Programmed Cell Death 4 (PDCD4) is a known tumour suppressor, lost in carcinomas of the breast, prostate, colon, lung and ovary. This study found significantly reduced levels of PDCD4 mRNA and protein in both primary patient oral squamous cell carcinomas (OSCCs) and OSCC cell lines. Moreover, lower PDCD4 mRNA levels were significantly correlated with nodal metastasis (P=0.019). To determine the functional significance of PDCD4 down-regulation in OSCC we asked whether PDCD4 played a role in invasion. In fact, over-expression of PDCD4 decreased invasion of OSCC lines. We then sought to determine a mechanism for PDCD4 down-regulation in OSCC. Previous studies in breast and colon carcinomas suggested that reduced PDCD4 expression was due to over-expression of miR-21. Interestingly, miR-21 was inversely correlated to PDCD4 mRNA (P=0.002) and PDCD4 protein (P<0.001) levels in OSCC patient samples. Moreover, we found that miR-21 directly regulated PDCD4 protein expression in OSCC cell lines. This is the first report in OSCC that demonstrates that PDCD4 is down-regulated by miR-21 and may play a role in OSCC invasion.

Programmed Cell Death 4 (PDCD4) is a known tumour suppressor, lost in carcinomas of the breast, prostate, colon, lung and ovary. This study found significantly reduced levels of PDCD4 mRNA and protein in both primary patient oral squamous cell carcinomas (OSCCs) and OSCC cell lines. Moreover, lower PDCD4 mRNA levels were significantly correlated with nodal metastasis (P=0.019). To determine the functional significance of PDCD4 down-regulation in OSCC we asked whether PDCD4 played a role in invasion. In fact, over-expression of PDCD4 decreased invasion of OSCC lines. We then sought to determine a mechanism for PDCD4 down-regulation in OSCC. Previous studies in breast and colon carcinomas suggested that reduced PDCD4 expression was due to over-expression of miR-21. Interestingly, miR-21 was inversely correlated to PDCD4 mRNA (P=0.002) and PDCD4 protein (P<0.001) levels in OSCC patient samples. Moreover, we found that miR-21 directly regulated PDCD4 protein expression in OSCC cell lines. This is the first report in OSCC that demonstrates that PDCD4 is down-regulated by miR-21 and may play a role in OSCC invasion.

Oral cancer is the 6th most common cancer in the world, with a poor prognosis and frequent late-stage diagnosis, which significantly impacts survival and quality of life. The key to better control of this disease is early detection, preferably at a precancerous stage. In order to facilitate this early detection and diagnosis, it is critical to identify the factors potentially impacting on the time lag from initial detection to diagnostic biopsy. The overall goal is to develop effective strategies for early identification of oral cancers in order to achieve better control over this disease. There are 2 components in this thesis: the objectives of part I (personal interview) were 1) to develop an interview-style questionnaire, 2) to collect data from patients with high-risk oral lesions (HRL’s) and 3) to characterize the experiences of these individuals that may have impacted the time interval leading up to diagnosis. The objectives of Part II (focus group discussion) were 1) to gather feedback regarding the questionnaire developed in Part I, 2) to obtain recommendations for future planning and delivery of province-wide questionnaire and 3) as a group, to share information on patients’ experiences to diagnosis and patients’ perspectives on their interactions with health professionals (HP’s) throughout this journey. An interview-style questionnaire was developed to collect both qualitative and quantitative data on patients’ experiences. Forty patients with HRL’s diagnosed within 12 months were recruited and interviewed in the Dysplasia Clinic of the BC Oral Cancer Prevention Program. Two focus groups were conducted and feedback from participants regarding the questionnaire and patients’ experiences was recorded. Among 40 patients interviewed, 21 (53%) initially self-identified their lesions (SIG) and 19 (47%) were identified by health professional screening (PSG; 84% by dental professionals). The SIG showed higher rates of invasive SCC at diagnosis as compared to those in the PSG (76% vs. 32%, P = 0.01) and SIG took twice as long to have the initial biopsy performed as the PSG (23 ± 52 vs. 11 ± 28 months). Notably, the main symptom of patients in SIG was pain or presence of non-healing ulcers (18/21; 86%). In contrast, all lesions in PSG were asymptomatic. The mean time from detection to diagnosis was 17.5 ± 42.3 months (range: 0-240 months). Fourteen patients (35%) experienced a time lag of greater than 6 months from first detection of an oral lesion until the first diagnostic biopsy was performed. Both patient and professional factors impact on the time lag. The main contributing factors for this time lag include both patient factors (a lack of concern, fear, and a lack of oral cancer awareness) and the professional factors (lack of knowledge in differentiating high-risk lesions, delay in initiating the referral or ‘watch and wait’, and delay in scheduling of referral appointments to the specialists). Focus group results supported the format and content of the questionnaire, provided input in designing of future province-wide survey and emphasized that patients require continued post-diagnostic and treatment care. A general lack of awareness of oral cancer in general population and in HP’s in addition to a lack of screening activities have been brought forward as critical factors that result in delay to diagnosis. In conclusion, these results suggest HP’s, especially dental professionals, can play a critical role in early identification of HRL’s at an asymptomatic, pre-invasive stage through regular screening. Strategies in raising awareness of oral cancer in both the general population and among HP’s are essential for early identification of oral cancers in order to achieve better control over this disease.

Cancer morbidity and mortality is greatly reduced when the disease is diagnosed and treated early in its development. Tissue biopsies are the gold standard for cancer diagnosis, and an accurate diagnosis requires a biopsy from the malignant portion of an organ. Light, guided through a fiber optic probe, could be used to inspect regions of interest and provide real-time feedback to determine the optimal tissue site for biopsy. This approach could increase the diagnostic accuracy of current biopsy procedures. The studies in this thesis have characterized changes in tissue optical signals with carcinogenesis, increasing our understanding of the sensitivity of optical techniques for cancer detection. All in vivo studies were conducted on the dimethylbenz[alpha]anthracene treated hamster cheek pouch model of epithelial carcinogenesis. Multiphoton microscopy studies in the near infrared wavelength region quantified changes in tissue morphology and fluorescence with carcinogenesis in vivo. Statistically significant morphological changes with precancer included increased epithelial thickness, loss of stratification in the epithelium, and increased nuclear diameter. Fluorescence changes included a statistically significant decrease in the epithelial fluorescence intensity per voxel at 780 nm excitation, a decrease in the fluorescence lifetime of protein-bound nicotinamide adenine dinucleotide (NADH, an electron donor in oxidative phosphorylation), and an increase in the fluorescence lifetime of protein-bound flavin adenine dinucleotide (FAD, an electron acceptor in oxidative phosphorylation) with precancer. The redox ratio (fluorescence intensity of FAD/NADH, a measure of the cellular oxidation-reduction state) did not significantly change with precancer. Cell culture experiments (MCF10A cells) indicated that the decrease in protein-bound NADH with precancer could be due to increased levels of glycolysis. Point measurements of diffuse reflectance and fluorescence spectra in the ultraviolet to visible wavelength range indicated that the most diagnostic optical signals originate from sub-surface tissue layers. Optical properties extracted from these spectroscopy measurements showed a significant decrease in the hemoglobin saturation, absorption coefficient, reduced scattering coefficient and fluorescence intensity (at 400 nm excitation) in neoplastic compared to normal tissues. The results from these studies indicate that multiphoton microscopy and optical spectroscopy can non-invasively provide information on tissue structure and function in vivo that is related to tissue pathology. / Dissertation

Defects in mismatch repair genes, particularly the hMLH1 and hMSH2 genes, are associated with pathogenesis and prognosis of some cancers. The lack of correlation between replication error phenotype and mutations in hMLH1 in sporadic human cancers suggested that inactivation of the hMLH1 gene may be associated with promoter hypermethylation. This study was to investigate the association of hMLH1 promoter hypermethylation and hMLH1 protein expression in oral cancer. Our results indicated that all 75 cases (100%) were without any methylation of hMLH1 promoter by use of methylation-specific PCR (MSP). Nineteen of 99 cases (19.2%) were partial methylation by HpaII-based PCR. In addition, 24 (26.1%) of 92 cases of OSCC had reduced levels of hMLH1 protein. The concordance analysis showed that the expression level of hMLH1 protein was not correlated with methylation of hMLH1 promoter. Furthermore, the prognosis significance of hMLH1 or hMSH2 proteins on OSCC was also investigated. We analyzed the association of hMLH1 and hMSH2 protein expression with clinicopathological data of 92 cases of OSCC at KSVGH. We found that 24 (26.1%) of 92 cases of OSCC had reduced levels of hMLH1 protein, however only 10 cases (10.9%) had reduced hMSH2 by use of IHC. In addition, the reduced expression of hMLH1 correlated with the tumor differentiation and N classification. However, none of these clinical and pathological characteristics of the OSCC patients were associated with the extent of hMSH2 expression. Finally, previous studies reports that the hMLH1 and Aurora-A are directly involved in the prognosis of several cancers. The expression levels of hMLH1 and Aurora-A protein were investigated in the 138 tumor samples for consecutive patients with pathological confirmed primary buccal carcinoma (BC). Then the association of the protein expression with clinicopathological data and survival were also evaluated. The loss of hMLH1 protein was found in 15 (10.9%) of 138 tumor sections by IHC. In addition, loss of hMLH1 protein expression was not any correlated with clinical features and patients¡¦ prognosis. The up-regulation of Aurora-A protein was found in 118 (85.5%) of 138 tumor sections by IHC. In addition, the up-regulation of Aurora-A protein expression was correlated with the pathological stage and T classification, but Aurora-A protein up-regulation was not correlated with prognosis. In conclusion, promoter methylation of hMLH1 might not play a potent role in the gene expression in oral cancer. Defective expression of hMLH1 but not hMSH2 was associated with the development of OSCC. In addition, the Aurora-A protein expression but not hMLH1 may affect the malignant behavior of BC. However, the hMLH1 and Aurora-A protein expression might be not the prognostic factors for BC patients.

The present study explored the effect of three anti-tumor drugs (cisplatin, fluorouracil, and temozolomide) on viability and cytosolic free Ca2+ concentrations ([Ca2+]i) in OC2 human oral cancer cells. The effect of cisplatin related mitogen-activated protein kinases (MAPKs) phosphorylation was also examined. Cisplatin at concentration of 25-150 £gM decreased viability in a concentration-dependent manner, and so did fluorouracil (50-1000 £gM) and temozolomide (50-600 £gM). The three anti-tumor drugs all failed to induce a [Ca2+]i increase; thus it seemed that these drugs induced cell death via Ca2+-independent pathways. Immunoblotting showed that OC2 cells have background phospho-ERK, phospho-JNK and phospho-p38 MAPKs. It was found that cisplatin influenced the phosphorylation of ERK, JNK and p38 MAPKs at different time points.

Oral cancer is the 6th most common cancer in the world, with a poor prognosis and frequent late-stage diagnosis, which significantly impacts survival and quality of life. The key to better control of this disease is early detection, preferably at a precancerous stage. In order to facilitate this early detection and diagnosis, it is critical to identify the factors potentially impacting on the time lag from initial detection to diagnostic biopsy. The overall goal is to develop effective strategies for early identification of oral cancers in order to achieve better control over this disease. There are 2 components in this thesis: the objectives of part I (personal interview) were 1) to develop an interview-style questionnaire, 2) to collect data from patients with high-risk oral lesions (HRL’s) and 3) to characterize the experiences of these individuals that may have impacted the time interval leading up to diagnosis. The objectives of Part II (focus group discussion) were 1) to gather feedback regarding the questionnaire developed in Part I, 2) to obtain recommendations for future planning and delivery of province-wide questionnaire and 3) as a group, to share information on patients’ experiences to diagnosis and patients’ perspectives on their interactions with health professionals (HP’s) throughout this journey. An interview-style questionnaire was developed to collect both qualitative and quantitative data on patients’ experiences. Forty patients with HRL’s diagnosed within 12 months were recruited and interviewed in the Dysplasia Clinic of the BC Oral Cancer Prevention Program. Two focus groups were conducted and feedback from participants regarding the questionnaire and patients’ experiences was recorded. Among 40 patients interviewed, 21 (53%) initially self-identified their lesions (SIG) and 19 (47%) were identified by health professional screening (PSG; 84% by dental professionals). The SIG showed higher rates of invasive SCC at diagnosis as compared to those in the PSG (76% vs. 32%, P = 0.01) and SIG took twice as long to have the initial biopsy performed as the PSG (23 ± 52 vs. 11 ± 28 months). Notably, the main symptom of patients in SIG was pain or presence of non-healing ulcers (18/21; 86%). In contrast, all lesions in PSG were asymptomatic. The mean time from detection to diagnosis was 17.5 ± 42.3 months (range: 0-240 months). Fourteen patients (35%) experienced a time lag of greater than 6 months from first detection of an oral lesion until the first diagnostic biopsy was performed. Both patient and professional factors impact on the time lag. The main contributing factors for this time lag include both patient factors (a lack of concern, fear, and a lack of oral cancer awareness) and the professional factors (lack of knowledge in differentiating high-risk lesions, delay in initiating the referral or ‘watch and wait’, and delay in scheduling of referral appointments to the specialists). Focus group results supported the format and content of the questionnaire, provided input in designing of future province-wide survey and emphasized that patients require continued post-diagnostic and treatment care. A general lack of awareness of oral cancer in general population and in HP’s in addition to a lack of screening activities have been brought forward as critical factors that result in delay to diagnosis. In conclusion, these results suggest HP’s, especially dental professionals, can play a critical role in early identification of HRL’s at an asymptomatic, pre-invasive stage through regular screening. Strategies in raising awareness of oral cancer in both the general population and among HP’s are essential for early identification of oral cancers in order to achieve better control over this disease.

<p>Background and Aims: While a single &ldquo / high quality&rdquo / oral liquid based cytology (LBC) study has shown a high sensitivity and specificity for the technique in detection of oral dysplasia and malignancy, the high unit cost of this technology cannot be borne by the developing African countries. This study aims to evaluate the efficiency of an alternative cost-effective technique, Shandon PapSpin (PS) LBC in&nbsp / diagnosis of oral and oropharyngeal dysplasia and malignancy. Materials and Methods.We compared the diagnostic accuracy of Shandon PS LBC with that of scalpel biopsy in 69 patients. Transepithelial cytology specimens were obtained using a cervical Cytobrush. The cytology specimens were graded and scored using a novel oral cytologic grading and scoring system respectively. Results: Histological diagnosis of dysplasia or invasive squamous cell carcinoma was made in 51 of the 69 cases. Histology confirmed the cytological diagnosis of dysplasia or malignancy in 49 of the 51 cases. There were two false negative and no false positive cases. The sensitivity was 96% and the specificity 100%. The cytologic grade correlated positively with histologic grade. The best cut off value for distinguishing reactive/mildly dysplastic lesions from high 9 grade/invasive squamous cell carcinoma was determined as a cytologic score of 3, representing a sensitivity of 95% and a specificity of 96%. Conclusion: The Shandon PS LBC in association with transepithelial brush biopsy technique (TBBT) is a highly sensitive, specific and economical screening test in detection of oral and oropharyngeal dysplasia and malignancy. The proposed oral cytologic grading system correlates well with histology. The novel oral cytologic scoring system shows promise as a simple, reliable and reproducible scoring system. In addition, the liquid residual allows for immunocytochemical (Podoplanin) testing.</p>

<p>Oral cancer is characterised by marked geographical differences in frequency and site preference as reported by various studies. In South Africa, a few studies have been reported on the patterns and aetiology of oral cancer, and age standardised incidence rates (ASIR). Studies in several countries have shown an increase in oral cancer incidence among younger people. Title:&nbsp / Epidemiology of oral cancer in South Africa 1996-2002.&nbsp / Aim and Objective: The aim of this study was to determine the age standardised incidence rates (ASIR) of oral cancer by age, gender, race&nbsp / and site in South Africa for a consecutive period of seven years. Method: Pathology case records of oral cancer diagnosed over a seven-year period from 1996 to 2002 and reported to the National&nbsp / Cancer Registry (NCR) were analysed for age, sex, race, and date of diagnosis, basis of diagnosis, topography and tumour type. The data was tabulated and categorised using Microsoft Excel. The South African population size for each year of the study was estimated by linear extrapolation using the 1996 and 2001 census results. Age standardisation incidence rates against the world&nbsp / population were calculated by the standard direct method. Results: The total number of oral squamous cell carcinoma cases over the 7-year period was 9702. The majority of cases (34%) were&nbsp / on the tongue. The male to female ratio was 1:3. The age standardized incidence rates in this study was lower among African women / (0.640 per 100000 per year) and the highest was 13.40 new cases per 100000 per year (coloured males). Lip cancer was highest among both males and females of the white population. The cumulative rate of developing oral cancer was 1:83 and 1:32 for males and females respectively.</p>

Aproximadamente 3% das neoplasias malignas são originadas da cavidade bucal e representadas na maioria pelo carcinoma espinocelular (CEC). Estudos tem demostrado variações nas características clínico-epidemiológicas do CEC de boca de acordo com área geográfica da população estudada. A compreensão das características de uma população específica é importante por muitas razões, incluindo a compreensão da extensão do problema, fatores relacionados com seu desenvolvimento, seu diagnóstico e prognóstico. No entanto, poucos estudos têm sido relatados sobre essa lesão na população Uruguaia. O objetivo deste estudo foi avaliar o perfil demográfico, os aspectos clínicos e terapêuticos, assim como, os fatores prognósticos dos carcinomas espinocelulares de boca (CECB) diagnosticados em serviços públicos no Uruguai. Foram selecionados todos os prontuários médicos de pacientes com diagnóstico histopatológico de carcinoma espinocelular de boca primário atendidos no período de Janeiro 2000 a Dezembro de 2010 em Hospitais Públicos de Uruguai. Os prontuários foram avaliados manualmente e foram coletadas informações quanto aos dados demográficos, fatores de risco, características clínicas do tumor, tratamento e evolução. Foi confeccionado um banco de dados com as informações coletadas nos prontuários. A análise descritiva de todas as variáveis foi realizada e a existência de associação entre as variáveis independentes e os desfechos (estadiamento clínico e evolução) foi avaliada através do teste Qui-quadrado de Pearson e o teste de Fisher, o nível de significância estabelecido foi de 5%. Dentre os 200 prontuários de pacientes analisados, 79.4% eram homens com distribuição homem:mulher de 3.8:1. A média de idade foi de 60,75 anos. A análise univariada mostrou que o estadiamento clínico tem associação significativa com o tabagismo (p = 0,04), quantidade de tabaco (p = 0,018), aspecto clínico (p = 0,009), tamanho do tumor (p = 0,001) e metástases regionais (p = 0,001). Os homens portadores de CEC foram associados com o consumo de tabaco e álcool. O prognóstico desfavorável dos CECB (óbito) foi significativamente relacionado com aspecto clínico (p = 0,02), tamanho (p = 0,001), metástases regionais (p = 0,016), estadiamento clínico (p = 0,002) e tratamento (p = 0,001). A maioria dos pacientes com CECB que evoluiram a óbito (pior prognóstico), exibiram úlcera (93,9%), tamanhos avançados - T3/T4 (90,2%), metástases regionais (66%), foram classificadas no estágio III/IV (94,1%) e receberam tratamento não cirúrgico ou paliativos. Conclui-se que no Uruguai o diagnóstico do CECB é tardio e associado a baixas taxas de sobrevida. Medidas educativas e preventivas para a população assim como, investimentos em estratégias para melhorar o diagnóstico precoce devem ser uma meta neste país. / Nearly 3% of malignant neoplasms originate from the oral cavity and are mostly represented by squamous cell carcinoma (SCC). Studies have demonstrated variations in clinical and epidemiological features of oral SCC according to geographical area of the study population. Understanding the characteristics of a specific population is important for many reasons, including the comprehension of the extent of the problem, factors associated with their development, diagnosis and prognosis. However, few studies have been developed in Uruguayan population about this lesion. The aims of the present study were to evaluate the demographic, clinical and therapeutic features, as well as, the predictive factors of poor prognosis in patients with primary OSCC evaluated during a period of 10-years in public health services in Uruguay. Medical records of patients with histological diagnosis of primary OSCC treated between January 2000 and December 2010 in Uruguayan Public Hospitals were selected. Information regarding demographics, risk factors, clinical features, treatment and outcome was collected. A descriptive analysis was performed, and the existence of association between independent variables and outcomes (clinical stage and evolution) was assessed using the Pearson Chi-Square test and Fisher's test. Out of a total of 200 patients with OSCC, 79.4% were men with 3.8:1 male:female ratio. The mean age was 60.75 years. Univariate analysis showed that clinical stage have significant association with smoking (p=0,04), amount of tobacco (p=0.018), clinical aspect (p=0.009), tumor size (p=0.001) and regional metastasis (p=0.001). OSCC male patients were associated with tobacco and alcohol comsumption. Worse overall survival (poor prognosis) was significant associated with clinical aspect (p=0.02), size (p=0.001), regional metastasis (p=0.016), clinical stage (p=0.002) and treatment (p=0.001). The majority of OSCC patients with worse overall survival presented oral ulcer (93.9%), T3/T4 tumor size (90.2%), regional metastasis (66%), were classified at stage III/IV (94.1%) and received nonsurgical or palliatives treatment. We conclude that in Uruguay the diagnosis of OSCC is late associated to low survival rate. Educational and preventive measures for the population and investment in strategies to improve early diagnosis should be a goal in this country.