RESUMEN
Objective@#To evaluate the value of methylation detection of plasma Septin9 gene in the diagnosis of colorectal cancer (CRC) and verify its performance. @*Methods@#The plasma samples from 32 CRC patients before colonoscopy and 10 healthy controls during October 2016 and May 2017 were collected, and the methylation levels of Septin9 gene in these samples were detected by the detection kit of plasma Septin9 gene methylation. The coincidence rate, detection limit and precision of the kit in the diagnosis of CRC were evaluated, and its diagnostic value was compared with that of carcinoembryonic antigen (CEA) and facal immunochemical tests (FIT). @*Results@#The positive and negative coincidence rates of the plasma Septin9 gene methylation kit in the detection of CRC were 100%. The reference materials assigned the detection limit were positive, and the coefficient of variation (CV) of precision was less than 5%, which met the basic performance requirements. The sensitivity, specificity, positive predictive value and negative predictive value of the kit in the diagnosis of CRC were 62.50%, 90.00%, 95.20% and 42.90%, respectively. The detection rate of CRC by the kit was 62.50%, significantly higher than those of FIT (28.13%) and CEA (28.13%) (all P<0.05). The area under the ROC curve (AUC ROC ) of the kit in the diagnosis of CRC was 0.762, and the detection rate of stage Ⅰ CRC by the kit was 50.00%. @*Conclusion@#The performance of the plasma Septin9 gene methylation kit meets the anticipated clinical requirements, which may be used as a serological marker for the assistant diagnosis of CRC.