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.

Métodos de rastreo del cáncer de colon / Colon cancer screening methods

El cáncer colorrectal presenta un problema para la salud pública a nivel mundial. En Argentina, se diagnostican aproximadamente 13.500 casos cada año. El tamizaje como medida de prevención secundaria es una medida beneficiosa para lograr un abordaje temprano con mejores resultados. Los dos métodos más utilizados para el tamizaje son la videocolonoscopía y la prueba de sangre oculta en materia fecal, sobre todo la de tipo inmunoquímico que con el paso de los años fue reemplazando a la prueba de guayaco por su mayor practicidad. El primero es un método invasivo y que requiere anestesia, mientras que el segundo no tiene un efecto adverso directo pero debe realizarse con una cadencia mayor. El objetivo de los autores de este artículo fue evaluar la evidencia sobre la sensibilidad y especificidad de ambos métodos, como también sus beneficios y daños a partir de la consulta de un paciente a su médico de familia. Ninguna prueba parecería ser inferior para el tamizaje de cáncer colorrectal en una población de riesgo promedio, y ambas pueden usarse en programas de rastreo. Sin embargo, no existen estudios que comparen ambos métodos de manera directa, y toda prueba inmunoquímica fecal positiva debe ser seguida de una colonoscopía. La elección de la prueba puede depender de los valores y preferencias de los pacientes. (AU)

Colorectal cancer presents a public health problem worldwide. In Argentina, approximately 13,500 cases appear each year. Screening as a secondary prevention measure is a beneficial measure to achieve an early approach with better results. The two most used methods for screening are video colonoscopy and faecal immunochemical test, the former being invasiveand requiring anaesthesia, while the latter does not have a direct adverse effect but must be performed at a higher rate. The objective of this article was to evaluate the evidence for the sensitivity and specificity of both methods, as well as their benefits and harms. No test would appear to be inferior for colorectal cancer screening in an average-risk population, and both can be used in screening programs. However, there are no studies comparing both methods directly, and any positive faecal immunochemical test should be evaluated with a colonoscopy. The choice of the test may depend on the values and preferences of the patients. (AU)

Efecto del aceite de Sacha Inchi (Plukenetia volubilis L.) en la carcinogénesis de colon inducida por 1,2–dimetilhidrazina en ratas Holtzman / Effect of Sacha Inchi oil (Plukenetia volubilis L.) on 1,2–dimethylhydrazine-induced colon carcinogenesis in Holtzman rats

Objetivos: Evaluar el efecto protector del aceite de Sacha Inchi (ASI) sobre el desarrollo de cáncer de colon (CC) inducido con 1,2–dimetilhidrazina (DMH) en ratas Holtzman. Materiales y métodos: Estudio experimental con 28 ratas albinas machos de la cepa Holtzman distribuidas al azar en 4 grupos: un grupo control positivo expuesto a DMH (C1), un grupo control negativo expuesto a ASI a 150 μL/kg/día (C2), y dos grupos experimentales expuestos a DMH con ASI a 150 μL/kg/día (E1) y ASI a 300 μL/kg/día (E2). La DMH se aplicó por 8 semanas y con un tiempo total de inducción de 22 semanas. Luego se realizó el análisis patológico mediante la identificación de lesiones tumorales cancerosas en los intestinos. El efecto protector se evaluó en base a las proporciones de ausencia de lesión en los grupos expuestos a DMH. Resultados: Se identificaron lesiones tumorales cancerosas en: dos especímenes del grupo C1, un espécimen del grupo E1 y dos especímenes del grupo E2. No se identificaron lesiones intestinales en el grupo C2. Las proporciones de ausencia de lesión fueron: en el grupo C1 de 75%, en el grupo E1 de 87,5% y en el grupo E2 de 75%. No se encontraron diferencias significativas (p>0,05). Conclusiones: No se evidenció un efecto protector significativo del ASI sobre el desarrollo de CC inducido con DMH en ratas Holtzman, respecto al grupo control.

Objectives: To evaluate the preventive effect of Sacha Inchi oil (SIO) on 1,2–dimethylhydrazine (DMH)-induced colon carcinogenesis (CC) in Holtzman rats. Materials and methods: Experimental study with 28 Holtzman male albino rats randomly distributed into 4 groups: a positive control group exposed to DMH (C1), a negative control group exposed to SIO at 150 uL/kg/ day (C2), and two experimental groups exposed to DMH with SIO at 150 uL/kg/day (E1) and SIO at 300 uL/kg/day (E2). The DMH was applied for 8 weeks and the total induction time was 22 weeks. Pathological examination was performed by identifying cancerous tumor lesions in the guts. The preventive effect was evaluated based on proportions of lack of lesion in the groups exposed to DMH. Results: Cancerous tumor lesions were identified in: two specimens of group C1, one specimen of group E1 and two specimens of group E2. No intestinal lesions were identified in group C2. The proportions of lack of lesion were: in group C1 of 75%, in group E1 of 87.5% and group E2 of 75%. No significant differences were found (p>0.05). Conclusions: It was not found a significant protective effect of SIO on DMH-induced CC in Holtzman rats, compared to control group.

Efecto quimioprotector del extracto alcaloideo de Melocactus bellavistensis (cactus globoso) sobre el cáncer de colon inducido con 1,2-dimetilhidrazina en ratas / Chemoprotective effect of the alkaloid extract of Melocactus bellavistensis against colon cancer induced in rats using 1,2-dimethylhydrazine

RESUMEN Objetivos Determinar la toxicidad y el efecto quimioprotector del extracto alcaloideo de Melocactus bellavistensis (cactus globoso) sobre el cáncer de colon inducido en ratas con 1,2 dimetilhidrazina (DMH). Materiales y métodos Se obtuvo el extracto alcaloideo de la parte carnosa de Melocactus bellavistensis, posteriormente, se realizó un ensayo de toxicidad aguda en 30 ratones de cepas Balb C57. Para evaluar su efecto quimioprotector se indujo el cáncer de colon en 45 ratas Holtzmann con DMH, según el siguiente diseño experimental: un grupo control con: polisorbato de sodio (PS) a 2 mL/kg y cuatro grupos con DMH 20 mg/kg más 0, 1, 5 y 10 mg/kg de extracto alcaloideo de Melocactus bellavistensis respectivamente. Resultados Con una muestra de 5 g de extracto alcaloideo se determinó una DL50 mayor a 1000 mg/mL en el ensayo de toxicidad aguda del extracto alcaloideo de Melocactus bellavistensis. Los resultados del efecto quimioprotector en los indicadores de estudio histopatológico revelaron que a las dosis de 5 y 10 mg/kg demostraron actividad antitumoral significativa en el cáncer de colon inducido por dimetilhidrazina en ratas con 100% de inhibición de neoplasia. Conclusiones En condiciones experimentales, el extracto de alcaloides de Melocactus bellavistensis demostró tener efecto quimioprotector en cáncer de colon inducido por dimetilhidrazina en ratas.

ABSTRACT Objectives To determine the toxicity and chemoprotective effect of the alkaloid extract of Melocactus bellavistensis against colon cancer induced in rats using 1,2-dimethylhydrazine (DMH). Materials and methods The alkaloid extract was obtained from the fleshy part of M. bellavistensis, and an acute toxicity test was then carried out on 30 mice of the Balb C57 strain. To assess its chemoprotective effect, colon cancer was induced in 45 Holtzman rats using DMH according to the following experimental design: one control group received 2 mL/kg sodium polysorbate, and four groups received 20 mg/kg DMH plus 0, 1, 5, or 10 mg/kg M. bellavistensis alkaloid extract. Results With a sample of 5 g of alkaloid extract, an LD50 greater than 1000 mg/mL was determined in the acute toxicity test. Histological indicators revealed that the 5 and 10 mg/kg doses had significant anti-tumor activity with 100% neoplasia inhibition against DMH- induced colon cancer in rats. Conclusions Under experimental conditions, the alkaloid extract of M. bellavistensis has a chemoprotective effect against DMH-induced colon cancer in rats.

Mucosectomía endoscópica por coloproctólogos. Resultados iniciales / Endoscopic mucosal resection by coloproctologists. initial results

ANTECEDENTES: La detección y resección de lesiones colónicas plipoideas, sésiles y planas, previene el desarrollo de cáncer de colon. La mucosectomía endoscópica ha surgido en 1970 como un procedimiento alternativo para el tratamiento de éstas lesiones y, en la actualidad, es considerado el procedimiento de elección, pudiendo evitar procedimientos quirúrgicos mayores. OBJETIVO: Evaluar los resultados y complicaciones de la técnica de mucosectomía realizada por cirujanos coloproctólogos. Con revisión de indicaciones y limitaciones de la técnica. MATERIAL Y MÉTODO: Se realizó un análisis descriptivo, retrospectivo y observacional de pacientes tratados con técnica de mucosectomía endoscópica en el Servicio de Coloproctología del Hospital Británico de Bs. As., desde junio de 2010 a junio 2015. Se aplicó la técnica de “elevación y corte” en lesiones polipoideas mayores a 1 cm. Se realizó la resección en bloque para aquellas lesiones de hasta 3 cm y, para aquellas mayores a los 3 cm, se utilizó la resección por técnica de piecemeal. Se evaluaron complicaciones y resultados según la técnica empleada al igual que tasa de recidiva, realizando en todos los casos seguimiento con control endoscópico. RESULTADOS: Se analizaron un total de 41 casos (25 mujeres y 16 hombres) realizándose un procedimiento por paciente. La edad promedio fue de 65,8 años (38-83 años) y el tamaño promedio de las lesiones de 20,3 mm (10 – 50 mm). Se realizó resección en bloque en 19 pacientes (representando el46,3% de nuestra serie) y logrando resección endoscópica y anatomopatológica completa en todos ellos. En tanto se empleó técnica de piecemeal en los 22 pacientes restantes (53,6%). La tasa de complicaciones en nuestra serie fue del 7,3% (3/41). El seguimiento promedio fue de 14,4 meses (2 – 48 meses) y la tasa global de recidiva local fue de 9,75%...

BACKGROUND: Detection and resection of colonic lesions polypoid sessile and flat, prevents the development of colon cancer. Endoscopic mucosal resection has emerged in 1970 as an alternative method for the treatment of these lesions and, at present it is considered the procedure of choice, being able to avoid major surgical procedures. Objectives evaluation of the results and complications of the technique mucosectomy by colorectal surgeons. Review of indications and limitations of the technique. MATERIAL AND METHODS: Descriptive, retrospective and observational analysis of patients treated with endoscopic mucosal resection technique in the Coloproctology Service of the British Hospital of Buenos Aires, from June 2010 to June 2015. Technique of "lift and cut" was used in polypoid lesions greater than 1 cm. The bloc resection is used for those injuries up to 3 cm, and the piecemeal resection technique was used for those older than 3 cm. Complications and results were evaluated according to the technique as recurrence rate , performing tracking in all cases with endoscopic control. RESULTS: forty one cases (25 women and 16 men) performing a procedure per patient were analyzed. The average age was 65.8 years (38-83 years) and the average lesion size of 20.3 mm (10-50 mm). The average age was 65.8 years (38-83 years) and the average lesion size of 20.3 mm (10-50 mm). Resection was performed in 19 patients block (representing the 46.3 % of our series) and achieving endoscopic resection and pathologic complete in all. Piecemeal technique was used in the remaining 22 patients (53.6 %). The complication rate in our series was 7.3% (3/41). Mean follow-up was 14.4 months (2-48 months) and overall local recurrence rate was 9.75%...

Conocimientos de los familiares de los pacientes con cáncer, sobre las medidas preventivas en cáncer de colon en el Servicio de Oncología Hospital Militar Central 2014 / Knowledge of the relatives of the cancer patients about preventive measures of the colon cancer in the Oncology Service, Hospital Militar Central 2014

El objetivo del estudio fue determinar los conocimientos de los familiares sobre las medidas preventivas en cáncer de colon en el servicio de oncología del Hospital Militar Central 2014. Material y Método: El estudio es de nivel aplicativo, tipo cuantitativo, método descriptivo de corte transversal. La población estuvo conformada por 30 familiares. La técnica fue la encuesta y el instrumento un cuestionario aplicado previo consentimiento informado. Resultados: Del 100 por ciento (30), 53 por ciento (16) no conoce y 47 por ciento (14) conoce. En relación a los conocimientos de los familiares en la dimensión prevención primaria, 60 por ciento (18) no conoce y 40 por ciento (12) conoce. Mientras que en la dimensión prevención secundaria, 67 por ciento (20) no conoce y 33 por ciento (10) conoce. Conclusiones: El mayor porcentaje de familiares de pacientes con cáncer de colon, no conocen sobre la edad para descartar cáncer de colon, la frecuencia para realizar actividad física, prueba recomendable, el consumo de carnes ahumadas, la definición de biopsia y manifestaciones de cáncer de colon; seguido de un porcentaje considerable de familiares que conocen los factores de riesgo de cáncer de colon, el signo característico del cáncer de colon, medidas para disminuir riesgos de cáncer y los alimentos que aumentan el riesgo de cáncer de colon, que hacer en caso de cáncer de un familiar, y los motivos para la realización de colonoscopia...

The objective of the study was to determine knowledge of family members on preventive measures in colon cancer in the 2014 Central Military Hospital Oncology service. Material and Method: The study is application level, quantitative, descriptive cross-sectional method. The population was formed by 30 relatives. The technique was the survey and the instrument a questionnaire applied prior informed consent. Results: 100 per cent (30), 53 per cent (16) not known and 47 per cent (14) meet. In relation to the knowledge of relatives in the primary prevention dimension, 60 per cent (18) does not know and 40 per cent (12) meet. While in the secondary prevention dimension, 67 per cent (20) does not know and 33 per cent (10) meet. Conclusions: The highest percentage of relatives of patients with colon cancer, don't know about the age to rule out colon cancer, the frequency to perform recommended physical activity, the consumption of smoked meats, the definition of biopsy and manifestations of colon cancer; followed by a considerable percentage of family members who know the risk factors for colon cancer, the hallmark of colon cancer, measures to reduce risks of cancer and foods that increase the risk of colon cancer, that make cancer of a family member, and the reasons for the realization of colonoscopy...

Efectos in vitro e in vivo de la pulpa de mango (Mangifera indica cv. Azúcar) en la carcinogénesis de colon / In vitro and in vivo effects of mango pulp (Mangifera indica cv. Azucar) in colon carcinogenesis.

La porción comestible del mango contiene ácido ascórbico, carotenoides, polifenoles, terpenoides y fibra que tienen efectos protectores para la salud, y posiblemente contra el desarrollo de cáncer de colon (CCO). El objetivo de este estudio fue evaluar la capacidad antiproliferativa en células de adenocarcinoma de colon (SW480) y preventiva en un modelo in vivo de CCO de un extracto acuoso de Mangifera indica cv. Azúcar. El contenido de fenoles totales, flavonoides y carotenoides también fue analizado. El extracto inhibió el crecimiento de las células SW480 en forma dosistiempo- dependiente hasta 22,3% luego de 72h de exposición al extracto (200 μg/mL). La carcinogénesis en el colon de ratones Balb/c fue inducida mediante dos inyecciones intraperitoneales de azoximetano (AOM) a la tercera y cuarta semana de haber iniciado el suministro de mango en el líquido de bebida (0,3%, 0,6%, 1,25%). Después de 10 semanas de tratamiento se observó inhibición dosis-dependiente de la formación de focos de criptas aberrantes (FCA); 0,3% de mango inhibió más del 60% de FCA (p=0,05) comparado con los controles que recibieron agua. Estos resultados muestran que la pulpa del mango de azúcar, un alimento natural, no tóxico, que forma parte de la dieta del ser humano contiene compuestos bioactivos capaces de reducir el crecimiento de células tumorales y prevenir la aparición de las lesiones precancerosas en colon durante el inicio de la carcinogénesis.

Mango pulp contains ascorbic acid, carotenoids, polyphenols, terpenoids and fiber which are healthy and could protect against colon cancer. The aim of this study was to evaluate the antiproliferative and preventive capacity of an aqueous extract of Mangifera indica cv. Azúcar on a human colon adenocarcinoma cell line (SW480) and in a rodent model of colorectal cancer, respectively. The content of total phenolics, flavonoids and carotenoids were also analyzed in the extract. SW480 cell growth was inhibited in a dose and time dependent manner by 22.3% after a 72h exposure to the extract (200 μg/ mL). Colon carcinogenesis was initiated in Balb/c mice by two intra-peritoneal injections of azoxymethane (AOM) at the third and fourth week of giving mango in drinking water (0.3%, 0.6%, 1.25%). After 10 weeks of treatment, in the colon of mice receiving 0.3% mango, aberrant crypt foci formation was inhibited more than 60% (p=0,05) and the inhibition was dose-dependent when compared with controls receiving water. These results show that mango pulp, a natural food, non toxic, part of human being diet, contains bioactive compounds able to reduce growth of tumor cells and to prevent the appearance of precancerous lesions in colon during carcinogenesis initiation.

Use of defatted flaxseed meal reduces precancerous colon lesions in C57BL/6 mice

PURPOSE: To investigate the hemopreventive effect of defatted flaxseed meal in C57BL/6 mice after induction of precancerous colon lesions with 1.2-dimethylhydrazine (DMH). METHODS: Thirty-six 12-week-old C57BL/6 mice were divided into three treatment groups(n=12 in each group): (1) diet with 10% defatted flaxseed meal; (2) diet with defatted flaxseed meal and precancerous colon lesions induced by DMH; and (3) precancerous colon lesions induced by DMH, without defatted flaxseed meal. The incidence of aberrant crypt foci (ACF), oxidative processes, expression of tumor suppressor proteins and cyclins, as well as the profile of short-chain fatty acids (SCFA) in animal feces were investigated in the presence and absence of DMH. RESULTS: The rats consuming defatted flaxseed meals showed lesions with lower multiplicity and a reduced incidence of lesions. No changes in the expression of tumor suppressor proteins and those involved in cell cycle control were detected. CONCLUSION: Defatted flaxseed meal protected the distal colon of mice from precancerous lesions.

Effect of probiotics on the development of dimethylhydrazine-induced preneoplastic lesions in the mice colon

PURPOSE: To determine the effect of probiotics on the development of chemically induced (1, 2-dimethylhydrazine) colonic preneoplastic lesions, in mice. METHODS: The animals were divided into five groups. The control group was injected with carcinogen alone and the other groups also received probiotics (1- Lactobacillus delbrueckii UFV-H2b20; 2- Bifidobacterium animalis var. lactis Bb12; 3- L. delbrueckii UFV-H2b20 plus B. animalis var. lactis Bb12; and 4- Saccharomyces boulardii) administered orally in drinking water throughout fourteen weeks. RESULTS: Consumption of lactobacilli and bifidobacteria alone resulted in a significant reduction of the total number of aberrant crypt foci (55.7% and 45.1%, respectively). Significant reduction in the number of these small foci (<3 aberrant crypts) was only observed in the group treated with lactobacilli (52.2%) in comparison to control group. The number of larger foci (>3 aberrant crypts) crypts had no significant reduction. CONCLUSION: L. delbrueckii UFV-H2b20 and B. animalis var. lactis Bb12 administered alone protect colonic preneoplastic lesions in mice, while the combined treatment of these bacteria and the administration of S.boulardii were not effective in reducing such colonic lesions.

[ promising extract suppresses cellular proliferation during the initiation phase of chemically induced colon carcinogenesis]

The present study was undertaken to investigate the chemopreventive efficacy of the ethanolic extract of indigenous Nigella sativa [NsE] seeds during the initiation phase of 1,2- dimethylhydrazine [DMH]-induced colon carcinogenesis in a rat model, and to appraise its potential impact on cellular proliferation. The results demonstrated that [NsE], at an orally daily dose equivalent to 150 mg of the seeds/kg body weight, has an inhibitory effect against colon carcinogenesis as reflected by significant reductions in tumor incidence, multiplicity and mean tumor volumes. These reductions were accompanied by a significant decrease in colonic proliferating cell nuclear antigen-Labeling index [PCNA-LI]. In conclusion, we provided evidence that [NsE] has a chemopreventive effect against DMH- induced colon carcinogenesis. We surmise that such effect of [NsE] is mediated, at least in part, through its ability to suppress cellular proliferation. The results could provide an effective chemopreventive approach in the primary prevention of colon cancer in humans in the next future

Effects of silk sericin on the proliferation and apoptosis of colon cancer cells

Sericin is a silk protein woven from silkworm cocoons (Bombyx mori). In animal model, sericin has been reported to have anti-tumoral action against colon cancer. The mechanisms underlying the activity of sericin against cancer cells are not fully understood. The present study investigated the effects of sericin on human colorectal cancer SW480 cells compared to normal colonic mucosal FHC cells. Since the size of the sericin protein may be important for its activity, two ranges of molecular weight were tested. Sericin was found to decrease SW480 and FHC cell viability. The small sericin had higher anti-proliferative effects than that of the large sericin in both cell types. Increased apoptosis of SW480 cells is associated with increased caspase-3 activity and decreased Bcl-2 expression. The anti-proliferative effect of sericin was accompanied by cell cycle arrest at the S phase. Thus, sericin reduced SW480 cell viability by inducing cell apoptosis via caspase-3 activation and down-regulation of Bcl-2 expression. The present study provides scientific data that support the protective effect of silk sericin against cancer cells of the colon and suggests that this protein may have significant health benefits and could potentially be developed as a dietary supplement for colon cancer prevention.

Questionnaire assessment based on signs, symptoms and history in the prevention of colorectal cancer

INTRODUCTION: Colorectal cancer (CRC) is an important pathology characterized by tumors in colorectal segments. Colonoscopy is the gold standard of CRC detection, but it is very expensive. Then, new methods are required for CRC screening to reduce mortality and improve the cost-benefit ratio. Objective: Evaluate the efficacy of a questionnaire (QSSA) based on signs and symptoms of CRC. METHODS: The QSSA was answered by 40 patients, before the colonoscopy procedure. The patients were divided into two groups: group I, with 20 patients showing positive result in the questionnaire, and group II, with 20 people showing negative result in the questionnaire. Colonoscopy was considered positive when presenting neoplasm or its precursor. The result was statistically analyzed by Fischer's exact test and sensitivity calculation. RESULTS: The results showed 14 positive and 26 negative colonoscopies. Group I had 9 positive and 11 negative colonoscopies and Group II, 5 positive and 15 negative (p=0.20) colonoscopies. The questionnaire presented sensitivity of 64.2%. CONCLUSION: The use of this questionnaire based on signs and symptoms of CCR alone was not effective in CCR screening. (AU)

INTRODUÇÃO: O câncer colorretal (CCR) é uma importante afecção caracterizada pela presença de tumores localizados no colón ou reto. A colonoscopia, padrão ouro na detecção do CCR, demanda alto custo. Assim, há necessidade de métodos de triagem eficazes, visando um melhor custo beneficio na diminuição da mortalidade do CCR. OBJETIVO: Avaliar a efetividade de um questionário de sinais, sintomas e antecedentes (QSSA) em predizer o CCR. Métodos: O QSSA foi aplicado a 40 pacientes, momentos antes da realização do exame colonoscópico, no intuito de compor dois grupos: grupo I formado pelos 20 primeiros que apresentassem o QSSA positivo, e grupo II formado pelos 20 primeiros com QSSA negativo. A colonoscopia positiva foi aquela com achado de neoplasia ou lesões precursoras do CCR. O resultado foi submetido à análise estatística através do Teste Exato de Fischer e do cálculo da sensibilidade, especificidade, acurácia e valores preditivos positivos e negativos. RESULTADO: Observaram-se 14 colonoscopias positivas e 26 colonoscopias negativas, assim distribuídas: grupo I, 9 positivas e 11 negativas; grupo II, 5 positivas e 15 negativas (p=0,20). O questionário apresentou sensibilidade de 64,2%. CONCLUSÃO: A utilização de um questionário de sinais, sintomas e antecedentes usado isoladamente não mostrou eficácia no rastreamento de lesões neoplásicas. (AU)

Efficacy of geraniol but not of β-ionone or their combination for the chemoprevention of rat colon carcinogenesis

β-ionone (βI), a cyclic isoprenoid, and geraniol (GO), an acyclic monoterpene, represent a promising class of dietary chemopreventive agents against cancer, whose combination could result in synergistic anticarcinogenic effects. The chemopreventive activities of βI and GO were evaluated individually or in combination during colon carcinogenesis induced by dimethylhydrazine in 48 3-week-old male Wistar rats (12 per group) weighing 40-50 g. Animals were treated for 9 consecutive weeks with βI (16 mg/100 g body weight), GO (25 mg/100 g body weight), βI combined with GO or corn oil (control). Number of total aberrant crypt foci (ACF) and of ACF ≥4 crypts in the distal colon was significantly lower in the GO group (66 ± 13 and 9 ± 2, respectively) compared to control (102 ± 9 and 17 ± 3) and without differences in the βI (91 ± 11 and 14 ± 3) and βI+GO groups (96 ± 5 and 19 ± 2). Apoptosis level, identified by classical apoptosis morphological criteria, in the distal colon was significantly higher in the GO group (1.64 ± 0.06 apoptotic cells/mm²) compared to control (0.91 ± 0.07 apoptotic cells/mm²). The GO group presented a 0.7-fold reduction in Bcl-2 protein expression (Western blot) compared to control. Colonic mucosa concentrations of βI and GO (gas chromatography/mass spectrometry) were higher in the βI and GO groups, respectively, compared to the control and βI+GO groups. Therefore, GO, but not βI, represents a potential chemopreventive agent in colon carcrvpdate=20110329inogenesis. Surprisingly, the combination of isoprenoids does not represent an efficient chemopreventive strategy.

Ácidos grasos omega-3 y cáncer, una alternativa nutricional para su prevención y tratamiento / Omega-3 fatty acids and cancer, a nutritional alternative for its prevention and treatment

Long-chain omega-3 polyunsaturated fatty acids (omega-3 LCPUFA) are essential for human beings and they should be incorporated to our body through the diet. For almost a century it is known that these fatty acids are essential for growth and development of individuals andfrom 1970 onwards, investigations have found solid evidence about several health properties attributed to these fatty acids, especially at the cardiovascular, neurological and anti-inflammatory level; it is in this sense that today a large number of investigations have focused to study the protective role of omega-3 LCPUFA against cancer, primarily based on the anti-inflammatory properties that they possess. In this paper we describe a series of evidences to establish a possible preventive and therapeutic use of omega-3 LCPUFA against cancer, specifically in prostate, breast and colon cancer.

Los ácidos grasos poliinsaturados de cadena larga omega-3 (AGPICL omega-3) son esenciales para el ser humano los que deben ser incorporados al organismo en la dieta. Desde hace casi un siglo se sabe que estos ácidos grasos son fundamentales para el crecimiento y desarrollo del individuo y desde 1970 en adelante, se han encontrado sólidas evidencias para atribuir diversas propiedades saludables a estos ácidos grasos, especialmente a nivel cardiovascular, neurológico y antiinflamatorio. En este sentido, en la actualidad un gran número de investigaciones se han centrado en estudiar el rol protector de los AGPICL omega-3 respecto al cáncer, principalmente por las propiedades antiinflamatorias que poseen. En el presente trabajo se exponen una serie de evidencias que permiten establecer un posible uso preventivo y terapéutico de los AGPICL omega-3 frente al cáncer, específicamente el de próstata, mama y colon.

Fish oil ingestion reduces the number of aberrant crypt foci and adenoma in 1, 2-dimethylhydrazine-induced colon cancer in rats

We determined the effect of fish oil (FO) ingestion on colonic carcinogenesis in rats. Male Wistar rats received 4 subcutaneous injections (40 mg/kg body weight each) of 1,2-dimethylhydrazine (DMH) at 3-day intervals and were fed a diet containing 18 percent by weight FO (N = 10) or soybean oil (SO, N = 10) for 36 weeks. At sacrifice, the colon was removed, aberrant crypt foci were counted and the fatty acid profile was determined. Intestinal tumors were removed and classified as adenoma or carcinoma. Liver and feces were collected and analyzed for fatty acid profile. FO reduced the mean (± SEM) number of aberrant crypt foci compared to SO (113.55 ± 6.97 vs 214.60 ± 18.61; P < 0.05) and the incidence of adenoma (FO: 20 percent vs SO: 100 percent), but carcinoma occurred equally in FO and SO rats (2 animals per group). The polyunsaturated fatty acid (PUFA) profile of the colon was affected by diet (P < 0.05): total ù-3 (FO: 8.18 ± 0.97 vs SO: 1.71 ± 0.54 percent) and total ù-6 (FO: 3.83 ± 0.59 vs SO: 10.43 ± 1.28 percent). The same occurred in the liver (P < 0.05): total ù-3 (FO: 34.41 ± 2.6 vs SO: 6.46 ± 0.59 percent) and total ù-6 (FO: 8.73 ± 1.37 vs SO: 42.12 ± 2.33 percent). The PUFA profile of the feces and liver polyamine levels did not differ between groups (P > 0.05). In conclusion, our findings indicate that chronic FO ingestion protected against the DMH-induced preneoplastic colon lesions and adenoma development, but not against carcinoma in rats.

Cancer screening and cancer mortality in Nevis, West Indies: Pesquisaje de cáncer y mortalidad por cáncer en Nevis, West Indies

OBJECTIVE: Cancer screening is one approach that can reduce morbidity and mortality through early detection of precancers; however anxiety, fear, and lack of information are important barriers to universal cancer screening in the Caribbean. Nevis is a small island located in the Eastern Caribbean. We report available data on screening prevalence and cancer mortality for four common cancers: cervical, breast, colon and prostate. METHODS: Demographic information, screening utilization (when available) and cancer mortality statistics were obtained from the Charlestown Health Clinic and the annual reports from the Ministry of Health. Moreover, physicians and key stakeholders were interviewed to assess current guidelines for cancer screening as well as to indicate areas of need. RESULTS: Cervical cancer screening is underutilized in Nevis. Between 2001 and 2007, the overall prevalence of Pap testing fluctuated minutely (mean: 6.87%, range: 6.06 - 7.41%). Systematic screening for breast, colon, and prostate cancer is not routinely performed, thus utilization rates are not available. Cancer mortality varied slightly between 2002 and 2006; prostate cancer had the highest overall crude mortality rate (30.6 deaths/100 000 persons). Physician interviews revealed that adherence to US and European cancer screening guidelines are inappropriate for their population of patients. Breast and prostate cancers are frequently diagnosed in these geographic areas before the age when cancer screening is currently recommended. CONCLUSION: Cancer is perceived as an important health problem by physicians, key stakeholders and citizens, however cancer screening is underutilized in Nevis. Future research should focus on generating screening guidelines that are relevant for this population, as well as methods to promote screening.

OBJETIVO: El pesquisaje de cáncer es un método que puede reducir la morbilidad y la mortalidad mediante la detección precoz de precánceres. Sin embargo, la ansiedad, el miedo, y la falta de información son barreras importantes que se erigen frente al pesquisaje universal del cáncer en el Caribe. Nevis es una pequeña isla situada en el Caribe Oriental. Reportamos datos disponibles sobre la prevalencia del pesquisaje y la mortalidad por cáncer en relación con cuatro tipos de cánceres comunes: el cervical, y el de mamas, colon y próstata. MÉTODOS: La información demográfica, la utilización de pesquisaje (de hallarse disponible) y las estadísticas sobre la mortalidad por cáncer, se obtuvieron de la Clínica de la Salud de Charlestown, y los reportes anuales del Ministerio de Salud. Además, los médicos y las partes interesadas claves, fueron entrevistados a fin de evaluar las guías actuales para el pesquisaje del cáncer así como para indicar las áreas de necesidad. RESULTADOS: El pesquisaje del cáncer cervical es subutilizado en Nevis. Entre 2001 y 2007, la prevalencia general de la prueba citológica tuvo una fluctuación mínima (promedio: 6.87%, rango: 6.06 - 7.41%). El pesquisaje sistemático del cáncer de mamas, colon, y próstata no se realiza como rutina, y por consiguiente no existen tasas de utilización disponibles. La mortalidad por cáncer varió ligeramente entre 2002 y 2006. El cáncer de próstata tuvo la tasa de mortalidad cruda general más alta (30.6 muertes/100 000 personas). Las entrevistas médicas revelaron que las guías de pesquisaje en USA y Europa son inapropiadas para la población de pacientes. Los cánceres de mamas y próstata son diagnosticados con frecuencia en estas áreas geográficas antes de la edad en que se recomienda el pesquisaje actualmente. CONCLUSIÓN: El cáncer es percibido como un importante problema de salud por los médicos, las partes interesadas claves, y los ciudadanos. No obstante, el pesquisaje del cáncer es subutilizado en Nevis. Las investigaciones futuras deben centrarse en producir guías de pesquisaje que sean pertinentes para esta población, así como en métodos de promover el pesquisaje.

role of pomegranate [punica granatum L.] in colon cancer

Colon cancer is one of the major causes of cancer-related death in the Western world. Although cytotoxic chemotherapeutic agents are available to treat the disease, these agents become ineffective as the disease advances to an invasive state. An alternative but viable approach to reduce the incidence of this deadly disease is then, to increase the dietary intake of relatively non-toxic fruits and vegetables. An example of a fruit with antioxidant, antidiabetic and anti-atherosclerotic properties is pomegranate. Pomegranate produces anticancer effects in experimental models of lung, prostate and skin cancer. More recently, pomegranate has been found to be anti-carcinogenic in the colon. This communication discusses pomegranate's effect in colon cancer