RESUMEN
AIM: To assess KRAS G12D mutation detection by droplet digital PCR (ddPCR) in stool-derived DNA from colorectal cancer (CRC) patients. METHODS: In this study, tumor tissue and stool samples were collected from 70 patients with stage I-IV CRC diagnosed by preoperative biopsy. KRAS mutational status was determined by pyrosequencing analysis of DNA obtained from formalin-fixed paraffin-embedded (FFPE) tumor tissues. The KRAS G12D mutation was then analyzed by ddPCR in FFPE tumors and stool-derived DNA from patients with this point mutation. Wild-type (WT) tumors, as determined by pyrosequencing, were included as controls; analysis of FFPE tissue and stool-derived DNA by ddPCR was performed for these patients as well. RESULTS: Among the total 70 patients included, KRAS mutations were detected by pyrosequencing in 32 (45.71%), whereas 38 (54.29%) had WT tumors. The frequency of KRAS mutations was higher in left-sided tumors (11 located in the right colon, 15 in the left, and 6 in the rectum). The predominant point mutation was KRAS G12D (14.29%, n = 10), which was more frequent in early-stage tumors (I-IIA, n = 7). In agreement with pyrosequencing results, the KRAS G12D mutation was detected by ddPCR in FFPE tumor-derived DNA, and only a residual number of mutated copies was found in WT controls. The KRAS G12D mutation was also detected in stool-derived DNA in 80% of all fecal samples from CRC patients with this point mutation. CONCLUSION: ddPCR is a reliable and sensitive method to analyze KRAS G12D mutation in stool-derived DNA from CRC patients, especially at early stages. This non-invasive approach is potentially applicable to other relevant biomarkers for CRC management.
Asunto(s)
Biomarcadores de Tumor/genética , Neoplasias Colorrectales/genética , Análisis Mutacional de ADN/métodos , Heces/química , Mutación , Reacción en Cadena de la Polimerasa , Proteínas Proto-Oncogénicas p21(ras)/genética , Anciano , Biopsia , Estudios de Casos y Controles , Neoplasias Colorrectales/patología , Estudios de Factibilidad , Femenino , Predisposición Genética a la Enfermedad , Humanos , Masculino , Tasa de Mutación , Estadificación de Neoplasias , Fenotipo , Valor Predictivo de las Pruebas , Datos Preliminares , Reproducibilidad de los ResultadosRESUMEN
BACKGROUND: The use of drains in patients undergoing abdominal surgery has been a subject of debate for several decades. In this paper, the usefulness of quantitative cultures of sonicated abdominal drains for diagnosing surgical site of infection (SSI) and the association between culture results with patient outcome is evaluated. METHODS: Forty-five abdominal drainage tubes from 35 patients who underwent abdominal surgery were studied. Samples were sonicated for 5 min, the sonicate was centrifuged, and the sediment was cultured on different media. Total bacterial counts were adjusted to the actual surface of the drainage tubing. Clinical information of the patients was reviewed retrospectively. RESULTS: A relation was observed between SSI and the use of drains for more than 3 d (p = 0.0216). The presence of a suspected pathogen was related to the prevalence of SSI (p = 0.035), complications (p = 0.013), and greater leukocyte count (p = 0.048 Mann Whitney test), as well as to the use of drains for more than 3 d (p = 0.0386) and to the serous appearance of the exudates at the point of insertion of the drain (p = 0.0399). The sonication procedure showed a sensitivity of 50%, specificity of 84.2%, positive predictive value of 72.72%, and negative predictive value of 66.67% in the diagnosis of SSI. The most commonly isolated group of organisms was coagulase-negative staphylococci, being present in 18 patients (51.43%) who, however, were not associated with SSI. One or two organisms considered as pathogens were detected in 11 patients (31.43%). The more common pathogens detected were Enterobacteriae spp. (nine patients): Enterobacter aerogenes (2), Enterobacter cloacae (1), Escherichia coli (4), Klebsiella pneumoniae (1), Morganella morganii (1); and Pseudomonas aeruginosa (five patients). Candida spp. and Enterococcus spp. were detected in one patient each one. CONCLUSIONS: The detection and quantification of organisms not present in skin microbiota after drain sonication is helpful in the diagnosis of SSI and it is associated with a worse outcome in patients. Duration of use of drainage tubes is an independent risk factor for the development of SSI.
Asunto(s)
Sonicación/métodos , Infección de la Herida Quirúrgica/diagnóstico , Adulto , Anciano , Anciano de 80 o más Años , Candidiasis/diagnóstico , Candidiasis/microbiología , Drenaje/métodos , Femenino , Infecciones por Bacterias Gramnegativas/diagnóstico , Infecciones por Bacterias Gramnegativas/microbiología , Humanos , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Infección de la Herida Quirúrgica/microbiología , Adulto JovenAsunto(s)
Derivación Gástrica , Gastroscopía , Laparoscopía , Complicaciones Posoperatorias , Úlcera Gástrica , Anastomosis Quirúrgica , Femenino , Humanos , Persona de Mediana Edad , Complicaciones Posoperatorias/diagnóstico , Complicaciones Posoperatorias/terapia , Úlcera Gástrica/diagnóstico , Úlcera Gástrica/terapia , Factores de TiempoRESUMEN
No disponible
Asunto(s)
Humanos , Femenino , Persona de Mediana Edad , Angioplastia/métodos , Anastomosis en-Y de Roux/métodos , Anastomosis Quirúrgica , Úlcera Gástrica/cirugía , Endoscopía del Sistema Digestivo/métodos , Omeprazol/uso terapéutico , Dolor Abdominal/etiología , Úlcera Gástrica/etiologíaAsunto(s)
3-Yodobencilguanidina , Neoplasias de las Glándulas Suprarrenales/diagnóstico por imagen , Lipoma/diagnóstico por imagen , Neoplasias Primarias Múltiples/diagnóstico por imagen , Feocromocitoma/diagnóstico por imagen , Radiofármacos , Neoplasias Retroperitoneales/diagnóstico por imagen , Tomografía Computarizada por Tomografía Computarizada de Emisión de Fotón Único , Adulto , Humanos , Masculino , Tomografía Computarizada por Tomografía Computarizada de Emisión de Fotón Único/métodosRESUMEN
No disponible