Beneficios y "maleficios" del cribado. El sobrediagnóstico y la medicina anticipativa / Benefits and damages of Screening. Overdiagnosis and anticipatory medicine

Mucho han cambiado los resultados en el tratamiento del cáncer de mama desde la publicación de trabajos que recomendaban la realización de cribados para diagnosticar precozmente los tumores de mama. Los posteriores re-análisis, que mostraron errores en las evaluaciones, los avances en la terapia oncológica y la concienciación de profesionales y público, han demostrado la dudosa efectividad de esta medida y como contrapartida los riesgos dependientes por sobrediagnóstico y sobretratamiento. Por otra parte la falta de información e incluso la desinformación existente sobre el tema, han ocasionado una desorientación entre los posibles beneficiarios del procedimiento. Se les ha recomendado, por parte de organizaciones, plataformas, sociedades privadas y servicios de salud pública, un procedimiento ocultando daños importantes: físicos, psicológicos y económicos. Es fácil promover el examen de mamografía si la mayoría de las mujeres cree que previene o reduce el riesgo de contraer cáncer de seno y salva muchas vidas mediante la detección temprana de tumores agresivos. Desgraciadamente eso no es así. A la vista de ello, existen muchos detractores del cribado que vienen recomendando la información fiable y correcta y la indicación personal no tanto del cribado como de la exploración como procedimiento diagnóstico. Las mujeres deben discutir con sus médicos su propio perfil de riesgo, los posibles beneficios, daños y complejidades de la mamografía de detección, y tomar decisiones informadas sobre la realización del cribado. Definir qué mujeres se beneficiarían de un seguimiento debido a factores de riesgo definidos y aquellas que por el contrario corren más riesgos que beneficios. Un programa de salud pública que claramente no produce más beneficios que daños es difícil de justificar. Proporcionar información clara e imparcial, promover la atención adecuada y prevenir el sobrediagnóstico y el sobretratamiento sería la mejor opción

Treatment of breast cancer has changed markedly since the publication of papers recommending screening programs for early diagnosis. Posterior reevaluations demonstrated mistakes; advances in oncological therapy and better knowledge of the problem have demonstrated the doubtful efficacy of these procedures which, on the other hand have also side effects with risk of overdiagnosis and overtreatment. Misinformation confuses patients. This procedure has been recommended by many institutions without explaining possible important risks. It is very easy to promote mammograms if the majority feel that it reduces risk of breast cancer and saves many lives. Unfortunately this is not the case. At present there are many people against screening who are recommending explicit and precise explanations of the procedure as well as of the importance of physical examination. Women must discuss with their physicians their own risk, possible benefits and eventual risks and damages of mammograms and they must take informed decision about screening. Women should be classified in those with potential benefits of mammograms and those with more risks than benefits. A program which does not offer clearly more benefits than risks cannot be implemented by Public Heath institutions. Complete and impartial information, adequate attention and prevention of overdiagnosis and overtreatment would be the best option

Medicina anticipatoria vs medicina preventiva. Como crear enfermos buscando la salud. (I) Las Estadísticas / Anticipatory medicine vs preventive medicine. How to create patients looking for health. (I) Statistics

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N-3 fatty acids, cancer and cachexia: a systematic review of the literature.

Use of n-3 fatty acids (FA) has been reported to be beneficial for cancer patients. We performed a systematic review of the literature in order to issue recommendations on the clinical use of n-3 FA in the cancer setting. A systematic search was performed in MEDLINE, EMBASE, Cochrane and Healthstar databases. We selected clinical trials or prospective observational studies including patients with cancer and life expectancy >2 months, in which enteral supplements with n-3 FA were administered. Parameters evaluated individually were clinical (nutritional status, tolerance, survival and hospital stays), biochemical (inflammatory mediators), and functional (functional status, appetite and quality of life (QoL)). Seventeen studies met the inclusion criteria; eight were of high quality. The panel of experts established the following evidence: (1) oral supplements with n-3 FA benefit patients with advanced cancer and weight loss, and are indicated in tumours of the upper digestive tract and pancreas; (2) the advantages observed were: increased weight and appetite, improved QoL, and reduced post-surgical morbidity; (3) there is no defined pattern for combining different n-3 FA, and it is recommended to administer > 1.5 g/day; and (4) better tolerance is obtained administering low-fat formulas for a period of at least 8 weeks. All the evidences were grade B but for 'length of treatment' and 'advantage of survival' it was grade C. Our findings suggest that administration of n-3 FA (EPA and DHA) in doses of at least 1.5 g/day for a prolonged period of time to patients with advanced cancer is associated with an improvement in clinical, biological and QoL parameters.

Practical aspects of peripheral parenteral nutrition.

PURPOSE OF REVIEW: The purpose of this review is to provide an update on the advantages and disadvantages of using peripheral parenteral nutrition, including the techniques, indications and results. RECENT FINDINGS: The new catheters, together with a better knowledge of intermediate metabolism, permit the use of peripheral parenteral nutrition in many clinical situations during short periods of time. SUMMARY: Peripheral parenteral nutrition is an alternative to total parenteral nutrition, and is a complement to enteral nutrition and the oral route. Progress in catheter design and materials, infusion techniques and an improved knowledge of the optimal nutriments has made peripheral parenteral nutrition a safe, efficient and useful method to treat patients over certain periods of time.

Clinical evidence for enteral nutritional support with glutamine: a systematic review.

OBJECTIVE: The purpose of this systematic review was to locate and assess the quality of scientific evidence to establish a graded recommendation based on the effectiveness of glutamine-enriched enteral nutrition in different medical and surgical conditions. We were concerned with the following topics: 1) benefits of enteral administration of glutamine in different pathologic conditions, and 2) dose, duration, and time of initiation of glutamine-enriched diets. METHODS: The sources consulted for the search were MEDLINE, EMBASE, Cochrane Database of Systematic Reviews, Healthstar and HSTAT. Ninety-one studies were assessed; after a methodologic review (primary review), only 16 studies met the inclusion criteria for analysis by a group of experts (secondary review). The coordinators supervised all data, and a final consensus was reached among the coordinators, experts, and methodologists. RESULTS AND CONCLUSIONS: Glutamine-enriched diets showed good overall tolerance, improvement of immunologic aspects in multiple trauma patients, cost reduction in critically ill patients, and improvement of mucositis in post-chemotherapy patients (grade B recommendations). The doses given and the duration of therapy varied widely depending on the pathologic condition. Intake of 20 to 30 g/d, early initiation of diet, and maintenance for 5 d or longer are recommended (grade C recommendations).

Immunonutrition in the intensive care unit. A systematic review and consensus statement.

OBJECTIVE: To systematically review the effects of enteral nutrition with pharmaconutrients-enriched diets in critically ill patients and to establish recommendations for their use. DATA SOURCES: Computerized bibliographic search of published research and citation review of relevant articles. STUDY SELECTION: Randomized clinical trials of critically ill patients treated with enteral nutrition comparing diets enriched with pharmaconutrients vs not enriched diets were included. Infectious complications and outcome variables (days on mechanical ventilation, ICU and hospital length of stay and mortality) were evaluated. Studies were classified in four subgroups according to the patient's primary diagnosis: surgical, trauma, burned or medical. DATA EXTRACTION: A group of experts in methodology performed data extraction and statistical processes. A global analysis of the studies was done and also a separate study for each subgroup. Results of the meta-analysis were discussed within a 'clinical group' of clinicians with experience in the nutritional support of ICU patients, in order to find agreement about recommendations for the use of pharmaconutrients-enriched diets in critically ill patients. RESULTS: Independent review of 267 articles identified 26 relevant primary studies. Global results indicate that there was a reduction in infection rate in the pharmaconutrition group, considering the appreciated lower incidence in abdominal abscesses (OR: 0.26, CI: 0.12-0.55) (P=0.005), nosocomial pneumonia (OR: 0.54, CI: 0.35-0.84) (P=0.007) and bacteremia (OR: 0.45, CI: 0.35-0.84) (P=0.0002). Also, patients treated with pharmaconutrition diets have a reduction in time on mechanical ventilation (mean 2.25 days, CI: 0.5-3.9) (P=0.009), ICU length of stay (mean reduction of 1.6 days, CI: 1.9-1.2) (P<0.0001) and hospital length of stay (mean reduction of 3.4 days, CI: 4.0-2.7) (P<0.0001). No effects were appreciated on mortality (OR: 1.10, CI: 0.85-1.42) (P=0.5). Nevertheless, the separate analysis for each subgroup showed that the reported beneficial effects were not the same for each patient population. Also, the clinician panel of experts identifies several problems in the published data about enteral pharmaconutrition in critically ill patients. In spite of the subgroup differences and of the problems detected, the clinician group considered that the appreciated results could support a Grade B recommendation for the use of these formulas in ICU patients. CONCLUSIONS: Considering the beneficial effects and the absence of detrimental ones, the use of diets enriched with pharmaconutrients could be recommended in ICU patients requiring enteral feeding. Nevertheless, more investigation is needed in this field in order to find the more appropriate population of patients that can benefit from this nutritional therapy.