Emerging concepts in colorectal neoplasia

An understanding of the mechanisms that explain the initiation and early evolution of colorectal cancer should facilitate the development of new approaches to effective prevention and intervention. This review highlights deficiencies in the current model for colorectal neoplasia in which APC mutation is placed at the point of initiation. Other genes implicated in the regulation of apoptosis and DNA repair may underlie the early development of colorectal cancer. Inactivation of these genes may occur not by mutation or loss but through silencing mediated by methylation of the gene's promoter region. hMLH1 and MGMT are examples of DNA repair genes that are silenced by methylation. Loss of expression of hMLH1 and MGMT protein has been demonstrated immunohistochemically in serrated polyps. Multiple lines of evidence point to a serrated pathway of neoplasia that is driven by inhibition of apoptosis and the subsequent inactivation of DNA repair genes by promoter methylation. The earliest lesions in this pathway are aberrant crypt foci (ACF). These may develop Into hyperplastic polyps or transform while still of microscopic size into admixed polyps, serrated adenomas, or traditional adenomas. Cancers developing from these lesions may show high- or low-level microsatellite instability (MSI-H and MSI-L, respectively) or may be microsatellite stable (MSS). The suggested clinical model for this alternative pathway is the condition hyperplastic polyposis. If colorectal cancer is a heterogeneous disease comprising discrete subsets that evolve through different pathways, it is evident that these subsets will need to be studied individually in the future.

Familial adult renal neoplasia

Our understanding of the molecular mechanisms underlying the tumorigenesis of renal cell carcinoma (RCC) has partially come from studies of RCC related familial cancer syndromes such as von Hippel-Lindau (VHL) disease and hereditary papillary RCC (HPRC). These studies have led to the identification of RCC related genes, which, besides allowing accurate diagnosis of these diseases, have been found mutated or abnormally expressed in the sporadic counterparts of these familial renal tumours. To date, a number of renal tumour related syndromes have been described. We review recent advances in this field and discuss a genetic approach to managing familial cases of renal tumours occasionally encountered by cancer geneticists and urologists.

Phenotypic impact of deregulated expression of class I histone deacetylases in urothelial cell carcinoma of the bladder

Deregulated expression of histone deacetylases (HDACs) has been implicated in tumorigenesis. Herein, we investigated class I HDACs expression in bladder urothelial cell carcinoma (BUCC), its prognostic value and biological significance. Significantly increased transcript levels of all HDACs were found in BUCC compared to 20 normal mucosas, and these were higher in lower grade and stage tumors. Increased HDAC3 levels were associated with improved patient survival. SiRNA experiments showed decrease cell viability and motility, and increased apoptosis. We concluded that class I HDACs play an important role in bladder carcinogenesis through deregulation of proliferation, migration and apoptosis, constituting putative therapeutic targets

A Utilização de Endopróteses na Síndrome da Veia Cava Superior por Neoplasia do Pulmão

Apresentam-se seis casos de síndrome da veia cava superior causado por neoplasia do pulmão e que foram tratados por endopróteses colocadas por via percutânea. Descreve-se a técnica e avaliam-se os resultados. Num caso ocorreu trombose aguda da endoprótese que foi tratada por uroquinase. Não se registaram outras complicações. Um doente faleceu 1 mês depois por progressão da doença. Os restantes mantinham-se sem queixas de síndrome da veia cava superior durante mais do que 6 meses. Conclui-se que a colocação de endopróteses é uma técnica pouco invasiva, eficaz e com melhoria imediata no síndrome da veia cava superior.

Utilidade da Broncofibroscopia no Diagnóstico de Neoplasia do Pulmão em Doentes com Pneumonia Arrastada

A broncofibroscopia (BF) é frequentemente efectuada em doentes com pneumonias de evolução arrastada com o objectivo de excluir patologia endobrónquica de etiologia neoplásica. Dado que a resolução radiográfica das pneumonias da comunidade é variável, sendo dependente de vários factores (agente etiológico, idade, doenças associadas) a decisão para efectuar uma BF é muitas vezes empírica. Com o objectivo de descrever a nossa experiência neste problema estudámos retrospectivamente 123 doentes com o diagnóstico de pneumonia da comunidade baseado em critérios clínicos e radiográficos e que, apesar da antibioferapia considerada adequada, não apresentavam melhoria radiográfica significativa ao fim de pelo menos 2 semanas. Obtivemós um diagnóstico histológico de neoplasia maligna do pulmão em 7 doentes (5,6° o), sendo todos do sexo masculino, com idade superior a 55 anos efuínadores de pelo menos 40 U.M.A. A análise comparativa com os restantes doentes mostrou diferenças com significado~estatístico em relação à idade e ao consumo tabágico. O tempo de evolução da doença,valores médios de hemoglobina, leucocitos, VS, existência ou não de alterações da função renal ou hepática não foram significativamente diferentes nos dois grupos. Concluimos que a BF deve ser efectuada precocemente nos doentes pertencentes ao grupo de risco identificado (fumadores, com mais de 55 anos) não se justificando a sua realização nos restantes doentes antes das 4 a 8 semanas de evolução, a menos que estejam presentes critérios clínicos objectivos tais como progressão da doença ou agravamento do estado geral.

Mutational Analysis of Portuguese Families with Multiple Endocrine Neoplasia Type 1 Reveals Large Germline Deletions

OBJECTIVE: To determine the spectrum of MEN1 mutations in Portuguese kindreds, and identify mutation-carriers. PATIENTS, DESIGN AND RESULTS: Six unrelated MEN1 families were studied for MEN1 gene mutations by single-strand conformational polymorphism (SSCP) and DNA sequence analysis of the coding region and exon-intron boundaries of the MEN1 gene. These methods identified 4 different heterozygous mutations in four families: two mutations are novel (mt 1539 delG and mt 655 ims 11 bp) and two have been previously observed (mt 735 del 46p and mt 1656 del C) all resulting in a premature stop codon. In the remaining two families, in whom no mutations or abnormal MEN1 transcripts were detected, segregation studies of the 5' intragenic marker D11S4946 and codon 418 polymorphism in exon 9 revealed two large germline deletions of the MEN1 gene. Southern blot and tumour loss of heterozygosity analysis confirmed and refined the limits of these deletions, which spanned the MEN1 gene at least from: exon 7 to the 3' untranslated region, in one family, and the 5' polymorphic site D11S4946 to exon 9 (obliterating the initiation codon), in the other family. Twenty-six mutant-gene carriers were identified, 6 of which were asymptomatic. CONCLUSIONS: These results emphasize the importance of the detection of MEN1 germline deletions in patients who do not have mutations of the coding region. Important clues indicating the presence of such deletions may be obtained by segregation studies using the intragenic polymorphisms D11S4946 and at codon 418. The detection of these mutations will help in the genetic counselling of clinical management of the MEN1 families in Portugal.

Hidatidose policística: cisto hidático calcificado, simulando neoplasia mesentérica, descoberto acidentalmente

É descrito um caso de hidatidose abdominal, sem comprometimento hepático, em paciente do Estado do Acre. O cisto, já em degeneração e parcialmente calcificado, foi descoberto, por acaso, mediante estudo radiológico da coluna vertebral feito para avaliação de hérnia de disco, detectada algum tempo antes. Embora as imagens sugerissem uma neoplasia do mesentério, o achado de acúleos rostelares no conteúdo pastoso da hidátide, removida cirurgicamente, permitiu reconhecer-se a natureza parasitária da lesão.

Nódulo pulmonar esquistossomótico simulando neoplasia: relato de caso

Paciente sadio em que, ao exame de rotina, foi detectado nódulo pulmonar esquistossomótico com verme adulto, 25 anos após o tratamento específico com oxamniquine® e distante da região endêmica. O nódulo simulava clinicamente neoplasia.

Esquistossomose mansônica simulando neoplasia da bexiga

Paciente de 36 anos de idade, proveniente de zona endêmica foi admitido com episódios de hematúria macroscópica total e disúria terminal. A citoscopia mostrou um tumor exofítico na parede anterior da bexiga, sugestivo de câncer. A biópsia revelou esquistossomose mansônica. Ressecção transuretral confirmou o diagnóstico. O paciente foi clinicamente tratado com oxamniquine, obtendo cura. O caso apresentado nesse trabalho enfatiza que nem todos os tumores de bexiga com hematúria microscópica são cânceres de bexiga.

Conization, frozen section examination, and planned hysterectomy in the treatment of high-grade cervical intraepithelial neoplasia

PURPOSE: We tested the role of frozen section examination of the cone specimen in the evaluation of the resection margin status and to rule out invasion in patients with high-grade cervical intraepithelial neoplasia. METHODS: Twenty-five patients with cervical intraepithelial neoplasia underwent conization followed by frozen section examination and planned hysterectomy. The results of the definitive paraffin exam were compared with frozen section examination. RESULTS: In the evaluation of the margins by frozen section examination, 16 patients (64%) had positive cone margins and 9 (36%) had negative margins. The definitive paraffin examination of margin status was concordant in all the cases. Intraoperative diagnosis of invasion was made in 5 cases, and 1 of these was microinvasive. Among the remaining 20 cases, we detected 2 additional microinvasive carcinomas after paraffin study, so the diagnosis of the frozen section examination was concordant with the paraffin sections in 23/25 cases (92%). Two cases of microinvasive carcinoma were diagnosed as cervical intraepithelial neoplasia by frozen section examination and had less than 2 mm stromal invasion. CONCLUSIONS: In high-grade cervical intraepithelial neoplasia, frozen section examination can provide immediate and precise evaluation of the cone margin status in high-grade cervical intraepithelial neoplasia. It can identify frank invasion and permit adequate treatment in a one-stage procedure. In early microinvasive disease, frozen section examination fails to detect the area of invasion but reliably detects clear resection margins.

Evolving hallmarks in urothelial bladder cancer: unveiling potential biomarkers

Urothelial bladder carcinoma (UBC), the most frequent type (90%) of bladder cancer and the second most common malignancy of the urogenital region, is a relatively well understood type of cancer, with numerous studies concerning pathogenetic pathways, natural history and bladder tumor biology being reported. Despite this, it continues to remain a challenge in the oncology field, mostly due to its relapsing and progressive nature, and to the heterogeneity in the response to cisplatin-containing regimens. Although the formulae based on clinical staging and histopathological parameters are classically used as diagnostic and prognostic tools, they have proven insufficient to characterize the individual biological features and clinical behaviour of the tumours. Understanding the pathobiology of the disease can add important information to these classical criteria, and contribute to accurately predict outcome and individualize therapy for UBC patients. In this line of investigation, we found that tumour angiogenesis and lymphangiogenesis, the process of invasion and metastasis and the energy metabolism reprogramming/tumour microenvironment encompass several potential biomarkers that seem to infl bladder cancer aggressiveness and chemoresistance. We particularly highlight the roles of lymphovascular invasion, and of RKIP, CD147 and MCT1 immunoexpressions, as relevant prognostic and/or predictive biomarkers, and as promising areas of therapeutic intervention, eliciting for the development of additional studies that can validate and further explore these biomarkers.

Urothelial bladder cancer progression: lessons learned from the bench

Urothelial bladder carcinoma (UBC) is an intricate malignancy with a variable natural history and clinical behavior. Despite developments in diagnosis/prognosis refinement and treatment modalities, the recurrence rate is high, and progression from non-muscle to muscle invasive UBC commonly leads to metastasis. Moreover, patients with muscle-invasive or extra-vesical disease often fail the standard chemotherapy treatment, and overall survival rates are poor. Thus, UBC remains a challenge in the oncology field, representing an ideal candidate for research on biomarkers that could identify patients at increased risk of recurrence, progression, and chemo-refractoriness. However, progress toward personalized medicine has been hampered by the unique genetic complexity of UBC. Recent genome-wide expression and sequencing studies have brought new insights into its molecular features, pathogenesis and clinical diversity, revealing a landscape where classical pathology is intersected by the novel and heterogeneous molecular groups. Hence, it seems plausible to postulate that only an integrated signature of prognostic/predictive biomarkers inherent in different cancer hallmarks will reach clinical validation. In this review, we have summarized ours and others' research into novel putative biomarkers of progression and chemoresistance that encompass several hallmarks of cancer: tumor neovascularization, invasion and metastasis, and energy metabolism reprogramming of the tumor microenvironment.

Biodegradable drug-eluting stents: Targeting urothelial tumors of upper urinary tract

INTRODUCTION & OBJECTIVES: Urothelial tumors of upper urinary tract are ranked among the most common types of cancers worldwide. The current standard therapy to prevent recurrence is intravesical Bacillus Calmetteâ Guerin (BCG) immunotherapy, but it presents several disadvantages such as BCG failure and intolerance. Another way is to use chemotherapy, which is generally better tolerated that BCG. In this case, drugs such as epirubicin, doxorubicin, paclitaxel and gemcitabine are used. Nevertheless, intravesical chemotherapy only prevents recurrence in the short-term. These failings can be partially attributed to the short residence time and low bioavailability of the drug within the upper urinary tract and the cancer cells, resulting in a need for frequent drug instillation. To avoid these problems, biodegradable ureteral stents impregnated by supercritical fluid CO2 (SCF) with each of the four anti-cancer drugs were produced. MATERIAL & METHODS: Four formulations with different concentrations of gelatin and alginate and crosslink agent were tested and bismuth was added to confer radiopaque properties to the stent. The preliminary in vivo validation studies in female domestic pigs was conducted at the University of Minho, Braga, after formal approval by the institutionâ s review board and in accordance with its internal ethical protocol for animal experiments. Paclitaxel, epirubicin, doxorubicin and gemcitabine were impregnated in the stents and the release kinetics was measured in artificial urine solution (AUS) for 9 days by UV spectroscopy in a microplate reader. The anti-tumoral effect of the developed stents in transitional cell carcinoma (TCC) and HUVEC primary cells, used as control, was evaluated. RESULTS: The in vivo validation of this second-generation of ureteral stents performed was herein demonstrated. Biodegradable ureteral stents were placed in the ureters of a female pigs, following the normal surgical procedure. The animals remained asymptomatic, with normal urine flow. The in vitro release study in AUS of the stent impregnated showed a higher release in the first 72h for the four anti-cancer drugs impregnated after this time the plateau was achieved and the stent degraded after 9 days. The direct and indirect contact of the anti-cancer biodegradable stents with the TCC and HUVEC cell lines confirm the anti-tumor effect of the stents impregnated with the four anti-cancer drugs, reducing around 75% of the viability of the TCC cell line after 72h and no killing effect in the HUVEC cells. CONCLUSIONS: The use of biodegradable ureteral stent in urology clinical practice not only reduce the stent-related symptoms but also open new treatment therapyâ s, like in urothelial tumors of upper urinary tract. Furthermore, we have demonstrated the clinical validation in vivo pig model. This study has thus shown the killing efficacy of the anti-cancer drug eluting biodegradable stents in vitro for the TCC cell line, with no toxicity observed in the control, non-cancerous cells.The direct and indirect contact of the anti-cancer biodegradable stents with the TCC and HUVEC cell lines confirm the anti-tumor effect of the stents impregnated with the four anti-cancer drugs, reducing around 75% of the viability of the TCC cell line after 72h and no killing effect in the HUVEC cells. This study has thus shown the killing efficacy of the anti-cancer drug eluting biodegradable stents in vitro for the TCC cell line, with no toxicity observed in the control, non-cancerous cells.

Interação entre especialidades: miocardiopatia dilatada e neoplasia de mama HER2 positiva

O progresso no conhecimento dos mecanismos da doença e suas potenciais possibilidades de tratamento, têm com o incremento da pesquisa básica, trazido a algumas situações inusitadas. Como quando algo observado em uma situação específica, definida na prática clínica, pode ser transportado para o laboratório, instigando a investigação de uma provável terapêutica em uma doença não relacionada e fazendo o caminho inverso da "bench-to-bedside". Nos últimos anos, o uso de um anticorpo monoclonal, o trastuzumabe, mostrou-se imprescindível no tratamento das neoplasias de mama com amplificação/superexpressão de HER2, com ganho de sobrevida significativo nos contextos adjuvante e terapêutico. A observação da ocorrência de cardiotoxicidade induzida pelo trastuzumabe, assim como a identificação dos mecanismos relacionados a esse efeito colateral, possibilitaram a pesquisa desses mesmos fatores na miocardiopatia dilatada, de uma forma muito interessante.