospective study of nivolumab for recurrent/metastatic oral squamous cell carcinoma.

OBJECTIVES: Immunotherapy with nivolumab for patients with recurrent/metastatic oral squamous cell carcinoma has not been evaluated. Here, we aimed to examine the efficacy, safety, and prognostic factors of nivolumab in these patients. MATERIALS AND METHODS: This multicenter retrospective observational study involved patients who received nivolumab between April 2017 and June 2019. The patient characteristics were evaluated for association with progression-free and overall survival. Progression-free and overall survival rates were calculated; parameters that were significant in the univariate analysis were used as explanatory variables. Independent factors for progression-free and overall survival were identified using multivariate analysis. RESULTS: Totally, 143 patients were included. The overall response and disease control rates were 27.3% and 46.2%, respectively. The median, 1- and 2-year progression-free survival rates were 2.7 months, 25.4%, and 19.2%, respectively; those for overall survival were 11.2 months, 47.3%, and 33.6%, respectively. The independent factors affecting progression-free survival were performance status and immune-related adverse event occurrence, whereas those affecting overall survival were performance status, target disease, and number of previous lines of systemic cancer therapy. Eight patients reported grade ≥3 immune-related adverse events. CONCLUSION: Nivolumab was effective for recurrent/metastatic oral squamous cell carcinoma treatment and was well tolerated by patients.

[Neutrophil-to-Lymphocyte Ratio(NLR)as a Predictive Indicator of the Response to Nivolumab in Patients with Oral Squamous Cell Carcinoma].

BACKGROUND: The immune checkpoint inhibitor (ICI) nivolumab has revolutionized the treatment for recurrent or metastatic advanced oral cancer. Because the response rate remains low, the identification of predictive indicators of the response to nivolumab is among the most critical issues. The neutrophil-to-lymphocyte ratio(NLR)is a potential predictive marker of the response to nivolumab in patients with various cancer types. However, the utility of the NLR as a biomarker for predicting the response of oral cancer patients to ICIs is poorly understood. PATIENTS AND METHODS: In this retrospective cohort study, we evaluated the association between NLR and nivolumab treatment outcome in 13 patients diagnosed with recurrent or metastatic oral squamous cell carcinoma(OSCC)treated with nivolumab at the Toyama University Hospital between December 2017 and December 2019. RESULTS: Complete response(CR)and partial response(PR)rates of 38.5%(5/13)and 0% (0/13), respectively, were observed in responders; stable disease(SD)and progressive disease(PD)rates of 7.7%(1/13) and 53.8%(7/13), respectively, were observed in non-responders. After nivolumab treatment, the median NLR among responders decreased to 3.3(3.0-3.9)from 4.1(3.7-4.3)during pre-treatment assessment and increased from 5.6(3.2- 9.2)at pre-treatment to 9.4(5.3-17.9)among non-responders. Moreover, patients with higher NLRs(≥5)in the post- treatment group had a significantly worse overall survival than those with lower NLRs(<5). Specifically, patients with a higher post-treatment NLR(≥10)had significantly worse outcomes for post-nivolumab salvage chemotherapy. CONCLUSION: The NLR could be a useful marker for predicting the treatment response to nivolumab or post-nivolumab salvage chemotherapy in OSCC patients.

CD36 expression on oral squamous cell carcinoma cells correlates with enhanced proliferation and migratory activity.

OBJECTIVE: Recent studies have demonstrated the pro-tumour role of CD36 in multiple cancer types. However, its role has not been well elucidated in oral squamous cell carcinoma (OSCC). Here, we aimed to evaluate the role of CD36 in proliferation and migration of OSCC cells. METHODS: Human OSCC cell lines HSC-2, HSC-3, HSC-4 and Ca9-22 were assessed for proliferation by staining with the cell proliferation marker Ki-67. We also assessed migration activity, and the expression of cell adhesion molecules such as E-cadherin and ß-catenin and platelet-derived growth factor receptors (PDGFRs) of CD36-positive cells. RESULTS: CD36-positive cells showed increased expression of Ki-67 and migration activity compared with CD36-negative cells. Moreover, CD36-positive cells showed reduced expression of E-cadherin and ß-catenin, whereas the expression of PDGFRs increased compared with that in CD36-negative cells. CONCLUSIONS: Our results strongly suggest that CD36 has an important role in facilitating the proliferation and migration activity of OSCC cells, indicating its usefulness in the diagnosis of high-grade tumour and targeted therapy of oral cancer.

Different PDGF Receptor Dimers Drive Distinct Migration Modes of the Mouse Skin Fibroblast.

BACKGROUND/AIMS: The migration of mesenchymal cells is a fundamental cellular process that has been implicated in many pathophysiological conditions and is induced by chemoattractants such as platelet-derived growth factors (PDGFs). However, the regulatory mechanisms shaping this migration remain to be elucidated. METHODS: Here, we prepared mouse skin fibroblasts inactivated for different PDGF receptor genes and systematically measured their chemotactic responses within a gradient of different chemoattractants. RESULTS: We found that PDGFRαß and PDGFRßß dimers were strong inducers of random and directionally-persistent migration, respectively, that was sustained for up to 24 h. MAPK and PI3K were necessary to mediate random and directional migration, respectively. Directional migration was accompanied by abundant ventral stress fiber formation and consistent cell shape with less frequent formation of branch-like processes. CONCLUSION: This is the first systematic study that characterized the chemotaxis mediated by three-different types of PDGFR dimers in mesenchymal cell migration. Our data demonstrate that PDGFR dimer formation is the critical step to determine the specific mode of fibroblast chemotaxis, while the accompanying cytoskeletal remodeling might contribute to migration persistence.

Successful multimodal treatment of intraoral salivary duct carcinoma in a patient with multiple lymph node metastases: a case report.

BACKGROUND: Salivary duct carcinoma (SDC) is a high-grade salivary gland malignancy that is associated with an aggressive clinical behavior and poor prognosis. Herein, we report on a long surviving case of SDC of the minor salivary gland with multiple lymph node metastases (LNMs). CASE PRESENTATION: An 83-year-old woman presented with a history of lymphadenopathy in the right side of the neck and recent onset and rapid growth of a mass in the right buccal region. Clinical examinations and biopsy findings were suggestive of a salivary gland malignant tumor with regional LNMs. The patient was treated with neoadjuvant chemotherapy. Tumor excision and ipsilateral radical neck dissection were performed, followed by adjuvant chemoradiotherapy. Postoperative histological examination revealed a tumor with irregular nests of atypical ductal epithelial cells, a cribriform growth pattern, and comedo-like central necrosis that lead to a final diagnosis of SDC. LNMs were observed in six lymph nodes of the right side of the neck. The patient underwent postoperative chemotherapy using single-agent cisplatin that was administered concurrently with radiotherapy (total, 65 Gy). There was no evidence of local recurrence or distant metastasis for >6 years. CONCLUSIONS: Although available data on treatment modalities for SDC remain limited, multimodal therapy may contribute to improved clinical outcomes in patients with advanced intraoral SDC.

Oral Focal Mucinosis of the Tongue: Case Report and Review of the Literature.

Oral focal mucinosis (OFM) is an oral mucosal lesion characterized by focal mucosal accumulation that rarely occurs on the tongue. This report describes a rare case of OFM on the right side of the tongue in a 71-year-old female patient. The clinical features of OFM have not been well defined, making it difficult to differentiate it from other lesions based solely on clinical manifestations; therefore, histopathological examinations are necessary. Although OFM on the tongue is rare and has a good prognosis with resection, it should be considered as differential for painless mass lesions in the oral cavity.

Treatment strategies for patients over 80 years of age with oral squamous cell carcinoma.

OBJECTIVE: To analyze the clinical characteristics of patients with oral squamous cell carcinoma aged ≥80 years, focusing on surgical treatments. STUDY DESIGN: We reviewed patients with oral squamous cell carcinoma aged ≥80 years who underwent surgery between 2005 and 2018. Basic information, comorbidities, multiple primary cancers, initial treatment, complications, and outcomes were evaluated. RESULTS: Of 197 patients aged ≥80 years, 119 patients underwent surgery (50 males, 69 females; mean age: 83.5 years). The gingiva was the most common primary tumor site (63 patients, 52.9 %). The stage classification was stage I in 35 patients (29.4 %), stage II in 44 (37 %), stage III in 16 (13.4 %), stage IVA in 22 (18.5 %), and stage IVB in 2 (1.7 %). Comorbidities were identified in 112 patients (94.1 %). Surgery was the initial treatment in 111 patients (93.3 %). Eight (6.7 %) patients received postoperative adjuvant chemotherapy/radiotherapy; 20 patients (16.8 %) underwent free tissue transplantation. Perioperative complications were observed in 36 patients (30.3 %). The cumulative 5-year and 10-year overall survival rates were 82 % and 68.3 %, respectively; the disease-specific survival rates were 90 %. CONCLUSION: Good treatment outcomes were obtained with radical surgery. Surgery should be the first choice if quality of life is assured and there are no issues with surgical tolerance, regardless of age.

PAK4 inhibition augments anti-tumour effect by immunomodulation in oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) is one of the most common malignant tumours, warranting novel treatments. Here, we examined the therapeutic efficacy of inhibiting p21 activated kinase 4 (PAK4) in OSCC and determined its immunomodulatory effect by focusing on the enhancement of anti-tumour effects. We examined PAK4 expression in OSCC cells and human clinical samples and analysed the proliferation and apoptosis of OSCC cells following PAK4 inhibition in vitro. We also investigated the effects of in vivo administration of a PAK4 inhibitor on immune cell distribution and T-cell immune responses in OSCC tumour-bearing mice. PAK4 was detected in all OSCC cells and OSCC tissue samples. PAK4 inhibitor reduced the proliferation of OSCC cells and induced apoptosis. PAK4 inhibitor significantly attenuated tumour growth in mouse and was associated with increased proportions of IFN-γ-producing CD8+ T-cells. Furthermore, PAK4 inhibitor increased the number of dendritic cells (DCs) and up-regulated the surface expression of various lymphocyte co-stimulatory molecules, including MHC-class I molecules, CD80, CD83, CD86, and CD40. These DCs augmented CD8+ T-cell activation upon co-culture. Our results suggest that PAK4 inhibition in OSCC can have direct anti-tumour and immunomodulatory effects, which might benefit the treatment of this malignancy.

Short-Term Follow-up of Surgical Management Verruca Vulgaris with Modified Estlander Flap: A Case Report and Recent Literature Review.

Background: Verruca vulgaris (VV), widely known as warts, is a common benign skin lesion, which is caused by human papilloma virus. In some cases, VV can be developed within the oral cavity. Surgical excision is considered as the most preferred treatment modality for both cutaneous and oral VV which could be challenge to deal with. Case Report: Herein, a short-term case of a 64-year-old male patient with a large oral VV, involving the lower and upper lips, and commissure was reported. The patient underwent a wide surgical excision, resulting in a significant lip defect. The modified Estlander flap technique was applied to treat the defect and restore lip function. At one year post operation, no signs of recurrence were recorded, and the Estlander flap technique displayed satisfactory outcomes. Conclusions: Surgical management of oral VV involving lips may leaves large defect, which requires consideration in defect reconstruction. This case report shows that reconstruction of the defect with a modified estlander flap resulted in a good outcome, with satisfactory functionality for the patient. Key words:Estlander flap, verruca vulgaris, surgical excision.

Development and Characterization of a Three-Dimensional Organotypic In Vitro Oral Cancer Model with Four Co-Cultured Cell Types, Including Patient-Derived Cancer-Associated Fibroblasts.

Background/Objectives: Cancer organoids have emerged as a valuable tool of three-dimensional (3D) cell cultures to investigate tumor heterogeneity and predict tumor behavior and treatment response. We developed a 3D organotypic culture model of oral squamous cell carcinoma (OSCC) to recapitulate the tumor-stromal interface by co-culturing four cell types, including patient-derived cancer-associated fibroblasts (PD-CAFs). Methods: A stainless-steel ring was used twice to create the horizontal positioning of the cancer stroma (adjoining normal oral mucosa connective tissue) and the OSCC layer (surrounding normal oral mucosa epithelial layer). Combined with a structured bi-layered model of the epithelial component and the underlying stroma, this protocol enabled us to construct four distinct portions mimicking the oral cancer tissue arising in the oral mucosa. Results: In this model, α-smooth muscle actin-positive PD-CAFs were localized in close proximity to the OSCC layer, suggesting a crosstalk between them. Furthermore, a linear laminin-γ2 expression was lacking at the interface between the OSCC layer and the underlying stromal layer, indicating the loss of the basement membrane-like structure. Conclusions: Since the specific 3D architecture and polarity mimicking oral cancer in vivo provides a more accurate milieu of the tumor microenvironment (TME), it could be crucial in elucidating oral cancer TME.

Rapamycin Induces Phenotypic Alterations in Oral Cancer Cells That May Facilitate Antitumor T Cell Responses.

OBJECTIVES: In this study, we investigated the antitumor immunomodulatory effects of rapamycin in oral cancer. STUDY DESIGN: We examined the proliferation, apoptosis, and migration of cancer cells and investigated the cell surface expression levels of immune accessory molecules and T cell immune responses in vitro. We investigated the effect of in vivo administration of rapamycin on immune cell distribution and T cell immune responses in oral tumor-bearing mice. RESULTS: Rapamycin treatment significantly inhibited OSCC cell proliferation and migration, increased apoptotic cell death, and upregulated cell surface expression of several immune accessory and adhesion molecules, including CD40, CD83, PD-L1, PD-L2, MHC class I, P-selectin, and VCAM-1. These cancer cells augmented T cell proliferation. In vivo rapamycin administration significantly attenuated mouse tumor growth with an increased proportion of immune cells, including CD4+ T cells, CD8+ T cells, and dendritic cells (DCs); decreased the proportion of immune suppressive cells, such as myeloid-derived suppressor cells and regulatory T cells; enhanced DC maturation and upregulated the surface expression of CD40, CD86, and ICAM-1. CONCLUSIONS: Our results suggest that the therapeutic effect of mTOR inhibition in oral cancer can cause direct antitumor and immunomodulatory effects.

The effects of carbon-ion beam irradiation on three-dimensional in vitro models of normal oral mucosa and oral cancer: development of a novel tool to evaluate cancer therapy.

Given that the original tumor microenvironment of oral cancer cannot be reproduced, predicting the therapeutic effects of irradiation using monolayer cultures and animal models of ectopic tumors is challenging. Unique properties of carbon-ion irradiation (CIR) characterized by the Bragg peak exert therapeutic effects on tumors and prevent adverse events in surrounding normal tissues. However, the underlying mechanism remains unclear. The biological effects of CIR were evaluated on three-dimensional (3D) in vitro models of normal oral mucosa (NOMM) and oral cancer (OCM3 and OCM4) consisting of HSC-3 and HSC-4 cells. A single 10- or 20-Gy dose of CIR was delivered to NOMM, OCM3, and OCM4 models. Histopathological and histomorphometric analyses and labeling indices for Ki-67, γH2AX, and TUNEL were examined after CIR. The concentrations of high mobility group box 1 (HMGB1) were measured. NOMM exhibited epithelial thinning after CIR, which could be caused by the decreased presence of Ki-67-labeled basal cells. The relative proportion of the thickness of cancer cells to the underlying stroma in cancer models decreased after CIR. This finding appeared to be supported by changes in the three labeling indices, indicating CIR-induced cancer cell death, mostly via apoptosis. Furthermore, the three indices and the HMGB1 release levels significantly differed among the OCM4 that received different doses and with different incubation times after CIR while those of the OCM3 models did not, suggesting more radiosensitivity in the OCM4. The three 3D in vitro models can be a feasible and novel tool to elucidate radiation biology.

Complete Response to Cetuximab Plus Paclitaxel Therapy in Nivolumab-Refractory Patients in Distant Metastasis of Squamous Cell Carcinoma of the Tongue: A Report of Two Cases.

Herein, we report two cases of patients diagnosed with nivolumab-refractory distant metastatic squamous cell carcinoma of the tongue who were successfully treated with a combination of paclitaxel and cetuximab. Case 1 had controllable local recurrence and distant metastasis. Case 2 had controllable distant metastatic disease. Thus, demonstrating that some nivolumab-refractory patients with recurrent or distant metastatic oral squamous cell carcinoma may benefit from subsequent salvage chemotherapy.