Targeting the epigenome of cancer stem cells in pediatric nervous system tumors.

Medulloblastoma, neuroblastoma, and pediatric glioma account for almost 30% of all cases of pediatric cancers. Recent evidence indicates that pediatric nervous system tumors originate from stem or progenitor cells and present a subpopulation of cells with highly tumorigenic and stem cell-like features. These cancer stem cells play a role in initiation, progression, and resistance to treatment of pediatric nervous system tumors. Histone modification, DNA methylation, chromatin remodeling, and microRNA regulation display a range of regulatory activities involved in cancer origin and progression, and cellular identity, especially those associated with stem cell features, such as self-renewal and pluripotent differentiation potential. Here, we review the contribution of different epigenetic mechanisms in pediatric nervous system tumor cancer stem cells. The choice between a differentiated and undifferentiated state can be modulated by alterations in the epigenome through the regulation of stemness genes such as CD133, SOX2, and BMI1 and the activation neuronal of differentiation markers, RBFOX3, GFAP, and S100B. Additionally, we highlighted the stage of development of epigenetic drugs and the clinical benefits and efficacy of epigenetic modulators in pediatric nervous system tumors.

Perfil dos pacientes pediátricos com tumores da glia internados para tratamento neurocirúrgico em hospital terciário no Rio de Janeiro / Clinical profile of patients with glial tumors hospitalized for neurosurgical treatment at a tertiary center in Rio de Janeiro

Os tumores do Sistema Nervoso Central representam uma patologia com grande impacto no sistema de saúde e sua incidência tem aumentado nos últimos anos. A maior parte destes tumores deriva das células da neuroglia e o tratamento neurocirúrgico é, muitas vezes, o primeiro passo na linha de tratamento oncológico multimodal. O presente estudo tem como objetivo descrever o perfil dos pacientes portadores de tumores da glia internados para tratamento neurocirúrgico em um centro terciário no Rio de Janeiro. Foram avaliados 74 registros de internação, com 70 pacientes entre 0 e 18 anos, através de revisão de prontuário, com resgate de informações referentes à história clínica, exame físico, exames de imagem, dados intra-operatórios e de internação em Unidade de Terapia Intensiva. No estudo, 57,1% dos pacientes pertenciam ao sexo masculino e a média de idade foi de 8,98 anos. A maioria dos tumores foi classificada como astrocitomas (50%) e a localização mais frequente foi a fossa posterior (54,28%), notadamente a região mediana do cerebelo. Não foi encontrada relação entre as características clínicas e o desfecho, mas a análise multivariada identificou quatro grupos que correspondem a perfis distintos, tanto no que se refere às características da lesão tumoral (histopatologia), tratamento neurocirúrgico (grau de ressecção, necessidade de reabordagens operatórias) e manejo peroperatório (duração da internação, complicações clínicas e cirúrgicas).

Central Nervous System tumors have a great impact on the health system and its incidence has increased in recent years. Most of these tumors are derived from the cells of the neuroglia and neurosurgical treatment is often the first step in the line of multimodal cancer treatment. The present study aims to describe the clinical profile of patients with glial tumors hospitalized for neurosurgical treatment at a tertiary center in Rio de Janeiro. A total of 74 hospitalization records were evaluated, with 70 patients between 0 and 18 years of age, through a review of medical records, retrieving informations on clinical history, physical examination, images, intraoperative and hospitalization in the Intensive Care Unit data. In the study, 57.1% of the patients were male and the average age was 8.98 years. Most tumors were classified as astrocytomas (50%) and the most frequent location was the posterior fossa (54.28%), notably the median region of the cerebellum. No relationship was found between clinical characteristics and outcome, but multivariate analysis identified four groups that correspond to distinct profiles, both regarding tumor lesion characteristics (histopathology), neurosurgical treatment (degree of resection, need for operative re-approaches) and perioperative management (length of stay, clinical and surgical complications).

Nimotuzumab y radioterapia en el tratamiento de tumores del tallo cerebral en niños y adolescentes / Nimotuzumab and radiotherapy in the treatment of brainstem tumors in children and adolescents

Introducción: Los tumores localizados en el tallo cerebral en los niños y adolescentes conllevan un mal pronóstico, especialmente aquellos infiltrantes y difusos. Con el tratamiento de radioterapia apenas llegan a más de 15 por ciento de supervivencia y no mejora la cifra con quimioterapia agregada. Objetivos: Estimar el efecto de la asociación del tratamiento radiante con el anticuerpo monoclonal Nimotuzumab en la supervivencia de niños y adolescentes con tumores del tallo cerebral. Método: Estudio clínico no aleatorizado, analítico, longitudinal y prospectivo. Se estudió una serie de 46 pacientes entre 2 y 18 años de edad que padecían de tumores del tallo cerebral, infiltrantes y difusos, desde enero de 2008 y en seguimiento hasta marzo de 2018. Todos se trataron con radioterapia, con dosis entre 54 y 59,8 cGrey, dosis diaria de 1,8 cGrey, y se irradiaban de lunes a viernes. Mientras duró el tratamiento radiante recibieron Nimotuzumab, en la dosis de 150 mg/m2 de superficie corporal, luego semanal con 8 dosis, y finalmente mensual durante uno o dos años. Resultados: Se alcanzó en la serie una supervivencia media de 18,4 meses, y una esperada de 42,9 por ciento a 2 años y 35,5 por ciento a 5 años, estabilizada hasta los 10 años. Conclusiones: La combinación de radioterapia y el anticuerpo monoclonal Nimotuzumab incrementa la supervivencia en niños y adolescentes con tumores del tallo cerebral y es bien tolerada, aun en periodos prolongados, e incluso en casos de recidiva(AU)

Introduction: Tumors localized in the brainstem of children and adolescents entail a bad prognosis, especially those that are intrinsic and diffuse. With radiotherapy treatment, patients barely get a 15 percent of survival, and the numbers don't improve with added chemotherapy. Objectives: To estimate the effect of the association of radiotherapy treatment with Nimotuzumab monoclonal antibody in the survival of children and adolescents with brainstem tumors. . Method: Non randomized, analytical, longitudinal and prospective clinical study that was authorized by the National Regulatory Authority. There was studied a group of 46 patients aged from 2 to 18 years that suffered from intrinsic and diffuse brainstem tumors, from January 2008 (and in follow up) to March 2018. All the patients were treated with radiotherapy, with doses among 54 and 59,8 Grey, daily doses of 1,8 Grey, and from Monday to Friday. While they were under radiotherapy treatment, they get Nimotuzumab, in doses of 150 mg/m2 of corporal surface; then weekly doses of 8 shots; and finally, monthly doses during one or two years. Results: In this group there was a survival mean of 18, 4 months, and an expected survival of 42, 9 percent for 2 years and 35, 5 percent for 5 years that can be stabilized to 10 years. Conclusions: Combination of radiotherapy and Nimotuzumab monoclal antibody can increase the survival from brainstem tumors in children and adolescents(AU)

Neuropsychiatry: Towards a Philosophy of Praxis / Neuropsiquiatría: hacia una filosofía de la práctica

Abstract Neuropsychiatry is a specialized clinical, academic and scientific discipline with its field located in the borderland territory between neurology and psychiatry. In this article, we approach the theoretical definition of neuropsychiatry, and in order to address the practical aspects of the discipline, we describe the profile of a neuropsychiatric liaison service in the setting of a large hospital for neurological diseases in a middle-income country. An audit of consecutive in-patients requiring neuropsychiatric assessment at the National Institute of Neurology and Neurosurgery of Mexico is reported, comprising a total of 1212 patients. The main neurological diagnoses were brain infections (21%), brain neoplasms (17%), cerebrovascular disease (14%), epilepsy (8%), white matter diseases (5%), peripheral neuropathies (5%), extrapyramidal diseases (4%), ataxia (2%), and traumatic brain injury and related phenomena (1.8%). The most frequent neuropsychiatric diagnoses were delirium (36%), depressive disorders (16.4%), dementia (14%), anxiety disorders (8%), frontal syndromes (5%), adjustment disorders (4%), psychosis (3%), somatoform disorders (3%), and catatonia (3%). The borderland between neurology and psychiatry is a large territory that requires the knowledge and clinical skills of both disciplines, but also the unique expertise acquired in a clinical and academic neuropsychiatry program.

Resumen La neuropsiquiatría es una disciplina médica cuyo campo clínico, académico y científico se localiza en el territorio fronterizo entre la neurología y la psiquiatría. En este artículo se aborda la definición teórica de la neuropsiquiatría y, con el objetivo de tratar los aspectos prácticos de la neuropsiquiatría, se describe el perfil de un servicio de interconsulta neuropsiquiátrica en el contexto de un hospital dedicado a las enfermedades del sistema nervioso, en un país de ingreso económico medio. Se incluyó a 1.212 pacientes evaluados consecutivamente en el Instituto Nacional de Neurología y Neurocirugía de México. Los diagnósticos principales fueron infecciones cerebrales (21%), neoplasias del sistema nervioso (17%), enfermedad cerebrovascular (14%), epilepsia (8%), enfermedades de la sustancia blanca (5%), neuropatías periféricas (5%), enfermedades extrapiramidales (4%), ataxias (2%) y traumatismos craneoencefálicos (1,8%). Los diagnósticos neuropsiquiátricos más frecuentes fueron síndrome confusional (36%), depresión (16,4%), demencia (14%), ansiedad (8%), síndromes frontales (5%), reacciones de ajuste (4%), psicosis (3%), trastornos somatoformes (3%) y catatonia (3%). El territorio fronterizo entre la neurología y la psiquiatría es extenso y requiere los conocimientos y fortalezas de ambas disciplinas, pero también la pericia entrenada mediante un programa clínico, científico y académico especializado.

Targeting effect of microRNA on CD133 and its impact analysis on proliferation and invasion of glioma cells.

MiR-200b, a member of the microRNA-200 family, has been identified to be capable of suppressing glioma cell growth through targeting CREB1 or CD133. However, whether miR-200b affects the biological behavior (proliferation, invasion, and migration) of glioma cells is poorly understood. The aim of this study was to evaluate the effect of miR-200b on the biological behavior of glioma cells in vitro. MiRNA-200b mimics, miRNA-200b inhibitor, and mimic control were transfected into conventionally cultured glioma U251 cells, followed by measuring the expression of miR-200b and CD133 in transfected cells by RT-PCR; effect of miR-200b on CD133 mRNA 3'-UTR luciferase activity by luciferase reporter assay; proliferation activity of transfected U251 cells by MTT method; and changes in U251 cell invasion and migration by Transwell method after transfection. Compared to that in the miRNA-200b inhibitor, mimic control, and blank control groups, miRNA-200b expression was significantly increased and CD133 mRNA expression was significantly decreased in the mimic miRNA-200b group in a time-dependent manner (P < 0.05). Meanwhile, dual luciferase reporter assay showed that miR-200b could inhibit CD133 activity through binding to the 3'-UTR of CD133 mRNA (P < 0.05). Furthermore, the proliferation activity and invasion and migration abilities of U251 cells transfected with miRNA-200b mimic were significantly decreased (P < 0.05). In conclusion, overexpression of miR-200b inhibited the proliferation, invasion, and migration of glioma cells possibly through targeting CD133.

Tumor Intraventricular de tipo astrocitoma subependimario de células gigantes en paciente con esclerosis tuberosa / Angiotomography in stenosis of the hepatic intraventricular tumor of subependymal giant cell astrocytoma in a patient with tuberous sclerosis

Paciente de sexo femenino, de 3 años de edad, con diagnóstico de esclerosis tuberosa y epilepsia refractaria a los farmacos antiepilépticos, que presenta en la resonancia magnética nuclear del cerebro (Figura1) un proceso ocupativo de aproximadamente 36x25x26 mm a nivel ependimario del asta frontal derecha, del núcleo caudado derecho y de la rodilla de la cápsula interna vecinal, que produce efecto de masa al septum pelucidum desplazándole a la izquierda. Es una imagen compatible con Astrocitoma. (AU)

Congenital hemangioma in spondylocostal dysostosis: a novel association

Abstract Congenital hemangioma is a benign tumor caused by dysfunction in embryogenesis and vasculogenesis, which progresses during fetal life to manifest as fully developed at birth. Although hemangiomas are the most common tumor of infancy, rapidly involuting congenital hemangioma has not been described in spondylocostal dysostosis. I report the novel association of congenital hemangioma and spondylocostal dysostosis in a Mexican newborn female patient with neural tube defects. Given the embryological relationship between skin and nervous system, I surmise that this association is not coincidental. I also propose that these morphologic alterations be incorporated to the spondylocostal dysostosis phenotype and specifically looked for in other affected children, in order to provide appropriate medical management and genetic counseling.

Congenital hemangioma in spondylocostal dysostosis: a novel association.

Congenital hemangioma is a benign tumor caused by dysfunction in embryogenesis and vasculogenesis, which progresses during fetal life to manifest as fully developed at birth. Although hemangiomas are the most common tumor of infancy, rapidly involuting congenital hemangioma has not been described in spondylocostal dysostosis. I report the novel association of congenital hemangioma and spondylocostal dysostosis in a Mexican newborn female patient with neural tube defects. Given the embryological relationship between skin and nervous system, I surmise that this association is not coincidental. I also propose that these morphologic alterations be incorporated to the spondylocostal dysostosis phenotype and specifically looked for in other affected children, in order to provide appropriate medical management and genetic counseling.

Evaluation of the retinoids with cisplatin and vincristine in xenograft models of neuroblastoma.

Retinoids have been studied for the treatment of children with neuroblastoma for >25 years. Posttransplant administration of isotretinoin is standard of care for children with high-risk neuroblastoma, whereas fenretinide remains investigational. Previous preclinical studies have evaluated the interaction of retinoids and cytotoxic agents with conflicting results. We evaluated the schedule-dependent interaction of the cytotoxic agents, vincristine and cisplatin, with the retinoids, isotretinoin and fenretinide, in xenograft models of neuroblastoma. Concomitant administration of isotretinoin or fenretinide with the cytotoxic agents did not result in any clear potentiation of cytotoxicity.

Bilateral vagus nerve neurolymphomatosis diagnosed using PET/CT and diffusion-weighted MRI.

In neurolymphomatosis, malignant lymphocytes infiltrate the peripheral nervous system in the presence of a known or unknown hematological malignancy. This report describes the findings of diffusion-weighted MRI and F-FDG PET/CT in a 65-year-old man with hoarseness. Results revealed a mass with restricted diffusion on diffusion-weighted imaging in the right visceral vascular space, increased uptake of F-FDG, and other masses at distant peripheral nerves. Restaging PET/CT showed involvement of the right brachial plexus and right sciatic nerve. Biopsy and immunohistochemistry of the right vagus nerve and cervical lymphadenopathy revealed a diffuse large B-cell non-Hodgkin lymphoma.

Tumores primarios del sistema nervioso central en personas de 15 años o más / Primary tumors of the central nervous system in people aged 15 years and older

Objetivo general: generar recomendaciones basadas en la mejor evidencia disponible acerca del manejo de personas con tumores primarios del sistema nervioso central o que hayan sido tratados por ello. Objetivos específicos: personas con tumores primarios del sistema nervioso central o que hayan sido tratados por ello, que reciben atención en el nivel secundario y nivel terciario de salud en el sector público y privado de salud. Usuarios de la guía: Médicos Generales, de Urgencia, Neurólogos, Neurocirujanos, Oncólogos, Radioterapeutas, y otros médicos y profesionales que participan en la atención integral de los pacientes con tumores primarios del sistema nervioso central o tratados por ello.

In vitro studies on Bothrops venoms cytotoxic effect on tumor cells.

BACKGROUND: Animal venoms are complex mixtures of proteins and non proteins components with several biological activities. Snake venoms represent an essentially unexplored source of bioactive compounds that may cure disease conditions which do not respond to currently available therapies. These venoms possess many pharmacological activities, as cytotoxic and/or lytic effects on tumor cells in vitro. Herein, were investigated the in vitro cytotoxicity of three Bothrops venoms in tumor cell lines. METHODS: Cytotoxic effect was evaluated in HCT-8 (colon - human), SF-295 (nervous system - human), HL-60 (human leukemia) and MDAMB-435 (breast - human). Cell density and membrane integrity were determined by the exclusion of propidium iodide. To determine whether Bothrops venoms treated cells were undergoing an apoptotic and/ or necrosis death, phosphatidylserine (PS) externalization was measured after the incubation with the venom. RESULTS: Botrhops venons showed significant cytotoxcity against all cell lines in study. Cell density and membrane integrity were determined by the exclusion of propidium iodide. The Bothrops venoms reduced the cell number and revealed the presence of a necrotic population when the cells was exposed to the B. pauloensis B. diporus and B. pirajai venoms. To determine whether Bothrops venoms treated cells were undergoing an apoptotic and/or necrosis death, PS externalization was measured after the incubation with the venom and it was observed necrotic and apoptotic cells. CONCLUSIONS: All Bothrops venoms tested showed cytotoxicity against tumor cell lines through inducing of necrosis and apoptosis.

Glioblastoma cells: a heterogeneous and fatal tumor interacting with the parenchyma.

Glioblastomas (GBMs) are considered to be one of the deadliest human cancers, characterized by a high proliferative rate, aggressive invasiveness and insensitivity to radio- and chemotherapy, as well as a short patient survival period. Moreover, GBMs are among the most vascularized and invasive cancers in humans. Angiogenesis in GBMs is correlated with the grade of malignancy and is inversely correlated with patient survival. One of the first steps in tumor invasions is migration. GBM cells have the ability to infiltrate and disrupt physical barriers such as basement membranes, extracellular matrix and cell junctions. The invasion process includes the overexpression of several members of a super-family of zinc-based proteinases, the Metzincin, in particular a sub-group, metalloproteinases. Another interesting aspect is that, inside the GBM tissue, there are up to 30% of microglia or macrophages. However, little is known about the immune performance and interactions of the microglia with GBMs. These singular properties of GBMs will be described here. A sub-population of cells with stem-like properties may be the source of tumors since, apparently, GBM stem cells (GSCs) are highly resistant to current cancer treatments. These cancer therapies, while killing the majority of tumor cells, ultimately fail in GBM treatment because they do not eliminate GSCs, which survive to regenerate new tumors. Finally, GBM patient prognostic has shown little improvement in decades. In this context, we will discuss how the membrane-acting toxins called cytolysins can be a potential new tool for GBM treatment.

Oral and neurocutaneous phenotypes of familial tuberous sclerosis.

OBJECTIVE: The objective of this study was to describe the pattern of inheritance and the clinical features in a large family with tuberous sclerosis (TS), and to focus on the general diagnosis after the initial oral examination. STUDY DESIGN: To characterize the pattern of inheritance and the clinical features, 61 familial members were systematically evaluated, including dermatologic, ophthalmologic, and orofacial examination. Imaging exams, such as abdomen ultrasonography, echocardiogram, fundoscopy, cranial cone-beam computerized tomography, and brain magnetic resonance, were performed. Hematoxylin and eosin stain and scanning electronic microscopy were performed to characterize TS-associated alterations in the teeth, nails, and hair. RESULTS: The pedigree of the family was constructed including the 4 last generations and revealed nonconsanguineous marriages and an autosomal dominant mode of TS transmission. We identified 13 family members affected by TS, with 6 of them completely fulfilling the diagnostic criteria of this disorder. Hypomelanotic macules in the skin, facial angiofibromas, and dental enamel pits were the most common features of affected patients. Central nervous system alterations were identified in 5 family members, whereas cardiac and renal alterations were found in 1 member each. CONCLUSION: We emphasize, in this study, the importance of oral findings such as dental enamel pits and gingival angiofibromas in the early diagnosis of familial TS which led to complete familial profile and pattern of inheritance establishment.

Estudio comparativo: prevalencia patologías bucales en pacientes pediátricos oncológicos 1997-2007 / Comparative study: oral pathologies prevalence in pediatric oncology patients 1997- 2007

Los pacientes pediátricos oncológicos con frecuencia presentan lesiones orales debido a su neoplasia o como efecto colateral del tratamiento. El objetivo de este estudio fue comparar la prevalencia de patologías de la mucosa oral en niños con cáncer que fueron hospitalizados y tratados con quimioterapia en el Hospital Regional de Concepción, en los años 1997 y 2007. Se realizó un estudio descriptivo retrospectivo longitudinal en datas de 148 pacientes (74 cada año) con patologías neoplásicas en tratamiento con quimioterapia (Leucemias, linfomas, tumores del Sistema Nervioso Central y otros), registrando sus datos generales y la patología bucal (mucositis (M), candidiasis (C), lesiones por Virus Herpes tipo 1 (VHS) y síndromes hemorragíparos (H) . Los datos se resumieron en tablas anuales y fueron sometidos a análisis estadísticos. Se encontró una disminución significativa del número de pacientes con patologías bucales en el año 2007 en relación al año 1997 (P<0.05, Tet de Fisher). Además se encontró una tendencia a la baja en los pacientes con candidiasis y con mucositis en el año 2007 en comparación con 1997. Es necesario seguir estudiando medidas para prevenir, diagnosticar y/o tratar tempranamente las patologías orales de los pacientes en tratamiento antineoplásico.

Pediatric oncology patients frequently have oral lesions due to malignancy or as a side effect of treatment. The aim of this study was to compare the prevalence of oral pathologies in oncology patients hospitalized and treated at the Regional Hospital of Concepción, Chile, in the years 1997 and 2007. A retrospective study was carried out in 74 patients each year. Patients suffered from acute lymphoblastic leukemia, acute myeloblastic leukemia, central nervous system tumors, lymphomas and other neoplasms. General data (age, gender, oncologic disease) and presence of oral pathologies (candidiasis, mucositis post-chemotherapy, herpetic lesions and hemorrhage) were obtained from their clinical records. Data was analyzed for statistical differences. A significant reduction in the number of patients with oral pathologies was found in 2007 in comparison to 1997 (P<0.05, Fisher´s test). In addition, candidiasis and oral mucositis showed less prevalence in 2007 as compared to 1997, although no significant differences were found. For the relevance of oral pathologies in the chemotherapy it´s important to continue studies about prevention, early detection and treatment of oral pathologies.

Lipids, mitochondria and cell death: implications in neuro-oncology.

Polyunsaturated fatty acids (PUFAs) are known to inhibit cell proliferation of many tumour types both in vitro and in vivo. Their capacity to interfere with cell proliferation has been linked to their induction of reactive oxygen species (ROS) production in tumour tissues leading to cell death through apoptosis. However, the exact mechanisms of action of PUFAs are far from clear, particularly in brain tumours. The loss of bound hexokinase from the mitochondrial voltage-dependent anion channel has been directly related to loss of protection from apoptosis, and PUFAs can induce this loss of bound hexokinase in tumour cells. Tumour cells overexpressing Akt activity, including gliomas, are sensitised to ROS damage by the Akt protein and may be good targets for chemotherapeutic agents, which produce ROS, such as PUFAs. Cardiolipin peroxidation may be an initial event in the release of cytochrome c from the mitochondria, and enriching cardiolipin with PUFA acyl chains may lead to increased peroxidation and therefore an increase in apoptosis. A better understanding of the metabolism of fatty acids and eicosanoids in primary brain tumours such as gliomas and their influence on energy balance will be fundamental to the possible targeting of mitochondria in tumour treatment.

The A61G EGF polymorphism is associated with development of extraaxial nervous system tumors but not with overall survival.

Epidermal growth factor can activate several signaling pathways, leading to proliferation, differentiation, and tumorigenesis of epithelial tissues by binding with its receptor. The EGF protein is involved in nervous system development, and polymorphisms in the EGF gene on chromosome band 4q25 are associated with brain cancers. The purpose of this study was to investigate the association between the single-nucleotide polymorphism of EGF+61G/A and extraaxial brain tumors in a population of the southeast of Brazil. We analyzed the genotype distribution of this polymorphism in 90 patients and 100 healthy subjects, using the polymerase chain reaction-restriction fragment length polymorphism technique. Comparison of genotype distribution revealed a significant difference between patients and control subjects (P < 0.001). The variant genotypes of A/G and G/G were associated with a significant increase of the risk of tumor development, compared with the homozygote A/A (P < 0.0001). When the analyses were stratified, we observed that the genotype G/G was more frequent in female patients (P=0.021). The same genotype was observed more frequently in patients with low-grade tumors (P=0.001). Overall survival rates did not show statistically significant differences. Our data suggest that the EGF A61G polymorphism can be associated with susceptibility to development of these tumors.

Atlas de mortalidad por cáncer en colombia 2010 / Atlas of cancer mortality in colombia 2010

El Instituto Nacional de Cancerología (INC), E. S. E., como ente asesor del Ministerio de la Protección Social, presenta la tercera edición del Atlas de mortalidad por cáncer en Colombia, que en esta oportunidad contempla el periodo 2000-2006. Este trabajo hace parte de la difusión periódica que hace el INC de la información producto de la vigilancia epidemiológica del cáncer en el país. La primera edición del Atlas de mortalidad fue publicada en 1994, con información correspondiente al periodo 1989-1991, donde se representó la cartografía de la mortalidad de cáncer en el país, por grandes regiones y departamentos. La segunda edición contempló información del periodo 1990-1996, y se desarrolló con la colaboración del Instituto Geográfico Agustín Codazzi (IGAC); en esa oportunidad se incorporaron aspectos novedosos desde el punto de vista metodológico, lo que permitió representar mapas temáticos de área pequeña, además de mapas a nivel departamental y mapas de tendencias. Esta nueva edición proporciona información para el periodo 2000-2006, con una metodología y una presentación similares a las de la edición anterior, con el objeto de facilitar la comparación entre ambas publicaciones. Un aspecto nuevo que se introdujo en esta entrega es que se presenta, en las tablas, la información de tendencias de mortalidad para dos periodos: 2000-2006 y 1998-2006. Esto permite al lector comparar el comportamiento de la mortalidad en un periodo corto y en un periodo largo, lo que para temas como el cáncer tiene particular relevancia. Al igual que la edición anterior, este trabajo obedece al esfuerzo coordinado con el IGAC, entidad encargada de producir la cartografía básica de Colombia. El insumo fundamental para su elaboración proviene del Departamento Administrativo Nacional de Estadística (DANE), en sus programas de estadísticas vitales, censos y proyecciones de población. Esperamos, una vez más, que el aporte realizado con la presente publicación constituya un elemento central para todas aquellas personas comprometidas con el control del cáncer en Colombia. Es nuestro deseo que esta publicación esté disponible para los tomadores de decisiones en salud en distintos ámbitos, así como para la comunidad científica, y que la información contenida en ella sea de valiosa ayuda no sólo para avanzar en el entendimiento sobre cómo se comporta cáncer en el país, sino, también, para orientar y evaluar las acciones departamentales y de país en el control de la enfermedad.