Diss. med. dent. Zürich. / Literaturverz.

Thesis (Ph.D.) - University of Queensland, 2005. / Includes bibliography.

Thesis (M.D.)--University of Hong Kong, 1995. / "September 1994". Includes bibliographical references. Also available in print.

Thesis (Ph. D.)--Ohio State University, 2005. / Available online via OhioLINK's ETD Center; full text release delayed at author's request until 2006 May 17

Thesis (M. Phil.)--University of Hong Kong, 2006. / Title proper from title frame. Also available in printed format.

Thesis (Ph.D.) - University of Queensland, 2005. / Includes bibliography.

Emerging from potentially malignant disorders that in most cases will never become cancerous, head and neck squamous cell carcinoma (HNSCC) is a cancer that is extremely difficult to diagnose early. This late stage diagnosis has allowed limited improvements in overall survival (OS) as patients are prone to local recurrence, secondary primary tumors, and distant metastasis. As a result, it has become vitally important to assess the prognostic value of biological marker screening to provide an avenue for early diagnosis and identification of local recurrence or residual secondary tumor sites. Many characteristic markers such as EGFR, p16, p53 and VEGF that are constitutively mutated in HNSCC have been identified. However, the dysregulation of VEGF marks a landmark mutation that accelerates the diseases progression and spread. An angiogenic protein normally expressed in response to hypoxic conditions, VEGF allows the creation of new vasculature to remove catabolites and bestows resistance to normal cellular apoptotic signals; pathways often employed by chemotherapeutics. Therefore, early identification of VEGF poses a unique opportunity to employ aggressive therapeutic regimens in combination with precision surgical resection to eliminate the cancer before neovascualture invasion has occurred and the tumor has expanded significantly. For this reason, this review will examine the current literature available on VEGFs role in HNSCC, its value as a prognostic marker.

Bisphosphonates (BPs) have been used clinically as anti-resorptive/cancer agents with confounded clinical outcomes and uncertain/conflicting biological understanding. This study was designed to evaluate the impact of clinically used anti-resorption drug alendronate (ALN) on cancer-bone metastasis and bone biology using novel 3D cancer-bone interaction model systems. To test the effects of ALN on the cancer-bone metastasis/interactions and bone biology we have utilized a novel 3D Co-cultures of live mouse neonatal calvarial bone organs with oral squamous cancer cells in a roller tube model systems (Curtin et al, 2012) in the absence and presence of ALN. These model systems under bone resorption and formation conditions were evaluated by chemical, biochemical, and histological analyses of the used media and calvarial bones. At the end of 8 days, the calvarial bones co-cultured with oral cancer cell lines in the absence and presence of ALN were processed for histological observations, TRAP and ALP enzyme activities, and neutral red staining. These studies were complemented by the effects of ALN on oral cancer cells under 2D classic cell culture conditions. In 3D-bone organ cultures under resorption conditions, oral cancer cells induce differentiation of osteoclasts and bone resorption and inclusion of ALN inhibited cancer-induced bone resorption. However, in both bone resorption and formation models the oral cancer cells colonized the bone and while treatment with ALN inhibits bone resorption, no effect on bone colonization was evident. Contrary to those under 2D cell culture conditions exposure to ALN of confluent and non-confluent oral cancer cells in the absence of live bone impacted oral cancer cells significantly in a dose dependent manner. Our studies using live bone organ cultures with oral cancer cells under specific dissociated bone remodeling stages, viz., resorption or formation only, revealed major and significant biological events which led to the conclusions that: (a) In the absence of bone in 2D cultures oral cancers are sensitive to ALN treatment whereas in the 3D live bone microenvironment tumors are resistant to ALN drug therapy, and (b) oral cancer-bone metastasis is independent of bone remodeling stage.

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.

Made available in DSpace on 2014-06-11T19:32:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-11-28Bitstream added on 2014-06-13T18:42:58Z : No. of bitstreams: 1 demathe_a_dr_araca.pdf: 333527 bytes, checksum: 481be7a0ed0bfcb0e04dcdc9c8824129 (MD5) / O papilomavirus humano (HPV) tem sido relacionado com a etiologia dos carcinomas epidermóides de cabeça e pescoço, em análise de tecidos cerca de 60% destes carcinomas podem ser HPV positivos. O objetivo deste trabalho foi analisar a presença do HPV em material genético obtidos de tecidos, secreção salivar e sangue de pacientes portadores de carcinoma epidermóide (CEC) de orofaringe e controles e a correlação da presença viral com as váriáveis sexo, idade, tabagismo, etilismo e perfil anatomopatologico do tumor. Foi realizada uma análise do material genético de 46 pacientes com diagnóstico de CEC de orofaringe e 40 pacientes sem carcinoma. A extração do DNA dos espécimes foi realizada utilizando o kit de extração de DNA QuiAMP. O DNA isolado foi submetido a PCR para beta-globina para confirmar a presença e integridade do DNA, em seguida, foram realizadas novas reações para detecção do DNA do HPV. Para análise estatística foram empregados o teste Qui-quadrado e teste exato de Fisher. A idade média de idade foi de 60 anos para os casos e 58,2 anos para os controles e a mediana foi de 59 e 56 anos, respectivamente. Os resultados obtidos com a metodologia descrita permitiram concluir que não houve diferenças estatisticamente significativas na análise das variáveis em relação à presença do papilomavírus humano nas amostras de tecidos biológicos dos pacientes estudados / Human papillomavirus (HPV) it has been related with head and neck SCC etiology, about 60% of these carcinomas tissues can be HPV positive. The aim of this study was to analyze the HPV presence in genetic material obtained from tissues, salivary secretion and blood of oropharyngeal SCC patients and controls and correlate the virus presence with variables: sex, age, smoking, alcoholism and pathological profile of the tumours.It was made molecular and statistical analysis of genetic material of 46 oral and oropharyngeal SCC patients and 40 controls patients without carcinoma. The DNA extraction of all specimens was accomplished using the DNA extraction kit QuiAMP. The isolated DNA was submitted PCR for beta-globin to confirm the DNA presence and integrity, after new reactions it was accomplished for HPV DNA detection. Chi-square test and Fisher exact test were used for statistical analysis. The average age was 60 years for cases and 58.2 years for controls and the median age was 59 and 56 years respectively. The results obtained with the described methodology shows there was no statistically significant differences between HPV presence in samples of biological tissues and the analyzed variables