Oral cancer in the UK: to screen or not to screen

Differences among oral carcinomas arising de novo from those associated with oral potentially malignant disorders: a systematic review and meta-analysis

OBJECTIVE

To analyze the frequency of sequential oral squamous cell carcinomas (s-OSCC), preceded by oral potentially malignant disorders, and OSCC de novo (OSCC-dn) and explore differences in their clinicopathologic presentations.

STUDY DESIGN

A structured electronic search strategy identified studies that analyzed frequency, clinical, biological, demographic, biomarkers, and prognostic features of s-OSCC and OSCC-dn according to PRISMA guidelines in PubMed, Scopus, Cochrane Library, and Google Scholar, up to January 31, 2023. Inclusion criteria were original English, Spanish, Portuguese, French, Italian, and German cross-sectional, cohort, and case-control studies. The quality of studies was assessed using the Agency for Research and Health Quality tool and the Newcastle-Ottawa Scale tool.

RESULTS

The final selection included 40 studies. OSCC-dn and s-OSCC represent, respectively, 71% and 29% of cases of OSCC (P = .00), showing a higher percentage of T1 or of T1+T2 in s-OSCC (P < .0001). The association meta-analysis showed OSCC-dn with a significant association. The meta-analysis showed that s-OSCC was significantly associated with smaller tumor size, absence of distant metastases, relapses, male sex, and tumor sites different from tongue; and OSCC-dn was associated with more advanced tumor size, more regional and distant metastases, more advanced stages, and worse survival.

CONCLUSIONS

S-OSCC was less frequent than expected. OSCC-dn seems to have specific clinical, biological, and prognostic features. Future perspectives on oral cancer prevention should address novel approaches and alternatives to screening, such as urgent referral of OSCC-dn.

Systematic Review: Cardiac Metastasis of Lingual Squamous Cell Carcinoma

INTRODUCTION

Lingual squamous cell carcinoma (LSCC) is an aggressive malignancy that carries significant mortality risk and the potential for cardiac metastasis. The authors performed a systematic review designed to characterize disease progression of LSCC cardiac metastasis by evaluating patient demographics, characteristics, management, and clinical outcomes.

METHODS

Two authors independently screened articles in Embase, PubMed, and Cochrane Database of Systematic Reviews up until December 2019 for study eligibility. Demographic data, patient symptomatology, imaging findings, management strategies, and patient outcomes were obtained and analyzed. The Oxford Centre for Evidence Based Medicine (OCEBM) Levels of Evidence categorization was implemented to determine the quality of studies selected in this review.

RESULTS

From this review, a total of 28 studies met inclusion criteria and received an OCEBM Level 4 evidence designation. Thirty-one patients were identified with cardiac metastasis from LSCC. Shortness of breath (29.0%) and chest pain (29.0%) were the most common presenting symptoms, and pericardial effusion (29.2%) and right ventricular outflow tract obstruction (25.0%) were the predominant echocardiogram findings. Cardiac metastases most often presented in the right ventricle (56.7%), followed by the left ventricle (43.3%). Palliative intervention (68.2%) or chemotherapy (40.9%) were typically implemented as treatments. All sample patients expired within one year of metastatic cancer diagnosis in cases that reported mortality outcomes.

CONCLUSIONS

Patients presenting with shortness of breath, tachycardia, and a history of squamous cell carcinoma of the tongue may indicate evaluation for LSCC cardiac metastasis. Although LSCC cardiac metastases typically favor the right and left ventricles, they are not exclusive to these sites. Palliative care may be indicated as treatment due to high mortality and overall poor outcomes from current interventions.

Comparison of nomogram with machine learning techniques for prediction of overall survival in patients with tongue cancer

BACKGROUND

The prediction of overall survival in tongue cancer is important for planning of personalized care and patient counselling.

OBJECTIVES

This study compares the performance of a nomogram with a machine learning model to predict overall survival in tongue cancer. The nomogram and machine learning model were built using a large data set from the Surveillance, Epidemiology, and End Results (SEER) program database. The comparison is necessary to provide the clinicians with a comprehensive, practical, and most accurate assistive system to predict overall survival of this patient population.

METHODS

The data set used included the records of 7596 tongue cancer patients. The considered machine learning algorithms were logistic regression, support vector machine, Bayes point machine, boosted decision tree, decision forest, and decision jungle. These algorithms were mainly evaluated in terms of the areas under the receiver-operating characteristic (ROC) curve (AUC) and accuracy values. The performance of the algorithm that produced the best result was compared with a nomogram to predict overall survival in tongue cancer patients.

RESULTS

The boosted decision-tree algorithm outperformed other algorithms. When compared with a nomogram using external validation data, the boosted decision tree produced an accuracy of 88.7% while the nomogram showed an accuracy of 60.4%. In addition, it was found that age of patient, T stage, radiotherapy, and the surgical resection were the most prominent features with significant influence on the machine learning model's performance to predict overall survival.

CONCLUSION

The machine learning model provides more personalized and reliable prognostic information of tongue cancer than the nomogram. However, the level of transparency offered by the nomogram in estimating patients' outcomes seems more confident and strengthened the principle of shared decision making between the patient and clinician. Therefore, a combination of a nomogram - machine learning (NomoML) predictive model may help to improve care, provides information to patients, and facilitates the clinicians in making tongue cancer management-related decisions.

Identification and characterization of a highly metastatic epithelial cancer cell line from rat tongue cancer

OBJECTIVES

Tongue squamous cell carcinoma (TSCC) is a clinically devastating disease. However, most established TSCC cell lines currently show undesirable malignant behaviours. The purpose of this study is to establish a highly metastatic TSCC cell line to serve as a useful tool for basic research.

MATERIALS AND METHODS

TSCCs were induced by 4-nitroquinoline-1-oxide (4NQO) in Sprague-Dawley rats. Tumor cells were obtained from the cancer tissues by primary culture and were then purified by an in vitro invasion assay and a limiting dilution assay. The growth rate, cell cycle distribution, apoptotic rate, tumorigenicity and distant metastatic phenotypes of the rat tongue cancer cells were fully investigated and characterized.

RESULTS

To date, the rat tongue cancer cell line, named Rca-T, has been continuously cultured in vitro for over 210 passages and exhibit a long spindle-shaped morphology, adherent growth, and a stable epithelial phenotype. The population doubling time of Rca-T cells is 23.35 h. Approximately 39.8% of these cells are in S phase, and the apoptosis rate of Rca-T cells is 7.46%. Furthermore, in immunodeficient nude mice, both the xenograft rate and the incidence of experimental lung metastasis are 100%. The in vitro assays further reveal the highly malignant and epithelial-mesenchymal transition-like properties of Rca-T cells.

CONCLUSION

In this study, the tumorigenic and highly distant metastatic TSCC cell line Rca-T was established. The malignant features of this cell line, especially its metastatic potential, will enable a wealth of functional studies on the molecular mechanisms of TSCC metastasis in the future.

The Role of Adipokines in the Establishment and Progression of Head and Neck Neoplasms

Adipokines constitute a family of protein factors secreted by white adipose tissue (WAT), that regulate the functions of WAT and other sites. Leptin, adiponectin and resistin, are the main adipokines present in serum and saliva, targeting several tissues and organs, including vessels, muscles, liver and pancreas. Besides body mass regulation, adipokines affect glucose homeostasis, inflammation, angiogenesis, cell proliferation and apoptosis, and other crucial cell procedures. Their involvement in tumor formation and growth is well established and deregulation of adipokine and adipokine receptors' expression is observed in several malignancies including those located in the head and neck region. Intracellular effects of adipokines are mediated by a plethora of receptors that activate several signaling cascades including Janus kinase/ Signal transducer and activator of transcription (JAK/ STAT pathway), Phospatidylinositol kinase (PI3/ Akt/ mTOR) and Peroxisome proliferator-activated receptor (PPAR). The present review summarizes the current knowledge on the role of adipokines family members in carcinogenesis of the head and neck region. The diagnostic and prognostic significance of adipokines and their potential role as serum and saliva biomarkers are also discussed.

In-vivo topical mucosal delivery of a fluorescent deoxy-glucose delineates neoplasia from normal in a preclinical model of oral epithelial neoplasia

Metabolic imaging of oral cavity mucosal surfaces could benefit early detection of oral squamous cell carcinoma (OSCC) and oral epithelial dysplasia (OED). Fluorescent deoxy-glucose agents provide contrast for glucose metabolism similar to ¹⁸FDG-PET imaging and allow use of optical imaging, which provides high resolution and lower potential cost. However, in-vivo topical mucosal delivery of fluorescent deoxy-glucose agents without injection or tissue resection has not been shown. We introduce in-vivo optical imaging of neoplasia following mucosal delivery of 2-deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl)amino]-D-glucose (2-NBDG) in an OSCC/OED hamster model and demonstrate uptake into epithelium across the mucosal surface without injection or disrupting the epithelium. 2-NBDG fluorescence intensity following 30-minutes topical application was 6-fold and 4-fold higher in OSCC and OED, respectively, compared to normal mucosa. Receiver operator characteristic analysis show 83% sensitivity and 73% specificity for detection of neoplasia vs benign (normal and inflammation). Faster 2-NBDG fluorescence temporal decay in neoplasia indicated higher uptake and glucose metabolic rate than normal mucosa. Mucosal delivery of 2-NBDG by topical application to the in-vivo oral surface is feasible and delineates neoplasia from normal mucosa, providing in-vivo noninvasive molecular imaging of dysregulated glucose metabolism, which could benefit preclinical studies of carcinogenesis or be developed for use in early detection.

Aberrant Promoter Methylation of PTEN Gene among Indian Patients with Oral Squamous Cell Carcinoma

Background and aims

Oral cancer is the second most common cancer in men and accounts for 50%-70% of the total cancer mortality in India. PTEN is a tumor suppressor gene that plays a critical role in controlling cell growth and survival. Promoter hypermethylation of the PTEN gene has been reported in many tumors. However, little is known about the association between promoter methylation and oral squamous cell carcinoma (OSCC). Therefore, we aimed to detect the role of PTEN hypermethylation in OSCC patients in the Indian population.

Methods

Genomic DNA was isolated from 100 fresh oral tumor specimens and was subjected to bisulfite conversion. Methylation-specific PCR was employed on the converted DNA to investigate the methylation status.

Results

Of the total cases examined for PTEN promoter methylation we found that 35% were positive and 65% were negative. When evaluated in connection with tumor differentiation it was found that 82% of poorly differentiated, 24% of moderately differentiated and 32% of well differentiated OSCC samples were methylated. Methylation was further correlated with patient age, sex and tumor grade. Interestingly, we found that patient age and grade of differentiation were significantly associated with PTEN promoter methylation (p=0.05 and 0.0019, respectively) while sex was not (p=0.9).

Conclusions

The present study underlines the importance of PTEN hypermethylation among Indian OSCC patients.

The potential role of microbes in oncogenesis with particular emphasis on oral cancer

For over a century, non-virus microorganisms, notably bacteria have been implicated as causal agents of cancers, a relatively small number of researchers have provided evidence to support the so-called “cancer germ” hypothesis. With the exception of the link between Helicobacter pylori and stomach cancer, other supposed links have been ignored. A wide range of bacteria and other non-virus microbes, including fungi, have been implicated over the years in oncogenesis, as well as the ability to induce inflammation, which may cause cancer. It seems that there is no single “cancer germ,” as most bacteria can apparently induce cancer. Here, the role of bacteria and other non-virus microorganisms and oral cancers will be discussed. By ignoring bacteria as a causal agent of cancer, we set back our understanding of this crucially important disease and, as a result, have hindered the development of potential cures.

Cancer Screening: Should Cancer Screening be Essential Component of Primary Health Care in Developing Countries?

Background:

Cancer is a fatal disease and is on the rise across the globe. In India, breast, cervix and the oral cavity are the leading cancer sites, but, unfortunately, in-spite of availability of screening tools, there is no organized cancer screening program in India. The main objective of this study was to review the performance of various cancer screening modalities in a resource poor setting.

Methods:

MEDLINE and web of science electronic database was searched from January 1990 to December 2013, using keywords such as “breast cancer, cervical cancer, oral cancer and their corresponding mesh terms were also used in combination with Boolean operators OR, AND.” Two authors independently selected studies published in English and conducted in India. A total of 16 studies was found relevant and eligible for the review. The data on sensitivity and specificity of various screening tool was extracted and analyzed.

Results:

Most of the reported screening trails in India are on cervical cancer and few on breast and oral cancer screening. The pooled estimates of sensitivity and specificity of cervical cancer screening test such as visual inspection with acetic acid, magnified visual inspection with acetic acid, visual inspection with Lugol's iodine, cytology (Papanicolaou smear) and human papillomavirus deoxyribonucleic acid was found to be 68.76% and 84.02%, 63.27% and 85.43%, 81.86% and 87.03%, 63.25% and 93.17% and 75.04% and 91.66%, respectively. Sensitivity and specificity of clinical breast examination was found to be 94.30% and 94.30%, respectively. Oral cancer screening through visual inspection by trained health care worker was found to have 87.90% sensitivity and 92.05% specificity.

Conclusions:

Our study highlights the availability and success of visual screening tools in early detection and mortality reduction of major neoplasia in resource-poor health care settings and recommends implementation of oral and cervical cancer screening as part of assured primary health care package in developing countries.

Dentists' perception of the role they play in early detection of oral cancer

BACKGROUND

Dentists are typically the first professionals who are approached to treat ailments within the oral cavity. Therefore they should be well-equipped in detecting suspicious lesions during routine clinical practice. This study determined the levels of knowledge on early signs and risk factors associated with oral cancer and identified which factors influenced dentist participation in prevention and early detection of oral cancer.

MATERIALS AND METHODS

A survey on dentists' knowledge and their practices in prevention and early detection of oral cancer was conducted using a 26-item self-administered questionnaire.

RESULTS AND CONCLUSIONS

A response rate of 41.7% was achieved. The level of knowledge on early signs and risk habits associated with oral cancer was high and the majority reported to have conducted opportunistic screening and advised patients on risk habit cessation. Factors that influenced the dentist in practising prevention and early detection of oral cancer were continuous education on oral cancer, age, nature of practice and recent graduation. Notably, dentists were receptive to further training in the area of oral cancer detection and cessation of risk habits. Taken together, the study demonstrated that the dental clinic is a good avenue to conduct programs on opportunistic screening, and continuous education in these areas is necessary to adequately equip dentists in running these programs. Further, this study also highlighted knowledge deficits and practice shortcomings which will help in planning and developing programs that further encourage better participation of dentists in prevention and early detection of oral cancer.

Beclin1 inhibits proliferation, migration and invasion in tongue squamous cell carcinoma cell lines

OBJECTIVES

The role of autophagy is still a controversy in cancer development. In our previous study, we confirmed that decrease of autophagy activity promotes malignant progression of tongue squamous cell carcinoma (TSCC). However, the role of autophagy-related protein, Beclin1, has not well been documented in TSCC. In this study, we aim to elucidate the role of beclin1 in TSCC progression and investigate its potential mechanisms.

MATERIALS AND METHODS

TSCC cell lines, SCC9 and SCC15 were used to generate the stable cells with transfection lentivirus BECN1 and sh-BECN1. Then, Beclin1 expression was detected with qPCR and western blot. Moreover, the expressions of autophagy-related proteins and tumor metastasis associated proteins were examined by western blot and ELISA. For functional analysis, MTT assay were performed to evaluate the proliferation activity and transwell assay was used to assess the migration and invasion ability. Finally, TSCC xenograft models were established to confirm the effect of Beclin1 on TSCC in vivo.

RESULTS

The results showed that BECN1 and sh-BECN1 virus transfection significantly increased or decreased the mRNA and protein expression of Beclin1 in the transfected TSCC cells. Meanwhile, we also observed that Beclin1 could enhance the expression levels of LC3-II, ATG4 and ATG5. Then, we revealed that overexpression of Beclin1 inhibited proliferation, migration and invasion while knockdown of Beclin1 promoted proliferation, migration and invasion in TSCC cells. Furthermore, we demonstrated that vascular endothelial growth factor (VEGF), matrix metalloproteinase-2 and -9 were involved in Beclin1-mediated inhibition of migration and invasion. More importantly, our data also confirmed that Beclin1 inhibited TSCC xenograft growth in vivo.

CONCLUSION

Taken together, the results indicate that autophagy regulating gene, Beclin1, may contribute to the malignant phenotypes of TSCC cells and can be a potential target for oral cancer gene therapy.

Neutrophils infiltration in the tongue squamous cell carcinoma and its correlation with CEACAM1 expression on tumor cells

OBJECTIVE

The present study aimed to explore the clinical significance of neutrophils infiltration and carcinoembryonic antigen related cell adhesion molecule 1 (CEACAM1) expression in the tongue squamous cell carcinoma (TSCC), and to probe the possible relationship between them.

MATERIALS AND METHODS

Tissue microarray and immunohistochemistry were used to detect neutrophils density and CEACAM1 expression in 74 cases of primary TSCC specimens and 17 cases of corresponding peritumoral tissues. The relationship of CEACAM1 expression and neutrophils density with clinicopathologic parameters and cancer-related survival of TSCC patients were evaluated. The correlation between CEACAM1 expression and neutrophils density was also evaluated. Real-time quantitative transcription polymerase chain reaction (qRT-PCR) was used to explore the possible molecular mechanisms between CEACAM1 expression and neutrophils infiltration.

RESULTS

Immunohistochemistry evaluation revealed that there was more neutrophils infiltration in TSCC tissues than in peritumoral tissues. High neutrophil density was associated with LN metastasis (P=0.01), higher clinical stage (P=0.037) and tumor recurrence (P=0.024). CEACAM1 overexpression was also associated with lymph node metastasis (P=0.000) and higher clinical stage (P=0.001). Survival analysis revealed that both neutrophils infiltration and CEACAM1 overexpression were associated with poorer cancer-related survival of TSCC patients (P<0.05), and neutrophils infiltration was an independent prognostic factor for TSCC (P<0.05). Furthermore, overexpression of CEACAM1 was correlated with more neutrophils infiltration in TSCC tissues (P<0.01). qRT-PCR results showed that CEACAM1-4L can upregulate the mRNA expression of IL-8 and CXCL-6, which were strong chemotactic factors of neutrophils.

CONCLUSION

Our results demonstrated that more neutrophils infiltration and overexpression of CEACAM1 were associated with poor clinical outcomes in TSCC tissues. Overexpression of CEACAM1 on tumor cells correlated with more neutrophils infiltration to some extent through upregulating mRNA expression of IL-8 and CXCL-6.

Diagnosis and therapy of oral squamous cell carcinoma

Oral squamous cell carcinoma ranks among the top ten most common cancers worldwide. Despite the success in diagnosis and therapy during the past 30 years, oral squamous cell carcinoma still belongs to the tumor types with a very unfavorable prognosis. In an effort to identify genomic alterations with prognostic relevance, we applied the comparative genomic hybridization technique on oral squamous cell carcinoma. The tumors exhibited from five up to 47 DNA copy number alterations, indicating a considerable degree of genomic imbalance. Out of 35 tumors, 19 showed a gain of chromosome band 7p12. Genomic imbalances were investigated by hierarchical cluster analysis and clustered image mapping to investigate whether genomic profiles correlate with clinical data. Results of the present investigation show that profiling of genomic imbalances in general, and especially of the epidermal growth factor receptor (EGFR) on 7p12, may be suitable as prognostic factors. In order to identify small-molecule inhibitors for EGFR, we established a database of 531 natural compounds derived from medicinal plants used in traditional Chinese medicine. Candidate compounds were identified by correlation analysis using the Kendall tau-test of IC50 values of tumor cell lines and microarray-based EGFR mRNA expression. Further validation was performed by molecular docking studies using the AutoDock program with the crystal structure of EGFR tyrosine kinase domain as docking template. We estimate these results will be a further step toward the ultimate goal of individualized, patient-adapted tumor treatment based on tumor molecular profiling.

Lin28a is a putative factor in regulating cancer stem cell-like properties in side population cells of oral squamous cell carcinoma

Cancer stem cells (CSCs) are among the target cells of cancer therapy because they are uniquely involved in both cancer progression and sensitivity to chemotherapeutic agents. We identified side population (SP) cells, which are known to be an enriched population of CSC, in five oral squamous cell carcinoma (OSCC) cells (SCC9, SCC25, TOSCC7, TOSCC17, and TOSCC23). The percentages of SP cells ranged from 0% to 3.3%, with TOSCC23 cells showing the highest percentages of SP cells (3.3% of the total cell population). The SP cells isolated from TOSCC23 cells also showed greater cell proliferation and invasion compared to non-SP (MP) cells. Therefore, our initial findings suggested that SP cells were enriched for CSC-like cells. Furthermore, DNA microarray analysis revealed that the expression of cell proliferation-related and anti-apoptotic genes was greater in SP cells compared to MP cells. We focused on Lin28a, which showed the highest expression (approximately 22-fold) among the upregulated genes. The overexpression of Lin28a in TOSCC23 cells increased their proliferation, colony formation, and invasion. These findings suggest that Lin28a is an appropriate CSC target molecule for OSCC treatment.

A decision support system for quality of life in head and neck oncology patients

BACKGROUND

The assessment of Quality of Life (QoL) is a Medical goal; it is used in clinical research, medical practice, health-related economic studies and in planning health management measures and strategies. The objective of this project is to develop an informational platform to achieve a patient self-assessment with standardized QoL measuring instruments, through friendly software, easy for the user to adapt, which should aid the study of QoL, by promoting the creation of databases and accelerating its statistical treatment and yet generating subsequent useful results in graphical format for the physician analyzes in an appointment immediately after the answers collection.

METHODS

First, a software platform was designed and developed in an action-research process with patients, physicians and nurses. The computerized patient self-assessment with standardized QoL measuring instruments was compared with traditional one, to verify if its use did not influence the patient's answers. For that, the Wilcoxon and t-Student tests were applied. After, we adopted and adapted the mathematic Rash model to make possible the use of QoL measure in the routine appointments.

RESULTS

The results show that the computerized patient self-assessment does not influence the patient's answers and can be used as a suitable tool in the routine appointment, because indicates problems which are more difficult to identify in a traditional appointment, improving thus the physician's decisions.

CONCLUSIONS

The possibility of representing graphically useful results that physician needs to analyze in the appointment, immediately after the answer collection, in an useful time, makes this QoL assessment platform a diagnosis instrument ready to be used routinely in clinical practice.

PTEN-mediated AKT activation contributes to the reduced apoptosis among Indian oral squamous cell carcinoma patients

PURPOSE

The tumor suppressor gene PTEN negatively regulates Akt, a downstream mediator phosphoinositol 3-kinase. Several studies have reported the role of PTEN gene in Akt downregulation and apoptosis induction in different cancers and cell lines. However, the role of loss of PTEN expression in Akt activation and spontaneous apoptosis in oral squamous cell carcinoma clinical specimens is not well established.

METHODS

We investigated the expression of PTEN and phospho-Akt in 146 formalin-fixed (archived) paraffin-embedded oral squamous cell carcinoma tissue sections through immunohistochemical analysis. Programmed cell death (apoptosis) was determined by Terminal deoxynucleotidyl Transferase Biotin-dUTP Nick End Labeling assay.

RESULTS

Sixty-one percent loss of PTEN expression and 68.5% Akt activation was observed in oral squamous cell carcinoma. A significant correlation was found between loss of PTEN expression and Akt activation. Loss of PTEN expression and Akt activation were further correlated with different clinical parameters and found to be significantly correlated with tumor stage. Apoptotic index was estimated and correlated with PTEN expression and Akt activation. The percentage of apoptotic cells varied from 0.2 to 14.1%. Low apoptotic index was observed in 105 (72%) of samples, and it was found to be significantly related with loss of PTEN expression and phospho-Akt

CONCLUSION

The present study confirms the contribution of loss of PTEN expression in Akt phosphorylation and spontaneous apoptosis suppression in the specimens of oral cancer. Both PTEN and phospho-Akt are likely to be concerned with oral cancer progression and reduced incidence of spontaneous apoptosis.

Effect of Mangrove Tea Extract from Ceriops decandra (Griff.) Ding Hou. on Salivary Bacterial Flora of DMBA Induced Hamster Buccal Pouch Carcinoma

The objective of this study was to investigate the effects of mangrove tea on salivary bacterial flora in DMBA induced hamster buccal pouch carcinoma. Tea from mangrove plant Ceriops decandra was administered against DMBA induced buccal pouch carcinoma in hamster rats. The chemical constitutions and quality of mangrove tea is similar with the commercial tea Camellia sinensis. The Hamster rats were painted thrice a week with DMBA in their right buccal pouch, and also administrated orally with 1.25% of Ceriops tea extract, on alternate days of the DMBA treatment. Appropriate control animals were maintained. After 14 weeks of treatment, bacterial species in saliva were enumerated, tumor incidences were analyzed using histopathological section and tumor volume in the animals was quantified using water-displaced method. The decreased counts of beneficial bacteria and increased counts of harmful bacteria were associated with increased volume of tumors. The present study concluded that the tea extract from C. decandra prevents the oral cancer incidences and maintain the good health conditions of the animals.

A population-based study of factors associated with early versus late stage oral cavity cancer diagnoses

Oral cavity cancers can be detected early yet many are diagnosed with advanced disease. We assessed risk factors for advanced stage disease in a population-based study. Study population was all Ontario patients with anterior tongue or floor of mouth cancers diagnosed between 1991 and 2000 (n=2033). Data are from a retrospective chart review. Risk factors included: demographic characteristics, co-morbidity, precancerous lesions, dental status, smoking, alcohol use, and social marginalization. Multivariate regression analyses assessed independent associations while controlling for disease grade and site. Forty percent had advanced disease. Eighty-nine percent presented with symptoms and 66% were referred by a family physician. Risk factors in the tongue group were being: age ≥80 (RR 1.47), widowed (RR 1.34), social marginalized (RR 1.69), a current smoker (RR 1.26), or a smoker-heavy drinker (RR 1.73). Risk factors in the floor of mouth group were being: age ≥70 (70-79: RR 1.24 and ≥80: RR 1.43), and socially marginalized (RR 1.22). Having a pre-cancerous lesion (RR 0.44) or a regular dentist (RR 0.84) was protective in the floor of mouth group. Risk factors for those with co-morbid illnesses were being: age ≥70 (70-79: RR 1.28 and ≥80: RR 1.55), separated/divorced (RR 1.26), socially marginalized (RR 1.37), or a smoker-heavy drinker (RR 1.44); while having a regular dentist was protective (RR 0.83). Targeted education to alert those at risk about oral cancer warning signs and better training coupled with opportunistic oral cavity exams by family physicians could reduce the burden of this disease.

Smoking, alcohol, and betel quid and oral cancer: a prospective cohort study

We aimed to investigate the association between smoking, alcoholic consumption, and betel quid chewing with oral cancer in a prospective manner. All male patients age ≥18 years who visited our clinic received an oral mucosa inspection. Basic data including personal habits were also obtained. A multivariate logistic regression model was utilized to determine relevant risk factors for developing oral cavity cancer. A total of 10,657 participants were enrolled in this study. Abnormal findings were found in 514 participants (4.8%). Three hundred forty-four participants received biopsy, and 230 patients were proven to have oral cancer. The results of multivariate logistic regression found that those who smoked, consumed alcohol, and chewed betel quid on a regular basis were most likely to develop cancer (odds ratio: 46.87, 95% confidence interval: 31.84-69.00). Therefore, habitual cigarette smokers, alcohol consumers, and betel quid chewers have a higher risk of contracting oral cancer and should receive oral screening regularly so potential oral cancer can be detected as early as possible.

Pilot study to estimate the accuracy of mouth self-examination in an at-risk group

BACKGROUND

Mouth self-examination (MSE) is a possible method of detecting oral cancer early. This study aimed to determine whether those at risk of developing oral cancer are able to correctly detect potentially malignant oral lesions via MSE.

METHODS

Participants (53 smokers aged over 45 years) received an oral mucosal examination by the dentist and then performed MSE after education through a self-read leaflet. The dentist and participant both recorded the presence and absence of potentially malignant oral lesions.

RESULTS

The prevalence of potentially malignant oral lesions was 22%. The sensitivity of MSE was 33% and the specificity was 54%. MSE had a positive predictive value of 17% and a negative predictive value of 73%.

CONCLUSION

The at-risk group were poor at correctly identifying the presence or absence of potentially malignant oral lesions. A leaflet may be an ineffective training tool to aid self-identification of potentially malignant oral lesions.

Over-expression of Gadd45a enhances radiotherapy efficacy in human Tca8113 cell line

AIM

To investigate the effect of the growth arrest- and DNA damage-inducible Gadd45a gene on the radiosensitivity of human tongue squamous cell carcinoma cell line to ionizing radiation (IR).

METHODS

Short interfering ribonucleic acid (si-RNA) targeting Gadd45a or an irrelevant mRNA (nonsense si-RNA) was chemically synthesized. The constructed si-RNAs were transfected into Tca8113 cells and Gadd45a expression was determined using quantitative real-time PCR and Western-blot. After 24-h exposure to IR at a dose rate of 4 Gy/min, apoptosis of Tca8113 cells was detected using flow cytometry, and radiosensitivity was measured using MTT assays.

RESULTS

IR apparently increased the expression of Gadd45a at mRNA and protein levels in Tca8113 cells. The effect was efficiently inhibited by transfection with Gadd45a si-RNA (P<0.01). Furthermore, silencing Gadd45a gene significantly increased cell viability and decreased the percentage of apoptotic cells during irradiation, which indicated that IR-induced Gadd45a over-expression could increase the radiosensitivity of Tca8113 cells.

CONCLUSION

These results indicated that targeting Gadd45a may have important therapeutic implications in sensitizing Tca8113 cells to IR.

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

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

The role of bacteria in oral cancer

Despite the widening interest in the possible association between bacteria and different stages of cancer development, our knowledge in its relation to oral cancers remains inadequate. The aim of this review article is to derive a better understanding on the role of various micro-organisms in the etiogenesis of oral cancers through all the available data on the pubmed. Different bacteria have been proposed to induce carcinogenesis either through induction of chronic inflammation or by interference, either directly or indirectly, with eukaryotic cell cycle and signaling pathways, or by metabolism of potentially carcinogenic substances like acetaldehyde causing mutagenesis. Studies have shown diversity of isolated bacterial taxa between the oral cancer tissue specimens and the control, with Exiguobacterium oxidotolerans, Prevotella melaninogenica, Staphylococcus aureus and Veillonella parvula being specific for tumorogenic tissues. Most isolates are saccharolytic and acid tolerant. Streptococcus anginosus, commonly linked with esophageal and pharyngeal cancers, is not of significance in oral cancers. Similarly, significant salivary specificity is noted for three bacteria, namely, Capnocytophaga gingivalis, P. melaninogenica, and Streptococcus mitis in oral cancer patients, making these species salivary markers for the early detection of oral cancers and thus improving the survival rate significantly. Also, such high degree of bacterial specificity in oral cancers has also provoked the designing of new treatment options for cancer prevention by way of vaccine delivery. However, for the success of these steps, a deeper exploration into this subject with a greater understanding is warranted.

Correlation of NF-kappaB signal pathway with tumor metastasis of human head and neck squamous cell carcinoma

Background

Nuclear factor-kappa B (NF-κB) signaling constitutes a key event in the multistep process of carcinogenesis, progression and treatment in many cancer types. However, the significance of NF-κB pathway for complex and tissue-specific aspects of head and neck cancer progression, such as invasion and metastasis, is less understood.

Methods

The expression of NF-κB p65 in squamous cell carcinoma of the head and neck (SCCHN) clinical specimens by immunohistochemistry. The role of NF-κB activity in head and neck squamous cell carcinoma was determined by western blot, reporter assay and EMSA analysis in vitro and metastasis assays in vivo in different metastatic potential tumor cells. Furthermore, the apoptosis rate and expression of metastasis-related protein such as MMP9 and VEGF were examined by Annexin V/PI staining and Western blot, respectively.

Results

A higher level of active nuclear-localized NF-κB was observed in the metastatic SCCHN specimens group (p < 0.01). The NF-κB activities of SCCHN cell lines with different metastatic potentials were then determined and in excellent agreement with results found in SCCHN specimens, highly metastatic SCCHN cell lines expressed high level of NF-κB activity. The treatment of highly metastatic SCCHN cells with NF-κB inhibitors reduced the in vitro cell invasion capacity of the cells without affecting the apoptotic rate. Additionally, the NF-κB inhibitors significantly inhibited the experimental lung metastasis of Tb cells and lymph node metastasis of TL cells in nude mice. Furthermore, the expression of metastasis-related proteins, such as matrix metalloproteinase 9 and vascular endothelial growth factor, was inhibited by pyrrolidine dithiocarbonate.

Conclusions

This study suggests that NF-κB activity significantly contributes to tumor hematologic and lymphatic metastases and may aid in the development of early detection methods or therapies targeting non-conventional molecular targets.

Overexpression of Kif2a promotes the progression and metastasis of squamous cell carcinoma of the oral tongue

The aim of this study was to examine the Kif2a expression and its role in tumor progression, invasion and metastasis in squamous cell carcinoma of the oral tongue (SCCOT). The study included 44 cases of primary tumor and the corresponding adjacent tissues, 20 cases of primary tumor with lymph node metastasis. Immunohistochemistry was used to observe the Kif2a expression and its correlation with clinicopathologic factors in oral tongue cancer. The immunohistochemistry showed that Kif2a expression was stronger in oral tongue cancer tissues than in paired adjacent tissues (P<0.01), and the higher expression of Kif2a was also significantly associated with lymph node metastasis (P<0.01), tumor clinical stage (P<0.01). In addition, in vitro results from transwell chamber assay showed that Tca8113 cells transfected with Kif2a-siRNA had a decreased migratory ability (P<0.01) compared to nonsense-siRNA-transfected cells. Therefore we speculate the overexpression of Kif2a might be involved in the progression, invasion and metastasis of SCCOT and Kif2a should be as a predictor for prognosis.

Clinical analysis of head and neck cancer cases in south-west China 1953 - 2002

The occurrence of head and neck cancers varies worldwide. This study retrospectively analysed the incidence and types of 8646 cases of head and neck cancers in south-west China that were treated at the West China Stomatology Hospital of Sichuan University between 1953 and 2002. Overall mean patient age was 50.3 years and the overall male:female ratio was 2.38:1; mean age increased and the male:female ratio decreased over the study period. Peak incidence occurred between the ages of 40 and 60 years. Primary tumours most frequently developed in the tongue, followed by the bucca and gingiva. Histologically, squamous cell carcinomas were most frequently recorded. The parotid gland and palate were the most common locations for salivary gland tumours. Over the study period the incidence of head and neck cancers increased with time and the rate of increase was greater in females than males. The frequency of histological types and topography were similar to previous reports.

Training in the Primary Prevention and Early Detection of Oral Cancer: Pilot Study of its Impact on Clinicians’ Perceptions and Intentions

In this pilot study, we tested a new program for training medical care providers in the primary prevention and early detection of oral cancer. The training program consisted of two modules: (1) oral cancer epidemiology and head and neck examinations for the early detection of oral cancer and (2) assessment and counseling of patients in tobacco cessation. On a pretraining questionnaire, the 8 participating clinicians (3 primary care physicians, 4ENT nurses, and 1 physician assistant) indicated that they had only a limited awareness of oral cancer, that they generally did not routinely examine asymptomatic patients for oral cancer, and that they engaged in only a limited amount of risk assessment/counseling with their patients. On a post-training questionnaire, they indicated that their training had been well received and would prompt them to increase their efforts to examine their patients for early signs of oral cancer and to counsel them about its risks.

Frequent inactivation of RUNX3 by promoter hypermethylation and protein mislocalization in oral squamous cell carcinomas

PURPOSE

RUNX3 is a functionally important component in transforming growth factor-beta (TGF-beta) mediated signaling pathway. Epigenetic silencing expression of RUNX3, as well as aberrant cytoplasmic retention of RUNX3 protein are causally involved in gastric carcinogenesis. Here, we examined the expression of RUNX3 gene and protein in oral squamous cell carcinomas (OSCCs) and analyzed the methylation status of RUNX3 promoter region.

METHODS

About 10 normal oral mucosa and 30 OSCCs were collected to examine RUNX3 expression by RT-PCR analysis and immunohistochemistry assay using anti-RUNX3 monoclonal antibody R3-6E9. Methylation-specific PCR was carried out on the same specimens to analyze the methylation status of RUNX3 promoter. In addition, the stored paraffin-embedded specimens, including 40 oral leucoplakia (OLK) and 120 OSCCs, were examined by immunohistochemistry assay.

RESULTS

RUNX3 gene and protein were underexpressed in OSCCs due to promoter hypermethylation. Protein mislocalization occurred frequently. Both downregulation of RUNX3 protein expression (P = 0.001) and protein mislocalization (P = 0.001) were correlated with the differentiation grades in OSCCs.

CONCLUSIONS

RUNX3 plays an important role in oral carcinogenesis. It may be a useful diagnostic marker and a potential therapeutic target for OSCC.

Global epidemiology of oral and oropharyngeal cancer

This review presents data on incidence, mortality, survival and trends in cancers of the lip, oral cavity and oropharynx using available recent data sources around the world. Oral and pharyngeal cancer, grouped together, is the sixth most common cancer in the world. The review focuses primarily on several high-risk countries in an attempt to gain insight into the geographic variations in the incidence of this cancer in the globe and to relate the high incidence in some populations to their life style. With an estimated half a million cases around the globe and the rising trends reported in some populations, particularly in the young, urgent public health measures are needed to reduce the incidence and mortality of oral and oropharyngeal cancer.

SEM analysis of oral lichen planus before and after treatment with 13 cis-retinoic acid

Cancer of the oral cavity is a frequent worldwide neoplasia, averaging 4% in men and 2% in women. Cancer of the oral cavity is often preceded by particular epithelial lesions, called precancerous lesions. The aim of this study is to evaluate, by SEM microscope analysis, before and after treatment with 0.1% 13-cis-retinoic, the morphostructural variation of the surface of the oral mucous affected by lichen planus in respect to healthy oral mucous. Following topical therapy with 0.1% 13-cis-retinoic acid for 8 weeks, a restoration of the physiological morphostructure was observed by SEM, demonstrating the efficaciousness of the treatment and the SEM analysis for identifying the lesions of oral epithelium.

Exposure to alcohol or tobacco affects the pattern of maturation in oral mucosal cells: a cytohistological study

OBJECTIVE

To assess the maturation pattern of oral mucosal cells of patients exposed to tobacco and alcohol.

METHODS

(i) Group without lesions. Smears obtained from the lower lip, border of the tongue and floor of the mouth of 31 control individuals (group I), 49 tobacco users (group II) and 27 tobacco/alcohol users (group III) were stained using the Papanicolaou method. The first 100 cells counted on each smear determined the maturation pattern and the keratinization index (KI). Analysis of variance (ANOVA) and the Tukey multiple comparison test were used for statistical analysis, at a 5% significance level. (ii) Group with lesions. Cytopathological and histopathological studies were conducted for 15 patients: eight with leucoplakia without epithelial dysplasia, two with epithelial dysplasia and five with squamous cell carcinoma.

RESULTS

(i) Group without lesions. Statistical analysis revealed a smaller number of superficial cells with nuclei in all sites of the group of tobacco/alcohol users (group III) when compared to the control group (group I), and this difference was statistically significant (P<0.005). (ii) Group with lesions. The severity of histopathological findings increased with the increase in the number of cells of the deeper epithelial layers, with a statistically significant difference in the number of intermediate (P=0.013) and parabasal cells (P=0.049), which increased with the severity of the epithelial maturation disorder: leucoplakias with dysplasia had a greater number of intermediate and parabasal cells than leucoplakias without dysplasia; and the number in squamous cell carcinomas was greater than in leucoplakias with dysplasia.

CONCLUSION

The maturation pattern of cells in the three anatomic sites showed changes that may be associated with the synergistic effect of tobacco and alcohol. Also, the severity of histopathological findings was associated with the increase in the number of cells in the deeper epithelial layers.

Metastasis of squamous cell carcinoma of the oral tongue

Squamous cell carcinoma of the oral tongue (SCCOT) is one of the most prevalent tumors of the head and neck region. Despite advances in treatment, the survival of patients with SCCOT has not significantly improved over the past several decades. Most frequently, treatment failure takes the form of local and regional recurrences, but as disease control in these areas improves, SCCOT treatment failures are occurring more often as distant metastasis. The presence of cervical lymph node metastasis is the most reliable adverse prognostic factor in patients with SCCOT, and extracapsular spread (ECS) of cervical lymph nodes metastasis is a particularly reliable predictor of regional and distant recurrence and death from disease. Decisions regarding the elective and therapeutic management of cervical lymph node metastases are made mainly on clinical grounds as we cannot always predict cervical lymph node metastasis from the size and extent of invasion of the primary tumors. Therefore, the treatment of these metastases in the management of SCCOT remains controversial. The promise of basing treatment decisions on biomarkers has yet to be fully realized because of our poor understanding of the mechanisms of regional and distant metastases of SCCOT. Here we summarize the current status of investigations of SCCOT metastases and the potential of these studies to have a positive impact on the clinical management of SCCOT in the future.

Visual screening of oral cavity cancer: The role of otolaryngologists

OBJECTIVES

Because most screening was done by dentists, the purpose of this prospective cohort study was to evaluate the effectiveness of oral visual screening by otolaryngologists. In addition, we wanted to determine which group of enrolled patients was at potential risk of contracting oral cancer.

METHODS

All male patients age > or =18 years who visited our clinic received oral mucosal screening. Basic data, including personal habits, were also obtained. A multivariate logistic regression model was devised to determine relevant risk factors for developing oral cancer.

RESULTS

A total of 5,825 patients were enrolled in this study. Positive findings were found in 226 patients (3.9%). One hundred seventy-two patients received biopsy and 131 patients were proven to have oral cancer (sensitivity rate: 76.2%). The results showed that those who smoked, consumed alcohol, and chewed betel quid on a regular basis were most likely to contract oral cancer (odds ratio = 49.81, 95% confidence interval = 29.38-84.42).

CONCLUSIONS

The otolaryngologists involved in this study successfully performed the oral screening. The sensitivity and specificity rates were both satisfactory. We suggest that those who are habitual cigarette smokers, alcohol consumers, and betel quid chewers should receive oral mucosal screening regularly so that potential oral cancer can be detected as early as possible.

Oral cancer: experiences and diagnostic abilities elicited by dentists in North-western Spain

BACKGROUND

Opinions, knowledge, behaviours and attitudes of general dental practitioners on oral cancer prevention and detection have been reported from many countries. However, experiences and skills of oral cancer detection have not been evaluated systematically.

OBJECTIVE

To obtain information on behaviours of screening and ability to correctly detect oral cancer and precancer among general dentists (GDP) in North-western Spain.

SUBJECTS AND METHODS

Thirty-two randomly selected GDPs completed questionnaires and then classified 50 projected images of clinical lesions, into cancer, precancer or benign lesions.

RESULTS

87.5% reported conducting routine oral examinations, 84.4% provided routine advice to their subjects for risk modifications and 84.4% claimed to biopsy a suspected oral mucosal lesion that they detected in practice. In a quasi research setting using clinical slides, the sensitivity of visual diagnosis of a cancerous lesion was 61.4% and precancer 59.5%. The diagnostic accuracy reported here is lower than what is already reported by evaluation of published screening programmes by dentists.

CONCLUSIONS

Our data from Spain suggest a need for improving the diagnostic ability of GDPs in the visual detection of oral cancer/precancer by strengthening continuing professional education.

Viable bacteria present within oral squamous cell carcinoma tissue

Despite increasing interest in the possible relationships between bacteria and the different stages of cancer development, the association of bacteria with cancer of the oral cavity has yet to be adequately examined. With that in mind, the primary objective of this study was to identify any bacterial species within oral squamous cell carcinoma tissue using a standard microbiological culture approach. At the time of surgery, a 1-cm3 portion of tissue was harvested from deep within the tumor mass using a fresh blade for each cut. Whenever possible, "superficial" portions from the mucosa overlying the tumor and nontumorous control specimens from at least 5 cm away from the primary tumor site were also obtained. Surface contamination was eliminated by immersion in Betadine and washing with phosphate-buffered saline. Each specimen was aseptically macerated and cultured on nonselective media under both aerobic and anaerobic conditions. Isolates were identified by 16S rRNA gene sequencing. Twenty deep-tissue specimens, 19 with corresponding superficial tissues and 12 with control tissues, were successfully processed. A diversity of bacterial taxa were isolated and identified, including several putatively novel species. Most isolates were found to be saccharolytic and acid-tolerant species. Notably, some species were isolated only from either the tumorous or nontumorous tissue type, indicating a degree of restriction. Successful surface decontamination of the specimens indicates that the bacteria detected were from within the tissue. A diversity of bacterial groups have been isolated from within oral squamous cell carcinoma tissue. The significance of these bacteria within the tumor warrants further study.

Screening programmes for the early detection and prevention of oral cancer

BACKGROUND

Screening programmes for major cancers, such as breast and cervical cancer have effectively decreased the mortality rate and helped to reduce the incidence of these cancers. Although oral cancer is a global health problem with increasing incidence and mortality rates, no national population-based screening programmes for oral cancer have been implemented. To date there is debate on whether to employ screening methods for oral cancer in the daily routine work of health providers.

OBJECTIVES

To assess the effectiveness of current screening methods in decreasing oral cancer mortality.

SEARCH STRATEGY

Electronic databases (MEDLINE, CANCERLIT, EMBASE, the Cochrane Central Register of Controlled Trials; 1966 to July 2005, The Cochrane Library - Issue 3, 2005), bibliographies, handsearching of specific journals and contact authors were used to identify published and unpublished data.

SELECTION CRITERIA

Randomised controlled trials of screening for oral cancer or precursor oral lesions using visual examination, toluidine blue, fluorescence imaging or brush biopsy.

DATA COLLECTION AND ANALYSIS

The search found 112 citations and these have been reviewed. One randomised controlled trial of screening strategies for oral cancer was identified as meeting the review's inclusion criteria. Validity assessment, data extraction and statistics evaluation were undertaken by two independent review authors.

MAIN RESULTS

One 10-year randomised controlled trial has been included (n = 13 clusters: 191,873 participants). There was no difference in the age-standardised oral cancer mortality rates for the screened group (16.4/100,000 person-years) and the control group (20.7/100,000 person-years). Interestingly, a significant 34% reduction in mortality was recorded in high-risk subjects between the intervention cohort (29.9/100,000 person-years) and the control arm (45.4/100,000). However, this study has some methodological weaknesses. Additionally, the study did not provide any information related to costs, quality of life or even harms of screening from false-positive or false-negative findings.

AUTHORS' CONCLUSIONS

Given the limitation of evidence (only one included randomised controlled trial) and the potential methodological weakness of the included study, it is valid to say that there is insufficient evidence to support or refute the use of a visual examination as a method of screening for oral cancer using a visual examination in the general population. Furthermore, no robust evidence exists to suggest that other methods of screening, toluidine blue, fluorescence imaging or brush biopsy, are either beneficial or harmful. Future high quality studies to assess the efficacy, effectiveness and costs of screening are required for the best use of public health resources. In addition, studies to elucidate the natural history of oral cancer, prevention methods and the effectiveness of opportunistic screening in high risk groups are needed. Future studies on improved treatment modalities for oral cancer and precancer are also required.

Autofluorescence and Photofrin-induced fluorescence imaging and spectroscopy in an animal model of oral cancer

Developments in the fluorescence detection of cancer aim either to distinguish tissue autofluorescence from that of injected fluorophores or to exploit differences in autofluorescent spectra of normal versus transforming, premalignant and malignant tissue. This study evaluates the utility of autofluorescence and Photofrin-induced fluorescence imaging and spectroscopy to distinguish tissue transformation associated with early malignant change in the oral cavity. The model of tissue transformation used was that induced by the carcinogen DMBA in the hamster buccal cheek pouch. Fluorescence spectra were obtained using a high-sensitivity fiber optic spectrometer, while imaging was performed using a Multispectral Fluorescence Guidance (MFG) system designed for use in intraoperative fluorescence imaging during photodynamic therapy. The results demonstrate that Photofrin fluorescence can be used to predict the pathologic state of tissue, the fluorescence intensity being directly proportional to the degree of malignant transformation. Autofluorescence detection measured two parameters that are altered by transformation stage: the red/green fluorescence ratio and the total fluorescence intensity. The most striking feature was the change in the latter in malignant tissue. The MFG imaging device performed as well as spectroscopy: the sensitivity and specificity for the imaging system were 65% and 90% for autofluorescence and 87% and 85% with Photofrin. This indicates that either the autofluorescence intensity index of the tissue or the Photofrin-induced fluorescence may provide a good parameter for the "first approximation" characterization of the tissue.

Risk perception of oral cancer in smokers attending primary care: a randomised controlled trial

To encourage the public to attend and accept oral cancer screening, further understanding is required of the ability of structured information to alter patient knowledge and risk perceptions. Previous work has shown the benefit of written information for those at high risk of oral cancer, especially for tobacco smokers. This study investigated three hypotheses: first that a patient information leaflet (PIL) would enhance risk perceptions, and second that the effect of the leaflet on knowledge would be confirmed as in previous studies and third that these improvements would be associated with smoking behaviour. Patients (N = 995) attending 20 general dental practices in Northern Ireland were invited to participate, 28 refused (response rate = 97%). Patients were randomised into two groups. The experimental group received a PIL and then completed a self-report questionnaire, whereas the control group followed same procedure without the PIL. Measures included a 36 item oral cancer knowledge scale and two items to assess risk perception. Usable data were available from 944 patients; mean (SD) age = 42 (15), 65% female. Risk perceptions of oral cancer were minimally effected by the PIL (p = 0.023). This effect was demonstrable in smokers. Smokers were sixteen (95% CI: 8-30) times more likely to believe that they were at greater risk of oral cancer than non-smokers. A clear benefit of the PIL on patients' oral cancer knowledge was found, particularly for smokers and those with a history of smoking. These findings demonstrate that public awareness of smokers can be raised with written information although health beliefs such as risk perceptions require more intensive intervention.

Factors associated with delay in presentation among younger patients with oral cancer

Despite the reported increase in the incidence of oral squamous cell carcinoma (OSCC) in under 45-year-olds, little is known regarding the pattern and reasons for delay in presentation in this younger age group. The aim of this study was to investigate factors predictive of patient (primary) delay in a sample of 53 newly diagnosed patients under the age of 45 years. Multiple logistic regression was used to estimate odds ratios (OR) and 95% confidence intervals (95% CI) for primary delay (> or = 21 days between patient first noticing signs or symptoms and seeking professional advice). Self-reported delay ranged from less than 1 week to 104 weeks, with a median of 5 weeks. A total of 33 patients (62%) reported a delay of at least 21 days. Three variables: lack of further education, perceptions of being under stress in the period prior to diagnosis, and lower amounts of tobacco smoked per day were included in the final model and together explained 43% of the variance in patient delay (R2 = 0.432). Although OSCC is relatively rare in this age group, the rise in incidence and the change in profile of risk factors may increase the odds of patient delay. This has important implications for increasing sign and symptom awareness among the public and primary health care professionals such as general medical practitioners and general dentists.

An oral cancer information leaflet for smokers in primary care: results from two randomised controlled trials

OBJECTIVES

To investigate whether primary care patients who claim to smoke tobacco gain greater benefit of a patient information leaflet (PIL) on oral cancer than nonsmokers.

METHODS

Two studies were conducted. Study 1 examined the research question initially, and Study 2 acted as a replication and inclusion of additional secondary outcome measures. The leaflet was designed and tested in an earlier study. Knowledge of oral cancer was assessed by a previously validated 36-dichotomous-item scale. A single-item question ascertained self-reported smoking status (kappa = 0.94). Study 1 participants were drawn from 14 practices (6 medical, 8 dental). A randomised control group design was adopted. The experimental group received the leaflet on attendance to the practice and then completed the questionnaire. The control group received the questionnaire only. Complete data were collected from 739 respondents. The design of Study 2 was identical; 786 new respondents from 16 practices (7 medical, 9 dental) were collected.

RESULTS

Both studies confirmed that smokers knew less about oral cancer than nonsmokers (P < 0.05) when access to the leaflet had been denied. On receipt of the leaflet, there was no distinction in oral cancer knowledge between the smoking status categories of respondents. Evidence of reassurance about screening from leaflet exposure was supported by the second study.

CONCLUSION

This programmed research has demonstrated an effect of a brief PIL to offset the decrement in oral cancer knowledge observed in primary care patients who use tobacco in comparison to their nonsmoking counterparts. The leaflet reduced anxiety about oral health screening in smokers.

Opportunistic screening for oral cancer and precancer in general dental practice: results of a demonstration study

OBJECTIVES

To demonstrate the feasibility of opportunistic oral cancer and precancer screening in general dental practice and to determine the prevalence of relevant lesions and risk habits in a population of general dental practice attenders.

DESIGN

A prospective demonstration study, recruiting patients opportunistically.

SETTING

General dental practices.

METHODS

Eighteen general dental practitioners took part in this study. Each attended training sessions to be advised of the study protocol and the criteria of a positive and negative screen. Patients over the age of 35 years were prospectively and opportunistically recruited. Each patient was asked to complete a health questionnaire concerning age, gender, ethnicity, smoking and drinking habits. The dentist then examined the soft tissues and recorded the presence or absence of lesions independently on a second form. The forms were collated and data were analysed to determine prevalence of lesions and associations with risk habits.

RESULTS

Data on 2,265 patients were available for analysis. Oral lesions were detected in 319 patients (14.1%). Ninety-four patients (4.2%) had lesions considered to be either malignant or potentially malignant. There was a significant association between positive lesions and male gender(IRR 1.86, 95% CI 1.22-2.82), heavy smoking (males: IRR 3.68, 95% Cl2.10-6.43: female; IRR 3.58, 954b CI 1.35-9.50) and heavy alcohol use in males (IRR 2.98, 95%q CI 1.06-3.47).

CONCLUSIONS

The results suggest that patients attending general dental practices are representative of the general population both in terms of lesion prevalence and high risk habits such as smoking and drinking. This supports the view that opportunistic screening in a general dental practice setting may be a realistic alternative to population screening. Further research is needed to determine the cost effectiveness of this approach and to investigate the value of targeting high risk groups within this population. General dental practice is ideal for the evaluation of such systems prior to extending these studies to other healthcare settings.

Screening programmes for the early detection and prevention of oral cancer

BACKGROUND

Although the second half of the last century has generated a rich and complex body of knowledge, the burden of oral cancer is still largely present. As with other cancers, there has been a strong debate whether screening strategies for oral cancer such as visual examination, the use of toluidine blue or newer methods such as brush biopsy or fluorescence imaging are effective in reducing the mortality rate associated with oral cancer.

OBJECTIVES

To assess the effectiveness of current screening methods in decreasing oral cancer mortality.

SEARCH STRATEGY

Electronic databases (MEDLINE, CANCERLIT, EMBASE, the Cochrane Central Register of Controlled Trials; 1966 to September 2002, The Cochrane Library - Issue 2, 2002), bibliographies, handsearching of specific journals and contact authors were used to identify published and unpublished data.

SELECTION CRITERIA

Randomised controlled trials of screening for oral cancer or potentially premalignant oral lesions using visual examination, toluidine blue, fluorescence imaging or brush biopsy.

DATA COLLECTION AND ANALYSIS

The search found 100 citations and these have been reviewed. One randomised controlled trial of screening strategies for oral cancer was identified as meeting the review's inclusion criteria. Validity assessment, data extraction and statistics evaluation have been undertaken by two independent reviewers.

MAIN RESULTS

One ongoing randomised controlled trial has been included (n = 13 clusters: 153,708 eligible subjects, 130,799 included subjects). There was no difference in the age-standardised oral cancer mortality rates for the screened group (21.2/1000,000 person years) and the control group (21.3/100,000 person years). However this study has some methodological weaknesses.

REVIEWER'S CONCLUSIONS

Given the limitation of evidence (only one included randomised controlled trial) and the potential methodological weakness in the included study, it is valid to say that there is no evidence to support or refute the use of a visual examination as a method of screening for oral cancer using a visual examination in the general population. Furthermore, no robust evidence exists to suggest other methods of screening, toluidine blue, fluorescence imaging or brush biopsy, are either beneficial or harmful. Further cost-effective, high quality studies to assess the efficacy and effectiveness of screening are required. In addition, studies to elucidate the natural history of oral cancer, prevention methods and the effectiveness of opportunistic screening in high risk groups are needed.