Biomarcadores genéticos en sangre, una nueva herramienta para el diagnóstico, pronóstico y supervivencia en pacientes con gliomas de alto grado / Genetic biomarkers in blood, a new tool for diagnosis, prognosis, and survival in patients with high-grade gliomas / Biomarcadores genéticos no sangue, uma nova ferramenta para diagnóstico, prognóstico e sobrevida em pacientes com gliomas de alto grau

Durante mucho tiempo, la clasificación de los tumores del sistema nervioso central (SNC) se ha basado en hallazgos histológicos respaldados por pruebas complementarias, como la inmunohistoquímica, establecidas en tejidos. La quinta edición de la clasificación de tumores del SNC de la Organización Mundial de la Salud (OMS), publicada en 2021 (SNC-5) incorpora numerosos marcadores moleculares con utilidad clínico-patológica que son importantes para una clasificación más precisa de las neoplasias del SNC. Ello permiten ayudar a definir los gliomas difusos del adulto, oligodendroglioma mutado para el gen de la IDH (isocitrato deshidrogenasa láctica), con codeleción 1p/19q grados 2 a 3, astrocitoma mutado para IDH sin codeleción 1p/19q, grados 2 a 4 y glioblastoma (GBM) silvestre para IDH. La mediana de sobrevida en los pacientes con GBM es de solo 14.6 meses, debido a la resistencia al protocolo de terapia más utilizado en el mundo, el cual involucra cirugía, radioterapia y quimioterapia con temozolamida (TMZ), un potente alquilante genotóxico. Los criterios de selección del tratamiento y la estimación del pronóstico en pacientes con esta enfermedad son clínico-patológicos. En los últimos años se reportaron numerosas alteraciones moleculares que amplían la comprensión de la biología de estos tumores, pero solo unas pocas influyen como biomarcadores en la toma de decisiones clínicas y del tratamiento. En este artículo se revisan las alteraciones moleculares reportadas para gliomas de alto grado en sangre periférica, también se resalta la importancia de estandarizar nuevos biomarcadores junto a los hallazgos histológicos para mejorar el conocimiento de estos tumores.

For a long time, the classification of central nervous system (CNS) tumors has been based on histological findings supported by complementary tests, such as immunohistochemistry, established in tissues. The fifth edition of the World Health Organization (WHO) Classification of Tumors of the Central Nervous System, published in 2021 (CNS-5), incorporates numerous molecular markers with clinical-pathological utility that are important for a more accurate classification of CNS neoplasms. These markers help to define adult diffuse gliomas, including IDH-mutant oligodendroglioma with 1p/19q codeletion (grades 2-3), IDH-mutant astrocytoma without 1p/19q codeletion (grades 2-4), and wild-type IDH glioblastoma (GBM). The median survival in patients with GBM is only 14.6 months, primarily due to resistance to the most widely used treatment protocol worldwide, which involves surgery, radiotherapy, and chemotherapy with temozolomide (TMZ), a potent genotoxic alkylating agent. The selection criteria for treatment and the estimation of prognosis in patients with this disease are predominantly based on clinical and pathological factors. In recent years, numerous molecular alterations have been reported, expanding our understanding on the biology of these tumors. However, only a few of these molecular alterations serve as biomarkers that influence clinical decision-making and treatment strategies. This article reviews the molecular alterations reported in peripheral blood for high-grade gliomas and emphasizes the importance of standardizing new biomarkers alongside histological findings to enhance our knowledge of these tumors.

Por muito tempo, a classificação dos tumores do sistema nervoso central (SNC) baseou-se em achados histológicos respaldados por exames complementares, como a imuno-histoquímica, estabelecidos nos tecidos. A quinta edição da classificação de tumores do SNC da Organização Mundial da Saúde (OMS), publicada em 2021 (CNS-5), incorpora inúmeros marcadores moleculares com utilidade clinicopatológica importantes para uma classificação mais precisa das neoplasias do SNC. Isso permite definir gliomas difusos adultos, oligodendroglioma mutado para o gene IDH (lactic isocitrato desidrogenase), com codeleção 1p/19q graus 2 a 3, astrocitoma mutado para IDH sem codeleção 1p/19q, graus 2 a 4 e wild- tipo glioblastoma (GBM) para IDH. A sobrevida mediana em pacientes com GBM é de apenas 14,6 meses, devido à resistência ao protocolo terapêutico mais utilizado no mundo, que envolve cirurgia, radioterapia e quimioterapia com temozolamida (TMZ), um potente alquilador genotóxico . Os critérios de seleção para o tratamento e estimativa do prognóstico em pacientes com essa doença são clínico-patológicos. Nos últimos anos, foram relatadas inúmeras alterações moleculares que ampliam o entendimento da biologia desses tumores, mas apenas algumas influenciam na decisão clínica e terapêutica como biomarcadores. Este artigo revisa as alterações moleculares relatadas para gliomas de alto grau no sangue periférico, destacando também a importância da padronização de novos biomarcadores juntamente com os achados histológicos para melhorar o conhecimento desses tumores

Flow cytometry in peripheral blood reticulocytes as a marker of chromosome instability in highgrade glioma patients

Introduction: The quantification of chromosomal instability is an important parameter to assess genotoxicity and radiosensitivity. Most conventional techniques require cell cultures or laborious microscopic analyses of chromosomes or nuclei. However, a flow cytometry that selects the reticulocytes has been developed as an alternative for in vivo studies, which expedites the analytical procedures and increases up to 20 times the number of target cells to be analyzed. Objectives: To standardize the flow cytometry parameters for selecting and quantifying the micronucleated reticulocytesCD71+ (MN-RET) from freshly drawn peripheral blood and to quantify the frequency of this abnormal cell subpopulation as a measure of cytogenetic instability in populations of healthy volunteers (n =25), and patients (n=25), recently diagnosed with high-grade gliomas before the onset of treatment. Materials and methods: Blood cells were methanol-fixed and labeled with anti-CD-71-PE for reticulocytes, antiCD-61-FITC for platelet exclusion, and propidium iodide for DNA detection in reticulocytes. The MN-RETCD71+ cell fraction was selected and quantified with an automatic flow cytometer. Results: The standardization of cytometry parameters was described in detail, emphasizing the selection and quantification of the MN-RETCD71+ cellular fraction. The micronuclei basal level was established in healthy controls. In patients, a 5.2-fold increase before the onset of treatment was observed (p <0.05). Conclusion: The data showed the usefulness of flow cytometry coupled with anti-CD-71-PE and anti-CD-61-FITC labeling in circulating reticulocytes as an efficient and high resolution method to quantify chromosome instability in vivo. Finally, possible reasons for the higher average of micronuclei in RETCD71+ cells from untreated high-grade glioma patients were discussed.

Citometría de flujo en reticulocitos de sangre periférica como indicador de inestabilidad cromosómica en pacientes con gliomas de alto grado / Flow cytometry in peripheral blood reticulocytes as a marker of chromosome instability in highgrade glioma patients

Resumen Introducción. La cuantificación de la inestabilidad cromosómica es un parámetro importante para evaluar la genotoxicidad y la radiosensibilidad. Las técnicas convencionales requieren cultivos celulares o laboriosos análisis microscópicos de cromosomas o núcleos. La citometría de flujo en reticulocitos ha surgido como una alternativa para los estudios in vivo, ya que reduce los tiempos de análisis e incrementa hasta en 20 veces el número de células analizables. Objetivos. Estandarizar los parámetros de citometría de flujo requeridos para seleccionar y cuantificar reticulocitos micronucleados (RET-MN) a partir de muestras de sangre periférica, y cuantificar la frecuencia de esta subpoblación anormal como medida de inestabilidad citogenética en sendas poblaciones de voluntarios sanos (n=25) y pacientes (n=25) recién diagnosticados con gliomas de alto grado antes de iniciar el tratamiento. Materiales y métodos. Las células sanguíneas se marcaron con anti-CD71-PE para reticulocitos, anti- CD61-FITC para la exclusión de plaquetas y yoduro de propidio para detectar el ADN en reticulocitos. La fracción celular MN-RETCD71+ se seleccionó y se cuantificó con un citómetro de flujo automático. Resultados. Se describió detalladamente la estandarización de los parámetros citométricos, con énfasis en la selección y la cuantificación de la subpoblación celular MN-RETCD71+. Se establecieron los niveles basales de MN-RETCD71+ en la población de control y en los pacientes se encontró un incremento de 5,2 veces antes de iniciar el tratamiento (p<0,05). Conclusión. Los resultados evidenciaron la utilidad de la citometría de flujo acoplada a la marcación de las células RETCD71+ como método eficiente para cuantificar la inestabilidad cromosómica in vivo. Se sugieren posibles razones del incremento de micronúcleos en células RETCD71+ de pacientes con gliomas.

Abstract Introduction: The quantification of chromosomal instability is an important parameter to assess genotoxicity and radiosensitivity. Most conventional techniques require cell cultures or laborious microscopic analyses of chromosomes or nuclei. However, a flow cytometry that selects the reticulocytes has been developed as an alternative for in vivo studies, which expedites the analytical procedures and increases up to 20 times the number of target cells to be analyzed. Objectives: To standardize the flow cytometry parameters for selecting and quantifying the micronucleated reticulocytesCD71+ (MN-RET) from freshly drawn peripheral blood and to quantify the frequency of this abnormal cell subpopulation as a measure of cytogenetic instability in populations of healthy volunteers (n =25), and patients (n=25), recently diagnosed with high-grade gliomas before the onset of treatment. Materials and methods: Blood cells were methanol-fixed and labeled with anti-CD-71-PE for reticulocytes, antiCD-61-FITC for platelet exclusion, and propidium iodide for DNA detection in reticulocytes. The MN-RETCD71+ cell fraction was selected and quantified with an automatic flow cytometer. Results: The standardization of cytometry parameters was described in detail, emphasizing the selection and quantification of the MN-RETCD71+ cellular fraction. The micronuclei basal level was established in healthy controls. In patients, a 5.2-fold increase before the onset of treatment was observed (p <0.05). Conclusion: The data showed the usefulness of flow cytometry coupled with anti-CD-71-PE and anti- CD-61-FITC labeling in circulating reticulocytes as an efficient and high resolution method to quantify chromosome instability in vivo. Finally, possible reasons for the higher average of micronuclei in RETCD71+ cells from untreated high-grade glioma patients were discussed.

Efficacy and safety of Levetiracetam vs. other antiepileptic drugs in Hispanic patients with glioblastoma.

Epilepsy is a common symptom in patients with glioblastoma (GB). 213 patients with GB from RedLANO follow-up registry were included. All patients underwent surgery, if feasible, followed by chemoradiation based on temozolomide (Stupp platform). Information was recorded regarding demographics, seizure timing, anti-epileptic drugs (AEDs), dosage, time to next seizure, total seizures in 6 months, and main side effects of AEDs. The relationship between epilepsy treatment and overall survival (OS) was evaluated. Mean age was 53 years old and 56.8% were male. Seventy-eight patients (37%) were treated with levetiracetam (LEV), 27% were given another AED and 36% did not require any AED. Choice of AED was not associated with age (p = 0.67), performance status (p = 0.24) or anatomic tumor site (p = 0.34). Seizures and AED requirement were greater in those having primary GB (p = 0.04). After starting an AED, the mean time until next crisis was 9.9 days (SD ± 6.3), which was shorter in those receiving LEV (p = 0.03); mean number of seizures during the first 3 and 6 months were 2.9 and 4, respectively. Most patients treated with LEV (n = 46) required less than two medication adjustments compared to those treated with other AEDs (p = 0.02). Likewise, less patients exposed to LEV required a coadjuvant drug (p = 0.04). Additionally, patients receiving LEV had significantly less adverse effects compared to patients treated with another AED. OS was significantly higher in the group treated with LEV compared to other AEDs (25.5 vs. 17.9 months; p = 0.047). Patients treated with LEV had better seizure control and longer OS compared to other AEDs.

Genotyping low-grade gliomas among Hispanics.

BACKGROUND: Low-grade gliomas (LGGs) are classified by the World Health Organization as astrocytoma (DA), oligodendroglioma (OD), and mixed oligoastrocytoma (OA). TP53 mutation and 1p19q codeletion are the most-commonly documented molecular abnormalities. Isocitrate dehydrogenase (IDH) 1/2 mutations are frequent in LGGs; however, IDH-negative gliomas can also occur. Recent research suggests that ATRX plays a significant role in gliomagenesis. METHODS: We investigated p53 and Olig2 protein expression, and MGMT promoter methylation, 1p19q codeletion, IDH, and ATRX status in 63 Colombian patients with LGG. The overall survival (OS) rate was estimated and compared according to genotype. RESULTS: The most common histology was DA, followed by OD and OA. IDH1/2 mutations were found in 57.1% and MGMT+ (positive status of MGMT promoter methylation methyl-guanyl-methyl-transferase gene) in 65.1% of patients, while overexpression of p53 and Olig2 was present in 30.2% and 44.4%, respectively, and 1p19q codeletion in 34.9% of the patients. Overexpression of ATRX was analyzed in 25 patients, 16% tested positive and were also mutations in isocitrate dehydrogenase and negative 1p19q-codelition. The median follow-up was 15.8 months (95% CI, 7.6-42.0) and OS was 39.2 months (95% CI, 1.3-114). OS was positively and significantly affected by MGMT+, 1p19q codeletion, surgical intervention extent, and number of lobes involved. Multivariate analysis confirmed that MGMT methylation status and 1p19q codeletion affected OS. CONCLUSIONS: This is the first study evaluating the molecular profile of Hispanic LGG patients. Findings confirmed the prognostic relevance of MGMT methylation and 1p19q codeletion, but do not support IDH1/2 mutation as a relevant marker. The latter may be explained by sample size and selection bias. ATRX alterations were limited to patients with DA and were mutations in isocitrate dehydrogenase and negative 1p19q-codelition.

Complejo esclerosis tuberosa / Tuberous sclerosis complex

INTRODUCCIÓN: El complejo esclerosis tuberosa (TSC) es el prototipo de malformación relacionada con alteraciones en la diferenciación y el crecimiento celular de fenotipos variables con implicaciones sistémicas. OBJETIVO: caracterizar y describir el TSC para facilitar el entendimiento de las neurodermatosis en la población Colombiana. MATERIALES Y MÉTODOS:la información fue extraída a partir de búsquedas practicadas en las bases de datos MEDLINE, en BIOSIS y en EMBASE desde 1966, 1994 y 1974, respectivamente, hasta el 1 de Marzo de 2011, usando la plataforma OVID y múltiples términos clave. Se diseñaron estrategias adicionales para las bases de datos LILACS, Best Evidence y CINHAL con criterios similares. También se recopilaron datos obtenidos de sociedades científicas relacionadas con el tema en estudio. RESULTADOS:los criterios diagnósticos han permanecido inmodificados a pesar de que el estudio molecular permite caracterizar la enfermedad. El entendimiento de la patogénesis del TSC ha favorecido el desarrollo de opciones terapéuticas contra blancos moleculares que se encuentran alterados. La vía mTOR explica la mayor parte de las alteraciones fenotípicas en pacientes con TSC. CONCLUSIÓN:El documento del Consorcio Colombiano para el Estudio de las Neurodermatosis muestra una revisión integral del conocimiento respecto del diagnóstico y tratamiento del TSC.

INTRODUCTION: The Tuberous Sclerosis Complex (TSC) is the mainstay of malformation related to alterations in cellular growth and differentiation, with highly variable phenotypes, and systemic impact. OBJETIVES: To characterize and describe TSC to facilitate understanding of the neurodermatosis in the Colombian population. MATERIALS AND METHODS: Information was obtained from searches performed in MEDLINE, BIOSIS, and EMBASE from 1966, 1994 and 1974, respectively, until March 1, 2011, using the OVID platform and multiple key terms. Additional strategies were designed for other databases like LILACS, CINAHL and Best Evidence using similar criteria. We also collected data from scientific societies related to the topic under study. RESULTS: the diagnostic criteria have not been modified instead molecular characterizations leads to a better understanding of the disease. The characterization of pathogenesis leads to the development of target therapies against those molecular alterations. mTOR pathway explains phenotypic alterations in patients suffering of TSC. CONCLUSION: the document of the Colombian Consensus for the Neurodermathosis, wants to show an integral review of the knowledge about the development, diagnosis and treatment of TSC.

Stem cells in brain tumorigenesis and their impact on therapy.

The concept that the genesis of new cells in the adult mammalian brain is negligible has long influenced our perception and understanding of the origin and development of central nervous system (CNS) tumors. The discovery that neurons and glia are produced throughout life from neural stem cells provides new possibilities for candidate precursor cells of CNS neoplasms. The emerging hypothesis is that alterations in the cellular and genetic mechanisms that control adult neurogenesis might contribute to brain tumorigenesis. As such, opportunities become available to identify new therapeutic strategies.

Neuropatía inducida por el tratamiento médico del cáncer: [revisión] / Neuropathy induced by medical cancer therapy: [review]

Los avances recientes en el tratamiento de las enfermedades neoplásicas han mejorado las tasas de supervivencia. Las intervenciones médicas generan diversos efectos adversos agudos que comprometen el tracto gastrointestinal y la medula ósea, mientras la neurotoxicidad tiende a ser tardía y evoluciona en el tiempo. En el sistema nervioso periférico es frecuente documentar la neuropatía inducida por el tratamiento médico del cáncer, hallazgo relacionado con la administración de agentes quimioterapéuticos utilizados para controlar los tumores hematológicos y sólidos. El tratamiento oncológico genera una gran variedad de cambios estructurales y funcionales en los nervios periféricos, incluyendo la afectación de los cuerpos neuronales del sistema de transporte axonal, del recubrimiento mielínico y de las estructuras de soporte glial. Cada agente presenta un espectro de toxicidad único que se relaciona con su mecanismo de acción, eventos que pueden mitigarse gracias a los resultados de múltiples estudios. Gracias al reconocimiento de los efectos devastadores de la neuropatía inducida por el tratamiento médico del cáncer en la calidad de vida, la investigación básica y clínica ha empezado a evaluar el papel de múltiples terapias para prevenir y tratar el daño neurológico. Esta revisión integra información seleccionada a partir de búsquedas estructuras realizadas en las bases de datos biomédicas más relevantes, haciendo énfasis en el diagnóstico y en las intervenciones farmacológicas y no farmacológicas descritas como parte del manejo de la neuropatía inducida por el tratamiento médico del cáncer, que con frecuencia es subvalorada. En conclusión, la información disponible hasta el momento permite establecer los mecanismos de la enfermedad y sugiere el desarrollo de un número mayor de estudios que permitan validar las estrategias descritas hasta el momento.

Recent advances in the development and administration of therapy for malignant diseases have been rewarded with prolonged survival rates. Unlike more immediate toxicities that affect the gastrointestinal tract and bone marrow, chemotherapy-induced neurotoxicity is frequently delayed in onset and may progress over time. In the peripheral nervous system, the major brunt of the toxicity is directed against the peripheral nerve, resulting in cancer therapy-induced peripheral neuropathy. Chemotherapeutic agents used to treat hematologic and solid tumors target a variety of structures and functions in the peripheral nervous system, including the neuronal cell body, the axonal transport system, the myelin sheath, and glial support structures. Each agent exhibits a spectrum of effects unique to its mechanism of action, and recent studies in this fi eld have yielded clearer ideas on how to mitigate injury. Combined with the call for a greater recognition of the devastating effects of cancer therapy-induced peripheral neuropathy on quality of life, basic and clinical researchers have begun to investigate therapy to prevent and treat neurologic damage. This review was made based on relevant information avaliable on international databases concerning cancer therapyinduced peripheral neuropathy and summarizes the evidence for diagnosis, pharmacologic and nonpharmacologic approaches to the management of this commonly unrecognized condition. In conclusion, the information avaliable in this moment establish the mechanisms of the disease and exposes the importance of the development of statistically stronger clinical trials that complement current data available in this moment.

Valor genómico de la isocitratodeshidrogenasa(IDH1/2) en el origen yprogresión de los gliomas (OncolGroup) / Genomic value of isocitrate-dehydrogenase (IDH1/2) in glioma origin and progression (ONCOLGroup)

Introduccción. Las mutaciones heterocigotas del gen que codifica la isocitrato deshidrogenasa (IDH) ocurren con relativa frecuencia en los gliomas; sin embargo, su relevancia durante el desarrollo tumoral es desconocida. Estas alteraciones provocan una pérdida en la afinidad de la enzima por el sustrato, inhibiendo la actividad de la isoforma silvestre de la IDH1 a través de la formación de heterodímeros inactivos. La expresión forzada de la mutación IDH1/2 en cultivos celulares reduce la formación del producto de la enzima, el α-ketoglutarato (α-KG), e incrementa los niveles del factor inducido por la hipoxia tipo 1 (HIF-1α, un elemento de transcrip¬ción que facilita el crecimiento tumoral en presencia de bajas concentraciones de oxígeno, hallazgo regulado en parte por el α-KG. La expresión del HIF-1α suele ser mayor entre los gliomas portadores de la mutación IDH, en los que la vía de señalización del HIF está implicada en su progresión. Varios grupos independientes han demostrado el papel que tienen las mutaciones del gen IDH1/2 como marcador pronóstico, especialmente para los pacientes con gliomas de bajo grado y con glioblastomas secundarios que presentan un patrón oligo¬dendroglial. Este conocimiento proporciona una clara oportunidad para mejorar las estrategias diagnósticas y terapéuticas para los pacientes con gliomas, que en la actualidad no se encuentran dirigidas contra alteraciones moleculares específicas. Este artículo presenta una revisión detallada del papel de las mutaciones del gen IDH en la progresión y el mantenimiento de los gliomas, y explora algunas opciones terapéuticas dirigidas contra este entorno.

Heterozygous mutations in the gene encoding isocitrate dehydrogenase (IDH) occur in gliomas, but theirmechanistic role in tumor development is unknown. Tumor-derived IDH mutations impair the enzyme’saffinity for its substrate and dominantly inhibit wild-type IDH1 activity through the formation of catalytically inactive heterodimers. Forced expression of mutant IDH1 in cultured cells reduces formation of the enzyme product, α-ketoglutarate (α-KG), and increases the levels of hypoxia-inducible factor subunit 1 (HIF-1α, a transcription factor that facilitates tumor growth when oxygen is low and whose stability is regulated by α-KG. HIF-1α levels were higher in human gliomas harboring an IDH1 mutation than in tumors without a mutation, thus, IDH1/2 contributes to tumor progression in part through induction of the HIF-1 pathway. Numerous independent research groups had demonstrated the role of IDH mutations as a prognostic marker, especially for those patients with low grade gliomas and secondary glioblastomas with oligodendroglial pattern. This knowledge indicates great opportunities to improve diagnostic and therapeutic strategies for gliomas, whichare not currently targeted at the specific molecular alterations. This paper presents a detailed review of the role of the IDH gene mutations in progression and manteinance of gliomas, and explores some therapeutic options directed against this environment.

Caracterización neuropsicológica de pacientes con glioma tratados en el instituto de cancerología de Medellín / Neuropsychological characteristics of patients with glioma treated in the Institute of cancer of Medellín Colombia

INTRODUCCIÓN: el 50 al 80 por ciento de los pacientes con gliomas presentan perturbaciones cognitivas, lo cual empeora la calidad de vida del enfermo. OBJETIVOS: analizar las características neuropsicológicas en pacientes con gliomas del instituto de cancerología de Medellín. MATERIAL Y MÉTODOS: se seleccionaron 50 pacientes con glioma, a quienes se les aplicó una batería neuropsicológica para evaluar atención, memoria, habilidades visuales y constructivas, lenguaje y función ejecutiva. Se compararon los promedios de los pacientes con los de la población general colombiana, también entre grupos de acuerdo con la localización, el tamaño, el grado de malignidad; lo mismo que entre grupos según edad, escolaridad y género. RESULTADOS: la proporción entre hombres (52 por ciento) y mujeres (48 por ciento) fue similar. La localización más frecuente fue del lóbulo frontal (32 por ciento) con predominio del lado derecho (20 por ciento). El tamaño del tumor en el 48 por ciento de la muestra fue de 3cm o más y en 50 por ciento se encuentra en un grado de malignidad avanzado. Hubo alteración en todas las funciones neuropsicológicas en comparación con la población general. Los lesionados del lado izquierdo tuvieron alteraciones significativas en la fluidez verbal y en la capacidad de categorización. Aquellos con lesiones posteriores tuvieron ejecuciones más bajas que los pacientes con lesiones frontales en la capacidad intelectual, las habilidades constructivas y en memoria. Como dato inesperado no se encontraron diferencias significativas en las variables de función ejecutiva. CONCLUSIONES: los pacientes con glioma tuvieron lentitud en las ejecuciones, fallas en el almacenamiento y evocación de la información y características de afasia sensorial transcortical.

INTRODUCTION: 50 to 80 per cent of the patients with brain gliomas have cognitive impairment, which produces worsening of the quality of life. OBJECTIVE: to analyze the neuropsychological characteristics in patients with gliomas from the Instituto de Cancerología (Cancer Institute) of Medellín. MATERIALS AND METHODS: 50 patients with malignant brain tumors (gliomas) were selected. A neuropsychological battery to assess attention, memory, visual and motor skills, language and executive function was administered. Patient’s performance was compared to Colombian general population; also groups of patients according to tumor localization, size and grade of severity were analyzed; similar comparisons were done between age, gender and school achievement groups. RESULTS: gender distribution was similar (males 52 per cent and females 48 per cent). Frontal localizations (32 per cent) were the most frequent, and predominate in the right hemisphere (20 per cent). Tumor size was over 3 cm in 48 por ciento of the sample, and 50 per cent had a severe malignity grade. There was alteration in all of the assessed neuropsychological functions, compared to general population. Patients with left tumors had significant impairment in verbal fluency and categorization ability. Those with posterior lesions had low performance in intellectual level, motor skills and memory. As an unexpected data significant differences were not found in executive function related to frontal lobe localization. CONCLUSIONS: patients with gliomas had slowing to store and to retrieve information, and had features of sensory transcortical aphasia.