A importância da avaliação do assoalho pélvico após a prostatectomia radical e seu impacto na disfunção erétil

Pós-graduação em Bases Gerais da Cirurgia - FMB

Segundo tumor primário, radioinduzido, em pacientes com neoplasias de próstata, após radioterapia

Pós-graduação em Pesquisa e Desenvolvimento (Biotecnologia Médica) - FMB

Modelos de tratamento para adenocarcinomas de próstata tratados por radioterapia conformacional 3D

Radiotherapy is a branch of medical physics related to the treatment of malignant neoplasm, being an important instrument in the fight against cancer, when combined with the effort of a multidisciplinary team, composed of, physicians, physicists, nurses and technicians. Every year more than 3.5 million new cases of cancer are recorded in the world, being the prostate cancer responsible for approximately 25% of this amount (INCA and IARC, 2008). In this type of cancer, radiotherapy is a method indicated for treatement. The technological advance in this area over years has allowed a greater accuracy in the tumor location, more conformation of the radiation beam around the tumor, reducing the dose in healthy tissues and a consequent dose increase on treatment (Bedford et al., 1999). A radiotherapy planning, in which the physicist develops an important role, is composed of several steps, including choosing the best configuration of treatment beams. This choice has a close relationship with success of therapy and is critical to achieve the best distribution of dose inside the tumor and expose the least as possible the healthy tissue to radiation. In this work, two options for setting up camps in the first phase in a treatment of prostate cancer were simulated in computer planning: 4 fields orthogonal or “Box” with gantry angles in 00, 1800, 2700 e 90° and 4 fields angled or “X” (1350, 450, 3150 e 2250). The percentage of the rectal volume exposed to 40, 50, 60, 72 and 76 Gy should be limited to 60, 50, 25, 15 and 5% respectively (Greco et al., 2003). The femoral toxicity have limited dose by 70% of the total dose prescribed in a prostate treatment (Bedford et al., 1999). The planning of 27 patients with prostate adenocarcinoma submitted to 3D conformal radiotherapy were accompanied. As a result, it was assessed that the best TCP (tumor control probability)... (Complete abstract click electronic access below)

Key participants of the tumor microenvironment of the prostate: An approach of the structural dynamic of cellular elements and extracellular matrix components during epithelial-stromal transition

Cancer is a multistep process that begins with the transformation of normal epithelial cells and continues with tumor growth, stromal invasion and metastasis. The remodeling of the peritumoral environment is decisive for the onset of tumor invasiveness. This event is dependent on epithelial–stromal interactions, degradation of extracellular matrix components and reorganization of fibrillar components. Our research group has studied in a new proposed rodent model the participation of cellular and molecular components in the prostate microenvironment that contributes to cancer progression. Our group adopted the gerbil Meriones unguiculatus as an alternative experimental model for prostate cancer study. This model has presented significant responses to hormonal treatments and to development of spontaneous and induced neoplasias. The data obtained indicate reorganization of type I collagen fibers and reticular fibers, synthesis of new components such as tenascin and proteoglycans, degradation of basement membrane components and elastic fibers and increased expression of metalloproteinases. Fibroblasts that border the region, apparently participate in the stromal reaction. The roles of each of these events, as well as some signaling molecules, participants of neoplastic progression and factors that promote genetic reprogramming during epithelial–stromal transition are also discussed.

Segmentation of Cell Nuclei Regions in Epithelium of Prostate Glands

This paper proposes a method for segmentation of cell nuclei regions in epithelium of prostate glands. This structure provides information to diagnosis and prognosis of prostate cancer. In the initial step, the contrast stretching technique was applied in image in order to improve the contrast between regions of interest and other regions. After, the global thresholding technique was applied and the value of threshold was defined empirically. Finally, the false positive regions were removed using the connected components technique. The performance of the proposed method was compared with the Otsu technique and statistical measures of accuracy were calculated based on reference images (gold standard). The result of the mean value of accuracy of proposed method was 93% ± 0.07.

Relationship between head and neck cancer therapy and some genetic endpoints

Head and neck cancer (HNC) is the sixth most common human malignancy worldwide. The main forms of treatment for HNC are surgery, radiotherapy (RT) and chemotherapy (CT). However, the choice of therapy depends on the tumor staging and approaches, which are aimed at organ preservation. Because of systemic RT and CT genotoxicity, one of the important side effects is a secondary cancer that can result from the activity of radiation and antineoplastic drugs on healthy cells. Ionizing radiation can affect the DNA, causing single and double-strand breaks, DNA-protein crosslinks and oxidative damage. The severity of radiotoxicity can be directly associated with the radiation dosimetry and the dose-volume differences. Regarding CT, cisplatin is still the standard protocol for the treatment of squamous cell carcinoma, the most common cancer located in the oral cavity. However, simultaneous treatment with cisplatin, bleomycin and 5-fluorouracil or treatment with paclitaxel and cisplatin are also used. These drugs can interact with the DNA, causing DNA crosslinks, double and single-strand breaks and changes in gene expression. Currently, the late effects of therapy have become a recurring problem, mainly due to the increased survival of HNC patients. Herein, we present an update of the systemic activity of RT and CT for HNC, with a focus on their toxicogenetic and toxicogenomic effects.

Influence of melatonin on the proliferative and apoptotic responses of the prostate under normal and hyperglycemic conditions

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Modeling spatial distribution of cancer incidence in Cordoba, Argentina

Background: Cancer is the second leading cause of death in Argentina, and there is little knowledge about its incidence. The first study based on population-based cancer registry described spatial incidence and indicated that there existed at least county-level aggregation. The aim of the present work is to model the incidence patterns for the most incidence cancer in Córdoba Province, Argentina, using information from the Córdoba Cancer Registry by performing multilevel mixed model approach to deal with dependence and unobserved heterogeneity coming from the geo-reference cancer occurrence. Methods: Standardized incidence rates (world standard population) (SIR) by sex based on 5-year age groups were calculated for 109 districts nested on 26 counties for the most incidence cancers in Cordoba using 2004 database. A Poisson twolevel random effect model representing unobserved heterogeneity between first level-districts and second level-counties was fitted to assess the spatial distribution of the overall and site specific cancer incidence rates. Results: SIR cancer at Córdoba province shown an average of 263.53±138.34 and 200.45±98.30 for men and women, respectively. Considering the ratio site specific mean SIR to the total mean, breast cancer ratio was 0.25±0.19, prostate cancer ratio was 0.12±0.10 and lower values for lung and colon cancer for both sexes. The Poisson two-level random intercepts model fitted for SIR data distributed with overdispersion shown significant hierarchical structure for the cancer incidence distribution. Conclusions: a strong spatial-nested effect for the cancer incidence in Córdoba was observed and will help to begin the study of the factors associated with it.

Prostate biopsy in patients with long-term use of indwelling bladder catheter: What is the rationale?

Objective: Acute urinary retention (AUR) is expected to occur in 2% to 39% men with benign prostatic hyperplasia. To date, no study has elucidated the effect of long-term use of indwelling bladder catheter on serum prostate specific antigen (PSA) levels and on the incidence of prostate cancer (CaP). The aim of the present study is to analyze the incidence of CaP in patients with long-term use of indwelling bladder catheter and determine some practice patterns on this issue. Materials and methods: The study comprised a retrospective analysis of data from 1,651 patients who had undergone transrectal ultrasound (TRUS)-guided prostate biopsy from July 2004 to June 2009. Among these patients, 198 (12%) were using an indwelling bladder catheter during the biopsy for at least 1 month. The incidence of CaP was recorded according to total PSA levels. Other variables such patient age, free/total PSA rate, PSA density, prostate volume, and duration of catheter use was also analyzed. Men with a digital rectal examination suspicious for cancer were not considered for analysis. Results: Median patient age was 71 years (37 to 89 years). Overall, 25% of patients presented a CaP diagnosis. CaP incidence according to the PSA levels was 0%, 18.9%, 24.5%, and 40.6% for patients with PSA <= 4.0, 4.1-10.0, 10.1-20.0, and >20.0 ng/ml, respectively. When prostate volume was analyzed together, we demonstrated that only 1 (2.4%) patient with PSA below 10.0 ng/ml and prostate volume >60 g had CaP. Median total PSA, PSA density, and prostate volume were statistically different between patients with and without CaP. Conclusions: Prostate biopsy should not be indicated for all patients with diagnosis of BPH and AUR who present an elevated PSA level. Patients with PSA below 10.0 ng/ml, and prostate volume >60 g should only undergo biopsy in selected cases. Patients with PSA >20.0 ng/ml and a prostate volume <= 60 g are at higher risk of CaP diagnosis. (C) 2012 Elsevier Inc. All rights reserved.

Obstrução de vias lacrimais associada ao tratamento radioiodoterápico de carcinoma de tireoide

OBJETIVO: Descrever uma série de pacientes portadores de obstrução do sistema lacrimal associado à radioiodoterapia para tratamento de carcinoma de tireoide, revisar os dados clínicos e a resposta ao tratamento cirúrgico desta rara complicação. MÉTODOS: Foi realizada uma análise retrospectiva dos achados oftalmológicos de pacientes com histórico de carcinoma de tireoide previamente submetidos à tireoidectomia e à RIT que foram encaminhados para cirurgia de vias lacrimais. RESULTADOS: Dezessete pacientes com carcinoma de tireoide tratados com tireoidectomia e RIT apresentaram obstrução do ducto nasolacrimal sintomática após período médio de 13,2 meses do tratamento do câncer. Onze pacientes tiveram epífora bilateral, 8 com mucocele de saco lacrimal. A idade dos pacientes variou entre 30 e 80 anos, sendo 10 com idade menor ou igual a 49 anos. A dose cumulativa média de radioiodo administrada foi de 571 mCi (variação entre 200-1200 mCi). Sintomas de obstrução nasal e aumento de glândulas salivares ocorreram em 53% dos pacientes. Todos os pacientes foram submetidos à dacriocistorrinostomia. Observou-se ainda que nos 3 pacientes mais jovens houve maior sangramento intraoperatótio e dilatação de saco lacrimal. A resolução completa da epífora e da dacriocistite ocorreu em 82,4%, e foi parcial em 17,6% (3 pacientes mantiveram queixa unilateral após a correção da obstrução bilateralmente). O seguimento médio foi de 6 meses (intervalo: 2-24 meses). CONCLUSÕES: Alta dose cumulativa de radioiodo, disfunção nasal e de glândulas salivares estão associadas à obstrução das vias lacrimais. Observa-se uma maior porcentagem de pacientes mais jovens apresentando quadro de dacriocistite quando comparado à dacrioestenose idiopática. A absorção de iodo radioativo pela mucosa do ducto nasolacrimal com subsequente inflamação, edema e fibrose parece ter relação direta com a obstrução do ducto nasolacrimal. O conhecimento desta complicação é importante para o estudo e abordagem correta desses pacientes.

Inhibition of Aurora kinases enhances chemosensitivity to temozolomide and causes radiosensitization in glioblastoma cells

Glioblastoma remains one of the most devastating human malignancies, and despite therapeutic advances, there are no drugs that significantly improve the patient survival. Altered expression of the Aurora kinases was found in different malignancies, and their inhibition has been studied in cancer therapy. In this study, we analyzed the expression of Aurora A and Aurora B in glioblastoma samples and also analyzed whether the effects of Aurora kinase inhibition were associated with temozolomide or not on cell lines and primary cultures of glioblastoma. RT-PCR assays were used to determine the mRNA expression in glioblastoma tumor samples and in the cell lines. Cell proliferation was measured by XTT assay, and apoptosis was determined by flow cytometry. Drug combination analyses were made based in Chou-Talalay method. Gamma radiation for clonogenic survival used the doses of 2, 4 and 6 Gy. Changes in Aurora B level were assessed by Western blot analysis. Aurora A and B were expressed in glioblastoma samples as well as in the glioblastoma cell lines (n = 6). Moreover, ZM447439, a selective Aurora kinase inhibitor, decreased the proliferation separately and synergistically with temozolomide in primary cultures and cell lines of glioblastoma. ZM also enhanced the effects of radiation on the two cell lines studied (U343 and U251), mainly when associated with TMZ in U343 cells. Treatment with ZM induced apoptotic cell death and diminished Aurora B protein level. These data suggest that Aurora kinase inhibition may be a target for glioblastoma treatment and could be used as adjuvant to chemo- and radiotherapy.

Gene expression down-regulation in CD90+ prostate tumor-associated stromal cells involves potential organ-specific genes

Abstract Background The prostate stroma is a key mediator of epithelial differentiation and development, and potentially plays a role in the initiation and progression of prostate cancer. The tumor-associated stroma is marked by increased expression of CD90/THY1. Isolation and characterization of these stromal cells could provide valuable insight into the biology of the tumor microenvironment. Methods Prostate CD90+ stromal fibromuscular cells from tumor specimens were isolated by cell-sorting and analyzed by DNA microarray. Dataset analysis was used to compare gene expression between histologically normal and tumor-associated stromal cells. For comparison, stromal cells were also isolated and analyzed from the urinary bladder. Results The tumor-associated stromal cells were found to have decreased expression of genes involved in smooth muscle differentiation, and those detected in prostate but not bladder. Other differential expression between the stromal cell types included that of the CXC-chemokine genes. Conclusion CD90+ prostate tumor-associated stromal cells differed from their normal counterpart in expression of multiple genes, some of which are potentially involved in organ development.

Trattamento radioterapico ipofrazionato ad alte dosi del carcinoma prostatico con tecnica ad intensità modulata (IMRT) guidata dalle immagini (IGRT)

Obiettivo: valutare la tossicità ed il controllo di malattia di un trattamento radioterapico ipofrazionato ad alte dosi con tecnica ad intensità modulata (IMRT) guidata dalle immagini (IGRT) in pazienti affetti da carcinoma prostatico a rischio intermedio, alto ed altissimo di recidiva. Materiali e metodi: tutti i pazienti candidati al trattamento sono stati stadiati e sottoposti al posizionamento di tre “markers” fiduciali intraprostatici necessari per l’IGRT. Mediante tecnica SIB – IMRT sono stati erogati alla prostata 67,50 Gy in 25 frazioni (EQD2 = 81 Gy), alle vescichette 56,25 Gy in 25 frazioni (EQD2 = 60,35 Gy) e ai linfonodi pelvici, qualora irradiati, 50 Gy in 25 frazioni. La tossicità gastrointestinale (GI) e genitourinaria (GU) è stata valutata mediante i CTCAE v. 4.03. Per individuare una possibile correlazione tra i potenziali fattori di rischio e la tossicità registrata è stato utilizzato il test esatto di Fisher e la sopravvivenza libera da malattia è stata calcolata mediante il metodo di Kaplan-Meier. Risultati: sono stati arruolati 71 pazienti. Il follow up medio è di 19 mesi (3-35 mesi). Nessun paziente ha dovuto interrompere il trattamento per la tossicità acuta. Il 14% dei pazienti (10 casi) ha presentato una tossicità acuta GI G ≥ 2 e il 15% (11 pazienti) ha riportato una tossicità acuta GU G2. Per quanto riguarda la tossicità tardiva GI e GU G ≥ 2, essa è stata documentata, rispettivamente, nel 14% dei casi (9 pazienti) e nell’11% (7 pazienti). Non è stata riscontrata nessuna tossicità, acuta o cronica, G4. Nessun fattore di rischio correlava con la tossicità. La sopravvivenza libera da malattia a 2 anni è del 94%. Conclusioni: il trattamento radioterapico ipofrazionato ad alte dosi con IMRT-IGRT appare essere sicuro ed efficace. Sono comunque necessari ulteriori studi per confermare questi dati ed i presupposti radiobiologici dell’ipofrazionamento del carcinoma prostatico.

Effect of electroporation-mediated diphtheria toxin A expression on PSA positive human prostate xenograft tumors in SCID mice

Current therapies to treat prostate cancer are often limited. Since it has been shown that very low concentrations of diphtheria toxin A (DT-A) result in abrogation of protein synthesis and apoptosis of cells, DT-A might serve as an efficient killer in cancer gene therapy. For this purpose we investigated in a quantitative manner using a stereological approach the apoptotic effect of DT-A in androgen receptor (AR) and prostate specific antigen (PSA) expressing cells after tumor formation in both flanks of SCID mice.

Parallel determination of NeuroD1, chromogranin-A, KI67 and androgen receptor expression in surgically treated prostate cancers

Neuroendocrine differentiation is a hallmark of prostate cancer. The aim of our study was the detection of the parallel expression of neuroendocrine related markers using a prostate tissue microarray (TMA).