The dental implant survival rate in 18 patients with post-operation revolutionary jaw reconstruction using free fibular flap, dental implants, and overdentures.

Background/purpose: This retrospective study assessed the risks and complications associated with dental implants after jaw surgery and radiotherapy for large defects, highlighting challenges for reconstructive surgeons and prosthetic dentists. Materials and methods: From 2002 to 2008, National Taiwan University's Department of Maxillofacial Surgery used preoperative stereolithographic models and microvascular flaps for mandibular reconstruction in 18 patients with defects from ameloblastoma or advanced gingival cancer. They received free fibular flap grafts, followed by 46 osseointegrated dental implants. Patient outcomes, monitored for up to 60 months, were assessed through clinical and radiographic evaluations of implant success. Results: The overall survival rate of dental implants following tumor surgery and radiotherapy was 84.8%. Seven implants failed due to peri-implantitis (3), tumor recurrence (2), and osteoradionecrosis (ORN) (2). The ameloblastoma group did not contribute to implant failure, with 4 implant failures in the stage III gingival cancer group, and 3 implant failures in the stage IV gingival cancer group. Conclusion: Following segmental mandibulectomy for mandible lesions, free fibular bone graft reconstruction restored mandible continuity, while subsequent dental implantation and overdenture fabrication restored occlusion and aesthetics for patients. Besides considering treatment strategies for ameloblastoma groups, similar approaches can be extended to oral cancer patients undergoing post-operative reconstruction. However, additional considerations (peri-implant soft tissue condition, tumor recurrence, ORN, etc.) are necessary for oral cancer patients predisposed to dental implant failure post-surgery.

Evaluation of the prognostic and therapeutic potential of inhibin beta B for oral squamous cell carcinoma.

Background/purpose: Oral squamous cell carcinoma (OSCC) is a common cancer worldwide, and its metastasis is difficult to predict and prevent. Inhibin beta B (INHBB) protein has been linked to cancer prognosis and epithelial-mesenchymal transition (EMT). However, previous study about INHBB expression focused on patients in a single region while the risk factors vary among regions. This study aimed to provide a broader perspective on INHBB expression in OSCC. Materials and methods: Tissue micro-arrays comprising 118 specimens were subjected to immunohistochemistry, and all slides were quantified using StrataQuest software. Results: The ratio of INHBB-positive cells to total cells was significantly higher in OSCC samples than in normal samples, and the intensity of INHBB expression was significantly greater in the late-stage OSCC. After classifying specimens into high and low INHBB expression groups, a significant association with clinical staging was found. Though a previous study suggested that menin regulates INHBB, menin expression was not detected in specimens. Conclusion: The ratio of INHBB-positive cells in OSCC may be druggable for targeting tumor cells or assisting in diagnosis, and the intensity of INHBB expression may provide prognostic information for predicting potential metastasis. Moreover, the regulatory mechanism of INHBB in OSCC remains unclear and requires further investigation.

Fibroblast growth factor 5 expression predicts the progression of oral squamous cell carcinoma.

BACKGROUND/PURPOSE: Fibroblast growth factor (FGF) 5 is a member of the FGF family that functions as a regulator of tissue growth and regeneration. Aberrant FGF5 expression has been previously associated with the progression of a number of different malignancies. However, its potential role in oral cancer remains unclear. In this study, we explored the relationship between the expression of FGF5 protein in oral squamous cell carcinomas (OSCCs) and the clinicopathological parameters of OSCCs and whether the expression of FGF5 protein in OSCCs could be a prognostic factor for OSCC patients. METHODS: The FGF5 protein expression was examined in 64 OSCC and 34 normal oral mucosal specimens by immunohistochemical staining. Stress induced upregulation and intracellular redistribution of FGF5 were verified using xenograft animal model and OSCC cell lines. RESULTS: The mean FGF5 protein labelling index was significantly higher in OSCC than in normal oral mucosal samples, with high FGF5 protein labelling index (>58%) being correlated with advanced stage and poor survival of OSCC patients. Apart from the peri-cytoplasmic staining pattern characteristic of paracrine growth factors, FGF5 protein was localized as distinct punctate structures in the cytoplasm of advanced stage or stressed-induced cells. This redistribution and upregulation of FGF5 protein could be sustained after termination of the stress induction in cell line and xenograft animal models. CONCLUSION: FGF5 can be induced by cellular stress and risk factors of OSCC, where high expression levels of FGF5 is potentially a useful parameter for predicting OSCC progression and patient survival.

Metastasis and immunosuppression promoted by mtDNA and PD-L1 in extracellular vesicles are reversed by WGP ß-glucan in oral squamous cell carcinoma.

The suppressive regulatory T cells (Treg) are frequently upregulated in cancer patients. This study aims to demonstrate the hypothesis that arecoline could induce the secretion of mitochondrial (mt) DNA D-loop and programmed cell death-ligand 1 (PD-L1) in extracellular vesicles (EVs), and attenuate T-cell immunity by upregulated Treg cell numbers. However, the immunosuppression could be reversed by whole glucan particle (WGP) ß-glucan in oral squamous cell (OSCC) patients. Arecoline-induced reactive oxygen specimen (ROS) production and cytosolic mtDNA D-loop were analyzed in OSCC cell lines. mtDNA D-loop, PD-L1, IFN-γ, and Treg cells were also identified for the surgical specimens and sera of 60 OSCC patients. We demonstrated that higher mtDNA D-loop, PD-L1, and Treg cell numbers were significantly correlated with larger tumor size, nodal metastasis, advanced clinical stage, and areca quid chewing. Furthermore, multivariate analysis confirmed that higher mtDNA D-loop levels and Treg cell numbers were unfavorable independent factors for survival. Arecoline significantly induced cytosolic mtDNA D-loop leakage and PD-L1 expression, which were packaged by EVs to promote immunosuppressive Treg cell numbers. However, WGP ß-glucan could elevate CD4+ and CD8+ T-cell numbers, mitigate Treg cell numbers, and promote oral cancer cell apoptosis. To sum up, arecoline induces EV production carrying mtDNA D-loop and PD-L1, and in turn elicits immune suppression. However, WGP ß-glucan potentially enhances dual effects on T-cell immunity and cell apoptosis and we highly recommend its integration with targeted and immune therapies against OSCC.

Lysyl oxidase-like 2 promotes stemness and enhances antitumor effects of gefitinib in head and neck cancer via IFIT1 and IFIT3.

Lysyl oxidase-like 2 (LOXL2) is a matrix-remodeling enzyme that has recently been identified as an important regulator of tumor progression and metastasis. This study discovered that LOXL2 expression in oral squamous cell carcinoma (OSCC) tissues was significantly associated with tumor clinical stage, lymph node metastasis and patients' overall survival time. LOXL2-overexpressing human buccal SCC TW2.6 (TW2.6/LOXL2) and hypopharyngeal SCC FaDu (FaDu/LOXL2) cells exhibited enhanced migration, invasion, epithelial-mesenchymal transition (EMT), and cancer stem cell (CSC) phenotypes, independently of its enzymatic activity. Moreover, TW2.6/LOXL2 significantly increased tumor-initiating frequency in SCID mice. We further demonstrated that LOXL2 increased the levels of interferon-induced protein with tetratricopeptide repeats 1 (IFIT1) and IFIT3 in TW2.6/LOXL2 and FaDu/LOXL2 cells. We also identified IFIT1 and IFIT3 as key downstream components of LOXL2 action in migration, invasion, EMT, and CSC phenotypes in TW2.6 and FaDu cells. Furthermore, a significant positive correlation between LOXL2 expression and IFIT1 and IFIT3 overexpression in human OSCC tissues was observed. In addition, TW2.6/LOXL2 and FaDu/LOXL2 cells were 3.3- to 3.6-fold more susceptible to the epidermal growth factor receptor (EGFR) inhibitor gefitinib than were their respective control cells. The antitumor effect of gefitinib on orthotopic TW2.6/LOXL2 xenograft tumor was fourfold higher than that on controls. Our results indicate that LOXL2 expression is a strong prognostic factor for OSCC and may be used as a marker to identify patients most likely to respond to EGFR-targeted therapy.

ZNF582 hypermethylation as a prognostic biomarker for malignant transformation of oral lesions.

OBJECTIVES: This hospital-based cohort study evaluated whether ZNF582 and PAX1 methylation levels at baseline can be used as biomarkers to identify lesions with a high potential for malignant transformation in patients with normal mucosa and oral potentially malignant disorders. PATIENTS AND METHODS: We recruited 171 adult patients with normal mucosa and oral potentially malignant disorders in 2012-2014. They were followed until 2017. Outcomes, including advanced histopathological findings and oral cancer occurrence, were obtained from medical charts, the Taiwan Cancer Registry, and cause-of-death data. Kaplan-Meier analysis and Cox proportional hazards regression models were used to examine the association of ZNF582 and PAX1 methylation levels at baseline with subsequent outcome occurrences. RESULTS: After 260,192 days of follow-up, 11 cases of oral cancer and 4 cases of advanced histopathological progression occurred. Patients with higher ZNF582 and PAX1 methylation levels at baseline had a higher incidence of disease progression. After adjustment for all studied factors using Cox proportional hazards regression models, ZNF582m level (adjusted hazard ratio, 11.41; 95% CI, 2.05-63.36; p = 0.005) was the only significant and independent predictor of disease progression. CONCLUSIONS: ZNF582 hypermethylation can be an effective and noninvasive biomarker for identifying oral lesions with a high potential for malignant transformation.

ß-glucan therapy converts the inhibition of myeloid-derived suppressor cells in oral cancer patients.

OBJECTIVES: The myeloid-derived suppressor cells (MDSCs) frequently have a high expansion in cancer patients. This research explored whether administration of ß-glucan could increase anti-tumor immunity in oral squamous cell carcinoma (OSCC) patients. MATERIALS AND METHODS: This study evaluated the MDSC level of circulating blood as CD33+ /CD11b+ /HLA-DR-/low by flow cytometry in 30 healthy donors (HDs, group I), in 48 oral squamous cell carcinoma (OSCC) patients before and after 14-day preoperative administration of ß-glucan (group II), and in 52 OSCC patients without taking ß-glucan (group III). RESULTS: A significantly higher mean MDSC level was observed in 100 OSCC patients than in 30 HDs (p < .001). There was a significant reduction of the mean MDSC level in group II patients after taking ß-glucan (p < .001). Moreover, we discovered a significantly higher recurrence-free survival (RFS) in group II than in group III patients (p = .026). Finally, the multivariate Cox regression further identified the MDSC level ≤1% and administration of ß-glucan as more favorable prognostic factors for OSCC patients. CONCLUSION: Preoperative administration of ß-glucan can augment anti-tumor immunity and increase RFS rate via subversion of suppressive function of MDSC in OSCC patients.

Upregulated NPM1 is an independent biomarker to predict progression and prognosis of oral squamous cell carcinomas in Taiwan.

BACKGROUND: Nucleophosmin/nucleoplasmin family 1 (NPM1) has broad physiological functions, such as DNA replication, transcription, ribosome biogenesis, and centrosome replication. This study explored the clinicopathological importance of NPM1 as a prognostic marker for oral squamous cell carcinoma (OSCC). METHODS: We collected specimens from 96 OSCC, 45 oral epithelial dysplasia (OED), and 29 normal oral mucosa (NOM). NPM1 expression was analyzed via immunohistochemistry. Correlations between NPM1and clinical parameters were analyzed using Student t test, chi-squared test, and Kaplan-Meier product-limit method. RESULTS: The NPM1 labeling indices (LIs) were significantly higher in OSCCs than in NOM and oral OED. Higher NPM1 expression was significantly correlated with larger tumor size, nodal metastasis, and advanced clinical stage. Multivariate analysis revealed that higher NPM1 LIs were an unfavorable independent factor for survival. CONCLUSIONS: Upregulated NPM1 is an independent biomarker of poor prognosis and NPM1 inhibitors may be promising in molecular targeted therapy against OSCC.

Increased salivary AKR1B10 level: Association with progression and poor prognosis of oral squamous cell carcinoma.

BACKGROUND: Aldo-keto reductase family 1 member B10 (AKR1B10) expression in oral squamous cell carcinoma (OSCC) tissue specimens is correlated with the progression and prognosis of OSCC. METHODS: Saliva samples were obtained from 35 normal controls and 86 patients with OSCC before cancer surgery. The AKR1B10 levels were determined using enzyme-linked immunosorbent assay (ELISA). RESULTS: The mean salivary AKR1B10 levels were significantly higher in the patients with OSCC than in the normal controls (P < .001). Higher salivary AKR1B10 levels were significantly associated with larger tumor size, more advanced clinical stage, and areca quid chewing habit. Patients with OSCC with a higher salivary AKR1B10 level (>646 pg/mL) had a significantly poorer survival than those with a lower (≤646 pg/mL) salivary AKR1B10 level (P = .026). CONCLUSION: The salivary AKR1B10 level may be a promising biomarker for screening high-risk patients with OSCC and monitoring the progression of OSCC.

Hypermethylated ZNF582 and PAX1 genes in mouth rinse samples as biomarkers for oral dysplasia and oral cancer detection.

BACKGROUND: Effective biomarkers for oral cancer screening are important for early diagnosis and treatment of oral cancer. METHODS: Oral epithelial cell samples collected by mouth rinse were obtained from 65 normal control subjects, 108 patients with oral potentially malignant disorders, and 94 patients with oral squamous cell carcinoma (OSCC). Methylation levels of zinc-finger protein 582 (ZNF582) and paired-box 1 (PAX1) genes were quantified by real-time methylation-specific polymerase chain reaction after bisulfite conversion. RESULTS: An abrupt increase in methylated ZNF582 (ZNF582m ) and PAX1 (PAX1m ) levels and positive rates from mild dysplasia to moderate/severe dysplasia, indicating that both ZNF582m and PAX1m are effective biomarkers for differentiating moderate dysplasia or worse (MODY+) oral lesions. When ZNF582m /PAX1m tests were used for identifying MODY+ oral lesions, the sensitivity, specificity, and odds ratio (OR) were 0.65/0.64, 0.75/0.82, and 5.6/8.0, respectively. CONCLUSION: Hypermethylated ZNF582 and PAX1 genes in oral epithelial cells collected by mouth rinse are effective biomarkers for the detection of oral dysplasia and oral cancer.

Comparison of long-term outcomes between pull-through resection and mandibular lip-split surgery for T4a tongue/floor of mouth cancers.

BACKGROUND: The purpose of this study was to determine whether the pull-through resection is better than the mandibular lip-split for advanced tongue/floor of mouth (FOM) cancers, which remains inconclusive. METHODS: A retrospective cohort study was performed on 91 patients with T4a tongue/FOM cancers from 2009 to 2014. Cases with mandibular resection were excluded. The pull-through resection was used when the mouth opening was ≥15 mm; otherwise the mandibular lip-split was used. RESULTS: Fifty-eight patients received pull-through resections and 33 underwent mandibular-lip splits and the mean follow-up periods were 42 and 45 months, respectively. Surgical margin, locoregional recurrence, and 5-year survival were similar between the 2 groups. The pull-through approach had a significantly shorter operation time, lower rates of flap infection, osteoradionecrosis, metal plate exposure, loss of tooth vitality, and better aesthetics. CONCLUSION: Our data suggest that the pull-through resection does not compromise disease control for advanced tongue/FOM cancers and is superior to the mandibular lip-split in terms of operation time, postoperative complications, and aesthetics.

Hypermethylated ZNF582 and PAX1 genes in oral scrapings collected from cancer-adjacent normal oral mucosal sites are associated with aggressive progression and poor prognosis of oral cancer.

OBJECTIVE: This study assessed whether hypermethylated ZNF582 and PAX1 genes in oral scrapings are correlated with the progression and prognosis of oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: Methylation levels of ZNF582 and PAX1 genes in oral scrapings, collected from the cancer and adjacent normal oral mucosal sites of 80 OSCC patients before surgical cancer excision, were quantified using real-time methylation-specific PCR after bisulfite conversion. RESULTS: Both the mean methylation (M)-indices of ZNF582 and PAX1 genes in oral scrapings were significantly higher at the cancer sites than at the adjacent normal oral mucosal sites (both P < .001). In the oral scrapings collected from the adjacent normal oral mucosal sites, the higher M-index of methylated ZNF582 (ZNF582m) was significantly correlated with a more advanced clinical stage (P = .04). Moreover, the higher M-index of methylated PAX1 (PAX1m) was significantly related to larger tumor size (P = .046). When the 80 OSCC patients were classified based on gene methylation tests, using the oral scrapings collected from the adjacent normal oral mucosal sites, we found a significantly shorter 3-year overall survival in ZNF582m-positive, PAX1m-positive, and ZNF582m/PAX1m-positive OSCC patients than in ZNF582m-negative (P = .02), PAX1m-negative (P = .04), and ZNF582m/PAX1m-negative OSCC patients (P = .02), respectively. Multivariate Cox regression analyses identified ZNF582m and ZNF582m/PAX1m as independent unfavorable prognostic factors. CONCLUSION: Hypermethylated ZNF582 and PAX1 genes in the oral scrapings collected from adjacent normal oral mucosal sites rather than cancer sites are associated with aggressive progression and poor prognosis of OSCC.

Expression of AKR1B10 as an independent marker for poor prognosis in human oral squamous cell carcinoma.

BACKGROUND: Aldo-keto reductase family 1 member B10 (AKR1B10) is implicated in xenobiotic detoxification and has disparate functions in tumorigenesis that are dependent on the cell types. The purpose of this study was to investigate the clinicopathological significance of AKR1B10 as a prognostic marker for oral squamous cell carcinomas (OSCCs). METHODS: AKR1B10 protein expression was analyzed by immunohistochemistry in 77 patients with OSCC. RESULTS: The AKR1B10 labeling score for OSCCs (1.16 ± 1.14) was significantly higher than that for normal oral mucosa (0.10 ± 0.23; p < .0001). High expression of AKR1B10 significantly correlated with large tumor size (p = .041), advanced TNM classification (p = .037), and patient's areca quid chewing habit (p = .025). Multivariate analysis revealed that high AKR1B10 labeling score >1.16 (hazard ratio, 3.647; p = .001) significantly correlated with mortality. CONCLUSION: AKR1B10 overexpression is an independent poor prognostic biomarker for OSCC. AKR1B10 inhibitors may be promising in clinical trials against OSCC. © 2017 Wiley Periodicals, Inc. Head Neck 39: 1327-1332, 2017.

Factors influencing the incidence and prognosis of second primary tumors in patients with oral squamous cell carcinoma.

BACKGROUND: Although second primary tumors are common in patients with oral squamous cell carcinoma (OSCC), their predisposing factors and treatment guideline remain uncertain. METHODS: Three hundred ninety-four patients with OSCC who received radical surgery from January 2002 to December 2009 were retrospectively reviewed. RESULTS: Forty-five patients developed oral second primary tumors. Areca quid chewing, tongue tumors, and nodal metastasis were risk factors for second primary tumors. Multivariate analyses revealed that no second primary tumor (hazard ratio [HR] = 5.046; 95% confidence interval [CI] = 3.704-12.246; p = .003), contralateral neck dissection for ipsilateral second primary tumors (HR = 6.254; 95% CI = 3.027-13.365; p = .007), and postoperative radiotherapy (RT; HR = 3.987; 95% CI = 1.099-10.381; p = .040) were independent favorable prognostic factors. CONCLUSION: Areca quid chewing, tongue tumors, and nodal metastasis predisposed patients with OSCC to second primary tumor development. Elective dissection of the contralateral neck in patients with second primary tumors ipsilateral to index tumors and postoperative RT for eligible patients should always be considered in the management of oral second primary tumors. © 2016 Wiley Periodicals, Inc. Head Neck 38: First-1466, 2016.

Phenethyl isothiocyanate enhances TRAIL-induced apoptosis in oral cancer cells and xenografts.

OBJECTIVES: Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) has been regarded as a promising candidate for cancer therapy. However, most of oral cancer cell lines are resistant to the TRAIL-induced cytotoxicity. The aim of this study was to investigate the ability of phenethyl isothiocyanate (PEITC) to sensitize TRAIL-induced apoptosis in TRAIL-resistant oral cancer cells and xenografts. MATERIALS AND METHODS: Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling assay, Western blotting, and a mouse xenograft model were used to study the effects of PEITC and TRAIL on two TRAIL-resistant human oral cancer cells, SAS and Ca9-22. RESULTS: PEITC upregulated death receptor 4 (DR4) and DR5 protein expression and increased reactive oxygen species (ROS) production in both SAS and Ca9-22 cells. Antioxidant N-acetyl-L-cysteine (NAC) and c-Jun NH2-terminal kinase (JNK) inhibitor SP600125 inhibited PEITC-induced DR4 and DR5 expression. Inhibitor experiments showed that PEITC induced apoptosis through ROS-mediated JNK activation and upregulation of DR4 and DR5. Furthermore, treatment with PEITC significantly increased TRAIL-induced apoptosis in both cells. Combined treatment with PEITC and TRAIL had greater effect on the inhibition of tumor growth than either agent alone. CONCLUSIONS: We showed for the first time that PEITC overcomes TRAIL resistance in oral cancer cells and enhance the therapeutic potential of TRAIL in vivo. CLINICAL RELEVANCE: PEITC, either alone or in combination with TRAIL, can be used as a new therapeutic approach for the treatment of oral cancers.

Upregulation of vascular endothelial growth factor mRNA level is significantly related to progression and prognosis of oral squamous cell carcinomas.

BACKGROUND/PURPOSE: Vascular endothelial growth factor (VEGF) is a potent angiogenic factor. This study evaluated whether the VEGF mRNA level in oral squamous cell carcinoma (OSCC) tissue could be a biomarker to predict the progression and prognosis of OSCCs in Taiwan. METHODS: This study used quantitative real-time reverse transcription-polymerase chain reaction (quantitative RT-PCR) to detect the VEGF mRNA levels in 60 OSCC specimens. Threshold cycle (CT) was defined as the PCR cycle number needed to generate a predetermined amount of DNA (threshold). The relative amount of tissue VEGF mRNA, standardized against the amount of glyceraldehyde 3-phosphate dehydrogenase (GAPDH) mRNA, was expressed as ΔCT = (VEGF CT - GAPDH CT). For a chosen threshold, a smaller starting copy number of mRNA results in a higher CT value. Thus, the lower the ΔCT, the greater the copy number of VEGF mRNA in tissues. RESULTS: The lower mean VEGF mRNA ΔCT value was significantly associated with OSCCs with larger tumor size (p = 0.040), positive lymph node metastasis (p = 0.023), and more advanced clinical stages (p = 0.008). VEGF mRNA ΔCT value < 4.2 (p = 0.026) was identified as an independent unfavorable prognosis factor using multivariate regression analyses. Moreover, Kaplan-Meier curve showed that OSCC patients with a VEGF mRNA ΔCT value < 4.2 had a significantly poorer overall survival than those with a VEGF mRNA ΔCT value ≥4.2 (log-rank test, p = 0.0427). CONCLUSION: The OSCC tissue VEGF mRNA level can be used to predict the progression and prognosis of OSCCs in Taiwan.