Prognostic value of HLA class I expression in patients with oral squamous cell carcinoma.

Human leukocyte antigen (HLA) class Ⅰ molecules play a central role in anticancer immunity, but their prognostic value in oral squamous cell carcinoma (OSCC) remains unclear. We examined HLA class I expression in 2 distinct tumor compartments, namely, the tumor center and invasive front, and evaluated the association between its expression pattern and histopathological status in 137 cases with OSCC. Human leukocyte antigen class Ⅰ expression was graded semiquantitatively as high, low, and negative. At the invasive front of the tumor, HLA class I expression was high in 72 cases (52.6%), low in 44 cases (32.1%), and negative in 21 cases (15.3%). The HLA class I expression in the tumor center was high in 48 cases (35.0%), low in 58 cases (42.4%), and negative in 31 cases (22.6%). The 5-year overall survival and disease-specific survival rates were good in cases with high HLA class I expression at the invasive front; however, there was no significant difference in survival based on HLA class I expression in the tumor center. In addition, high HLA class I expression was correlated with high CD8+ T cell density, whereas negative HLA class I expression was correlated with low CD8+ T cell density at the invasive front. These results suggest that it is easier for CD8+ T cells to recognize presented peptides in the case of high HLA class Ⅰ expression at the tumor invasive front and could be a prognostic factor for OSCC.

Quantitative Evaluation of Cephalometric Radiographs of Patients With Hemifacial Microsomia.

OBJECTIVE: To clarify the morphological characteristics of hemifacial microsomia (HFM) by quantitative analysis of cephalometric radiographs. DESIGN: Retrospective study of imaging data. SETTING: Imaging data were obtained from the records of Sapporo Medical University Hospital. PATIENTS: A total of 183 patients with HFM. MAIN OUTCOME MEASURES: We used linear and angular measurements and analyzed the middle face and lower face. RESULTS: The ratios of the affected side to the unaffected (A/U) side of the lateral distance of the mandibular condyle, the mandibular ramus height, and the length of the body of the mandible in the HFM group were significantly lower than in the control group. The inclination of the body of the mandible was significantly larger in the side with HFM than in the unaffected side, and the extent of the mandibular ramus was significantly lower than in the unaffected side. The A/U ratios of the extent of the angle of the mandible and the inclination of the body of the mandible in the HFM group were larger than in the control group. Moreover, the length and the inclination of the body of the mandible had significant correlations with the distance of the shift of the menton. CONCLUSIONS: It is suggested that improving the hypoplasia of the length of the body of the mandible and the extent of the angle of the mandible on the affected side will lead to more effective treatment of jaw deformity in patients with HFM.

Targeted next-generation sequencing of 50 cancer-related genes in Japanese patients with oral squamous cell carcinoma.

Somatic mutation analysis is a standard of practice for human cancers to identify therapeutic sensitization and resistance mutations. We performed a multigene sequencing screen to explore mutational hotspots in cancer-related genes using a semiconductor-based sequencer. DNA from oral squamous cell carcinoma samples was used as a template to amplify 207 regions from 50 cancer-related genes. Of the 80 oral squamous cell carcinoma specimens from Japanese patients, including formalin-fixed paraffin-embedded samples, 56 specimens presented at least one somatic mutation among the 50 investigated genes, and 17 of these samples showed multiple gene somatic mutations. TP53 was the most commonly mutated gene (50.0%), followed by CDKN2A (16.3%), PIK3CA (7.5%), HRAS (5.0%), MET (2.5%), and STK11 (2.5%). In total, 32 cases (40.0%) were human papillomavirus positive and they were significantly less likely to have a TP53, mutation than human papillomavirus-negative oral squamous cell carcinomas (8/32, 25.0% vs 32/48, 66.7%, p = 0.00026). We also detected copy number variations, in which segments of the genome could be duplicated or deleted from the sequencing data. We detected the tumor-specific TP53 mutation in the plasma cell-free DNA from two oral squamous cell carcinoma patients, and after surgery, the test for these mutations became negative. Our approach facilitates the simultaneous high-throughput detection of somatic mutations and copy number variations in oral squamous cell carcinoma samples.

Diverticulum of the buccal mucosa: a rare case report and review of the literature.

BACKGROUND: Cases of diverticula of the buccal mucosa are extremely rare. Literature searches of databases such as PubMed/MEDLINE for this condition have revealed only 10 case reports. In this case report, we describe our experience in the management of this rare condition and review the previous 10 previously reported cases. CASE PRESENTATION: A 66-year-old man presented with a pouch containing inspissated food debris located posterior to the papilla of the parotid duct in his left buccal mucosa. The diagnosis of a diverticulum arising from the buccal mucosa was confirmed based on clinical and radiographic findings. Gross examination of the locally resected tissue specimen revealed a pouch measuring 14 mm in diameter and 8 mm in depth, that was whitish in color and had an elastic, soft, and smooth surface. Microscopic examination revealed a cyst-like lesion lined by stratified squamous epithelium and granulation tissue, with a chronic inflammatory infiltration in the peripheral stromal tissue of the epithelial layer. After surgical excision of the lesion, there was no recurrence during the follow-up period of 5 years and 10 months. CONCLUSIONS: We have presented a rare case of a diverticulum of the buccal mucosa. This is the first report of a case confirmed not only by the clinicopathological findings, but also by computed tomography and magnetic resonance imaging findings. From the magnetic resonance imaging and intraoperative findings, we inferred that the diverticulum was caused by an idiopathic developmental anomaly due to a partial defect of the buccinator muscle.

Microenvironmental stresses induce HLA-E/Qa-1 surface expression and thereby reduce CD8(+) T-cell recognition of stressed cells.

Hypoxia and glucose deprivation are often observed in the microenvironment surrounding solid tumors in vivo. However, how they interfere with MHC class I antigen processing and CD8(+) T-cell responses remains unclear. In this study, we analyzed the production of antigenic peptides presented by classical MHC class I in mice, and showed that it is quantitatively decreased in the cells exposed to either hypoxia or glucose deprivation. In addition, we unexpectedly found increased surface expression of HLA-E in human and Qa-1 in mouse tumor cells exposed to combined oxygen and glucose deprivation. The induced Qa-1 on the stressed tumor model interacted with an inhibitory NKG2/CD94 receptor on activated CD8(+) T cells and attenuated their specific response to the antigen. Our results thus suggest that microenvironmental stresses modulate not only classical but also nonclassical MHC class I presentation, and confer the stressed cells the capability to escape from the CD8(+) T-cell recognition.

Additive effect of radiosensitization by 2-deoxy-D-glucose delays DNA repair kinetics and suppresses cell proliferation in oral squamous cell carcinoma.

BACKGROUND: It has well known that, compared to normal cells, tumor cells have a different manner of energy metabolism, which influences the sensitivity of radiotherapy. However, whether inhibition of glycolysis enhances the efficacy of radiotherapy is a matter of debate in oral squamous cell carcinoma (OSCC). The aim of this study was to characterize whether the combination of radiotherapy with the glucose inhibitor 2-deoxy-D-glucose (2-DG) affected DNA repair kinetics. METHODS: To compare the synergistic effect of 2-DG, we examined the cell survival after treatment with radiation, 2-DG, and a combination of the two in five OSCC cell lines and one lip fibroblast cell line, determined using clonogenic survival assay. Changes in the protein levels of DNA repair kinetics such as PARP, Rad51, and Ku-70 were analyzed by Western blotting. Then, using one of the five OSCC cell lines, we assessed the inhibition of xenograft tumor growth in vivo. RESULTS: We found that 2-DG with radiation induced significant inhibition of cell proliferation in cell line SAS (P<.01, one-way ANOVA). Radiation treatment was associated with decreased expression of the DNA repair markers. In additional, combinational treatment with 2-DG and radiation significantly inhibited the xenograft tumor growth compared to the control (P<.05), and treatment with 2-DG or radiation alone. CONCLUSIONS: Our study suggests that 2-DG has synergistic cytotoxic effects when combined with radiotherapy, which might lead to the design of an effective metabolic target therapy in vitro and in vivo.

Relationship Between Mandibular Ramus Height and Masticatory Muscle Function in Patients With Unilateral Hemifacial Microsomia.

OBJECTIVE: To clarify the relationship between mandibular ramus height and function of masticatory muscles in patients with hemifacial microsomia. DESIGN: Retrospective study of imaging and physiological data. SETTING: Images and physiological data were obtained from the records of Sapporo Medical University Hospital. PATIENTS: A total of 29 patients with hemifacial microsomia who showed Pruzansky grades I, II deformity. MAIN OUTCOME MEASURES: Mandibular ramus height and masticatory muscle volume were evaluated with multi-detector row computed tomography. The electromyographic value was measured by the K7 Evaluation System. The hemifacial microsomia patients were classified into three groups based on the mandibular ramus height ratio of the affected and unaffected sides: group 0, >1.00; group 1, 1.00 to 0.85; group 2, <0.85. The Tukey-Kramer method and Games-Howell method were used to determine correlations between parameters. RESULTS: Decreased mandibular ramus height was significantly correlated with both reduced electromyographic values of the masseter muscle (P < .05) and the amount of mandibular lateral deviation at the time of maximum opening (P < .05) on the affected side. These differences were prominent in unilateral hemifacial microsomia patients classified as group 2. CONCLUSIONS: Decreased mandibular ramus height may cause dysfunction of the masseter muscles but not the temporal muscle on the affected side in patients with hemifacial microsomia.

Six-transmembrane epithelial antigen of the prostate-1 plays a role for in vivo tumor growth via intercellular communication.

Six-transmembrane epithelial antigen of the prostate-1 (STEAP-1) is a novel cell surface protein overexpressed only in the prostate among normal tissues and various types of cancer including prostate, bladder, lung, and ovarian cancer. Although its function in prostate and tumor cells has been remained unclear, due to its unique and restricted expression, STEAP-1 is expected to be an attractive target for cancer therapy. Here, we show that knockdown of STEAP-1 in human cancer cells caused the retardation of tumor growth compared with wild type in vivo. In contrast, STEAP-1 introduced tumor cells augmented the tumor growth compared with STEAP-1-negative wild type cells. Using dye transfer assay, we demonstrate that the STEAP-1 is involved in intercellular communication between tumor cells and adjacent tumor stromal cells and therefore may play a key role for the tumor growth in vivo. These data indicate the inhibition of the STEAP-1 function or expression can be a new strategy for cancer therapy.

Macroscopic and microscopic features of the mandibular condyle in autopsied elderly individuals.

Many studies have attempted to classify the macroscopic shapes of the mandibular condyle in humans; however, no consensus has yet been reached because the shapes vary. One problem is that classification of macroscopic morphological changes of the condylar surface has been largely based on bones from ancient people, with few bones from modern people covering many different age groups. In this study, 144 condyles from 78 cadavers (40 men, 38 women; age at death: >70 years) were investigated. The macroscopic shapes of the condyles were classified from posterior and lateral views into four types: convex, flattened, angled, and irregular. Of the 144 condyles, 25 were investigated microscopically. On macroscopic examination, in both posterior and lateral views, convex-type condyles were most frequently observed. Most posterior convex-type condyles were also categorized as the lateral convex type. On histological examination, we observed an increase in cartilage cells (7 condyles, 28%), a decrease in cartilage cells (3 condyles, 12%). Increases in cartilage cells were seen only in angled and irregular types (P = 0.001), whereas decreases in cartilage cells were only observed in the flattened type (P = 0.01). A convex macroscopic form appears to be standard for human mandibular condyles, even in the elderly. The histological findings suggest that mandibular condyles tend to not only undergo flattening, but also undergo progressive changes toward protrusion with age due to increased numbers of cartilage cells. In other words, this study suggests that there is potential for progressive alterations in mandibular condyles in the elderly.

Small proline-rich protein-1B is overexpressed in human oral squamous cell cancer stem-like cells and is related to their growth through activation of MAP kinase signal.

Cancer stem-like cells (CSCs)/cancer-initiating cells (CICs) are considered to be essential for tumor maintenance, recurrence and metastasis. Therefore, eradication of CSCs/CICs is essential to cure cancers. However, the molecular mechanisms of CSCs/CICs are still elusive. In this study, we investigated the molecular mechanism of the cell growth of oral CSCs/CICs. Oral CSCs/CICs were isolated as aldehyde dehydrogenase 1 bright (ALDH1(br)) cells by the ALDEFLUOR assay. Small proline-rich protein-1B (SPRR1B) gene was shown to be overexpressed in ALDH1(br) cells by a cDNA microarray and RT-PCR. SPRR1B was shown to have a role in cell growth and maintenance of ALDH1(br) cells by SPRR1B overexpression and knockdown experiments. To elucidate the molecular mechanism by which SPRR1B regulates cell growth, further cDNA microarray analysis was performed using SPRR1B-overexpressed cells and cells with SPRR1B knocked down by siRNA. Expression of the tumor suppressor gene Ras association domain family member 4 (RASSF4) was found to be suppressed in SPRR1B-overexpressed cells. On the other hand, the expression of RASSF4 was enhanced in cells in which SPRR1B expression was knocked down by SPRR1B-specific siRNA. RASSF4 has an RA (Ras association) domain, and we thus hypothesized that RASSF4 modulates the MAP kinase signal downstream of the Ras signal. MAP kinase signal was activated in SPRR1B-overexpressed cells, whereas the signal was suppressed in SPRR1B knocked down cells. Taken together, the results indicate that the expression of SPRR1B is upregulated in oral CSCs/CICs and that SPRR1B has a role in cell growth by suppression of RASSF4.

Silencing of GLUT-1 inhibits sensitization of oral cancer cells to cisplatin during hypoxia.

BACKGROUND: During tumor development, cells are exposed to a hypoxic microenvironment. Tumor hypoxia also has a profound influence on the sensitivity of cancer chemotherapy. The objective of this study was to investigate the mechanism of cisplatin (CDDP) resistance of oral squamous cell carcinoma (OSCC) cells under hypoxia by analyzing gene expression profiles to identify key genes and factors involved. METHODS: Cell viability was measured following culture of the cells in the presence or absence of CDDP, under normoxic or hypoxic conditions, using a CCK-8 assay. Analysis of the expression of HIF target genes in hypoxia-treated cells was performed using an HIF-regulated cDNA plate array. Changes in the mRNA expression of selected HIF target genes were analyzed using RT-PCR, and changes in the protein levels of these genes were analyzed by Western blotting. Tumor cell apoptosis was assessed by flow cytometry. RESULTS: The OSCC cell lines responded differently to CDDP under normoxic and hypoxic conditions. The expression of glucose transporter protein-1 (GLUT-1) was up-regulated in human squamous cell carcinoma of mouth (HSC-2) cells under hypoxia. Furthermore, there was little correlation between the cisplatin sensitivity of human squamous cell carcinoma of tongue (SAS) in normoxia and hypoxia. After GLUT-1 knockdown, CDDP treatment resulted in increased rates of apoptosis under hypoxia as compared with normoxia in cell lines HSC-2, Ca9-22, and SAS (P = 0.025). CONCLUSION: The results of this study suggest that knockdown of GLUT-1 inhibits sensitization of oral squamous cells to CDDP during hypoxia in HSC-2, Ca9-22, and SAS cells.

High expression of ALDH1 and SOX2 diffuse staining pattern of oral squamous cell carcinomas correlates to lymph node metastasis.

One of the major factors involved in the prognosis of oral squamous cell carcinoma (OSCC) patients is metastasis. Recent progress in cancer stem-like cell/cancer-initiating cell (CSC/CIC) research indicates that CSCs are related to metastasis. Aldehyde dehydrogenase 1 - (ALDH1) and SRY-related HMG-box gene 2 (SOX2) have recently been shown to be putative CSC markers for several human malignancies. The aim of this study was to determine the association of ALDH1 and SOX2 expression in oral squamous cell carcinoma (OSCC) with lymph node metastasis. Immunohistochemical staining of ALDH1, SOX2 and Ki67 was performed in 80 OSCC tissues. High expression rates of ALDH1 (2%-40%) were found to be related to lymph node metastasis (P = 0.0017). Interestingly, we found that SOX2 staining could be classified into two patterns: (i) peripheral staining pattern; and (ii) diffuse staining pattern. The diffuse staining pattern showed a significant correlation with lymph node metastasis (P < 0.001). No correlation was found between Ki67 staining and lymph node metastasis (P = 0.4724). The ALDH1 positive staining rates in metastatic lymph nodes were higher than that in corresponding primary OSCC tissues. These results indicate that high expression rates of ALDH1 and SOX2 diffuse staining patterns might be novel prediction markers for OSCC lymph node metastasis.

Clinical significance of computed tomographic assessment and anatomic features of the inferior alveolar canal as risk factors for injury of the inferior alveolar nerve at third molar surgery.

PURPOSE: To assess the clinical features of the inferior alveolar canal (IAC) using computed tomography (CT) and to analyze the significance of CT examination at third molar surgery. MATERIALS AND METHODS: A retrospective cohort study was performed involving 99 patients (145 teeth). The relationship between cortication status, buccolingual position, and shape of the IAC on the CT image and inferior alveolar nerve (IAN) injury after third molar surgery were statistically analyzed. RESULTS: The shape of the IAC was categorized into 3 groups: round/oval, teardrop, and dumbbell. IAN injury was observed in 7 of 145 cases (4.8%). All 7 cases exhibited absence of cortication; 3 were dumbbell shape and 4 were round/oval. According to logistic regression analysis of cases with absence of cortication, IAC shape was closely related to IAN injury. CONCLUSIONS: These results suggest that assessment of the IAC shape and cortication status at third molar surgery may be clinically useful.

Clinical and histopathologic effects of neoadjuvant intra-arterial chemoradiotherapy with cisplatin in combination with oral S-1 on stage III and IV oral cancer.

OBJECTIVE: The aim of this study was to examine the clinical and histopathologic effects of neoadjuvant intra-arterial chemoradiotherapy (IACRT) using cisplatin in combination with oral S-1 (tegafur/gimeracil/oteracil potassium) on stage III and IV oral squamous cell carcinoma. STUDY DESIGN: Thirty patients received infusions of superselective intra-arterial cisplatin 60 mg/m2 by the Seldinger method and conventional external beam radiotherapy (total 40 Gy) combined with oral S-1 on the day of irradiation. Curative surgery and neck dissection were performed 4 to 6 weeks after IACRT. The clinical response of the primary lesion was evaluated approximately 4 weeks after IACRT. The surgically resected specimens were examined for histologic features according to the grading system for histologic evaluation and for residual tumor grade (RGrades). RESULTS: Histopathologic evaluation of the therapeutic effect was grade 2 in 10 patients and grade 3 in 16 patients. According to the distribution of RGrades, the remaining tumor cells were mostly in the central area of the primary lesion, as seen in 24 patients. CONCLUSIONS: These findings indicate that neoadjuvant IACRT with cisplatin and oral S-1 was an effective treatment, suggesting the possibility of reducing the extent of curative surgery based on RGrades.

Phase I clinical trial of survivin-derived peptide vaccine therapy for patients with advanced or recurrent oral cancer.

Survivin, a member of the inhibitor of apoptosis protein (IAP) family, is abundantly expressed in most malignancies, but is hardly detectable in normal adult tissues. Previously we have identified a human leukocyte antigen (HLA)-A24-restricted antigenic peptide, survivin-2B80-88 (AYACNTSTL), recognized by CD8(+) cytotoxic T lymphocytes (CTL). Survivin-2B80-88-specific CTL were induced efficiently from peripheral blood mononuclear cells (PBMC) of oral cancer patients after stimulation with the peptide in vitro. We conducted a phase I clinical study to evaluate the safety and the efficacy of survivin-2B80-88 peptide vaccination in HLA-A24-positive patients with advanced or recurrent oral cancer. The vaccines were given subcutaneously or intratumorally six times at 14-day intervals. Eleven patients were enrolled and 10 patients completed the vaccination protocol. No adverse events were observed in any patients. In two patients, the levels of serum squamous cell carcinoma (SCC) antigen decreased transiently during the period of vaccination. Tumor regression that was compatible with a partial response (PR) was noted in one patient. The remaining nine patients experienced progressive disease (PD). Immunologically, an increase of the peptide-specific CTL frequency was detected in six of the eight patients evaluated by HLA-A24/peptide tetramer analysis. The present clinical trial revealed that survivin-2B peptide vaccination was safe and had therapeutic potential for oral cancer patients. However, subsequent clinical trials in combination with various adjuvant drugs will be required to improve the immunological and therapeutic efficacy. This trial was registered with University Hospital Medical Information Network (UMIN) number UMIN000000976.

Prognostic Value of CD45Ro+ T-Cell Expression in Patients With Oral Squamous Cell Carcinoma.

BACKGROUND/AIM: The role of tumour-infiltrating CD45Ro+ T-cells in oral squamous cell carcinoma (OSCC) is unclear. This study aimed to evaluate prognostic biomarkers for OSCC. PATIENTS AND METHODS: We determined the density of tumour-infiltrating CD45Ro+ T cells in the parenchyma and stroma at the tumour centre (TCe) and invasive front (IF) and examined the association between the density of these cells and histopathological status in 142 patients. RESULTS: Five-year overall survival (OS) and recurrence-free survival were favourable in patients with high CD45Ro+ T-cell density in the TCe stroma. OS was favourable in patients with high CD45Ro+ T-cell density in the IF stroma. Stepwise Cox regression model analysis indicated that CD45Ro+ T-cells in the stroma of the IF and TCe were an independent prognostic factor for OS. CONCLUSION: CD45Ro+ T-cells in the stroma of the IF and TCe play a role in cancer immune surveillance and may be a useful prognostic factor.

Prognostic value of FoxP3 and CTLA-4 expression in patients with oral squamous cell carcinoma.

BACKGROUND: Tumor-infiltrating lymphocytes include tumor-reactive lymphocytes and regulatory T-cells. However, the prognostic value of tumor-infiltrating lymphocytes in oral squamous cell carcinoma (OSCC) remains unclear. METHODS: We used immunohistochemistry to evaluate the presence of tumor-infiltrating FoxP3⁺ T-cells and CTLA-4⁺ cells in four distinct histological compartments (tumor parenchyma and stroma at the tumor center, and parenchyma and stroma at the invasive front) and assessed the association between the prevalence of these cells and the histopathological status of 137 patients with OSCC. RESULTS: Five-year overall survival, disease-specific survival, and recurrence-free survival were favorable in patients with high numbers of FoxP3⁺ T-cells in the parenchyma of the invasive front. Recurrence-free survival and metastasis-free survival were decreased in patients with high numbers of CTLA-4⁺ cells in the parenchyma of the invasive front. CONCLUSIONS: The presence of FoxP3⁺ T-cells in the parenchyma of the invasive front may be a useful prognostic factor. Our results indicate that FoxP3⁺ T-cells may exert site-specific anti-tumor effects but may not play an immunosuppressive role in OSCC. In addition, our results suggest that CTLA-4+ cells suppress the function of FoxP3+ T-cells and promote anti-tumor immunity in OSCC.

Comparative study on the immunogenicity between an HLA-A24-restricted cytotoxic T-cell epitope derived from survivin and that from its splice variant survivin-2B in oral cancer patients.

BACKGROUND: We previously reported an HLA-A24-restricted cytotoxic T-cell epitope, Survivin-2B80-88, derived from a splice variant of survivin, survivin-2B. In this report, we show a novel HLA-A24-restricted T-cell epitope, Survivin-C58, derived from a wild type survivin, and compared their immunogenicity in oral cancer patients. METHODS: By stimulating peripheral blood lymphocytes of HLA-A24-positive cancer patients with Survivin-C58 peptide in vitro, the peptide-specific CTLs were induced. In order to compare the immunogenic potential between C58 peptide and 2B80-88 peptide, peripheral blood T-cells from thirteen HLA-A24-positive oral cancer patients were stimulated with either or both of these two peptides. RESULTS: Survivin-2B80-88 peptide-specific CTLs were induced from four patients, and C58 peptide-specific CTLs were induced from three out of eight patients with over stage II progression. The CTLs exerted cytotoxicity against HLA-A24-positive tumor cells. In contrast, CTL induction failed from a healthy volunteer and all four patients with cancer stage I. CONCLUSION: It was indicated that a splicing variant-derived peptide and wild type survivin-derived peptide might have a comparable potency of CTL induction, and survivin targeting immunotherapy using survivin-2B80-88 and C58 peptide cocktail should be suitable for HLA-A24+ oral cancer patients.

[Clinical investigation of bisphosphonate-related osteonecrosis of the jaws].

We examined the clinical features of bisphosphonate(BP)-related osteonecrosis of the jaws(BRONJ), a serious complication resulting from intravenous BP treatment for multiple myeloma and malignant tumors with bone metastasis. We retrospectively reviewed the medical records of 36 patients who received intravenous BP therapy for the above-mentioned conditions, at Sapporo Medical University Hospital between July 2006 and October 2008. BP therapy caused BRONJ in 7 of 24 patients, but did not affect the bones of the other 17 patients. The other 12 of the 36 patients involved in the study were prescribed BP only after they had undergone an oral examination and treatment for dental inflammation. Of these patients, 7 developed BRONJ with BP treatment, after tooth extraction or acute dental inflammation. Treating dental inflammation before prescribing BP prevented the development of BRONJ. BRONJ is highly intractable and does not resolve with the standard treatment for osteomyelitis. Therefore, preventive therapy, which can be achieved by cooperation between medical doctors and dentists, is currently the most effective strategy for BRONJ. Conservative treatment with antibiotics may also be useful for maintaining or improving the quality of life of BRONJ patients.

Selective Neck Dissection and Survival in Pathologically Node-Positive Oral Squamous Cell Carcinoma.

The most important prognostic factor in oral squamous cell carcinoma (OSCC) is neck metastasis, which is treated by neck dissection. Although selective neck dissection (SND) is a useful tool for clinically node-negative OSCC, its efficacy for neck node-positive OSCC has not been established. Sixty-eight OSCC patients with pN1⁻3 disease who were treated with curative surgery using SND and/or modified-radical/radical neck dissection (MRND/RND) were retrospectively reviewed. The neck control rate was 94% for pN1⁻3 patients who underwent SND. The five-year overall survival (OS) and disease-specific survival (DSS) in pN1-3 OSCC patients were 62% and 71%, respectively. The multivariate analysis of clinical and pathological variables identified the number of positive nodes as an independent predictor of SND outcome (OS, hazard ratio (HR) = 4.98, 95% confidence interval (CI): 1.48⁻16.72, p < 0.01; DSS, HR = 6.44, 95% CI: 1.76⁻23.50, p < 0.01). The results of this retrospective study showed that only SND for neck node-positive OSCC was appropriate for those with up to 2 lymph nodes that had a largest diameter ≤3 cm without extranodal extension (ENE) of the neck and adjuvant radiotherapy. However, the availability of postoperative therapeutic options for high-risk OSCC, including ENE and/or multiple positive lymph nodes, needs to be further investigated.