An Overview of Epidemiology and Common Risk Factors for Oral Squamous Cell Carcinoma

Evaluation of Paxillin Expression in Epithelial Dysplasia, Oral Squamous Cell Carcinoma, Lichen Planus with and without Dysplasia, and Hyperkeratosis: A Retrospective Cross-Sectional Study

BACKGROUND

Paxillin is a cytoskeletal protein involved in the pathogenesis of several types of cancers. However, the roles of paxillin in epithelial dysplasia (ED), oral squamous cell carcinoma (OSCC), oral lichen planus with dysplasia (OLPD), hyperkeratosis (HK), and oral lichen planus (OLP) have remained unnoticed in the literature. This study aimed to evaluate its attainable functions in the pathogenesis and malignant transformation of potentially malignant oral epithelium and benign lesions.

METHODS

In this retrospective cross-sectional study, paxillin expression was investigated in 99 tissue samples, including 18 cases of OSCC, 21 ED, 23 OLP, 21 OLPD, and 16 cases of HK. The tissue sections also underwent immunohistochemical paxillin staining using 3,3-diaminobenzidine (DAB) chromogen. The intensity, location, and percentage of staining were examined across all groups. Data were analyzed using the Shapiro-Wilk test, ANOVA, Pearson chi-square, Kruskal-Wallis, and Dunn's post hoc test.

RESULTS

The cytoplasmic percentage and intensity staining of Paxillin expression were evident in the central/suprabasal and basal/peripheral layers of all the obtained samples. The final staining score was significantly higher in OSCC and dysplasia compared to HK and OLP (p = 0.004). It was found that paxillin expression is associated with the grade of dysplastic samples (p < 0.001).

CONCLUSION

The present study provides evidence that paxillin may be involved in the pathogenesis of OSCC and the development and progression of dysplastic tissue, since the paxillin expression was higher than that of HK and OLP.

Molecular Research on Oral Diseases and Related Biomaterials: A Journey from Oral Cell Models to Advanced Regenerative Perspectives

Oral diseases such as gingivitis, periodontitis, and oral cancer affect millions of people worldwide. Much research has been conducted to understand the pathogenetic mechanisms of these diseases and translate this knowledge into therapeutics. This review aims to take the reader on a journey from the initial molecular discoveries to complex regenerative issues in oral medicine. For this, a semi-systematic literature search was carried out in Medline and Web of Science databases to retrieve the primary literature describing oral cell models and biomaterial applications in oral regenerative medicine. First, an in vitro cell model of gingival keratinocytes is discussed, which illustrates patho- and physiologic principles in the context of oral epithelial homeostasis and carcinogenesis and represents a cellular tool to understand biomaterial-based approaches for periodontal tissue regeneration. Consequently, a layered gradient nonwoven (LGN) is described, which demonstrates that the key features of biomaterials serve as candidates for oral tissue regeneration. LGN supports proper tissue formation and obeys the important principles for molecular mechanotransduction. Furthermore, current biomaterial-based tissue regeneration trends, including polymer modifications, cell-based treatments, antimicrobial peptides and optogenetics, are introduced to represent the full spectrum of current approaches to oral disease mitigation and prevention. Altogether, this review is a foray through established and new concepts in oral regenerative medicine and illustrates the process of knowledge translation from basic molecular and cell biological research to future clinical applications.

Epigenetic Deregulation of Protein Tyrosine Kinase 6 Promotes Carcinogenesis of Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) accounts for over 90% of oral cancers and causes considerable morbidity and mortality. Epigenetic deregulation is a common mechanism underlying carcinogenesis. DNA methylation deregulation is the epigenetic change observed during the transformation of normal cells to precancerous and eventually cancer cells. This study investigated the DNA methylation patterns of PTK6 during the development of OSCC. Bisulfite genomic DNA sequencing was performed to determine the PTK6 methylation level. OSCC animal models were established to examine changes in PTK6 expression in the different stages of OSCC development. The DNA methylation of PTK6 was decreased during the development of OSCC. The mRNA and protein expression of PTK6 was increased in OSCC cell lines compared with human normal oral keratinocytes. In mice, the methylation level of PTK6 decreased after treatment with 4-nitroquinoline 1-oxide and arecoline, and the mRNA and protein expression of PTK6 was increased. PTK6 hypomethylation can be a diagnostic marker of OSCC. Upregulation of PTK6 promoted the proliferation, migration, and invasion of OSCC cells. PTK6 promoted carcinogenesis and metastasis by increasing STAT3 phosphorylation and ZEB1 expression. The epigenetic deregulation of PTK6 can serve as a biomarker for the early detection of OSCC and as a treatment target.

Oral squamous cell carcinoma – clinical characteristics, treatment, and outcomes in a single institution retrospective cohort study

<b>Introduction:</b> Squamous cell carcinoma (SCC) is a common malignancy with high morbidity and mortality. </br></br> <b>Aim:</b> The aim of this study was to analyze the data of patients treated for malignant tumours of the oral cavity at the Department of Otolaryngology, Head and Neck Surgery, and Laryngological Oncology Ludwik Rydygier Collegium Medicum in Bydgoszcz between 2003–2011 to asses the influence of risk factors on survival in patients with squamous cell carcinoma of the oral cavity. </br></br> <b> Material and methods:</b> Material was collected from 62 patients treated for oral SCC between 2003–2011. Forty-three were men (69.35%) with a mean age of 56.33 years. The medical records were analysed, especially history, operative reports, histopathology reports, survival, adjuvant treatment and recurrence. </br></br> <b>Results:</b> All patients underwent surgical treatment (33.87% also had partial removal of the lower jaw, 67.74% adjuvant radio-therapy, 11.29% radiochemotherapy). More than half reported to the doctor within 6 to 15 weeks from the onset of symptoms. The majority smoked and drank alcohol (96.32%). Five-year disease specific survival (DSS) was 68.69%. </br></br> <b>Conclusions:</b> The age over 65 did not significantly influence DSS. The location on the anterior two thirds of the tongue gave the best outcome, while the worst outcome was observed in the retromandibular triangle area which was statistically almost significant (p = 0.06843). In the case of higher degrees of local and regional advancement and a higher stadium, a worse out-come was recorded. Positive surgical margins were identified in 11.29% of the cases, but they had no impact on the results of treatment. No worsening of the outcome was proven for the patients who reported to the doctor later than 15 weeks following the occurrence of symptoms.

Micro-RNA Regulation on Oct4 Gene Expression and Functional Differentiation in Skin Cancer Cells

Micro-RNA has a very important role in gene regulation. The stem gene Oct4 is related with the growth, mobility, and infiltration of skin cancer cells. Studying the regulatory mechanism of micro-RNAs of Oct4 in skin cancer cells is of important clinical significance. Oct4 gene was analyzed using bioinformatics methods to find mir-RNA with regulatory functions. mir-RNA high-expression vector and suppression vector with pcDNA3.1-EGFP was transfected to skin cancer cell line HS-4 followed analysis of Oct4 expression 24 h and 48 h after transfection and transwell in-vitro cell invasion assay. Bioinformatics showed that mir-335 has relationship with the Oct4 gene. pcDNA3.1-EGFP-335-up and pcDNA3.1-EGFP-335-down were successfully constructed. 24 and 48 hours after transfection, the Oct4 expression in the high-expression group was gradually and significantly decreased (P < 0.05). Meanwhile, the cell migration and infiltration capacity was decreased significantly and showed time dependence with significant differences between groups (P < 0.05). mir-335 expression in suppression group was reduced without change of Oct4 (P > 0.05). Increased mir-335 can decrease the performance of Oct4 in skin cancer cells and inhibit the infiltration ability of cells without affecting cell infiltration capability.

TNFα Signaling Is Increased in Progressing Oral Potentially Malignant Disorders and Regulates Malignant Transformation in an Oral Carcinogenesis Model

Oral carcinogenesis represents a multi-stage process which encompasses several genetic and molecular changes that promote the progression of oral potentially malignant disorders (OPMDs) to oral squamous cell carcinomas (OSCCs). A better understanding of critical pathways governing the progression of OMPDs to OSCCs is critical to improve oncologic outcomes in the future. Previous studies have identified an important role of tumor necrosis factor α (TNFα) and TNF receptor 1 (TNFR1) in the invasiveness of oral cancer cell lines. Here, we investigate the expression of TNFα and TNFR1 in human OPMDs that progress to OSCC compared to non-progressing OPMDs utilizing fluorescent immunohistochemistry (FIHC) to show increased TNFα/TNFR1 expression in progressing OPMDs. In order to interrogate the TNFα/TNFR1 signaling pathway, we utilized a 4-nitroquinoline 1-oxide (4-NQO) mouse model of oral carcinogenesis to demonstrate that TNFα/TNFR1 expression is upregulated in 4-NQO-induced OSCCs. TNFα neutralization decreased serum cytokines, inhibited the development of invasive lesions and reduced tumor-associated neutrophils in vivo. Combined, this data supports the role of TNFα in oral malignant transformation, suggesting that critical immunoregulatory events occur downstream of TNFR1 leading to malignant transformation. Our results advance the understanding of the mechanisms governing OSCC invasion and may serve as a basis for alternative diagnostic and therapeutic approaches to OPMDs and OSCC management.

Nigella sativa extract kills pre-malignant and malignant oral squamous cell carcinoma cells

In this study, the potential of Nigella sativa was evaluated in the management of oral cancer through assays designed to mimic conditions expected when chewing the whole seeds or use of a seed extract. For this purpose, a water-based extract of N. sativa seeds was prepared, mimicking the chewing process. This extract demonstrated significant cytotoxic effect on oral cancer and pre-cancerous leukoplakia cells in vitro at a much lower concentration than the predicted oral concentration that could be achieved upon seed chewing. When the active constituent(s) in this water-based N. sativa seed extract, was explored significant quantities of the compound α-hederin was detected but only modest quantities of thymoquinone suggesting that thymoquinone is not fully released into the aqueous medium during the chewing process. While the N. sativa seed extract induced a different effect on the cells than that of pure thymoquinone, α-hederin alone induced a very similar effect on the cells to that of the extract. These results suggest that α-hederin and not thymoquinone, is the major component of the seed that is responsible for the inhibitory effect observed in vitro. Therefore, chewing N. sativa whole seeds or applying a concentrated extract on the oral lesions may be an inexpensive, widely available, and effective option for patients at risk of developing oral cancer who are receiving no other preventive treatment.

NOTCH1 mutations as prognostic marker in oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is the most common malignancy of the oral cavity with poor prognosis. The dysregulation of Notch signaling pathway has been implicated in the OSCC tumorigenesis. However, the clinical implication of NOTCH1 mutation status in OSCC remains unelucidated. We extracted the NOTCH1 gene mutations from a whole exome sequencing dataset of 168 frozen OSCC tumor specimens and validated these NOTCH1 gene mutations by Sanger sequencing. We also assessed these NOTCH1 gene mutations and its pathological significance in our OSCC tumor tissues using immunohistochemistry. Univariate and multivariate analyses were also used to determine whether the association between NOTCH1 mutation status and prognostic factors was independent of other parameters. In this study, we have identified 44 (26.19 %) NOTCH1 gene mutations from a whole-exome sequencing of 168 OSCC formalin-fixed, paraffin-embedded (FFPE) tissue specimen. These mutations distributed in different NOTCH1 function domains, including the EGF-like repeats region, negative regulatory region, and Ankyrin repeats region. The immunohistochemical staining analysis revealed that NOTCH1 expression was increased in oral cancer tissues. In addition, of the 43 OSCC tumors with NOTCH1 mutations, we observed that the majority were negative for NOTCH1 intracellular domain 1 (NICD1) staining (76.74 %), and 10 tumors were positive for NICD1 staining (23.26 %). In conclusion, our study suggested that NOTCH1 expression is associated with the progression of OSCC. We also demonstrated that presence of a mutated NOTCH1 gene will help prognostic stratification in OSCC when combined with other clinicopathologic parameters.

Role of Interleukin-10 Promoter Polymorphisms in Oral Cancer Susceptibility: A Meta-Analysis

Role of interleukin-10 (IL-10) promoter polymorphisms in the risk of oral cancer (OC) remains controversial. The present study aimed to explore the relation between IL10 promoter polymorphisms and the progression of oral cancer by performing meta-analysis. Seven studies with a total of 2141 controls and 1928 cases were included in our analysis. Overall results showed significant associations between IL-10-1082A/G gene polymorphism and OC susceptibility under all five models. However, OC was not significantly related to the IL-10-592A/C or -819 T/C polymorphism (p > 0.05).

Comprehending the crosstalk between Notch, Wnt and Hedgehog signaling pathways in oral squamous cell carcinoma - clinical implications

BACKGROUND

Oral squamous cell carcinoma (OSCC) is a malignant oral cavity neoplasm that affects many people, especially in developing countries. Despite several advances that have been made in diagnosis and treatment, the morbidity and mortality rates due to OSCC remain high. Accumulating evidence indicates that aberrant activation of cellular signaling pathways, such as the Notch, Wnt and Hedgehog pathways, occurs during the development and metastasis of OSCC. In this review, we have articulated the roles of the Notch, Wnt and Hedgehog signaling pathways in OSCC and their crosstalk during tumor development and progression. We have also examined possible interactions and associations between these pathways and treatment regimens that could be employed to effectively tackle OSCC and/or prevent its recurrence.

CONCLUSIONS

Activation of the Notch signaling pathway upregulates the expression of several genes, including c-Myc, β-catenin, NF-κB and Shh. Associations between the Notch signaling pathway and other pathways have been shown to enhance OSCC tumor aggressiveness. Crosstalk between these pathways supports the maintenance of cancer stem cells (CSCs) and regulates OSCC cell motility. Thus, application of compounds that block these pathways may be a valid strategy to treat OSCC. Such compounds have already been employed in other types of cancer and could be repurposed for OSCC.

Comparative analysis of the impact of e-cigarette vapor and cigarette smoke on human gingival fibroblasts

Human gingival fibroblasts (HGF) play a vital role in wound healing, oral cancer, and are among the first cells being exposed to e-cigarette vapor (eCV) or cigarette smoke (CS) during inhalation. Although the cell-damaging effect of CS has been well studied, the effects of eCV on gingival cells are still unclear. The aim of this in vitro study was to compare the effects of eCV and CS on HGF in terms of proliferation, metabolic activity, cell death, and formation of reactive oxygen species (ROS). After 24 h cell numbers in CS-exposed cells in contrast to eCV-exposed cells were significantly decreased compared to the control. At later points in time, such differences could no longer be observed. Compared to the control, HGF stimulated with eCV showed a significantly higher metabolic activity 1 h, 24 h, and 48 h after exposure. 24 h after exposure, the metabolic activity was increased in both test groups. No caspase 3/7 activation nor significant differences in the amount of apoptosis/necrosis among the groups were seen. Only in CS-exposed cells ROS formation was increased at 1 h, 3 h, and 6 h after exposition. In conclusion, when compared to conventional CS, a less harmful effect of eCV on HGF can be assumed.

KCNQ1OT1 promotes migration and inhibits apoptosis by modulating miR-185-5p/Rab14 axis in oral squamous cell carcinoma

Long non-coding RNAs (lncRNAs) play essential roles in the regulation of gene transcription in carcinogenesis and metastasis via interacting with microRNA. In this study, we explored the expressions and functions of lncRNA KCNQ1OT1 and miR-185-5p in oral squamous cell carcinoma (OSCC) cells. KCNQ1OT1 expression in OSCC tissues and cells was examined by qRT-PCR. Small interfering RNAs against KCNQ1OT1 (si- KCNQ1OT1) were used to knockdown KCNQ1OT1 in OSCC cells. Cell function was assessed by wound healing assay, transwell assay, and apoptosis detection. The binding region between KCNQ1OT1 and miR-185-5p was confirmed by luciferase assays. MiR-185-5p expression was measured by qRT-PCR. Rab14 was confirmed as a downstream target gene of miR-185-5p by measuring luciferase activities. The protein level of Rab14 in OSCC cells transfected with miR-185-5p or si-KCNQ1OT1 was determined by Western blot. The OSCC cell function and Rab14 expression after co-transfection of si-KCNQ1OT1 and miR-185-5p inhibitor were also examined. KCNQ1OT1 was upregulated in OSCC tissues and cells. KCNQ1OT1 silencing suppressed OSCC cell malignancy and downregulated miR-185-5p level, which showed upregulated expression in OSCC samples. Rab14 as a target gene of miR-185-5p was highly expressed in OSCC. KCNQ1OT1 knockdown impaired the invasion capability of OSCC cells, promoted apoptosis, and suppressed Rab14 expression. The inhibition of miR-185-5p in KCNQ1OT1 silencing cells reversed the suppression of Rab14 and restored the cancerous growth of OSCC cells. These results indicated that KCNQ1OT1 promoted OSCC tumorigenesis via the modulation of miR-185-5p/Rab14 axis, which may serve as a therapeutic target for the treatment of OSCC.

CXCL12 is associated with FoxP3+ tumor-infiltrating lymphocytes and affects the survival of patients with oral squamous cell carcinoma

The role of tumor-infiltrating lymphocytes (TILs) suggests that cancer is a disease with not only a genetic, but also an immunological basis. Additionally, immune cell infiltration is an important feature of oral cancer. C-X-C motif chemokine ligand 12 (CXCL12) serves an important role in immune suppression in the tumor microenvironment. Therefore, the present study investigated how CXCL12 expression in oral squamous cell carcinoma (OSCC) was associated with clinicopathological parameters and TILs distribution. Complete CXCL12, TIL and clinical data were available for 45 patients with oral cancer treated by surgery. Expression levels of CXCL12, CD8⁺ TILs and forkhead box P3 (FoxP3⁺) TILs were assessed by immunohistochemistry in OSCC samples. CXCL12 expression in OSCC cells was observed in 32 (68.9%) cases and was associated with poor differentiation (P=0.045), advanced stages (P<0.001), tumor recurrence (P=0.011), poor overall survival (P=0.0476) and a higher density of FoxP3⁺ TILs (P<0.001). The CD8⁺/FoxP3⁺ ratio was lower in patients with poor differentiation (P=0.034), advanced stage tumors (P=0.015) and tumor recurrence (P=0.002). In addition, the ratio of CD8⁺/FoxP3⁺ TILs was significantly associated with the 5-year overall survival rate (P<0.001). The CD8⁺/FoxP3⁺ ratio was indicated to be a stronger prognostic indicator compared with the density of FoxP3⁺ TILs or CD8⁺ TILs. The present study identified an association between increased CXCL12 expression and FoxP3⁺ cell infiltration in OSCC. Targeting the CXCL12/C-X-C motif chemokine receptor 4 axis in OSCC may be employed as a novel strategy of tumor immunotherapy in the future.

Tobacco and oral squamous cell carcinoma: A review of carcinogenic pathways

INTRODUCTION

Tobacco is one of the most important risk factors for premature death globally. More than 60 toxic chemicals in tobacco can invade the body’s various systems. Oral squamous cell carcinoma (OSCC) is a pathological type of oral cancer, accounting for over 90% of oral cancers. A vast quantity of scientific, clinical and epidemiological data shows that tobacco is associated with the development of oral squamous cell carcinoma, and its carcinogenic pathways may be complicated.

METHODS

We conducted a thorough electronic search by Cochrane, EMBASE and PubMed to identify relevant studies. Studies published up to the end of October 2018 were included. After assessing and selecting articles based on eligibility criteria, studies were classified and elaborated according to the pathogenesis.

RESULTS

Tobacco as an important risk factor can cause epigenetic alteration of oral epithelial cells, inhibit multiple systemic immune functions of the host, and its toxic metabolites can cause oxidative stress on tissues and induce OSCC. In addition, some specific viruses such as EBV and HPV are thought to play a role in the development of OSCC.

CONCLUSIONS

Oral cancer ranks eighth among the most common causes of cancer-related deaths worldwide, and tobacco is one the most important carcinogenic factors of OSCC. This review of the literature attempts to provide directions and ideas for future related research, and emphasizes the need for efforts to reduce tobacco consumption.

Association Between Matrix Metalloproteinase-1, 2, 3 Polymorphisms and Oral Cancer Risk: A Meta-Analysis

PURPOSE

Numerous studies have estimated the association between matrix metalloproteinases (MMPs) polymorphisms and the risk of oral cancer; the results, however, are inconsistent and conflicting. Therefore, we conducted a meta-analysis to evaluate the association of MMP-1, 2, and 3 polymorphisms with oral cancer risk.

METHODS

A computerized literature search was conducted of electronic databases and search engines. Odds ratios (OR) and 95% confidence intervals (CI) were calculated for each gene, and the heterogeneity among studies was estimated using the Q-test and I² values. Overall and subgroup analyses were undertaken. Statistical analyses were conducted using Review Manager v5.3 and Stata v12.0 software.

RESULTS

Eighteen studies were included in this meta-analysis. For MMP-1(-1607) 1G/2G, a significant association was observed using the recessive genetic model (OR = 1.47; 95% CI = 1.14-1.91; I² = 64%, p_{heterogeneity} = 0.003). In the subgroup studies, a significant association was observed in the Asian subgroup (OR = 1.68; 95% CI = 1.42-1.99; I² = 17%, p_{heterogeneity} = 0.30 for the recessive model; and OR = 1.59; 95% CI = 1.19-2.13; I² = 80%, p_{heterogeneity} < 0.00001 for the allelic contrast model) and in the European subgroup (OR = 0.65; 95% CI = 0.44-0.98; I² = 21%, p_{heterogeneity} = 0.26 for the allelic contrast model). No significant associations were observed with either MMP-2(-1306) C/T or MMP-3(-1171) 5A/6A.

CONCLUSIONS

The MMP-1(-1607) 1G/2G polymorphism is associated with oral cancer risk, and the 2G allele played different roles in Asian and European populations.

The localization and risk factors of squamous cell carcinoma in the oral cavity: A retrospective study of 1501 cases

Head and neck cancer is the tenth leading cause of cancer mortality. Ninety percent of tumours in the oral cavity are squamous cell carcinomas. Information about the exact localisation of OSCC is missing in the literature. In the present study, we retrospectively analysed a total of 1501 OSCC patients, who were treated between 1975 and 2009. The purpose of this study was to examine the localisation of OSCC tumours and to analyse the influence of various parameters on tumour localisation. 71.5% of these patients were male and 28.5% were female. The mean age was 60 years. The most common sites of OSCC occurrence were the floor of the mouth and the anterior base of the mouth. The hard palate was the most affected anatomical area of the maxilla. Descriptive statistical analysis, chi-square testing and a multivariate analysis using a multinomial logistical model showed a significant correlation of younger age and female gender with tumour occurrence in the maxilla and the tongue. We provide a very detailed anatomical mapping of OSCC.

Associated factors with oral cancer: a study of case control in a population of the Brazil's Northeast

OBJECTIVE

This study aimed at assessing the association between factors such as age, sex, skin color, occupation, educational level, marital status, place of residence, and tobacco and alcohol consumptions and oral cancer in individuals in a city in the northeast of Brazil between 2002 and 2012.

METHODS

This is a case-control study. The case group consisted of 127 people attended at the Oral Injury Reference Center with histopathological diagnosis of oral squamous cell carcinoma. The control group consisted of 254 individuals treated at the same center. The study considered two controls for each case. The cases and controls were adjusted according to sex and age. Univariate and bivariate analyses were performed (Pearson χ2-test) to verify the correlation between the dependent variable (oral cancer) and the independent variables; odds ratio (OR) and the confidence interval of 95% (95%CI) were calculated. Finally, in the multivariate analysis, it was used as the hierarchical model with logistic regression to explain the interrelationships between the independent variables and oral cancer.

RESULTS

Consumption of more than 20 cigarettes per day [OR = 6.64; 95%CI 2.07 - 21.32; p ≤ 0.001], an excessive alcohol consumption [OR = 3.25; 95%CI 1.03 - 10.22; p ≤ 0.044], and the synergistic consumption of tobacco and alcohol [OR = 9.65; 95%CI 1.57 - 59.08; p ≤ 0.014] are the most important risk factors for oral cancer.

CONCLUSION

It was concluded that tobacco and alcohol consumptions are the most important factors for the development of oral cancer. Sociodemographic factors were not associated with this neoplasm after adjusting for smoking and drinking.

Clinical relevance of the utilization of vital Lugol's iodine staining in detection and diagnosis of oral cancer and dysplasia

OBJECTIVES

The aim of this study is to assess the clinical relevance of the utilization of vital Lugol's iodine staining in detection of oral cancer and dysplastic lesions as well as demarcation of the extent of these lesions.

MATERIALS AND METHODS

A prospective, cross-sectional, hospital-based study was performed in Khartoum Teaching Dental Hospital, Sudan. Suspicious oral epithelial lesions indicating incisional biopsy were stained with 10 % Lugol's iodine solution and were clinically designated as "negative" for dysplasia or neoplasia when no unstained lesion (USL) area was observed, or as "positive" when a USL area is observed. Incisional biopsies involving both the unstained portion and the stained portion were obtained and histologically evaluated for definitive diagnosis.

RESULTS

Forty-five biopsies were obtained from 28 patients. Histopathological examination of the specimens confirmed some degree of dysplasia or neoplasia in all clinically positive specimens with oral squamous cell carcinoma (OSCC) being the most common definitive diagnosis (17 patients, 60.7 %). Clinical relevance level of vital Lugol's iodine staining in detecting oral cancer and dysplasia was found to be 90.9 % (SE = 0.05, P = 0.05).

CONCLUSION

The findings of this study showed that Lugol's iodine is an easy, safe, and effective method of visualizing oral epithelial lesions and differentiating epithelial carcinoma and dysplasia from other benign mucosal lesions. Despite certain limitations, its use is of great value in detection and diagnosis of oral cancer and dysplasia.

CLINICAL RELEVANCE

Lugol's iodine staining can effectively be used in detection of the dysplastic and malignant superficial lesions of the oral epithelium.

Antioxidant enzymes in oral verrucous carcinoma

BACKGROUND

Verrucous carcinoma is a non-metastasizing variant of welldifferentiated squamous cell carcinoma, which has been associated with reactive oxygen species generated by betel quid chewing. Salivary antioxidant systems have been suggested to play a protective role in reducing the oxidative damage. Herein, we investigated the difference of the enzymatic antioxidant system expressions in oral verrucous carcinoma and oral squamous cell carcinoma.

METHODS

The enzymatic antioxidant system expressions, including manganese superoxide dismutase, glutathione peroxidase, and catalase were evaluated by immunohistochemistry in a series of 202 surgically resected oral squamous cell carcinoma and 20 oral verrucous carcinoma specimens, using tissue microarray slides.

RESULTS

The immuno-staining intensities of superoxide dismutase and glutathione peroxidase were strongest in the oral squamous cell carcinoma group than in verrucous carcinoma. The catalase expression showed no difference between different pathological groups.

CONCLUSIONS

The different degrees of superoxide dismutase and glutathione expressions in verrucous carcinoma and squamous cell carcinoma may be helpful for pathologists to differentiate these two entities, especially between oral verrucous carcinoma and well differentiated oral squamous cell carcinoma.

Expression of p53, p21(CIP1/WAF1) and eIF4E in the adjacent tissues of oral squamous cell carcinoma: establishing the molecular boundary and a cancer progression model

The present study evaluated the expression of key molecules and the status of DNA in both oral squamous cell carcinoma (OSCC) and adjacent tissues to establish a molecular surgical boundary and provide a cancer progression model. Biopsy samples from 50 OSCC patients were divided into T (cancer), P1 (0–0.5 cm), P2 (0.5–1 cm), P3 (1–1.5 cm) and P4 (1.5–2 cm) groups based on the distances from the visible boundary of the primary focus. Twenty samples of normal mucosa were used as controls. We used immunohistochemical staining and flow cytometry to evaluate p53, p21^CIP1/WAF1, eIF4E and Ki-67 expression and to determine DNA status, respectively. Sub-mucosal invasion was present in the P1 and P2 groups as determined by haematoxylin and eosin staining. Mutant p53 expression decreased gradually from cancerous to normal mucosae, whereas p21^CIP1/WAF1 expression displayed an opposite trend. eIF4E expression decreased from cancerous to normal mucosae. Ki-67 expression, the heteroploidy ratio, S-phase fraction and proliferative index decreased gradually with the distance from the tumour centre. Based on these results, we suggest that the resection boundary in OSCC surgery should be beyond 2 cm from the tumour. Additionally, the adjacent tissues of the primary focus could be used as a model for assessing cancer progression.

The illness experience of middle-aged men with oral cancer

AIMS AND OBJECTIVES

To explore the essence of the illness experiences of middle-aged men with oral cancer.

BACKGROUND

Having oral cancer creates great challenges in the lives of middle-aged men and their families. Understanding patients' experiences provides a sound basis for patient-centred and individualised care. Research is limited regarding the illness experience of middle-aged men with oral cancer with regard to facing both the invasion of disease and the responsibilities of middle age.

DESIGN

A phenomenology approach was used.

METHODS

Nine men diagnosed with oral cancer within one year were recruited during 2009 and 2010. Data were collected through individual in-depth interviews and analysed using Colaizzi's phenomenological analysis procedures.

RESULTS

The following five themes emerged from the patterns of categorised interview data: the psychological journey in facing oral cancer, the question of how patients can control their disease as well as the sequelae of cancer treatment, the continuous disturbance and turmoil resulting from the disease, the appreciation of the support from family and friends, and the ability to learn to actively face the future.

CONCLUSIONS

Patients with oral cancer experienced tremendous physical, psychosocial and financial challenges. Although burdened with multiple stressors, these middle-aged men were able to learn from their experiences and exhibit positive growth in life.

RELEVANCE TO CLINICAL PRACTICE

Patients with oral cancer have to constantly adjust to the impact of their disease. The study results may serve as a reference for improving clinical practice and the quality of care among patients with oral cancer. Cancer care is multidimensional and holistic. Healthcare professionals should develop a set of plans by which patients receive complete medical care and support, as well as assistance from professionals and family members, as their treatment progresses to help patients face the challenges of cancer.

Percepção dos profissionais quanto à pertinência dos indicadores de saúde bucal em uma metrópole do Nordeste brasileiro

Estudo exploratório-descritivo, com abordagem quali-quantitativa, que buscou analisar a percepção dos profissionais quanto à pertinência dos indicadores de saúde bucal do Programa Nacional de Melhoria do Acesso e da Qualidade da Atenção Básica (PMAQ-AB) em Fortaleza, Ceará. A desmotivação, a descontinuidade no fornecimento de insumos odontológicos, o abandono do tratamento por parte do paciente, a cultura popular de que a gestante não pode realizar tratamento odontológico e a insegurança do profissional no manejo clínico relacionado à prótese dentária, ao atendimento à gestante, ao atendimento à urgência odontológica e ao diagnóstico de alteração da mucosa oral dos usuários foram problemas identificados na operacionalização desses indicadores e mencionados como interferência para o cumprimento de suas metas.

Comparative Studies of Salivary and Blood Sialic Acid, Lipid Peroxidation and Antioxidative Status in Oral Squamous Cell Carcinoma (OSCC)

Objective: Oral squamous cell carcinoma (OSCC) is considered to be a serious life threatening issue for almost two decades. The objective of this study was to evaluate the over production of lipid peroxidation (LPO) byproducts and disturbances in antioxidant defense system in the pathogenesis of oral cancer.

Methods: Lipid peroxidation and antioxidant status in OSCC patients were estimated and compared the sensitivity and specificity of circulating biomarkers (MDA, Sialic acid, Catalase, SOD, GSH and Neuraminidase) with β-2 microglobulin (β-2MG) at different thresholds in blood and saliva using receiver operating characteristics (ROC) curve design.

Results: Our results showed that the levels of MDA and Sialic acid were significantly increased in plasma of OSCC patients as compared to healthy subjects whereas antioxidant level was significantly decreased.

Conclusion: ROC analysis indicated that MDA in saliva is a better diagnostic tool as compared to MDA in blood and β-2MG in blood is better diagnostic marker as compared to β-2MG level in saliva.

Review of the complications associated with treatment of oropharyngeal cancer: a guide for the dental practitioner

OBJECTIVES

Oropharyngeal cancer (OPC) is the sixth most common cancer worldwide. Focus on risk factors, improved diagnostic methods and effective management strategies have made it possible to successfully treat OPC. However, the 5-year survival rate has not improved for several years due to multiple treatment complications, tissue morbidity, loss of function, and diminished quality of life. Survivors are faced with complications like oral mucositis, hyposalivation, osteoradionecrosis, tissue fibrosis, morbidity from jaw resection, disfigurement, and loss of function that further diminish quality of life. The aim of this review is to highlight major complications associated with treatment of OPC via a literature search and review of available options for identification and management of these complications.

DATA SOURCES

Relevant publications on oral complications of OPC therapy were thoroughly reviewed from the literature published between the years 1988 and 2012. We evaluated reported incidence, prevalence, and risk factors for oral complications of chemotherapy and radiotherapy for OPC. The authors conducted an electronic search using English language databases, namely PubMed Plus, Medline (Pre-Medline and Medline), Cochrane Database of Systematic Reviews (evidence-based medicine), Dentistry & Oral Sciences Source, A ccessScience, Embase, Evidence-Based Medicine Reviews Multifile, Google Scholar, ISI Journal Citation Reports, and Ovid Multi-Database.

CONCLUSION

We identified the most common complications associated with the treatment of oral cancers. Based on the information gathered, there is evidence that survival of OPC extends beyond eradication of the diseased tissue. Understanding the potential treatment complications and utilizing available resources to prevent and minimize them are important. Caring for OPC survivors should be a multidisciplinary team approach involving the dentist, oncologist, internist, and social worker to improve the currently stagnant 5-year survival rate of OPC. More emphasis on improved quality of life after elimination of the cancer will ultimately improve OPC survivorship.

Thymoquinone induces apoptosis in oral cancer cells through p38β inhibition

Oral cancer is a common malignancy associated with high morbidity and mortality. While p38 MAPK is reported to be involved in different cellular activities such as proliferation and differentiation, reports rarely define the roles of the individual members of the p38 MAPK family in cancer. We used two unique cell lines developed by our lab representing chemically induced oral cancer cells (T28) and non-tumor cells (N28) obtained from tissues surrounding the induced cancer as a model to screen out whether p38 MAPK is involved in the malignant transformation processes. The results suggest an association between p38β not p38α and oral cancer development. Additionally, the anti-cancer activity of thymoquinone (TQ) was screened out and we found evidences suggesting that the anti-tumor activity of TQ may be attributed to the downregulation of p38β MAPK.

Vascular endothelial growth factor 936 c>T polymorphism increased oral cancer risk: evidence from a meta-analysis

AIM

The vascular endothelial growth factor (VEGF) plays a major role in angiogenesis. The association between VEGF 936 C>T (rs3025039) gene polymorphisms and oral cancer (OC) risk is still contentious and ambiguous. To assess the relationship between the VEGF 936 C>T genotype and the risk of developing OC, we performed a meta-analysis to summarize the possible association.

METHODOLOGY

We assessed published studies of the association between 936 C>T polymorphisms and OC risk from four studies with 440 controls and 556 OC cases. We calculated pooled odds ratios (ORs) and 95% confidence interval (CI), considering the frequency of allele, homozygous, heterozygous genotypes and comparison of dominant and recessive genetic models.

RESULTS

The combined results showed that the T allele was significantly associated with increased OC risk (T vs. C: p=0.001; OR=1.521, 95% CI=1.194-1.938). The heterozygous genotype CT had a 1.5-fold increased risk (CT vs. CC: p=0.002; OR=1.582, 95% CI=1.184-2.114). In addition the dominant genetic model demonstrated a 1.6-fold increased risk of developing OC (TT+CT vs. CC: p=0.001; OR=1.621, 95% CI=1.226-2.143).

CONCLUSION

Our results suggest that the VEGF gene polymorphism (936 C>T) contributes increased susceptibility to OC. However, larger studies with a stratified case-control population and biological characterization are needed to validate this finding.

Simulation for training in oral cancer biopsy: a surgical model and feedback from GDPs

Objectives: To describe a new bench model for oral precancer/cancer biopsy training and to assess its effectiveness in terms of trainees’ perception. Study design: Cross-sectional, descriptive, performed on 424 general dental practitioners (GDP) who undertook biopsies on a pig tongue. The participants were assessed by direct observation for 2.5 hours using specific check-lists and by means of a self-applied questionnaire. Results: The workshop was perceived as “very interesting” even by those with previous surgical experience (Xi - Xj = 0.07; 95%CI= -0.20-0.09). Most GDPs considered themselves able to undertake oral biopsies on real patients after the workshop. Those who had previously received theoretical continuous education courses on oral biopsy scored higher values within the group (Xi - Xj = 0.20; 95%CI= 0.04-0.37). Conclusions: There is a need for including clinical abilities workshops when instructing on oral biopsy techniques. More studies are needed to validate the procedure and to address cognitive and communication skills.

Key words:Models, animal, education, dental, continuing, biopsy, oral cancer, oral surgical procedures.

[Smokeless tobacco]

Use of smokeless tobacco (ST) (chewing tobacco and snuff) can lead to a number of consequences detrimental to health. ST rapidly delivers high doses of nicotine, which can lead to dependence and is also a source of carcinogenic nitrosamines. Changes usually develop in the mouth area where the ST is most often placed. Non-malignant oral lesions include leuko-oedema, hyperkeratotic lesions of the oral mucosa and localised periodontal disease. Oral premalignant lesions are leukoplakia, erythroplakia, submucosal fibrosis and lichen planus. Betel chewing, with or without tobacco, may increase the incidence of oral cancer. There is conflicting evidence with regard to snuff users about the risk of oral and gastro-oesophageal cancer. ST use is a risk factor for pancreatic cancer and may increase the risk of fatal myocardial infarction and ischemic stroke. During pregnancy, ST is associated with an increase in pre-eclampsia, preterm delivery and stillbirth. Nicotine replacement therapy and bupropion reduce withdrawal symptoms and tobacco craving during ST cessation. However, they have not been shown to help long-term abstinence. Information concerning the potential hazards of ST products should be incorporated into educational programmes to discourage its use and to help users to quit. Smokeless tobacco is not recommended to help smoking cessation.

The changing trends in tobacco smoking for young Arab women; narghile, an old habit with a liberal attitude

Narghile smoking by young females is becoming more acceptable than cigarettes in the conservative societies of Arab countries. Lack of social constraints on narghile smoking has resulted in an increased prevalence of narghile smoking among young Arab females and an earlier age of onset of this habit when compared to cigarette smoking.

Documented health hazards of narghile smoking including pulmonary, cardiovascular and neoplastic ailments are consequently expected to affect this vulnerable sector of the population together with their offspring. In this commentary, we shed some light on the changing trend of tobacco use among young Arabic women as shown by an increasing number of studies investigating habits of tobacco use in young people.

Proliferative activity and diagnostic delay in oral cancer

BACKGROUND

Tumor stage may relate to the chronology of neoplasm growth and has been used as an outcome variable when studying diagnostic delay in oral cancer. However, tumor growth rate may act as a confounding factor.

METHODS

We reviewed a total of 63 incident cases of oral cancer. The variables considered for the study included age, sex, smoking history, tumor site, TNM stage, Ki-67 score, and diagnostic delay.

RESULTS

Significant differences between survivors and exitus were found in terms of tumor stage at diagnosis (I-II vs III-IV), sex, and Ki-67 scores. When the analysis was adjusted for tumor stage at diagnosis (I-II vs III-IV), proliferative activity resulted to be an independent prognostic factor for survival, whereas diagnostic delay did not influence survival.

CONCLUSION

These results seem to suggest that survival from oral cancer is affected more by the biology of the cancer (rapid tumor growth) than by diagnostic delay.

Outcome of oral tongue squamous cell carcinoma in patients with and without known risk factors

BACKGROUND

Tobacco smoking and high alcohol consumption are considered major risk factors of oral tongue squamous cell carcinoma. This study compared disease outcome between patients with and without known risk factors.

METHODS

Patients with oral tongue squamous cell carcinoma treated at two major medical centers from 1994 to 2008 were identified by cancer registry search. The medical files were reviewed for background-and-disease-related data, risk factors, and outcome.

RESULTS

The study sample consisted of 291 patients: 175 had a history of heavy tobacco smoking and alcohol abuse and 116 did not. Comparison of the patients without risk factors between the two centers yielded no differences in background features. Men accounted for 74% of the total patients with risk factors and comprised 77% of the risk-factor group. The risk-factor group was characterized by a significantly higher mean tumor grade (p=0.0001) and greater tumor depth of invasion (p=0.022) than the non-risk-factor group. The 5-year local and regional control rates were 85.3% and 74%, respectively, with no significant difference between the groups. The 5-year overall survival rate was 68% in the risk-factor group and 64% in the non-risk-factor group (p=NS). Separate analysis of patients aged <40 years at diagnosis revealed a worse overall (p=0.015) and disease-free survival (p=0.038) in those without risk factors.

CONCLUSIONS

The outcome of oral tongue carcinoma is similar in patients with and without risk factors. The worse prognosis in younger patients (<40 years) without risk factors suggests that the pathogenesis in these cases involves factors other than smoking and alcohol.

Oral cancer in Western Australia, 1982-2006: a retrospective epidemiological study

OBJECTIVE

To report differences and trends in oral cancer incidence by gender, age, indigenous status and area of residence and on mortality in Western Australia.

METHODS

Data were provided by Western Australian Cancer Registry. Oral cancer definition included ICD-O-3 codes C00C08. Age-specific, direct age-standardized rates and mortality:incidence ratios were computed with 95% confidence intervals.

RESULTS

The incidence and death rates of oral cancer accounted for 2.3% and 1.3% of all cancers respectively. Over 25 years, the male:female incidence ratio was 2.4:1. Eighty-eight percent of new cases were over the age of 40, peaking in the sixth decade of life. The incidence rates were 14.6 and 6.2 per 100,000 per annum in men and women respectively. Over 17 years, standardized mortality rates were less than 1 per 100,000 per year, with double the deaths in men. Mortality:incidence ratios for oral cancer were between 0.4 and 0.6 with the exception of lip.

CONCLUSIONS

Cancer registries are the only reliable source of data for epidemiologic surveillance of cancer incidence and mortality. Results from this study are comparable with studies on oral cancer in Australia and globally.

Early Diagnosis of Oral Cancer

Survival rates for oral cancer are very poor, at approximately 50% overall, and have not improved markedly in recent decades despite advances in therapeutic interventions. Detecting oral cancer at an early stage is believed to be the most effective means of reducing rates of death, morbidity and disfigurement from this disease. Tobacco and alcohol consumption and pre-malign lesions are the most common aetiological factors. The proportion of patients presenting with oral cancer at an advanced stage is troubling. Early diagnosis is the most effective way of reducing the individual burden of the disease, decreasing morbidity and mortality and improving quality of life. For early diagnosis, healthcare providers should perform oral cancer examinations as part of their patient care regime, and need to be knowledgeable about early signs of oral carcinoma. Oral cancer awareness among the public should also be improved.

Proteomic profiling of differential display analysis for human oral squamous cell carcinoma: 14-3-3 σ Protein is upregulated in human oral squamous cell carcinoma and dependent on the differentiation level

Oral squamous cell carcinoma (OSCC) has an absolute majority of all oral cancer. We used proteomic technology to analyze the protein expression profile in OSCC tissues and accompanying surrounding normal tissues in four oral locations (buccal mucosa, gingival mucosa, oral floor, and tongue). Ten protein spots were overexpressed more strongly in cancer tissues than normal ones, and were identified as proliferating cell nuclear antigen, 14-3-3 ε, 14-3-3 σ, proteasome subunit α type 5, translationally controlled tumor protein, eukaryotic translation initiation factor 3 subunit, macrophage capping protein, and mitochondrial isocitrate dehydrogenase subunit α. Macrophage capping protein and mitochondrial isocitrate dehydrogenase subunit α had two spots. Especially, we focused on 14-3-3 σ protein, one of the eight identified proteins, and assessed its expression level in four oral locations of OSCC by using differential display methods. The expression level of 14-3-3 σ protein was upregulated in four locations of oral cavity. Eight proteins which we identified in this study may play an important role in OSCC carcinogenesis and progression and could be used as diagnostic biomarkers of OSCC.