Pruebas no invasivas para el tamizaje del cáncer colon: fundamentos básico-clínicos y recientes avances biotecnológicos / Non-invasive tests for colorectal cancer screening: basic-clinical fundamentals and recent biotechnological advances

Colorectal Cancer (CRC) is the third most frequent neoplasia worldwide. Despite the significant advances in surgical techniques and the development of new targeted antineoplastic therapies for this type of tumor, primary prevention and early diagnosis of malignant precursor lesions will continue to be the best strategies to reduce their incidence, morbidity, and mortality. Technologies for CRC screening can be classified into two groups, those of an invasive nature, such as colonoscopy and all its different modalities of use, and those of a non-invasive nature, such as laboratory tests and imaging. This review, will focus exclusively on non-invasive screening tests, excluding imaging. Specifically, it will address those that use depositions as a sample. This review will approach the latest international recommendations, regarding the age at which they should be used, their technical-biological bases, the two main types currently used (biochemical and immunological), and we will put into perspective their advantages and their possible disadvantages. Towards the end of this article, the most recent biotechnological developments in relation to molecular tests based on the study of blood samples, will be discussed. Although these tests are not yet in routine clinical use given their high costs, they are promising for the early detection of CRC.

El cáncer colorrectal (CCR) es la tercera neoplasia más común en todo el mundo. A pesar de los avances significativos en las técnicas quirúrgicas y en el desarrollo de nuevas terapias antineoplásicas para este tipo de tumor, la prevención primaria y el diagnóstico precoz de lesiones precursoras malignas siguen siendo las mejores estrategias para reducir la incidencia, morbilidad y mortalidad asociadas al CCR. Existen dos tipos de tecnologías para el tamizaje del CCR: las invasivas, como la colonoscopia, y las no invasivas, como los ensayos de laboratorio y la imagenología. Esta revisión, se centrará exclusivamente en las pruebas de tamizaje no invasivas que utilizan muestras de deposiciones, excluyendo las imágenes. Se abordarán las últimas recomendaciones internacionales sobre el momento etario en que se deben utilizar, sus bases técnico-biológicas, los dos principales tipos utilizados en la actualidad (bioquímico e inmunológico) y pondremos en perspectiva sus ventajas y posibles desventajas. Al final de esta revisión, se discutirá brevemente los últimos avances biotecnológicos relacionados con pruebas moleculares basadas en el estudio de muestras sanguíneas. Aunque estas pruebas aún no son de uso clínico habitual debido a sus altos costos, representan una prometedora innovación para la detección temprana del CCR.

Caracterización de la incidencia del cáncer de mama en un servicio público de salud chileno en el período 2006-2015 / Characterization of incidence rates of breast cancer in public health service, period 2006-2015

OBJETIVO: El cáncer de mama constituye la primera causa de muerte oncológica en mujeres chilenas. Las tasas de incidencia solo han sido estimadas según el registro 2003-2007. Nuestro objetivo fue estimar las tasas de incidencia en un período de 10 años en un servicio de salud y caracterizar dicha población. MÉTODO: Se calcularon las tasas de incidencia del período 2006-2015, por método directo, y se analizó la tendencia por Prais-Winsten. Se caracterizó la población según la edad y la etapa al diagnóstico. RESULTADOS: De 2862 casos, la tasa de incidencia estandarizada promedio fue de 66,6 por 100.000 mujeres. En el período hubo una tendencia al alza del diagnóstico de 0,63/100.000 anualmente (p = 0,5; intervalo de confianza del 95%: −1,73 a 2,99). La mayor tasa de incidencia bruta fue en el grupo de 70 y más años (154,8/100.000). El 49% correspondieron a casos diagnosticados de 50 a 69 años. El 56% se diagnosticó precozmente; la etapa I tuvo la más alta tasa (15,8/100.000). CONCLUSIONES: En este estudio, las tasas de incidencia son mayores que las reportadas en informes nacionales previos. El diagnóstico es mayoritariamente en etapas precoces, lo que difiere del resto de los países de la región. Nuestros datos pueden aportar a mejorar las políticas públicas.

OBJECTIVE: Breast cancer is the leading cause of cancer death in Chilean women. Incidence rates have only been estimated based on population records (2003-2007). Our objective was to estimate the incidence rates in a 10-year period in a health service and portray in words this cohort. METHOD: Incidence rates were calculated between 2006-2015 by direct method and trends were analyzed with the Prais-Winsten model. The population was defined according to age and stage at diagnosis. RESULTS: Of a total of 2862 cases, the average incidence rate was 66.6 out of 100,000 women. Between 2006-2015, the trend rose in breast cancer diagnosis of 0.63/100,000 annually (p = 0.5; 95% confidence interval: −1.73, 2.99). The highest crude rate of incidence was in the group aged 70 and over (154.8/100,000). 49% correspond to cases diagnosed between 50 and 69 years. 56% were in early stages, stage I, being the most frequent (15.8/100,000). CONCLUSIONS: On this research the incidence rates were higher than the ones reported on previous national reports. Diagnosis is mostly in early stages which differs from other countries in the region, our data can help improve public health policies.

Consenso chileno para el diagnóstico y tratamiento de gliomas del adulto / Diagnosis and treatment of glioma in adult: Chilean consensus

Resumen Los tumores cerebrales se caracterizan por su gran morbilidad y mortalidad. La gran mayoría corresponde a tumores secundarios (metástasis). Dentro de los tumores primarios del sistema nervioso central, los gliomas corresponden al 30% de éstos. En EEUU, entre el 2007-2011, se estima una incidencia aproximada de 21,4 casos por 100.000 habitantes. Los recientes avances en la comprensión molecular de la biología de estos tumores han permitido mejorar sustancialmente su clasificación, posibilitando realizar un mejor correlato con los desenlaces clínicos y el pronóstico. En esta línea, hoy en día es posible estratificar a los pacientes por riesgo y entregar tratamientos capaces de prolongar la sobrevida global entre 5-7 años, para los gliomas grado II y III. El presente consenso, elaborado por un panel multidisciplinario de expertos de diversas sociedades científicas chilenas y, por tanto, de todas las especialidades involucradas en el manejo médico-quirúrgico de las personas portadoras de gliomas cerebrales. A la luz de este nuevo conocimiento desarrollado al alero de la oncología molecular, esta propuesta ofrece un insumo de utilidad clínica real, que, articulado a una revisión actualizada en relación con el tratamiento y seguimiento de estos pacientes, permite entender la relevancia de estos biomarcadores en el manejo de precisión de la enfermedad. Cabe señalar que, este manuscrito emerge de la misma fuerza de trabajo, que elaboró el Protocolo Clínico de Gliomas del Adulto 2019, publicado por el Ministerio de Salud, y que ha diferencia de esta, que ofrece los detalles clínicos-operativos, como flujogramas y dosis, nuestra revisión intenta relevar los avances imagenológicos y moleculares y como estos impactan en el manejo actual de la enfermedad.

Brain tumors are characterized by high morbidity and mortality. The vast majority correspond to secondary tumors (metastasis). On the other hand, within the primary tumors of the central nervous system, gliomas correspond to 30% of these. In the US, between 2007-2011, an approximate incidence of 21.4 cases per 100,000 inhabitants was estimated. Recent advances in the molecular understanding of the biology of these tumors have made it possible to substantially improve their classification, allowing a better correlation with clinical outcomes and prognosis. Along these lines, today, it is possible to stratify patients by risk and deliver treatments capable of prolonging global survival between 5-7 years, for grade II and III gliomas. The present consensus, prepared by a multidisciplinary panel of experts from various Chilean scientific societies and, therefore, from all the specialties involved in the medical and surgical therapy. Enlightened from the molecular oncology, this proposal offers an input of clinical utility, which, together with an updated review in relation to the treatment and follow-up of these patients, allows us to understand the relevance of these biomarkers in precision disease management. It should be noted that this manuscript emerges from the same work force, which prepared the Clinical Protocol for Adult Gliomas 2019, published by the Ministry of Health, and that differs from it, which offers clinical-operative details, such as flowcharts and dose, our review attempts to reveal imaging and molecular advances and how they impact the current management of the disease.

La inhibición de los puntos de control inmunológico, una terapia en evolución: remembranza del Premio Nobel de Medicina 2018 / Immune checkpoint inhibitors: a breakthrough in cancer therapy

Professors James P. Allison and Tasuku Honjo were awarded with the 2018 Nobel Prize in Medicine for their contributions in cancer immunotherapy. The latter is a breakthrough in cancer therapy, aimed to overcome tumor-induced immunosuppression, leading to the reactivation of the immune system against cancer cells. Under physiological conditions, the CTLA-4 and PD-1 proteins expressed on T-cells and discovered by the awarded scientists, lead to immune tolerance. Cancer cells exploit these control points to enhance the inhibition of T-cells. The expression of PD ligands (PD-L1) in tumor cells and CTLA-4 ligands in antigen presenting cells, which bind the PD-1 receptor and CTLA-4 respectively, block anti-tumor immunity. This situation led to a biotechnological race focused on the development of effective antibodies able to "turn-on" the immune system cheated by the tumor. Anti-CTLA-4 and anti-PD-1 antibodies improve life-expectancy in cancer patients. In this review, we perform an historical overview of Professors Allison and Honjo contribution, as well as the immunological basis of this new and powerful therapeutic strategy, highlighting the clinical benefits of such intervention.

Planificación sanitaria a partir de los datos ómicos: ¿es posible esta idea para Chile?

With or without a COVID19 pandemic, cancer is and will continue to be one of the greatest health challenges on the planet. In Chile, during 2016, this disease was the second cause of death in the country and during 2019, it was the first cause in seven Chilean regions, surpassing cardiovascular diseases. With the advent of precision medicine as a powerful tool for cancer control, it is necessary to have genomic, proteomic, and molecular data in general, ideally on a population scale. This is essential for decision-making, for example in public and private oncology, to be as cost-effective as possible. Chile has a mass of high-quality researchers in cancer. However, until today the investment in research and development is far below the peers in the OECD. In this work we put into perspective the role of precision medicine and omic sciences as essential tools for public health. We offer a brief national diagnosis of the knowledge collected to date by the local scientific community regarding onco-genomic data from our own population. We finally discuss the potential behind the strengthening of this scientific knowledge, aiming to optimize the comprehensive management of cancer.

Implementación del diagnóstico molecular del VPH: experiencia chilena en curso / Molecular diagnosis of human papillomavirus infection: the Chilean experience

Cervical Cancer (CaCu) has a heterogeneous epidemiological behavior throughout the planet, depending on regional socioeconomic development level. Some developed countries predict a potential eradication of this cancer in the next 100 years, while in Chile it still constitutes a pending challenge. Incidence rates show a slow but sustained downward prob, however, mortality has continued to fluctuate between 500-600 cases per year. A few years ago, vaccination against Human Papillomavirus (HPV), the main causal agent for this tumor, was consolidated as a public policy, both in girls and in boys. However, the technological leap in the screening prob was pending, from cytology to molecular diagnosis of the agent (HPV). In this report, we update our most recent data (2018) regarding CaCu mortality, then review global guidelines and experiences in HPV screening. Finally, we offer an account of the strategies that our health system is promoting to address the screening of the disease and whose molecular approach generates the widest worldwide scientific consensus. We also recognize the main barriers and future challenges, which, if overcome, would allow us to be in line with the mandate of WHO to control this women's health problema.

Bases biológicas del cáncer: una propuesta de contenidos mínimos para las carreras de la salud / Biological bases of cancer: a proposal of minimum contents for health schools

El cáncer constituye la segunda de causa de muerte a nivel mundial y se estima será la primera, superando a las cardiovasculares. El estudio de sus bases moleculares ha permitido el desarrollo de la quimioterapia clásica, como de nuevas terapias biológicas. Si bien estos avances han redundado en un aumento en la sobrevida, no ha impactado en una menor incidencia de los casos. Esto último se debe, en parte, al desconocimiento de los múltiples factores carcinogénicos existentes y los efectos de sus interacciones para cada uno de los tumores. En este sentido, es interesante notar que, en los currículos de las escuelas de salud de las universidades chilenas, el cáncer u oncología como tal, no constituye una cátedra en sí misma, siendo sus contenidos tangencialmente abordados en distintos momentos de la formación; en biología celular, medicina interna y cirugía, entre otros. Con estos antecedentes, el propósito de este trabajo es ofrecer un propuesta sencilla y accesible para los estudiantes, respecto de los contenidos que, a nuestro juicio, son esenciales para comprender las bases biológicas de esta enfermedad y enfrentar con mejores conocimientos el ciclo clínico posterior. A continuación, el lector se encontrará con principios fundamentales de la biología humana normal (como el ciclo celular y el dogma central de la biología molecular), que permiten obtener una visión global de los mecanismos fisiológicos cuya desregulación conlleva a una neoplasia maligna. Luego se entregarán algunas definiciones amplias en relación con los conceptos de neoplasia, tumor benigno y maligno. Para, finalmente, abordar las principales etapas que permiten el desarrollo del cáncer; (i) iniciación, (ii) promoción y (iii) progresión. En esta última, se profundizará por separado, en angiogénesis, degradación de la matriz extracelular, migración y evasión de la respuesta inmune. Este trabajo no aborda materias relacionadas con la hipótesis metabólica del cáncer.

Cancer constitutes the second most common cause of death worldwide and is expected to become the leading one, even above cardiovascular diseases. The understanding of the cellular and molecular basis of cancer has led not only to the proper development of chemotherapy but also of target therapies. Although these advances are related with improved survival rates among cancer patients, it has poorly impacted its incidences. In this regard, the lack of knowledge regarding the impact that the several carcinogenic factors and their interactions have on different types of cancers may explain at least in part the difficulties to reduce incidence rates. However, is worth noticing that in several health schools of chilean universities, cancer does not constitute a formal course, being only partially approached during other courses, such as cell biology, internal medicine, and surgery. Thus, the aim of our work is to provide students a simple and resumed manuscript about essential topics necessary to understand the biological basis of cancer. First, the reader will find some fundamentals about human biology including the cell cycle and the central dogma of molecular biology, which offers an overview of the physiological mechanisms leading to malignant neoplasia. Then, we will provide current definitions of neoplasia, benign and malignant tumors are provided. Finally, the different stages of tumor progression will be approached to allow the understanding of cancer development. These stages include (i) initiation, (ii) promotion, and (iii) progression. For the last one, metastasis, angiogenesis, extracellular matrix degradation, migration, and immune evasion will also be addressed. This work will not consider the metabolic hypothesis of cancer.

Formación científica en el pregrado de medicina en Chile: ¿dónde estamos? y ¿hacia dónde vamos? / An analysis of scientific formation in medical schools

For more than a century the training of medical professionals has been organized according to the Flexnerian model, which comprises three cycles: basic, clinical and clerkship. On the other hand, the accelerated development of biomedical sciences modified the competences of the first cycle. Additionally, new skills required for medical practice, such as teamwork and innovation as a tool to solve health problems, challenged in recent years the classic paradigm of medical education. Therefore, the medical schools have developed multiple strategies to deal with it, such as curricular integration using competency-based education models, incorporating basic and clinical sciences in parallel during the curriculum, ensuring a relevant and applicable scientific knowledge throughout the training process. Although in Chile the Flexner prototype is still followed, the basic sciences are taught as single or integrated courses or using a systems approach. In this article we report a diagnosis about the local integration of fundamental sciences in medical training. We also compare our schools with those of Canada, Europe and Latin America. Recommendations aimed at modernizing medical school curricula are made.

Oportunidad en la salud digital: una respuesta al control de las demencias / Digital health services as a means to control dementia

The increase of the elderly population with a significant load of non-communicable diseases, accelerates pathological aging and increases the risk of dementia, generating a huge health, social and economic cost for any country. Dementia does not have an effective treatment yet, therefore, the focus must remain on prevention and early diagnosis. The early stages of dementia are known as mild cognitive impairment; at this stage is still possible to mitigate the progression of the disease, however, health systems worldwide face difficulties to provide universal access to health services, due to a lack of specialists and geographical distances, interfering with the access to healthcare centers. In this scenario, WHO urged countries to implement strategies to democratize and to expand the reach of health institutions. In this document, we briefly review the global and local situation of dementias and discuss some attempts to control their progression by using revolutionary digital tools. We believe the focus should be on the population that is just beginning to show cognitive impairment.

Situación actual del cáncer de colon en Chile: una mirada traslacional / The present situation of colorectal cancer in Chile

Colorectal (CRC) is one of the most common types of cancer worldwide. Most tumors develop from an adenoma in a period of 10 to 15 years, but some may appear without previous adenomatous lesions. Seventy-five percent of colorectal cancers are sporadic, 20% have a family component (first or second-degree relatives with CRC) and 5% have a hereditary predisposition with a Mendelian pattern. The epidemiological evolution in the recent years in Chile has a worrisome evolution and the treatment costs of advanced stages are a burden for the healthcare system. We herein highlight the main Chilean medical and scientific contributions on the pathogenesis, early diagnosis, and treatment of CRC, which lead to its better understanding, and therefore better management, based on local evidence.

Impacto cardiovascular secundario a la terapia para el control del cáncer / The cardiovascular impact of cancer control therapy

Cardiovascular diseases and cancer account for 27 and 25% of mortality in Chile, respectively. In the last decades, survival of people with cancer has improved due to preventive programs, early detection strategies, advances in technology and development of new antineoplastic therapies. Consequently, a progressive number of cancer-surviving patients have been generated, who may develop cardiovascular diseases, secondary to the same cancer therapy. Cardio-Oncology has emerged as the necessary link between both specialties to promote the prevention and early detection of cardiac complications, in patients undergoing oncological therapies. The aim is to curb cardiovascular complications. Also, to acquire knowledge about the mechanisms and effects of drugs that lead to heart damage aiming to develop efficient cardioprotective therapies. In this article we review and propose a didactic organization and classification of the main cardiovascular effects of cancer control therapy. We recognize that there is still a knowledge gap in basic sciences about the mechanisms that underlie these alterations.

Una red de biobancos para Chile: investigar hoy, para curar mañana / The implementation of a Biobank network for Chile

The concept "Biobank" is relatively new in the scientific literature, and is not yet consensually defined, even for the World Health Organization (WHO). However, the use of human samples in biomedical research is a very old activity. The organized development of Biobanks in different places has grown in the last decade. The experience in different countries and continents has been diverse. In this special article we intend to summarize, organize and communicate to the national medical and scientific community, (i) the concept of Biobank, (ii) the international experience and a map of the Research Biobanks working in Chile, (iii) the basic biomedical and essential operational aspects to manage a Biobank for Research and (iv) the impact of a National Network of Biobanks implementation in the Chilean Health System. Ethical and regulatory aspects will not be included, given their intrinsic complexity, which should be discussed elsewhere.

Consecuencias de la fluoración del agua potable en la salud humana / The impact of tap water fluoridation on human health

The purpose of this review is to describe the osteological, neurological, endocrine and dermatological effects of fluoride ingestion. Additional aims are to evaluate whether the Chilean tap water fluoridation program has had any impact on dental health, and analyze the basis for the Chilean elementary school milk fluoridation program, which is targeted at children living in places where tap water has a fluoride concentration less than 0.3 mg/L, without any artificial fluoridation process. We discuss the finding that both public measures have no direct or remarkable effect on dental health, since topical dental hygiene products are the main and most effective contributors to the prevention of dental decay. We also suggest that the permanent and systematic ingestion of fluorides imposes health risks on the population. Therefore, we recommend reevaluating the national fluoridation program for public tap water and the elementary school milk program.

Realidad de la investigación en salud en Chile: participación de los médicos en el Fondo Nacional de Investigación (FONIS) en la última década / Reality of health research in Chile: participation of doctors in the National Research Fund (FONIS) in the last decade

Chile es uno de los países de la OCDE que menos invierte en ciencia y tecnología, y la investigación en salud no está exenta de este problema. Existe evidencia reportada en publicaciones nacionales de que la participación de médicos en la investigación ha experimentado un marcado retroceso en las últimas décadas. El objetivo de este artículo es analizar específicamente la participación de los médicos como investigadores responsables en proyectos financiados por el Fondo Nacional de Investigación en Salud (FONIS). Este programa fue diseñado para promover investigaciones que resuelvan problemas prioritarios de salud y de esa manera entregar enfoques diagnósticos y terapéuticos a la medida del fenotipo local. Nuestros análisis muestran un estancamiento real y una disminución porcentual, misma tendencia que estudios previos. La implementación de recomendaciones internacionales en el campo de la medicina rasnacional en las políticas de salud nacionales podría revertir el aparente proceso de retirada de los médicos de las actividades de I+D, lo que beneficiaría la salud de los pacientes y reduciría los costos para el sistema, de, por ejemplo, la importación de la terapéutica.(AU)

Chile is one of the OECD countries that invests less in science and technology, and health research is not exempt from this problem. Evidence reported in national publications shows that the participation of physicians in research has experienced a marked decline in recent decades. The objective of this article is to specifically analyze the participation of physicians as responsible researchers in projects funded by the National Fund for Health Research (FONIS). This program was designed to promote research that addresses priority health issues and thereby delivers diagnostic and therapeutic approaches tailored to the local phenotype. Our analyzes show a real stagnation and a percentage decrease, same trend as previous studies. The implementation of international recommendations in the field of translational medicine in national health policies could reverse the apparent process of withdrawal of physicians from R&D activities, which would benefit the health of patients and reduce the costs for the system, for instance, in the ones implied of importing therapeutics.(AU)