RESUMEN
BACKGROUND: Colorectal cancer (CRC) is one of the main five causes of morbidity and mortality by oncologic diseases in our country and worldwide. Recently, fecal immunochemical test (FIT) has proven to be a noninvasive screening test that allows to select patients most likely to have a pre-malign lesion in order to perform a colonoscopy. OBJECTIVE: To report the findings of a CRC screening program using FIT in our country population. METHOD: A multicentric study was performed, by inviting open population older than 50 years to participate in a CRC screening. Quantitative FIT specific for human hemoglobin was used, with a cut point of 100 ng/ml or higher to consider as positive. Those patients with positive results were asked to undergo a colonoscopy. In the cases where polypoid lesions were found, biopsies were performed. RESULTS: In total, 751 FIT were processed, and 51 (6.8) of those were positive, with a rate of 15.9 premalign lesions for 1,000 individuals, and 1.3 patients with CRC for every 1,000. CONCLUSIONS: The present study matches worldwide reports, supporting the initiative of establishing a formal and standardized CRC screening program in the public health sector.
ANTECEDENTES: El cáncer colorrectal (CCR) es una de las cinco primeras causas de morbimortalidad por cáncer en nuestro país y en todo el mundo. La prueba inmunoquímica fecal (FIT, fecal immunochemical test) es una herramienta de tamizaje no invasiva que permite seleccionar a los sujetos con mayor probabilidad de lesión premaligna en la colonoscopia. OBJETIVO: Reportar los resultados del programa de escrutinio para CCR mediante FIT en población abierta en México. MÉTODO: Estudio multicéntrico nacional en población abierta mayor de 50 años a través de medios de difusión masiva para participar en un programa de escrutinio de CCR. Se utilizó FIT cuantitativa específica para detectar hemoglobina humana con un punto de corte de 100 ng/ml (prueba positiva). Se realizó colonoscopia a los positivos. Se tomaron biopsias dirigidas de las lesiones premalignas/cáncer para análisis histopatológico. RESULTADOS: Se procesaron 751 FIT, de las cuales 51 (6.8%) fueron positivas, con una tasa de 15.9 lesiones premalignas por cada 1,000 sujetos evaluados, y 1.3 pacientes con CCR por cada 1,000 pacientes. CONCLUSIONES: Nuestro estudio concuerda con lo reportado en la literatura mundial, apoyando así la iniciativa de fomentar el establecimiento de un tamizaje formal y estandarizado dentro del sector de salud pública.
Asunto(s)
Neoplasias Colorrectales , Detección Precoz del Cáncer , Colonoscopía , Neoplasias Colorrectales/diagnóstico , Heces , Humanos , México/epidemiología , Sangre OcultaRESUMEN
The proton conductivity of radiation-grafted ethylenetetrafluoroethylene-grafted-poly(styrene sulfonic) acid (ETFE-g-PSSA) and Nafion 117 membranes between 25 and -37 degrees C is reported. The freezing of water in the membranes, which strongly depends on the internal acid concentration, results in a 4-fold decrease in proton conductivity. The activation energies before and after the freezing of the membranes are approximately 0.15 and 0.4 eV, consistent with proton transport through liquid water and strongly bound water, respectively. Differential scanning calorimetry data show that up to 14 H(2)O molecules per H(+)/SO(3)(-) group remain unfrozen at subzero temperatures and are believed to be responsible for the low temperature conductivity that is observed. These results indicate that proton conductivity in membranes may be achieved via strongly bound and highly polarized water.
