No description available.

No description available.

<p> Photodynamic therapy (PDn is an effective treatment option for various types of invasive tumors, the efficacy of which depends strongly on selective cell uptake and selective excitation of the tumor, which relies on proper dosage. The characterization of the fluorescence lifetimes of photosensitizers localized inside living cells may provide the basis for further investigation of in vitro PDT dosage measurements using time-domain spectroscopy and imaging. In this thesis, the fluorescence lifetimes of localized Photofrin ® and delta-aminolevulinic acid (ALA) induced protoporphyrin IX (PpiX) were investigated in living MAT-LyLu (MLL) rat prostate adenocarcinoma cells. Cells were incubated with the photosensitizers, and then treated with light under well-oxygenated conditions using a two-photon fluorescence lifetime imaging microscope (FLIM). Fluorescence lifetime images of these cells were recorded with average lifetimes of 5.5 ± 1.2 ns for Photofrin and 6.3 ± 1.2 ns for ALA-induced PpiX over 600 to 750 nm. Two channel FLIM revealed lifetimes of7.8 ± 0.5 ns for Photofrin® and 10.8 ± 1.7 ns for PpiX over 620 to 645 nm, while photoproducts observed on the second channel yielded lifetimes of 5.1 ± 0.4 ns over 650 to 670 nm for Photofrin® and 6.3 ± 1.0 ns over 670 to 690 nm for PpiX. Fluorescence lifetimes of both photosensitizers were found to be significantly shorter when localized in cells than when measured in solutions, suggesting that photosensitizers' lifetimes go through significant changes when bonded to intracellular components. These changes in lifetime also provide opportunities to quantitatively measure and monitor the binding states of the photosensitizers and their microenvironment, which may be used in real-time PDT dosimetry, as well as for diagnostic purposes. </p> / Thesis / Master of Applied Science (MASc)

Abstract not available

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide, with over 50,000 new cases in the United States annually. Major risk factors for HNSCC include chronic smoking and/or alcohol consumption, and more recently infection with human papillomaviruses (HPVs). HNSCC comprises a diverse collection of tumors, of which the oral cavity is the most affected site. Most HNSCC patients will die within the first 30 months of disease, an abysmal statistic largely reflecting a lack of effective treatment strategies. This challenge highlights the current unmet need to identify 1) distinct molecular subgroups of HNSCC and 2) prognostic biomarkers that can inform subgroup-specific treatment plans. The Lu Lab has identified a previously unappreciated HNSCC subgroup defined by alteration in NSD1, a histone methyltransferase enzyme mutated in up to 15% of HPV- HNSCC. NSD1 has specific di-methylase activity targeting histone H3 lysine 36 (H3K36). The formation of methylated H3K36 is associated with open chromatin and transcriptional activation. There are several distinct features of NSD1-mutant HPV- HNSCC tumors, including a) increased patient smoking history and mutational burden; b) a significantly better prognosis; and c) reduced immune cell infiltration in the tumor. These correlative findings may suggest a tumor-suppressive role of NSD1, yet the impact of NSD1-loss in HNSCC pathogenesis and the underlying mechanisms remain unclear. The scope of my thesis work aims to address this gap in knowledge through investigating the consequences of impaired NSD1 in normal epithelial tissue and in the setting of HNSCC tumors. In Chapter 2, we employed both a syngeneic tumor implantation model and a physiologic mouse model of HNSCC carcinogenesis to establish and characterize Nsd1-KO tumors. We found that mice harboring Nsd1-KO tumors are comparatively immune- ‘cold,’ a phenotype that persisted in human HNSCC patient samples. Our in vitro data suggests that depletion of NSD1 epigenetically silences the interferon response, an effect that was rescued through inhibition of epigenetic machinery that limits NSD1-deposited H3K36me2. These studies provide novel insight into the molecular underpinnings of observed immune-‘coldness’ in NSD1-mutated HNSCC. They also prompted us to probe the impact of NSD1-loss at early stages of tumor development. In Chapter 3, I describe a lingual-derived organoid system to assess unbiased transcriptional changes that occur upon Nsd1-loss during homeostasis, premalignancy, and overt tumor formation. Interestingly, we found that Nsd1-KO organoids harvested from stages preceding HNSCC featured downregulation in gene expression related to epithelial barrier formation and wound healing. Furthermore, organoids derived from Nsd1-KO tumors showed reduced expression of epithelial-to-mesenchymal transition (EMT) signature genes, potentially signifying a role of NSD1 in modulating cell adhesion and mobility. Several additional studies are needed to establish the functional basis of how NSD1 participates in these processes. Taken together, this body of work expands upon our current understanding of NSD1-loss in HNSCC development and presents a conceptual scaffold framing NSD1 as a multi-faceted player in the homeostatic maintenance and neoplastic events of the oral epithelium.

One of the most challenging questions in the study of cancer is the origin and the nature of the cells that initiate cancer. Accumulated studies have provided many molecular origins of cancers but we still do not know what kind of cells in the tissues transform to cancer cells. Therefore, identifying the cellular origin of these cells is critical for the development of better prognosis, diagnosis and treatment of cancer. A stem cell origin of cancer has been postulated over 150 years. Recent cancer stem cell studies have opened a new window on aspects of the cellular origin of cancer. In this communication, we will address two possible cellular origins of cancer in epithelial tumor development using mouse skin cancer model: tissue specific stem cells, and cells from other organs. To demonstrate contribution of the tissue specific stem cells in tumor development, we monitored the contribution of keratin-15 positive hair follicle bulge stem cells to skin tumor development in the multistage skin carcinogenesis model with Krtl- 15CrePRl;R26R transgenic mice. We found that labeled progeny of the keratin-15 positive bulge stem cells migrate into papillomas and these cells contribute to almost all papilloma samples by 20 weeks of promotion. Additionally, in contrast to the transient contribution of bulge-derived cells in skin wound healing, consistent percentage of the bulge-derived cells stay in the papillomas over 20 weeks. Furthermore, papillomas have heterogeneous expression of the codon 61 signature Ha-ras mutation, with approximately 30 percent of bulge-derived regions expressing the mutation. To determine the contribution of exogenous sources in skin tumor development, we examined bone marrow-derived cells (BMDCs) in the skin tumors from the allogeneic gender-mismatched bone marrow transplantation recipient mice after chemical skin carcinogenesis. We observed that genetically marked (EGFP) BMDCs were detected in the epithelial part of skin wounds and also skin tumors, and we found greater degree of BMDC contribution in chronic ulcer-related skin lesions. Lastly, an in-vitro assay demonstrated plasticity of BMDCs by inducing keratin-14 expressing cells from mesenchymal stem cells. These results demonstrated that hair follicle bulge stem cells and also BMDCs are able to contribute to skin tumor development.

Retinoblastoma (Rb) é o tumor ocular mais frequente na infância e cada grande Centro deve conhecer o perfil dos seus pacientes. Foi realizado um estudo do tipo coorte retrospectivo e incluiu pacientes com Rb atendidos entre 1983 e 2012 nos Serviços de Oncologia Pediátrica, Oftalmologia e Genética Médica do Hospital de Clínicas de Porto Alegre (HCPA). De um total de 165 registros no período foram efetivamente incluídos 140 pacientes, sendo 95,0% destes provenientes de municípios do Rio Grande do Sul. Os sinais mais frequentes ao diagnóstico foram: leucocoria (73,6%) e estrabismo (20,7%). Identificamos a seguinte distribuição: doença unilateral (65,0%), bilateral (32,9%) sendo 80,4% com doença multifocal (p=0,015), trilateral (2,1%). A idade média dos pacientes por ocasião dos primeiros sinais e sintomas foi de 18,1 meses [mediana=12,0] e a idade média ao diagnóstico foi 23,5 meses [mediana=16,5]. Cinquenta pacientes (35,7%) foram diagnosticados no 1º ano de vida. O tempo de diagnóstico médio da coorte foi 5,4 meses [mediana=3,0], (amplitude=0-77,0). A idade média aos primeiros sinais e sintomas do grupo com critérios de hereditariedade foi de 12,3 meses enquanto a do grupo não hereditário foi de 21,6 meses (p=0,001), enquanto a idade média ao diagnóstico foi de 15,9 meses vs. 28 meses, respectivamente (p<0,001). Entretanto não houve diferença na sobrevida entre esses subgrupos. O estadiamento ocular dos pacientes ao diagnóstico na sua maioria foi avançado (classificação de Reese V em 76,5%, Internacional D ou E em 78,1%), sendo que 35,2% dos unilaterais e 34,8% dos bilaterais já apresentavam doença extraocular em pelo menos um olho ao diagnóstico. Quinze pacientes (10,7%) tinham doença metastática ao diagnóstico. Em relação ao tratamento, diferentes modalidades foram utilizadas, sendo a maioria dos pacientes submetidos à cirurgia, sendo esta enucleação em 88,1% e exenteração em 11,9%. Uma parcela significativa dos pacientes foi tratada com quimioterapia sistêmica (57,1%) e/ou radioterapia (37,1%). Do total de pacientes recrutados, 131 (93,6%) permaneceram vinculados ao hospital até 2012 ou até o óbito. Destes, 32 (22,9%) recidivaram, resultando em 19 óbitos com 84,2% por progressão do Rb. Uma segunda neoplasia primária esteve presente em 4,3% (N=6) e dentre esses, um paciente teve uma terceira neoplasia primária. O tempo de seguimento médio foi 323,2 meses [300,3; 346,1]. As sobrevidas nos diferentes subgrupos foram as seguintes: sobrevida global 86,4%; no não metastático 92,0%; no metastático 40,0%; entre os intraoculares 94,0%; entre os extraoculares 68,5%; entre os unilaterais e bilaterais ambos com cerca de 88,0%; entre os trilaterais (N=3) todos foram a óbito; entre os unilaterais intraoculares 94,9% e extraoculares 75,0% e entre os bilaterais intraoculares 94,5% e extraoculares 68,4%. No nosso meio, o diagnóstico de Rb ainda é feito predominantemente em estadios avançados o que reduz a sobrevida dos pacientes e o índice de preservação do olho e da visão, além de aumentar a intensidade dos tratamentos realizados e consequentemente, toxicidade e efeitos tardios destes. Avaliações clínicas e oftalmológicas periódicas nos primeiros anos de vida da criança oferecem maior oportunidade de um diagnóstico precoce e o encaminhamento rápido à um Centro de Referência multidisciplinar que contemple cuidados terciários em Oftalmologia e Oncologia Pediátrica é fundamental. Existe grande necessidade de investimentos regionais que facilitem o acesso ao diagnóstico e tratamento do Rb, o tumor ocular mais frequente na infância. / Retinoblastoma (Rb) is the most frequent ocular tumor diagnosed in children and every pediatric hospital must be familiar with its clinical presentation and patient characteristics. A retrospective cohort study was undertaken, with patients diagnosed with retinoblastoma from 1983 until 2012, treated at the Pediatric Oncology Unit, Ophthalmology Unit, and Medical Genetics Unit of the Hospital de Clínicas de Porto Alegre (HCPA). Of a total of 165 registries during this time frame, 140 patients were included in this study, with 95% of them from the state of Rio Grande do Sul. The most frequent signs and symptoms at diagnosis were: leukocoria (73.6%) and strabismus (20.7%). The following distribution was identified: unilateral disease (65.0%), bilateral disease (32.9%), being 80.4% with multifocal disease, (P=0,015), and trilateral disease (2.1%). The average age of patients at the appearance of the first sign or symptom was 18.1 months [median=12.0] and the average age at diagnosis was 23.5 months [median=16.5]. Fifty patients (35.7%) were diagnosed during their first year of age. The average time to diagnosis was of 5.4 months [median=3.0], (amplitude=0-77.0). In the hereditary retinoblastoma group, the average age at the appearance of the first sign or symptom was 12.3 months, whereas the non-hereditary group presented the first sign or symptom on average at 21.6 months (P=0,001). The average age at diagnosis was 15.9 months vs. 28 months for the hereditary and non-hereditary patients, respectively (P<0.001). However, no significant difference in overall survival was found when both groups were compared. Ocular staging at diagnosis was, for the most part, advanced disease, (Reese V classification: 76.5%, Internacional Classification of Retinoblastoma D or E in 78.1% patients), being that 35.2% of cases were comprised of unilateral disease and 34.8% of patients with bilateral disease already presented with extraocular lesions in at least one eye at diagnosis. Fifteen patients (10.7%) presented with metastasis at diagnosis. With regards to treatment, differnet modalities were employed, being that most patients underwent surgery with enucleation in 88.1% and e exenteration in 11.9%. A significant number of patients received systemic chemotherapy (57.1%) and/or radiotherapy (37.1%). Of all patients included, 131 (93.6%) remained in follow up at the hospital until 2012 or until their demise. Of these patients, 32 (22.9%) relapsed, leading to 19 deaths, 84.2% of them due to disease progression. Secondary malignancies were present in 6 patients (4.3%) and, of these, one patient presented with two different secondary malignancies. The average time of patient follow up was 323.2 months [300.3; 346.1]. Overall survival was of 86.4%, with the following time frames among the different patient subgroups: 92.0% for non-metastatic patients, 40.0% for metastatic patients, intraoculares 94.0% for patients with intraocular disease, and 68.5% for patients with extraocular lesions. With regards to unilateral or bilateral disease, overall survival was of 88.0%; for patients with trilateral disease, (N=3) all patients expired. Survival of patients with unilateral and intraocular disease was of 94.9%; patients with unilateral and extraocular disease presented a overall survival of 75.0%. Patients with bilateral intraocular lesions overall survival was of 94.5%, whereas patients with bilateral and extraocular disease had an overall survival of 68.4%. In our setting, Rb diagnosis still occurs when the patients already manifest advanced disease, which reduces considerably their overall survival and preservation of the ocular globe and vision. Moreover, late diagnosis requires more agressive treatments, and consequently leads to more frequent toxicities and late side effects. Periodic clinical and ophthalmologic evaluations during the first years of a child's life offer a greater chance of early diagnosis and referral to a multidisciplinary pediatric oncology center, which is crucial for the patient’s well being. There is much need of further investments which facilitate patient access to diagnosis and treatment for Rb, which is the most common ocular tumor in children.

Retinoblastoma (Rb) é o tumor ocular mais frequente na infância e cada grande Centro deve conhecer o perfil dos seus pacientes. Foi realizado um estudo do tipo coorte retrospectivo e incluiu pacientes com Rb atendidos entre 1983 e 2012 nos Serviços de Oncologia Pediátrica, Oftalmologia e Genética Médica do Hospital de Clínicas de Porto Alegre (HCPA). De um total de 165 registros no período foram efetivamente incluídos 140 pacientes, sendo 95,0% destes provenientes de municípios do Rio Grande do Sul. Os sinais mais frequentes ao diagnóstico foram: leucocoria (73,6%) e estrabismo (20,7%). Identificamos a seguinte distribuição: doença unilateral (65,0%), bilateral (32,9%) sendo 80,4% com doença multifocal (p=0,015), trilateral (2,1%). A idade média dos pacientes por ocasião dos primeiros sinais e sintomas foi de 18,1 meses [mediana=12,0] e a idade média ao diagnóstico foi 23,5 meses [mediana=16,5]. Cinquenta pacientes (35,7%) foram diagnosticados no 1º ano de vida. O tempo de diagnóstico médio da coorte foi 5,4 meses [mediana=3,0], (amplitude=0-77,0). A idade média aos primeiros sinais e sintomas do grupo com critérios de hereditariedade foi de 12,3 meses enquanto a do grupo não hereditário foi de 21,6 meses (p=0,001), enquanto a idade média ao diagnóstico foi de 15,9 meses vs. 28 meses, respectivamente (p<0,001). Entretanto não houve diferença na sobrevida entre esses subgrupos. O estadiamento ocular dos pacientes ao diagnóstico na sua maioria foi avançado (classificação de Reese V em 76,5%, Internacional D ou E em 78,1%), sendo que 35,2% dos unilaterais e 34,8% dos bilaterais já apresentavam doença extraocular em pelo menos um olho ao diagnóstico. Quinze pacientes (10,7%) tinham doença metastática ao diagnóstico. Em relação ao tratamento, diferentes modalidades foram utilizadas, sendo a maioria dos pacientes submetidos à cirurgia, sendo esta enucleação em 88,1% e exenteração em 11,9%. Uma parcela significativa dos pacientes foi tratada com quimioterapia sistêmica (57,1%) e/ou radioterapia (37,1%). Do total de pacientes recrutados, 131 (93,6%) permaneceram vinculados ao hospital até 2012 ou até o óbito. Destes, 32 (22,9%) recidivaram, resultando em 19 óbitos com 84,2% por progressão do Rb. Uma segunda neoplasia primária esteve presente em 4,3% (N=6) e dentre esses, um paciente teve uma terceira neoplasia primária. O tempo de seguimento médio foi 323,2 meses [300,3; 346,1]. As sobrevidas nos diferentes subgrupos foram as seguintes: sobrevida global 86,4%; no não metastático 92,0%; no metastático 40,0%; entre os intraoculares 94,0%; entre os extraoculares 68,5%; entre os unilaterais e bilaterais ambos com cerca de 88,0%; entre os trilaterais (N=3) todos foram a óbito; entre os unilaterais intraoculares 94,9% e extraoculares 75,0% e entre os bilaterais intraoculares 94,5% e extraoculares 68,4%. No nosso meio, o diagnóstico de Rb ainda é feito predominantemente em estadios avançados o que reduz a sobrevida dos pacientes e o índice de preservação do olho e da visão, além de aumentar a intensidade dos tratamentos realizados e consequentemente, toxicidade e efeitos tardios destes. Avaliações clínicas e oftalmológicas periódicas nos primeiros anos de vida da criança oferecem maior oportunidade de um diagnóstico precoce e o encaminhamento rápido à um Centro de Referência multidisciplinar que contemple cuidados terciários em Oftalmologia e Oncologia Pediátrica é fundamental. Existe grande necessidade de investimentos regionais que facilitem o acesso ao diagnóstico e tratamento do Rb, o tumor ocular mais frequente na infância. / Retinoblastoma (Rb) is the most frequent ocular tumor diagnosed in children and every pediatric hospital must be familiar with its clinical presentation and patient characteristics. A retrospective cohort study was undertaken, with patients diagnosed with retinoblastoma from 1983 until 2012, treated at the Pediatric Oncology Unit, Ophthalmology Unit, and Medical Genetics Unit of the Hospital de Clínicas de Porto Alegre (HCPA). Of a total of 165 registries during this time frame, 140 patients were included in this study, with 95% of them from the state of Rio Grande do Sul. The most frequent signs and symptoms at diagnosis were: leukocoria (73.6%) and strabismus (20.7%). The following distribution was identified: unilateral disease (65.0%), bilateral disease (32.9%), being 80.4% with multifocal disease, (P=0,015), and trilateral disease (2.1%). The average age of patients at the appearance of the first sign or symptom was 18.1 months [median=12.0] and the average age at diagnosis was 23.5 months [median=16.5]. Fifty patients (35.7%) were diagnosed during their first year of age. The average time to diagnosis was of 5.4 months [median=3.0], (amplitude=0-77.0). In the hereditary retinoblastoma group, the average age at the appearance of the first sign or symptom was 12.3 months, whereas the non-hereditary group presented the first sign or symptom on average at 21.6 months (P=0,001). The average age at diagnosis was 15.9 months vs. 28 months for the hereditary and non-hereditary patients, respectively (P<0.001). However, no significant difference in overall survival was found when both groups were compared. Ocular staging at diagnosis was, for the most part, advanced disease, (Reese V classification: 76.5%, Internacional Classification of Retinoblastoma D or E in 78.1% patients), being that 35.2% of cases were comprised of unilateral disease and 34.8% of patients with bilateral disease already presented with extraocular lesions in at least one eye at diagnosis. Fifteen patients (10.7%) presented with metastasis at diagnosis. With regards to treatment, differnet modalities were employed, being that most patients underwent surgery with enucleation in 88.1% and e exenteration in 11.9%. A significant number of patients received systemic chemotherapy (57.1%) and/or radiotherapy (37.1%). Of all patients included, 131 (93.6%) remained in follow up at the hospital until 2012 or until their demise. Of these patients, 32 (22.9%) relapsed, leading to 19 deaths, 84.2% of them due to disease progression. Secondary malignancies were present in 6 patients (4.3%) and, of these, one patient presented with two different secondary malignancies. The average time of patient follow up was 323.2 months [300.3; 346.1]. Overall survival was of 86.4%, with the following time frames among the different patient subgroups: 92.0% for non-metastatic patients, 40.0% for metastatic patients, intraoculares 94.0% for patients with intraocular disease, and 68.5% for patients with extraocular lesions. With regards to unilateral or bilateral disease, overall survival was of 88.0%; for patients with trilateral disease, (N=3) all patients expired. Survival of patients with unilateral and intraocular disease was of 94.9%; patients with unilateral and extraocular disease presented a overall survival of 75.0%. Patients with bilateral intraocular lesions overall survival was of 94.5%, whereas patients with bilateral and extraocular disease had an overall survival of 68.4%. In our setting, Rb diagnosis still occurs when the patients already manifest advanced disease, which reduces considerably their overall survival and preservation of the ocular globe and vision. Moreover, late diagnosis requires more agressive treatments, and consequently leads to more frequent toxicities and late side effects. Periodic clinical and ophthalmologic evaluations during the first years of a child's life offer a greater chance of early diagnosis and referral to a multidisciplinary pediatric oncology center, which is crucial for the patient’s well being. There is much need of further investments which facilitate patient access to diagnosis and treatment for Rb, which is the most common ocular tumor in children.

Retinoblastoma (Rb) é o tumor ocular mais frequente na infância e cada grande Centro deve conhecer o perfil dos seus pacientes. Foi realizado um estudo do tipo coorte retrospectivo e incluiu pacientes com Rb atendidos entre 1983 e 2012 nos Serviços de Oncologia Pediátrica, Oftalmologia e Genética Médica do Hospital de Clínicas de Porto Alegre (HCPA). De um total de 165 registros no período foram efetivamente incluídos 140 pacientes, sendo 95,0% destes provenientes de municípios do Rio Grande do Sul. Os sinais mais frequentes ao diagnóstico foram: leucocoria (73,6%) e estrabismo (20,7%). Identificamos a seguinte distribuição: doença unilateral (65,0%), bilateral (32,9%) sendo 80,4% com doença multifocal (p=0,015), trilateral (2,1%). A idade média dos pacientes por ocasião dos primeiros sinais e sintomas foi de 18,1 meses [mediana=12,0] e a idade média ao diagnóstico foi 23,5 meses [mediana=16,5]. Cinquenta pacientes (35,7%) foram diagnosticados no 1º ano de vida. O tempo de diagnóstico médio da coorte foi 5,4 meses [mediana=3,0], (amplitude=0-77,0). A idade média aos primeiros sinais e sintomas do grupo com critérios de hereditariedade foi de 12,3 meses enquanto a do grupo não hereditário foi de 21,6 meses (p=0,001), enquanto a idade média ao diagnóstico foi de 15,9 meses vs. 28 meses, respectivamente (p<0,001). Entretanto não houve diferença na sobrevida entre esses subgrupos. O estadiamento ocular dos pacientes ao diagnóstico na sua maioria foi avançado (classificação de Reese V em 76,5%, Internacional D ou E em 78,1%), sendo que 35,2% dos unilaterais e 34,8% dos bilaterais já apresentavam doença extraocular em pelo menos um olho ao diagnóstico. Quinze pacientes (10,7%) tinham doença metastática ao diagnóstico. Em relação ao tratamento, diferentes modalidades foram utilizadas, sendo a maioria dos pacientes submetidos à cirurgia, sendo esta enucleação em 88,1% e exenteração em 11,9%. Uma parcela significativa dos pacientes foi tratada com quimioterapia sistêmica (57,1%) e/ou radioterapia (37,1%). Do total de pacientes recrutados, 131 (93,6%) permaneceram vinculados ao hospital até 2012 ou até o óbito. Destes, 32 (22,9%) recidivaram, resultando em 19 óbitos com 84,2% por progressão do Rb. Uma segunda neoplasia primária esteve presente em 4,3% (N=6) e dentre esses, um paciente teve uma terceira neoplasia primária. O tempo de seguimento médio foi 323,2 meses [300,3; 346,1]. As sobrevidas nos diferentes subgrupos foram as seguintes: sobrevida global 86,4%; no não metastático 92,0%; no metastático 40,0%; entre os intraoculares 94,0%; entre os extraoculares 68,5%; entre os unilaterais e bilaterais ambos com cerca de 88,0%; entre os trilaterais (N=3) todos foram a óbito; entre os unilaterais intraoculares 94,9% e extraoculares 75,0% e entre os bilaterais intraoculares 94,5% e extraoculares 68,4%. No nosso meio, o diagnóstico de Rb ainda é feito predominantemente em estadios avançados o que reduz a sobrevida dos pacientes e o índice de preservação do olho e da visão, além de aumentar a intensidade dos tratamentos realizados e consequentemente, toxicidade e efeitos tardios destes. Avaliações clínicas e oftalmológicas periódicas nos primeiros anos de vida da criança oferecem maior oportunidade de um diagnóstico precoce e o encaminhamento rápido à um Centro de Referência multidisciplinar que contemple cuidados terciários em Oftalmologia e Oncologia Pediátrica é fundamental. Existe grande necessidade de investimentos regionais que facilitem o acesso ao diagnóstico e tratamento do Rb, o tumor ocular mais frequente na infância. / Retinoblastoma (Rb) is the most frequent ocular tumor diagnosed in children and every pediatric hospital must be familiar with its clinical presentation and patient characteristics. A retrospective cohort study was undertaken, with patients diagnosed with retinoblastoma from 1983 until 2012, treated at the Pediatric Oncology Unit, Ophthalmology Unit, and Medical Genetics Unit of the Hospital de Clínicas de Porto Alegre (HCPA). Of a total of 165 registries during this time frame, 140 patients were included in this study, with 95% of them from the state of Rio Grande do Sul. The most frequent signs and symptoms at diagnosis were: leukocoria (73.6%) and strabismus (20.7%). The following distribution was identified: unilateral disease (65.0%), bilateral disease (32.9%), being 80.4% with multifocal disease, (P=0,015), and trilateral disease (2.1%). The average age of patients at the appearance of the first sign or symptom was 18.1 months [median=12.0] and the average age at diagnosis was 23.5 months [median=16.5]. Fifty patients (35.7%) were diagnosed during their first year of age. The average time to diagnosis was of 5.4 months [median=3.0], (amplitude=0-77.0). In the hereditary retinoblastoma group, the average age at the appearance of the first sign or symptom was 12.3 months, whereas the non-hereditary group presented the first sign or symptom on average at 21.6 months (P=0,001). The average age at diagnosis was 15.9 months vs. 28 months for the hereditary and non-hereditary patients, respectively (P<0.001). However, no significant difference in overall survival was found when both groups were compared. Ocular staging at diagnosis was, for the most part, advanced disease, (Reese V classification: 76.5%, Internacional Classification of Retinoblastoma D or E in 78.1% patients), being that 35.2% of cases were comprised of unilateral disease and 34.8% of patients with bilateral disease already presented with extraocular lesions in at least one eye at diagnosis. Fifteen patients (10.7%) presented with metastasis at diagnosis. With regards to treatment, differnet modalities were employed, being that most patients underwent surgery with enucleation in 88.1% and e exenteration in 11.9%. A significant number of patients received systemic chemotherapy (57.1%) and/or radiotherapy (37.1%). Of all patients included, 131 (93.6%) remained in follow up at the hospital until 2012 or until their demise. Of these patients, 32 (22.9%) relapsed, leading to 19 deaths, 84.2% of them due to disease progression. Secondary malignancies were present in 6 patients (4.3%) and, of these, one patient presented with two different secondary malignancies. The average time of patient follow up was 323.2 months [300.3; 346.1]. Overall survival was of 86.4%, with the following time frames among the different patient subgroups: 92.0% for non-metastatic patients, 40.0% for metastatic patients, intraoculares 94.0% for patients with intraocular disease, and 68.5% for patients with extraocular lesions. With regards to unilateral or bilateral disease, overall survival was of 88.0%; for patients with trilateral disease, (N=3) all patients expired. Survival of patients with unilateral and intraocular disease was of 94.9%; patients with unilateral and extraocular disease presented a overall survival of 75.0%. Patients with bilateral intraocular lesions overall survival was of 94.5%, whereas patients with bilateral and extraocular disease had an overall survival of 68.4%. In our setting, Rb diagnosis still occurs when the patients already manifest advanced disease, which reduces considerably their overall survival and preservation of the ocular globe and vision. Moreover, late diagnosis requires more agressive treatments, and consequently leads to more frequent toxicities and late side effects. Periodic clinical and ophthalmologic evaluations during the first years of a child's life offer a greater chance of early diagnosis and referral to a multidisciplinary pediatric oncology center, which is crucial for the patient’s well being. There is much need of further investments which facilitate patient access to diagnosis and treatment for Rb, which is the most common ocular tumor in children.

The design of the proposed study was to administer R-FB to 72-day old Min/+ mice for up to 42 days. In order to capture the process of tumor reduction, animals were necropsied at various time points. At each time point animals were evaluated for tumor loads and presence of apoptotic cells along the small intestine. Studies have shown that when R-flurbiprofen (R-FB) is administered in the Min/+ mouse model it can cause the prevention and regression on intestinal tumors.