Recent progress of biomarkers in oral cancers

Oral cancers are the seventh most common cancer globally. While progresses in oral cancer treatment have been made, not all patients respond to these therapies in the same way. To overcome this difficulty, numerous studies have been devoted to identifying biomarkers, which enable early identification of patients who may benefit from a particular treatment modality or at risk for poor prognosis. Biomarkers are protein molecules, gene expression, DNA variants, or metabolites that are derived from tumors, adjacent normal tissue or bodily fluids, which can be acquired before treatment and during follow-up, thus extending their use to the evaluation of cancer progression and prediction of treatment outcome. In this review, we employed a basic significance level (<0.05) as the minimal requirement for candidate biomarkers. Effect sizes of the biomarkers in terms of odds ratio, hazard ratio, and area under the receiver operating characteristic curves were subsequently used to evaluate the potential of their clinical use. We identified the CCND1 from the tumor, human papillomavirus, HSP70, and IL-17 from the peripheral blood, and high density of CD45RO+ tumor-infiltrating lymphocytes as the clinically relevant biomarkers for oral cancers.

Concurrent Chemoradiotherapy Induces Body Composition Changes in Locally Advanced Head and Neck Squamous Cell Carcinoma: Comparison between Oral Cavity and Non-Oral Cavity Cancer

Few prospective cohort trials have evaluated the difference in treatment-interval total body composition (TBC) changes assessed by dual-energy X-ray absorptiometry (DXA) between two patient subgroups with locally advanced head and neck squamous cell carcinoma (LAHNSCC) receiving concurrent chemoradiotherapy (CCRT): oral cavity cancer with adjuvant CCRT (OCC) and non-oral cavity with primary CCRT (NOCC). This study prospectively recruited patients with LAHNSCC. Clinicopathological variables, blood nutritional/inflammatory markers, CCRT-related factors, and TBC data assessed by DXA before and after treatment were collected. Multivariate linear regression analysis identified the factors associated with treatment-interval changes in body composition parameters, including lean body mass (LBM), total fat mass (TFM), and bone mineral content (BMC). A total of 127 patients (OCC (n = 69) and NOCC (n = 58)) were eligible. Body composition parameters were progressively lost during CCRT in both subgroups. Extremities lost more muscle mass than the trunk for LBM, whereas the trunk lost more fat mass than the extremities for TFM. BMC loss preferentially occurred in the trunk region. Different factors were independently correlated with the interval changes of each body composition parameter for both OCC and NOCC subgroups, particularly mean daily calorie intake for LBM and TFM loss, and total lymphocyte count for BMC loss. In conclusion, treatment-interval TBC changes and related contributing factors differ between the OCC and NOCC subgroups.

Allicin Could Potentially Alleviate Oral Cancer Pain by Inhibiting "Pain Mediators" TNF-alpha, IL-8, and Endothelin

To evaluate the effects of allicin on mediators of pain secreted by oral cancer cells in vitro, single-cell suspensions were prepared by enzymatic method from oral squamous cell carcinoma (OSCC). Cancer stem cells were isolated by the CD133+ selection method with magnetic cell sorting. Stemness markers were checked in both cancer cells and cancer stem cells by RT-PCR. Comparative analysis of pain mediators TNF-alpha, IL-8, and endothelin at both RNA and protein levels for normal epithelial cells, cancer cells, and cancer stem cells was carried out with and without allicin treatment. CD133 and CD44 expression levels were checked in cancer cells and cancer stem cells flow cytometrically. Allicin inhibited both gene and protein expression of TNF-alpha, IL-8, and endothelin in both cancer cells and cancer stem cells. Allicin is more likely to be a promising treatment in alleviating the levels of pain and inflammation in OSCCs.

Failure rate in the untreated contralateral node negative neck of small lateralized oral cavity cancers: A multi-institutional collaborative study

OBJECTIVES

The importance of treating the bilateral neck in lateralized small oral cavity squamous cell carcinoma (OCC) is unclear. We sought to define the incidence and predictors of contralateral neck failure (CLF) in patients who underwent unilateral treatment.

MATERIALS AND METHODS

We performed a multi-institutional retrospective study of patients with pathologic T1-T2 (AJCC 7th edition) OCC with clinically node negative contralateral neck who underwent unilateral treatment with primary surgical resection ± adjuvant radiotherapy between 2005 and 2015. Incidence of CLF was estimated using the cumulative incidence method. Clinicopathological factors were analyzed by univariate (UVA) and multivariate analysis (MVA) for possible association with CLF. Kaplan-Meier analysis was used to estimate overall survival (OS).

RESULTS

176 patients were evaluated with a median of 65.9 months of follow-up. Predominant pathologic T-stage was T1 (68%), 8.5% of patients were N1, 2.8% were N2b. Adjuvant radiotherapy was delivered to 17% of patients. 5-year incidence of CLF was 4.3% (95% CI 1.2-7.4%). Depth of invasion (DOI) > 10 mm and positive ipsilateral neck node were significant predictors for CLF on UVA. DOI > 10 mm remained significant on MVA (HR = 6.7, 95% CI 1.4-32.3, p = 0.02). The 2- and 5-year OS was 90.6% (95% CI 86.2-95.0%) and 80.6% (95% CI 74.5-86.8%), respectively.

CONCLUSION

Observation of the clinically node negative contralateral neck in small lateralized OCC can be a suitable management approach in well selected patients, however caution should be applied when DOI upstages small but deeply invasive tumors to T3 on 8th edition AJCC staging.

Inflammatory Response Mechanisms of the Dentine-Pulp Complex and the Periapical Tissues

The macroscopic and microscopic anatomy of the oral cavity is complex and unique in the human body. Soft-tissue structures are in close interaction with mineralized bone, but also dentine, cementum and enamel of our teeth. These are exposed to intense mechanical and chemical stress as well as to dense microbiologic colonization. Teeth are susceptible to damage, most commonly to caries, where microorganisms from the oral cavity degrade the mineralized tissues of enamel and dentine and invade the soft connective tissue at the core, the dental pulp. However, the pulp is well-equipped to sense and fend off bacteria and their products and mounts various and intricate defense mechanisms. The front rank is formed by a layer of odontoblasts, which line the pulp chamber towards the dentine. These highly specialized cells not only form mineralized tissue but exert important functions as barrier cells. They recognize pathogens early in the process, secrete antibacterial compounds and neutralize bacterial toxins, initiate the immune response and alert other key players of the host defense. As bacteria get closer to the pulp, additional cell types of the pulp, including fibroblasts, stem and immune cells, but also vascular and neuronal networks, contribute with a variety of distinct defense mechanisms, and inflammatory response mechanisms are critical for tissue homeostasis. Still, without therapeutic intervention, a deep carious lesion may lead to tissue necrosis, which allows bacteria to populate the root canal system and invade the periradicular bone via the apical foramen at the root tip. The periodontal tissues and alveolar bone react to the insult with an inflammatory response, most commonly by the formation of an apical granuloma. Healing can occur after pathogen removal, which is achieved by disinfection and obturation of the pulp space by root canal treatment. This review highlights the various mechanisms of pathogen recognition and defense of dental pulp cells and periradicular tissues, explains the different cell types involved in the immune response and discusses the mechanisms of healing and repair, pointing out the close links between inflammation and regeneration as well as between inflammation and potential malignant transformation.

Prognosis and predictive value of heat-shock proteins expression in oral cancer: A PRISMA-compliant meta-analysis

BACKGROUND

Heat-shock proteins (HSP) is a key chaperone protein which maintains intracellular proteostasis and is expressed on the surface of solid and hematological malignancies. Several studies have reported paradoxical evidence of the association between HSP expression and prognosis of oral cancer. To address the discrepancy, we carried out the meta-analysis to assess the role of HSP such as: HSP70, HSP90, HSP27, HSP60, and HSP105 in susceptibility, progression, and prognosis of oral cancer.

MATERIALS AND METHODS

We retrieved the PubMed, Embase, Web of science, China National Knowledge Infrastructure (CNKI), and Wanfang databases to acquire the eligible studies which were associated with HSP70, HSP90, HSP27, HSP60, and HSP105 protein expression and oral cancer. We applied hazard ratio (HR) and its 95% confidence interval (95% CI) to assess the value of HSP protein expression in overall survival of oral cancer; odds ratio (OR) and its 95% CI were used to evaluate the association of risk and clinical features of oral cancer. Funnel plot, Begg test, and Egger line regression test were utilized to observe publication bias among studies. All statistical analysis was performed with Stata 14.0 software (Stata Corporation, College Station, TX).

RESULTS

A total of 26 studies were included in the present meta-analysis. On based of the results, HSP70 and HSP27 had no significant association with progression of oral cancer. However, the pooled HR and 95% CI revealed a significant well effects of HSP70 and HSP27 expression on survival of oral cancer. Moreover, the susceptibility of oral cancer was significantly associated with HSP70 and HSP60 overexpression.

CONCLUSION

HSP70 and HSP27 protein overexpression might be valuable biomarkers for the prognosis of oral cancer. And HSP70 and HSP60 might have potential predictive effects on the risk of oral cancer.

Dental Implants in Patients with Oral Lichen Planus: A Systematic Review

Background and Objectives: To integrate the available published data on patients with oral lichen planus (OLP) rehabilitated with dental implants, as well as to review the recommendations for OLP patients receiving implants. Materials and Methods: An electronic search was undertaken in February 2019 using five databases. Publications reporting cases of patients with OLP and rehabilitated with implant-supported oral prosthesis were included. Results: Twenty-two publications were included (230 patients, 615 implants). The overall implant failure rate was 13.9% (85/610). In patients with oral squamous cell carcinoma (OSCC) the failure rate was 90.6% (29/32), but none of these implants lost osseointegration; instead, the implants were removed together with the tumor. One study presented a very high implant failure rate, 76.4% (42/55), in patients with “active lichen planus”, with all implants failing between 7–16 weeks after implant placement, and its conflicting and incongruent results are discussed in detail. There was a statistically significant difference between the failure rates in implants installed in different jaws (maxilla/mandible) and when implants of different surfaces were used (turned/moderately rough), but not between patients with reticular or erosive OLP types, or between male and female patients. If OSCC patients and the cases of the latter study are not considered, then the failure rate becomes very low (2.7%, 14/523). The time between implant placement and failure was 25.4 ± 32.6 months (range 1–112). The mean ± SD follow-up was 58.9 ± 26.7 months (1–180). Conclusions: When the results of the one study with a very high failure rate and of the cases that developed OSCC are not considered, the dental implant failure rate in OLP patients was 2.7% after a follow-up of approximately five years. Recommendations are given when treating OLP patients with dental implants.

What Factors Affect Changes in Body Composition and Swallowing Function in Patients Hospitalized for Oral Cancer Surgery?

PURPOSE

There are few studies about sarcopenia before and after surgery for oral cancer. Therefore, we examined body composition during hospitalization and factors affecting weight loss, skeletal muscle mass index (SMI) reduction, and swallowing function at discharge in this patient group.

PATIENTS AND METHODS

A prospective survey was conducted at Tokyo Medical and Dental University Dental Hospital for patients who underwent primary surgery for oral cancer and reconstruction using free flaps. We compared body weight, SMI, grip strength, and walking speed at admission and discharge. We also examined factors affecting weight loss and SMI reduction and the functional oral intake scale (FOIS) score at discharge.

RESULTS

There were 26 patients that we could survey during the period. As a result of Wilcoxon's signed-rank test, body weight, SMI, and grip strength were significantly reduced during hospitalization, but no reduction was noted for sarcopenia. As a result of multiple regression analysis, postoperative chemoradiotherapy was a risk factor for weight loss, reduced SMI, and low FOIS score at discharge.

CONCLUSION

Postoperative chemoradiotherapy is a risk factor for weight loss, muscle mass loss, and dysphagia at discharge, and chemoradiotherapy may affect rather than an invasion of surgery. After surgery, besides follow-ups for cancer, oral cancer patients should be followed up to assess dysphagia, undernutrition, and sarcopenia.

Geraniin inhibits oral cancer cell migration by suppressing matrix metalloproteinase-2 activation through the FAK/Src and ERK pathways

Geraniin has been reported to have numerous biological activities, including antiviral, antihypertensive, antihyperglycaemic, liver protective, antidiabetic, and apoptotic activities. However, the anti-migration effects of geraniin on oral cancer remain elusive. In this study, we revealed the potential antitumor mechanisms of geraniin through the inhibition of the migration and invasion of human oral cancer cell lines SCC-9 and SCC-14. The results of gelatin zymography and Western blot assays revealed that geraniin significantly reduced the activity and expression of matrix metalloproteinase-2 (MMP-2) of oral cancer cells in a concentration-dependent manner. Furthermore, geraniin potently suppressed the phosphorylation of focal adhesion kinase (FAK), Src, and extracellular signal-regulated kinase (ERK)1/2 but did not affect the phosphorylation of p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase 1/2. Moreover, blocking the MAPK/ERK1/2 pathway significantly enhanced the anti-migration ability of geraniin in oral cancer cells. In conclusion, we demonstrated that geraniin inhibits the motility of SCC-9 and SCC-14 cells in vitro through a molecular mechanism that involves the attenuation of MMP-2 expression and activity mediated by decreased FAK/Src and ERK1/2 pathways.

Measurement properties of oral health related patient reported outcome measures in patients with oral cancer: A systematic review using COSMIN checklist

Background

Oral cancer (OC) is one of the common malignant neoplasm resulting in a range of debilitating symptoms. Patient reported outcome measures (PROMs) could provide a valuable insight into the impact of OC on patients’ quality of life (QoL). Selecting an adequate instrument among available PROMs for OC has been challenging for clinicians due to lack of information on their psychometric quality. This systematic review provides an extensive overview of methodological quality of all currently available PROMs for OC.

Method

A systematic search was performed in PubMed, Scopus, Web of Science and CINAHL for relevant literature until 10^th January 2019 and data was extracted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The quality of the identified studies was assessed per measurement property according to the COnsensus-based Standards for the selection of health Measurements Instruments (COSMIN) checklist.

Results

Seven studies were found evaluating 6 health-related QoL PROMs. Among six, there were 1 disease-specific and 5 generic PROMs. Information regarding important measurement properties was often incomplete. The evidence for the quality of measurement properties was found to be variable, none of the instruments performed sufficient on all measurement properties. Considering results of this review, QOL-OC appeared to have adequate COSMIN measurement properties.

Conclusion

QOL-OC can be implemented in future studies to better understand symptoms and expectations of OC patients and help inform clinicians to formulate treatment strategies as per patients’ needs.

Association between nodal metastasis and histopathological factors in postoperative gingivo-buccal complex squamous cell carcinoma: A Retrospective Study

OBJECTIVE

To evaluate association between histopathological factors and cervical lymph node metastasis in postoperative gingiva-buccal complex squamous cell carcinoma.

METHODS

We retrospectively analyzed 98 postoperative gingiva buccal complex squamous cell carcinoma patients' clinical and histopathological findings. The variables assessed were age, sex, tumour site, tumour size, degree of differentiation (grade), depth of invasion (DOI), lymphovascular invasion (LVI), perineural invasion (PNI) and extracapsular extension (ECE) and their relation with nodal metastasis.

RESULT

Out of 98 patients, 76 patients were pathologically node positive (pN+), including 39 of the 53 patients who were classified as cN0 (clinically node negative). The prevalence of occult neck metastasis was 73.5 %. Various parameters like tumour size, LVI, PNI, ECE and Grade showed statistically significant association with lymph node metastasis (p value: 0.029, 0.007, 0.003, 0.001 and 0.001 respectively) on bivariate analysis. Depth of invasion increases incidence of nodal metastasis but was not statistically significant (p value: 0.166). On multivariate logistic regression analysis male gender and presence of PNI were found as independent predicting factors for nodal metastasis (Odds Ratio 7.0826 to 8.65 respectively) while poorly differentiated carcinoma grade appeared non-inferior factor paradoxically (Odds Ratio 0.1033, overall 82.65 % cases were correctly classified by this model and area under ROC curve (AUC) was 0.794 of the model.

CONCLUSION

Male gender, poorly differentiated carcinoma and presence of PNI were found as independent predicting factors for nodal metastasis. Male gender and PNI were found risk factors while poorly differentiated carcinoma grade appeared non-inferior factor (protective) paradoxical.

A model to predict nodal metastasis in patients with oral squamous cell carcinoma

Difficulty in precise decision making on necessity of surgery is a major problem when managing oral squamous cell carcinomas (OSCCs) with clinically negative neck. Therefore, use of clinical and histopathological parameters in combination would be important to improve patient management. The main objective is to develop a model that predicts the presence of nodal metastasis in patients with OSCC.623 patients faced neck dissections with buccal mucosal or tongue squamous cell carcinoma (SCC) were selected from patients’ records. Demographic data, clinical information, nodal status, Depth of invasion (DOI) and pattern of invasion (POI) were recorded. The parameters which showed a significant association with nodal metastasis were used to develop a multivariable predictive model (PM). Univariate logistic regression was used to estimate the strengths of those associations in terms of odds ratios (OR). This showed statistically significant associations between status of the nodal metastasis and each of the following 4 histopathological parameters individually: size of the tumour (T), site, POI, and DOI. Specifically, OR of nodal metastasis for tongue cancers relative to buccal mucosal cancers was 1.89, P-value < 0.001. Similarly, ORs for POI type 3 and 4 relative to type 2 were 1.99 and 5.83 respectively. A similar relationship was found with tumour size; ORs for T2, T3, and T4 compared to T1 were 2.79, 8.27 and 8.75 respectively. These four histopathological parameters were then used to develop a predictive model for nodal metastasis. This model showed that probability of nodal metastasis is higher among tongue cancers with increasing POI, with increasing T, and with larger depths while other characteristics remained unchanged. The proposed model provides a way of using combinations of histopathological parameters to identify patients with higher risks of nodal metastasis for surgical management.

Tumor budding is an independent prognostic marker in early stage oral squamous cell carcinoma: With special reference to the mode of invasion and worst pattern of invasion

Pathologically proven regional lymph node metastasis affects the prognosis in early stage oral cancer. Therefore we investigated invasive tumor patterns predicting nodal involvement and survival in patients with clinically node-negative T1 and T2 oral squamous cell carcinoma (cT1,2N0M0 OSCC). Ninety-one cases of cT1,2N0M0 OSCC treated with transoral resection of the primary tumor were assessed based on 3 types of invasive tumor patterns on histopathologic and pancytokeratin-stained immunohistological sections: the mode of invasion, worst pattern of invasion (WPOI), and tumor budding. The correlations among invasive tumor patterns, regional metastasis, and disease-free survival were analyzed. Of the 91 cases, 22 (24%) had pathologically proven regional metastasis. The mode of invasion (p<0.01) and tumor budding (p<0.01) were associated with regional metastasis as well as lymphovascular invasion (p = 0.04) in univariate analysis. In logistic regression analysis, however, tumor budding was the only independent predictor of regional metastasis (hazard ratio (HR) = 3.05, 95% confidence interval (CI) = 0.29–5.30, p<0.01). All three invasive patterns, the mode of invasion, WPOI, and tumor budding, were found to be significant predictors of 5-year disease-free survival (p<0.01, p = 0.03, and p<0.01, respectively) as well as lymphovascular invasion (p = 0.02) and perineural invasion (p = 0.02). A final model for Cox multivariate analysis identified the prognostic advantage of the intensity of tumor budding (HR = 2.19, 95% CI = 1.51–3.18, p<0.01) compared with the mode of invasion and WPOI in disease-free survival. Our results indicate that the intensity of tumor budding may be a novel diagnostic biomarker, as well as a therapeutic tool, for regional metastasis in patients with cT1,2N0M0 OSCC. If the pancytokeratin-based immunohistochemical features of more than five buds, and a grade 4C or 4D mode of invasion are identified, careful wait-and-see follow-up in a short period with the use of imaging modalities is desirable. If there are more than ten buds, a grade 4D mode of invasion, or WPOI-5 in the same section, wide resection of the primary tumor with elective neck dissection should be recommended.

Definitive chemoradiation for locally-advanced oral cavity cancer: A 20-year experience

OBJECTIVES

Definitive chemoradiation (CRT) for oral cavity squamous cell carcinoma (OC-SCC) is often criticized for poor efficacy or toxicity. We describe a favorable 20-year experience of primary CRT for locally-advanced OC-SCC.

MATERIALS AND METHODS

Patients with locally-advanced, stage III/IV OC-SCC receiving primary concomitant CRT on protocols from 1994 to 2014 were analyzed. Chemotherapy included fluorouracil and hydroxyurea with other third agents. Radiotherapy (RT) was delivered once or twice daily to a maximum dose of 70-75 Gy. Intensity-modulated RT (IMRT) was exclusively used after 2004. Progression-free survival (PFS), overall survival (OS), locoregional control (LRC), and distant control (DC) were calculated by the Kaplan-Meier method and compared across treatment decades using the log-rank test. Rates of osteoradionecrosis (ORN) requiring surgery were compared across treatment decades using the Chi-square test.

RESULTS

140 patients with locally-advanced OC-SCC were treated with definitive CRT. Of these, 75.7% had T3/T4 disease, 68.6% had ≥N2 nodal disease, and 91.4% had stage IV disease. Most common primary sites were oral tongue (47.9%) and floor of mouth (24.3%). Median follow-up was 5.7 years. Five-year OS, PFS, LRC, and DC were 63.2%, 58.7%, 78.6%, and 87.2%, respectively. Rates of ORN and long-term feeding tube dependence were 20.7% and 10.0%, respectively. Differences in LRC (P = 0.90), DC (P = 0.24), PFS (P = 0.38), OS (P = 0.10), or ORN (P = 0.38) were not significant across treatment decades.

CONCLUSION

Definitive CRT is a viable and feasible strategy for organ preservation for patients with locally-advanced OC-SCC.

Oral Cancer Knowledge and Awareness in Patients Visiting Kantipur Dental College

BACKGROUND

Lack of knowledge and awareness about oral cancer, its risk factors and negligence of the early warning signs play crucial role in raising the incidence of the disease. The present study was carried out to evaluate the awareness of oral cancer among patients visiting Kantipur Dental College, Kathmandu, Nepal.

METHODS

The cross-sectional study was done in 471 patients from 15-85 years. Self administered questionnaire was prepared which comprised of knowledge of oral cancer, source of information, its early signs and symptoms along with the awareness of its risk factors.

RESULTS

Most of the participants (41.80%) had not heard of oral cancer. 31.60% recognized tobacco smoking and tobacco chewing as the chief risk factor with 15.50% and 10.80% of participants who identified white patch and red patch as early sign of oral cancer respectively. Pearson's chi square test was used which showed statistically significant association of total mean knowledge score and awareness score with age, education level and occupation (p<0.05).

CONCLUSIONS

This study done in dental patients showed lack of knowledge and awareness in general public about oral cancer. There seem to be a need for more planned awareness programs through newspapers, radio, television and health campaigns regarding the association of habits in the development of oral cancer and benefits of detecting oral cancer at early stage for better prognosis.

Oral and maxillofacial non-Hodgkin lymphomas: Case report with review of literature

RATIONALE

Lymphomas take up about 14% of all head-neck malignancies, out of which 97% are non-Hodgkin lymphomas (NHL). The clinical courses, treatment responses, and prognoses of NHLs vary with different subtypes and anatomic sites. In the Chinese population (including the Taiwanese), head-neck NHLs are often seen with the tonsils, nasal cavity, nasal sinus, and the nasopharynx. However, oral NHLs are relatively rare. Delay of diagnosis is also often seen in clinical practice. Thus, we present 4 cases with delayed diagnosis of oral maxillofacial NHLs and discuss their clinical manifestations so as to draw a clue that can remind the doctors to take biopsies in time.

PATIENT CONCERNS

Four cases, including 3 males and 1 female aged between 43 and 70 years old with oral lesions (ulcerations and/or masses) and accompanying cervical lymphadenopathies and/or skin erythemas presented to the Department of Oral and Maxillofacial Surgery, the First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China from January 2010 to January 2015.

DIAGNOSES

The diagnoses of non-Hodgkin lymphomas were made by pathology, including nasal type extranodal NK/T-cell lymphoma, mycosis fungoides, subcutaneous panniculitis-like T-cell lymphoma, and extranodal marginal B-cell lymphoma of mucosa-associated lymphatic tissue. Their clinical courses until confirmed diagnosis varied between 2 months and 1 year and the follow-up/survival time from diagnosis ranged between 2 and 24 months. None of the biopsies was taken at the patients' initial medical consultations.

INTERVENTIONS

Cyclophosphamide, hydroxydaunorubicin, vincristine and prednisone (CHOP) and Rituximab, CHOP (R-CHOP) regimens were given to 2 (Cases 1 and 4) and 1 patient (Case 3), respectively. One patient refused further treatment.

OUTCOMES

Two patients, including the one who refused treatment, died at 2-2.5 months from diagnosis. The other two patients survived until their last follow-ups at 13 and 24 months from diagnosis, respectively.

LESSONS

Oral lesions with aggressive growth patterns, multiple lymphadenopathies, and comorbid systemic skin lesions, elevated serum lactate dehydrogenase and poor response to medical therapies should warn the doctors of the possibility of malignancy and the necessity of biopsy. Excisional biopsy without sacrificing organs or functions should be preserved for patients whose pathological diagnoses cannot be established through aspiration or punch biopsy.

Influence of time interval from diagnosis to treatment on survival for oral cavity cancer: A nationwide cohort study

OBJECTIVES

We aimed to explore the relationship between the time interval from diagnosis to treatment and survival of oral cavity squamous cell carcinoma patients.

MATERIALS AND METHODS

A population-based study was conducted between 2004 and 2010. Claims data of oral squamous cell carcinoma patients were retrieved from the Taiwan Cancer Registry Database. Secondary data were obtained from Taiwan's National Health Insurance Research Database.

RESULTS

A total of 21,263 patients were included in the final analysis. The majority of the patients received treatment within 30 days of diagnosis (n = 18,193, 85.5%), while 572 patients (2.7%) underwent treatment after 120 days. The patients who were treated after 120 days had a higher risk of death when compared to those treated within 30 days (Hazard ratio: 1.32, 95% Confidence intervals: 1.19 to 1.47).

CONCLUSION

A longer time interval from diagnosis to treatment was found to be associated with a poorer prognosis among patients suffering from oral squamous cell carcinoma.

Conversion of Normal To Malignant Phenotype: Telomere Shortening, Telomerase Activation, and Genomic Instability During Immortalization of Human Oral Keratinocytes

Normal somatic cells terminate their replicative life span through a pathway leading to cellular senescence, which is triggered by activation of p53 and/or pRb in response to critically shortened telomere DNA. Potentially neoplastic cells must first overcome the senescence checkpoint mechanisms and subsequently activate telomerase to propagate indefinitely. Although telomerase activation is closely associated with cellular immortality, telomerase alone is not sufficient to warrant tumorigenicity. Environmental factors, including chemical carcinogens and viral infection, often contribute to aberrant changes leading to tumorigenic conversion of normal cells. Of particular importance in oral cancer development are tobacco-related chemical carcinogens and human papillomavirus (HPV) infection. To describe the molecular mechanisms by which these environmental factors facilitate the genesis of oral cancer, we first established an in vitro multistep oral carcinogenesis model by sequential exposure of normal human oral keratinocytes (NHOK) to "high risk" HPV and chemical carcinogens. Upon introduction of the HPV genome, the cells bypassed the senescence checkpoint and entered into an extended, but not immortal, life span during which telomere DNA continued to shorten. In a few immortal clones surviving beyond the crisis, we found a marked elevation of telomerase activity and stabilization of telomere length. Furthermore, the E6 and E7 oncoproteins of "high risk" HPV disrupted the cell cycle control and DNA repair in immortalized HOK, and enhanced mutation frequency resulting from genomic instability. However, HPV infection alone failed to give rise to a tumorigenic cell population, which required further exposure to chemical carcinogens in addition to HPV infection. Analysis of the data presented suggests that oral carcinogenesis is a series of discrete genetic alterations that result from a continued genotoxic challenge by environmental risk factors. Our in vitro model may be useful for investigators with interest in furthering our understanding of oral carcinogenesis.

Tumor Size and Pretreatment Speech and Swallowing in Patients with Resectable Tumors

The pretreatment relationship of tumor burden to speech and swallowing function in 230 patients with oral or oropharyngeal cancer before surgery was assessed. Reduced articulation, reduced conversational understandability, or self-reported dysphagia were present in at least 34% of patients before treatment. Videofluoroscopy showed at least 9% of patients had reduced swallowing efficiency on liquid, paste, or cookie boluses. By use of regression techniques, the percentages of the oral tongue and of the anterior floor of mouth affected by neoplasm were found to be significantly related to reduced articulation; T stage and the percentage of the oral tongue affected with tumor were mildly related to reduced understandability; tumor volume and having soft palate affected by neoplasm were significantly related to self-reported dysphagia; and percentages of affected oral tongue and of affected tongue base were significantly related to reduced swallowing efficiency. Tumor burden may contribute to functional deficits at diagnosis in patients who have resectable tumors.

Bite Force and Masticatory Performance Using Implant-supported Overdentures After Treatment of Mandibular Cancer

AIM

To evaluate overdentures with regard to artificial restoration of oral function following mandibular cancer.

MATERIALS AND METHODS

We examined 32 patients who had undergone mandibular bone resection as treatment for malignancy and were using implant-supported overdentures. The patients were aged 55-87 years (mean=68.6) with a male to female ratio of 23:9. Marginal resection was performed in 29 patients and segmentectomy in 3.

RESULTS

Before and after using the attachment for overdenture, oral function differed significantly. After the setting of implant-retained overdentures, maximum bite force increased on average by 362% (average, from 16.2 N to 58.8 N; p<0.01). Xylitol gum examination showed a 363% increase in masticatory performance (average, 3.1 to 8.0 points; p<0.01).

CONCLUSION

Implant-retained overdenture resulted in improved oral function, that was lost after treatment for mandibular cancer.

The Yin-Yang Principle of Endoplasmic Reticulum Stress and oral cancer

The endoplasmic reticulum (ER) is an organelle, which performs several cellular functions and is thus an important site for maintaining cellular homeostasis. Sometimes pathways within the ER are disturbed, especially those regulating the protein folding, gene expression, cellular metabolism, and calcium signaling, and is called an "ER stress."(1) The accumulation of unfolded, misfolded, or damaged proteins can irreparably damage cellular functions and can pose a severe threat to the existence of the cell. Under such circumstances, ER functions become overwhelmed triggering the homeostatic "ER stress response" or "unfolded protein response" (UPR).(2).

The Contribution of Dental Implants to Functional Artificial Restoration After Treatment of Oral Cancer

BACKGROUND/AIM

The aim of this study was to evaluate dental implants with regard to artificial restoration of oral function and quality of life in patients with oral cancer.

PATIENTS AND METHODS

We examined 134 implants in 41 patients who had undergone jawbone resection as treatment for oral cancer. The patients were aged 44-89 (mean=61.5) years, and the male to female ratio was 27:14.

RESULTS

The 5-year implant success rate was 91.0%. Of the 12 unsuccessful implants, four were embedded on bone grafts with skin flaps, four were embedded on skin flaps using muscle, and four were embedded after peripheral resection. Of the 41 patients, 11 received radiation, but exposure to radiation was not associated with implant loss. The level of satisfaction on the visual analog scale before development of oral cancer was set at 100 mm. Satisfaction fell to 47.0 mm after primary treatment, but recovered to 82.6 mm after implant therapy.

CONCLUSION

Patient satisfaction after implant therapy was high, and the implants resulted in improved quality of life. A high proportion of cases involving use of skin flaps resulted in implant loss. Constructing an immobile mucous membrane by replacement of a skin flap with a skin graft may facilitate self-maintenance of implants.

Induction of Heat Shock Protein 70 Inhibits NF-kappa-B in Squamous Cell Carcinoma

OBJECTIVE: To determine the relationship between heat shock proteins (HSPs) and the proinflammatory, anti-apoptosis mediator NF-kappa-B in squamous cell carcinoma.

STUDY DESIGN AND SETTING: CA-9-22 cells were exposed to heat stress to induce the production of HSPs. Immunoblot and reporter gene experiments determined the inducibility of HSP production and the activation of cytokine-induced NF-kappa-B. Immunoblot experiments determined the presence of the inhibitor- k-B-α (I kBα).

RESULTS: CA-9-22 cells can be induced by heat stress to produce HSPs at 100-fold above baseline levels. The induction of HSPs prevents the activation and nuclear translocation of NF-kappa-B despite stimulation with IL-1β and TNF-α.

CONCLUSIONS: Constitutive activation of NF-kappa-B is prevented by HSP induction through an increase in I kBα synthesis.

SIGNIFICANCE: The induction of HSP70 alters the inflammatory milieu associated with squamous cell carcinoma progression through the inhibition of NF-kappa-B and may ultimately promote apoptosis in head and neck carcinoma.

[The effect of human PBMC on the growth of oral squamous cell carcinoma cell]

PURPOSE

To explore the effect and mechanism of activated peripheral blood mononuclear cell (PBM) on the growth and apoptosis of oral squamous carcinoma cells in vitro.

METHODS

ELISA, RT-PCR, MTT and flow cytometry were used to detect cytokines secretion and oral squamous carcinoma cell growth and apoptosis affected by activated PBMCs with PHA. The data was analyzed using SPSS17.0 software pakage.

RESULTS

The cytokines secretion, mRNA expression of granzyme B and perforin, inhibition of growth and induction of apoptosis of oral squamous carcinoma cells treated by the activated PBMCs with PHA were significantly higher than the control groups (P<0.05).

CONCLUSIONS

The human PBMC can be activated effectively with the stimulations of PHA, which can significantly inhibit growth and induce apoptosis of oral squamous carcinoma cells in vitro.

Nativity status and oral cancer survival in the United States: implications for dental clinical practice

OBJECTIVE

Nativity status is a major determinant of health and healthcare access in the United States. This study compared oral squamous cell carcinoma (OSCC) survival between US-born and foreign-born patients.

METHOD AND MATERIALS

Data were obtained from the 1988-2008 Surveillance, Epidemiology and End Results database. A Cox proportional hazards multivariate model was used to assess the eff ect of birthplace on OSCC survival, adjusting for other sociodemographic and clinical covariates.

RESULTS

US-born patients had a higher median survival time (19.3 years; 95% confidence interval [CI]: 18.6-19.7) compared to foreign-born patients (10.7 years; 95% CI: 10.1-11.3). After adjusting for other factors, being born in the US conferred a modest protective eff ect from OSCC mortality (hazard ratio [HR] = 0.93, 95% CI: 0.87- 0.99). Other factors that conferred better survival included involvement of paired structures (HR = 0.65; 95% CI: 0.58- 0.74), lip involvement rather than tongue lesions (HR = 0.76; 95% CI: 0.71-0.82), and receipt of either surgery (HR = 0.89; 95% CI: 0.84-0.94) or radiation therapy (HR = 0.92; 95% CI: 0.87-0.97).

CONCLUSION

US-born patients had significantly better OSCC survival compared to their foreign-born counterparts. This underscores the need for enhanced and sustained efforts to improve access to healthcare among immigrant populations. In addition, oral health professionals such as general dentists, oral pathologists, and oral surgeons providing care to immigrant patients should ensure that reasonable efforts are made to communicate effectively with patients with language barriers, especially in high-stake conditions such as cancer. This may help increase such patients' awareness of treatment provided and the critical issues regarding cancer care, resulting in enhanced treatment outcome.

[Rab23 enhances invasion of Sa3 cutaneous squamous cell carcinoma cells via up-regulating the expression of Rac1]

OBJECTIVE

To investigate the effect of Ras-related protein 23 (Rab23) on the invasion capacity of Sa3 cutaneous squamous cell carcinaoma (cSCC) cells and determine whether Rab23 can enhance the invasion of Sa3 cells through regulation of Ras-related C3 botulinum toxin substrate 1 (Rac1).

METHODS

Sa3 cells stably expressing exogenous Rab23 or Sa3 cells deprived of endogenous Rab23 were generated using lentivirus transfection. Transwell(TM) invasion assay was used to evaluate the invasion capacity in the above-mentioned cells. The effects of Rab23 overexpression or knockdown on Rac1 expression were assessed using Western blotting. In the last experimental setting, the engineered cells were pretreated with Rac1 inhibitor Z62954982 before being subjected to the assessment of invasion capacity by Transwell(TM) assay.

RESULTS

Rab23 overexpression enhanced the invasion ability, whereas ablation of Rab23 attenuated the invasion in Sa3 cells. Rab23 could up-regulate the expression level of Rac1. Finally, using Rac1 inhibitor, we successfully suppressed the invasion capacity of Sa3 cells stably overexpressing Rab23.

CONCLUSION

Rab23 may enhance cSCC cell invasion via up-regulating Rac1 signaling.

[Assessment of the quality of life of oral cancer patients after reconstruction with free anterolateral thigh perforator flaps]

OBJECTIVE

This study aims to evaluate the quality of life (QOL) of patients who underwent resection of oral cancer and reconstruction by free anierolateral thigh perforator flaps (ALTF).

METHODS

A total of 32 patients with oral and maxillofacial malignancies who had undergone the resection of oral cancer and reconstruction by ALTF were retrospectively analyzed. At 12 months postoperatively, the QOL of these patients was assessed by using the 14-item oral health impact profile (OHIP-14) and the medical outcome study short form-36 (SF-36) questionnaires.

RESULTS

A total of 32 questionnaires were collected. In SF-36, the highest scoring domains were bodily pain (78.58 ± 14.82), physical functioning (72.08 ± 27.86), and the role of physical (60.00 ± 42.63), whereas the lowest scoring domains were role-emotional (41.67 ± 39.62), followed by mental health (50.75 ± 13.07) and health transition (54.17 ± 21.75). In OHIP-14, the lowest scoring domains were social disability (34.50 ± 11.32) and handicap (36.04 ± 12.05), indicating the functional recovery was better; and the highest scoring domains were physical pain (73.50 ± 18.96) and psychological discomfort (60.17 ± 20.66), indicating the functional recovery was worse.

CONCLUSION

The ALTF is an ideal selection for the reconstruction of oral defects after cancer resection. In using this flap, the basic social need of patients after surgery can be satisfied. Moreover, the appearance and the functions of chewing, deglutition, and speech can be restored in varying degrees. Thus, ALTF can improve the patients' QOL.

Life expectancy and expected years of life lost to oral cancer in Taiwan: a nation-wide analysis of 22,024 cases followed for 10 years

OBJECTIVES

This analysis examined the life expectancies (LE) and expected years of life lost (EYLL) in relation to oral cancer in Taiwan.

MATERIALS AND METHODS

A semi-parametric extrapolation method was applied to estimate gender, age, histology, subsite, and stage stratified LE, EYLL of 22,024 pathologically verified oral cancer patients retrospectively recruited from the National Cancer Registry of Taiwan during 2002-2009, who were followed up to 2011.

RESULTS

The patients were predominantly male 20,101, (91.3%), and over 80% were less than 65years old. The mean age at diagnosis of males was younger than that of females (52.73years vs. 60.76years). The LE after diagnosis was longer among females than males (15.26years vs. 12.73years), with a smaller loss of the corresponding EYLL (8.88years vs. 14.05years), which prevails after stratification by age and stage. More than half of the oral cancer cases were diagnosed at a later stage, with 2921 cases (13.3%) of stage III and 8488 (38.5%) of stage IV. The five-year overall survival rate of oral cancer for stages I, II, III, and IV were 78.98%, 69.38%, 54.62%, and 36.17%, respectively. The earlier the diagnosis, the longer the life expectancy and the smaller the EYLL.

CONCLUSIONS

We concluded that early detection and early intervention of oral cancer can prolong life expectancy and reduce the years of life lost, indicating the importance of proactive screening and oral hygiene.

Evaluation of the Effects of Dental Implants on Oral Lesions

Objective

To determine whether dental implants impress oral lesions, and to evaluate the nature of their effect on the lesions.

Materials and methods

A comprehensive search was done via Google and PubMed for articles (including case reports and literature reviews) containing the keywords ‘oral squamous cell carcinoma’ (OSCC), ‘oral lichen planus’ (OLP), ‘lichenoid contact reaction’ (LCR), ‘osseointegrated implants’, and ‘dental implants’, in the last 10 years (2002-2012).

Results

The study included 24 articles involving patients with dental implants, and some oral lesions (e.g. oral lichen planus and oral squamous cell carcinoma) or with a history of lesions. In these publications, there is evidence suggesting the possibility of emergence, exacerbation, recurrence, or even malignant transformation of the oral lesions after implant placement in some cases.

Conclusion

Based on our review of the literature, implant treatment does not seem to be completely safe under any circumstances, but may have some complications in subjects with certain diseases (e.g. oral lesions, autoimmune diseases, malignancies, allergic reactions, etc.). Therefore prior to treatment, patients should be fully informed of the risks.

Clinical significance

Implant treatment is best done with caution in patients with cancer or mucocutaneous disorders.

How to cite this article

Agha-Hosseini F, Rohani B. Evaluation of the Effects of Dental Implants on Oral Lesions. J Contemp Dent Pract 2015;16(5):400-406.

Agrin and perlecan mediate tumorigenic processes in oral squamous cell carcinoma

Oral squamous cell carcinoma is the most common type of cancer in the oral cavity, representing more than 90% of all oral cancers. The characterization of altered molecules in oral cancer is essential to understand molecular mechanisms underlying tumor progression as well as to contribute to cancer biomarker and therapeutic target discovery. Proteoglycans are key molecular effectors of cell surface and pericellular microenvironments, performing multiple functions in cancer. Two of the major basement membrane proteoglycans, agrin and perlecan, were investigated in this study regarding their role in oral cancer. Using real time quantitative PCR (qRT-PCR), we showed that agrin and perlecan are highly expressed in oral squamous cell carcinoma. Interestingly, cell lines originated from distinct sites showed different expression of agrin and perlecan. Enzymatically targeting chondroitin sulfate modification by chondroitinase, oral squamous carcinoma cell line had a reduced ability to adhere to extracellular matrix proteins and increased sensibility to cisplatin. Additionally, knockdown of agrin and perlecan promoted a decrease on cell migration and adhesion, and on resistance of cells to cisplatin. Our study showed, for the first time, a negative regulation on oral cancer-associated events by either targeting chondroitin sulfate content or agrin and perlecan levels.

Clinical case of the month: a 22-year-old man with AIDS presenting with shortness of breath and an oral lesion

Since the development of combination antiretroviral therapy (cART), the incidence and mortality associated with Kaposi sarcoma (KS) have been reduced, although not eliminated. Clinical presentations of KS range from simple skin involvement to disseminated disease, including involvement of the oral cavity and viscera, which portends a more ominous prognosis. Multiple case reports and data from clinical trials indicate that administration of systemic corticosteroids may aggravate KS. We present a case of disseminated KS following administration of prednisone for presumed immune reconstitution inflammatory syndrome (IRIS) associated with fungal pneumonia in an HIV-infected individual. The discussion that follows outlines the pathophysiology and clinical presentations associated with KS and existing data for the role of corticosteroids in promoting KS progression.

[Nuclear translocation of epidermal growth factor receptor and its relation to clinicopathological factors in oral squamous cell carcinomas]

The epidermal growth factor receptor (EGFR) is one of the receptor tyrosine kinases. Some EGFRs are transferred from membrane to nucleus upon ligand binding and an increase of this translocation causes high-level expression of nuclear EGFR. The high-level expression of nuclear EGFR was reported to be a poor prognostic factor in various cancers such as breast cancer, ovarian cancer, gallbladder cancer, prostate cancer and oropharyngeal cancer. Regarding oral cancers, one report indicated that nuclear EGFR is detected in oral squamous cell carcinoma (OSCC) on immunohistochemical staining, but did not mention the clinicopathological prognostic value in detail. Therefore, we investigated the expression of nuclear EGFR in OSCC cell lines and primary tumor specimens of tongue SCCs to see whether nuclear EGFR could be a useful prognostic value. We verified the expression level of nuclear EGFR in OSCC cell lines and observed an increase in the amount of nuclear EGFR upon EGF stimulation with the expression level reaching its peak after 15 minutes. Nuclear EGFR positive tumors were found in 23 patients (28.0%) with tongue SCCs. However, we could not find any correlation between clinicopathological factors and the expression of nuclear EGFR in patients with tongue SCCs.

Cell proliferation and expression of connexins differ in melanotic and amelanotic canine oral melanomas

Melanoma is a malignant neoplasm occurring in several animal species, and is the most frequently found tumor in the oral cavity in dogs. Melanomas are classified into two types: melanotic and amelanotic. Prior research suggests that human amelanotic melanomas are more aggressive than their melanotic counterparts. This study evaluates the behavior of canine melanotic and amelanotic oral cavity melanomas and quantifies cell proliferation and the expression of connexins. Twenty-five melanomas (16 melanotic and 9 amelanotic) were collected from dogs during clinical procedures at the Veterinary Hospital of the School of Veterinary Medicine and Animal Science of the University of São Paulo, Brazil. After diagnosis, dogs were followed until death or euthanasia. Histopathology confirmed the gross melanotic or amelanotic characteristics and tumors were classified according to the WHO. HMB45 or Melan A immunostainings were performed to confirm the diagnosis of amelanotic melanomas. Cell proliferation was quantified both by counting mitotic figures and PCNA positive nuclei. Expressions of connexins 26 and 43 were evaluated by immunohistochemistry, qRT-PCR and Western blot. Dogs bearing amelanotic melanomas presented a shorter lifespan in comparison to those with melanotic melanomas. Cell proliferation was significantly higher in amelanotic melanomas. Expressions of Connexins 26 and 43 were significantly reduced in amelanotic melanomas. The results presented here suggest that oral cavity melanotic and amelanotic melanomas differ regarding their behavior, cell proliferation and connexin expression in dogs, indicating a higher aggressiveness of amelanotic variants.

Expression of angiopoietin-2 and vascular endothelial growth factor receptor-3 correlates with lymphangiogenesis and angiogenesis and affects survival of oral squamous cell carcinoma

Background

Both Ang-2 and VEGFR-3 are major regulators of angiogenesis and lymphangiogenesis, respectively, and thus may affect prognosis of OSCC. We sought to determine the associations between Ang-2 and VEGFR-3 expression and survival of OSCC.

Methods

Ang-2 and VEGFR-3 expression was determined immunohistochemically in tumor tissues from 112 patients with OSCC; OSCC-adjacent noncancerous oral tissue from 85 OSCC patients; and normal oral mucosa from 37 cancer-free individuals. A log-rank test and Cox proportional hazard models were used to compare survival among different groups with expression of Ang-2 and VEGFR-3.

Results

Ang-2 and VEGFR-3 expression was upregulated in OSCC compared to nontumor tissue (all P<0.05). High Ang-2 expression positively correlated with microvessel density (MVD) (P<0.01), and high VEGFR-3 expression positively correlated with lymph node metastasis (P<0.01) and lymphatic vessel density (LVD) (P<0.01). The patients with high expression of Ang-2 alone or in combination with VEGFR-3 had a significantly worse survival than in patients with low expression of Ang-2 or any other co-expression status (all P<0.05), respectively. Furthermore, multivariable analysis showed that patients with high expression of Ang-2 alone or in combination with VEGFR-3 had a significantly increased risk of death compared with those with low expression of Ang-2 or any other co-expression status (HR, 2.7, 95% CI, 1.1–6.2 and 5.0, 1.3–15.4, respectively).

Conclusions

These results suggest that increased expression in tumors of Ang-2 may individually, or in combination with VEGFR-3, predict poor prognosis of OSCC.

Functional assessment and rehabilitation: how to maximize outcomes

The number of oral cavity and oropharyngeal cancer survivors is rising. By 2030, oropharyngeal cancers are projected to account for almost half of all head and neck cancers. Normal speech, swallowing, and respiration can be disrupted by adverse effects of tumor and cancer therapy. This review summarizes clinically distinct functional outcomes of patients with oral cavity and oropharyngeal cancers, methods of pretreatment functional assessments, strategies to reduce or prevent functional complications, and posttreatment rehabilitation considerations.

Clinical presentation of oral squamous cell carcinoma

AIMS AND OBJECTIVES

This study aims to present the symptoms first observed by patients diagnosed of oral squamous cell carcinoma (OSCC) presenting at the University College Hospital, Ibadan between January 1990 and December 2008 as well as the time lag between the observation and presentation in the hospital.

PATIENTS AND METHODS

This is a retrospective review of patients that have been diagnosed histologically as squamous cell carcinoma of the oral cavity at the University College Hospital Ibadan, Nigeria between January 1990 and December 2008.

RESULTS

Painful tooth/teeth which are not mobile were the most common symptom in these patients (27.5%). However, about 59.4% of patients had painless symptoms at the onset of the disease. The interval between onset of symptoms and clinical presentation ranged from 3 weeks to 36 months with a mean duration of 7 ± 6.3 months. Paradoxically, patients that experienced painful symptoms at the onset of disease presented later than those who had painless symptoms

CONCLUSION

The first symptoms observed by these patients were not pathognomonic of oral cancer but are shared by several relatively more common oral diseases. Awareness of the populace about oral cancer should be increased as well as the index of suspicion of the medical practitioner for OSCC.

Abnormal expression of PI3K isoforms in patients with tobacco-related oral squamous cell carcinoma

BACKGROUND

The phosphatidylinositol 3-kinase (PI3K) signaling regulates several cellular functions such as motility, proliferation, angiogenesis and survival.

METHODS

Since there is no information on expression of PI3K isoforms in oral cancer, we studied the expression of different isoforms of PI3K (p110α, p110γ, PI3K-C2, Vps34p and p85α) in tumor samples and PBMC by RT and q-RTPCR and serum levels of PI3K p110α by SPR and ELISA techniques in 108 patients with tobacco-related oral squamous cell carcinoma (OSCC) and 46 normal subjects.

RESULTS

We observed significantly higher PI3K p110α (p<0.0001) and lower (p<0.0001) vesicular sorting protein 34p (Vps34p) mRNA both in PBMC and tissue samples of oral cancer patients as compared to the normal controls. Other PI3K isoforms did not show such change. Circulating PI3K p110α levels were higher in patients (p<0.0001) as compared to healthy subjects, the SPR data showed direct correlation with advancing stage of the disease. PI3K p110α was overexpressed in tumor samples but not in the normal buccal mucosa.

CONCLUSIONS

Upregulation of circulating PI3K p110α isoform and its direct correlation with increasing tumor load in OSCC patients indicates that it may be a significant prognostic indicator and a suitable target for therapeutic/chemo-preventive strategies for tobacco-related OSCC.

Progression of oral squamous cell carcinoma accompanied with reduced E-cadherin expression but not cadherin switch

The cadherin switch from E-cadherin to N-cadherin is considered as a hallmark of the epithelial-mesenchymal transition and progression of carcinomas. Although it enhances aggressive behaviors of adenocarcinoma cells, the significance and role of cadherin switch in squamous cell carcinomas (SCCs) are largely controversial. In the present study, we immunohistochemically examined expression of E-cadherin and N-cadherin in oral SCCs (n = 63) and its implications for the disease progression. The E-cadherin-positive carcinoma cells were rapidly decreased at the invasive front. The percentage of carcinoma cells stained E-cadherin at the cell membrane was reduced in parallel with tumor dedifferentiation (P<0.01) and enhanced invasion (P<0.01). In contrast, N-cadherin-positive cells were very limited and did not correlate with the clinicopathological parameters. Mouse tongue tumors xenotransplantated oral SCC cell lines expressing both cadherins in vitro reproduced the reduction of E-cadherin-positive carcinoma cells at the invasive front and the negligible expression of N-cadherin. These results demonstrate that the reduction of E-cadherin-mediated carcinoma cell-cell adhesion at the invasive front, but not the cadherin switch, is an important determinant for oral SCC progression, and suggest that the environments surrounding carcinoma cells largely affect the cadherin expression.

Histopathological changes in parotid and submandibular glands of patients treated with preoperative chemoradiation therapy for oral cancer

We retrospectively evaluated the relationship between computed tomography (CT)- and histopathological findings of parotid and submandibular glands in six patients treated for advanced oral cancer. Eligibility criteria were a pathologic diagnosis of oral squamous cell carcinoma, preoperative chemoradiation therapy (CRT) with a total dose of 30 Gy and oral S-1 (80 mg/m²/day), the availability of morphological assessments by CT and of functional assessments with the Saxon test before- and 2 weeks after CRT, and the availability of histopathological slides of irradiated parotid and submandibular glands. In the histopathological interpretation, gland structures were divided into acinar-, duct-, and adipose cells and other tissues. The Mann-Whitney test and the Spearman rank correlation test were used to determine histopathological changes. After 30-Gy irradiation, saliva production and parotid and submandibular volumes were significantly decreased (P < 0.05 each). Histopathological analysis demonstrated that 30-Gy irradiation resulted in a loss of acinar cells although acinar cells in the submandibular gland were relatively retained; the median acinar rate in the parotid and submandibular glands was 1.1% and 19.0%, respectively. The CT values after CRT were inversely correlated with adipose ratios (r = -0.98, P < 0.01) and there was a strong correlation between CT values before and after CRT (r = 0.97, P < 0.01). Our results suggested that acinar cell loss is a main contributor to changes in the volume and function of irradiated human parotid and submandibular glands. The CT value may reflect the adipose ratio rather than salivary function.

Characterization of Yemeni patients treated for oral and pharyngeal cancers in Saudi Arabia

OBJECTIVE

To determine the relative frequency and rank of oral cancer (OC) and pharyngeal cancer (PC) among Yemeni cancer patients who were treated and registered in the Kingdom of Saudi Arabia (KSA) over 14 years, and to characterize these patients by different grouping factors.

METHODS

In this retrospective study, the Saudi Cancer Registry, Riyadh, KSA officially provided the data regarding all Yemeni patients registered between 1994 and 2007. These data were reclassified and analyzed to present the cancer distribution by the main sites adopted by Globocan 2008. The OC and PC patients were statistically described and analyzed according to the demographic data and tumor details. This study was conducted at the Oral Medicine, Medically Compromised and Research Clinic, Department of Dentistry, Riyadh Military Hospital, Saudi Arabia between January and April 2011.

RESULTS

There were 5862 Yemenis registered with malignancies. The OC ranked the eighth most common malignancy (215, 3.7%) with 1.65:1 male to female ratio, whereas PC ranked the seventh (245, 4.2%) with 2.06:1 male to female ratio. The most affected oral sub-site was the tongue (91, 42.3%) while the nasopharynx accounted for 79% (194) of PC. The PC patients were significantly younger than those with OC (45.88+/-16.72 versus 55.6+/-15.75). The squamous cell carcinoma was the most frequent morphological type (289, 63.5%) but significantly more frequent in OC. Approximately 56% (255 patients) were diagnosed at advanced stage, however, significantly more frequent in PC (155, 64.6%).

CONCLUSION

The relative frequencies of oral and pharyngeal cancers in Yemen are quite high. The demographic and tumor characteristics of these cancers are obviously different.

5-lipoxygenase expression and tepoxalin-induced cell death in squamous cell carcinomas in cats

OBJECTIVE

To assess expression pattern and subcellular compartmentalization of 5-lipoxygenase in cutaneous, UV radiation-induced, and oral squamous cell carcinomas (SCCs) in cats and determine the effects of cyclooxygenase or 5-lipoxygenase inhibition on proliferation or apoptosis in a feline oral squamous cell carcinoma (SCCF1) cell line.

SAMPLE

60 archived paraffin-embedded samples of SCCs from 60 cats and SCCF1 cells.

PROCEDURES

Retrospective immunohistochemical analysis of the archived samples of SCCs (20 cutaneous, 20 UV radiation-induced, and 20 oral tumors) was performed. Cell culture proliferation assays involving SCCF1 cells were performed, and tepoxalin-induced apoptosis and signaling were examined via western blotting and annexin V staining.

RESULTS

Immunohistochemically, staining for 5-lipoxygenase was most frequently of greatest intensity in oral SCCs, whereas staining of cutaneous and UV radiation-induced lesions had less consistent 5-lipoxygenase expression. Exposure of SCCF1 cells to the 5-lipoxygenase inhibitor tepoxalin resulted in apoptosis; the effect appeared to be mediated via alteration of cell signaling rather than via suppression of lipid mediators that are typically produced as a result of 5-lipoxygenase activity.

CONCLUSIONS AND CLINICAL RELEVANCE

In cats, expression of 5-lipoxygenase in SCCs appeared to differ depending on tumor location. The influence of tepoxalin-induced 5-lipoxygenase inhibition on a 5-lipoxygenase-expressing cell line coupled with the notable expression of 5-lipoxygenase in oral SCCs suggested that 5-lipoxygenase inhibition may have therapeutic benefits in affected cats. Although the safety of tepoxalin in cats has yet to be investigated, 5-lipoxygenase inhibitors should be evaluated for use as a potential treatment for SCCs in that species.

Blood pressure and free flap oxygenation in head and neck cancer patients

CONCLUSION

This study suggests that although oxygen partial pressure in tissue (p(ti)O(2)) measurement is a feasible method for continuous postoperative monitoring of free flaps, low correlation between blood pressure (BP) and p(ti)O(2) might predict compromised overall outcome. Thus, it is of utmost importance to keep the BP optimal for adequate perfusion of re-anastomosed tissue transfers.

OBJECTIVE

Optimal BP is an important factor in assuring adequate blood flow in a free flap. Tissue oxygenation in free flaps as a postoperative monitoring target is in routine clinical use in some clinics. Correlation between p(ti)O(2) and systemic BP was investigated.

METHODS

Ten consecutive patients underwent resection of head and neck squamous cell carcinoma followed by microvascular reconstruction with a free microvascular flap. P(ti)O(2) of each flap was continuously monitored for 3 postoperative days with a polarographic measurement system. BP was measured invasively and continuously during the operation and during the first postoperative day at the intensive care unit. The correlation coefficient between p(ti)O(2) and BP was analysed.

RESULTS

The correlation coefficient between p(ti)O(2) and BP was relatively high in all patients with uneventful flap survival (r (mean) = 0.63, n = 5). In flaps with haemodynamic problems or compromised flap vitality the correlation appeared low (r(mean) = -0.02, n = 5).

Interleukin-23 receptor polymorphism as a risk factor for oral cancer susceptibility

BACKGROUND

The purpose of this study was to evaluate the influence of genetic polymorphisms of interleukin (IL)-23 and the IL-23 receptor (IL-23R) on the susceptibility to oral cancer.

METHODS

Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to measure polymorphisms of these genes in 240 controls and 240 patients with oral cancer.

RESULTS

Individuals with at least 1 varied C allele of rs10889677 (IL-23R polymorphism) had a 1.553-fold risk (95% confidence interval [CI], 1.073-2.241) of developing oral cancer compared with patients with the wild-type A/A homozygote. Patients with oral cancer with at least 1 varied C allele of rs10889677 had a 1.931-fold risk of tumor lymph node metastasis compared with patients with the C/C homozygote.

CONCLUSION

The varied C allele of the IL-23R gene may be considered a factor contributing to increased susceptibility and may be a predictive factor for tumor lymph node metastasis in Taiwanese with oral cancer.

Nasal-type NK/T-cell lymphoma with palatal ulcer as the earliest clinical manifestation: a case report with literature review

Extranodal nasal natural killer (NK)/T-cell lymphoma is a very rare kind of lymphoma, Oral cavity involvement of extranodal natural killer/T-cell lymphoma, nasal type is extremely rare, and its clinicopathologic features are also poorly understood. Recently, we experienced an unusual case of Epstein-Barr virus-associated, extranodal NK/T-cell type with a unhealed palatal ulcer as the earliest clinical feature. It is a challenge for oral medicine specialists to make the early diagnosis for this special type of tumor.

Areca nut and betel quid chewing among South Asian immigrants to Western countries and its implications for oral cancer screening

The South Asian community is the largest and one of the fastest growing minority groups in Canada, according to the 2006 census. These immigrants bring to Canada talents and skills that can promote Canada's economy and cultural diversity, but they also bring lifestyle habits that may lead to serious health issues. Chewing areca nut and betel quid (paan, with and without tobacco) is a known risk factor for oral cancer. This habit is common in the Indo-Canadian population, as evidenced by its sales in local Indian markets and restaurants. In this article, we present an overview of the sociocultural beliefs, knowledge and practices regarding betel quid/areca nut chewing, and discuss its implications for oral cancer screening among this immigrant population.

Plasmablastic lymphoma of the oral cavity: a rapidly progressive lymphoma associated with HIV infection

Plasmablastic lymphoma of the oral cavity is a form of non-Hodgkin lymphoma (NHL) and was first described in 1997. We describe a case of plasmablastic lymphoma in an HIV-infected patient who presented with an expanding oral lesion and symptoms of a toothache. We review all cases of plasmablastic lymphoma that have been reported in the literature. Plasmablastic lymphoma is strongly associated with immunodeficiency, and most particularly, with HIV infection. The pathophysiological origin of plasmablastic lymphoma has not been fully characterised, but the presence of Epstein-Barr virus (EBV) has often been documented in biopsy specimens, supporting a role for EBV in the pathogenesis of this lymphoma. The differential diagnosis for an expanding oral lesion includes both infectious and malignant processes. Biopsy is essential for making a correct and prompt diagnosis. Treatment usually involves chemotherapy, but antiretroviral therapy may also have an important role. Infectious disease clinicians should be aware of this newly described and increasingly encountered lymphoma, since it is prominently associated with immunosuppression and may be mistaken for other entities.

NADPH oxidase and uncoupled nitric oxide synthase are major sources of reactive oxygen species in oral squamous cell carcinoma. Potential implications for immune regulation in high oxidative stress conditions

The development of cancer is associated with high oxidative stress and at the same time with immune system activation. Tumors develop efficient mechanisms of protection against the immune response, which allow them to escape the immune surveillance. Simultaneously, key events in the process of carcinogenesis are related to oxidative stress. The relationship between the two remains unknown. Novel understanding of oxidative stress shows that discrete changes of activities of certain enzyme systems such as NADPH oxidases or nitric oxide synthases may be more important than the overall balance of production and removal of reactive oxygen species. Such imbalance of nitric oxide and superoxide production could modify inflammation and immune regulation. We studied superoxide anion production (by lucigenin enhanced chemiluminescence - 5 microM), NADPH oxidase activity and nitric oxide synthase (NOS) dysfunction. In parallel mRNA expression of immunomodulatory markers such as FoxP3 (T regulatory cell marker), CCR6 (mucosal homing effector T cell marker) and CD85j (NK cell/CD8 T cell Ig-like MHC class I inhibitory receptor) was determined. Basal superoxide production and NADPH oxidase activity are increased in oral squamous cell carcinoma. Tumor superoxide production was inhibited by NADPH oxidase inhibitor apocynin and by NOS inhibitor L-NAME. This indicates, for the first time, that oral squamous cell carcinoma is characterized by dysregulated nitric oxide synthase, which apart from increased NADPH oxidase activity contributes to oxidative stress and may be related to the immuno-pathology of these tumors. Studied tumors were infiltrated by CCR6+, but showed lower expression of both CD85j and FoxP3 mRNA. Finally, the CD85j mRNA expression was inversely correlated to oxidative stress parameters. These preliminary studies indicate that tumor oxidative stress, related to NADPH oxidase activity and NOS activity could be related to immune responses to cancer, thus therapeutic modification of oxidative stress, which could include the correction of NOS dysfunction, could facilitate immune surveillance.