Detection of methylated septin 9 DNA in blood for diagnosis, prognosis, and surveillance of colorectal cancer

Abstract

1. The sensitivity of methylated septin9 (mSEPT9) in blood was significantly higher than carcinoembryonic antigen (CEA) in detecting colorectal cancer (CRC) [73.9% vs 48.2%, P<0.001]. However, both were not sensitive enough for detecting colorectal adenoma (<28%). 2. In patients with colorectal cancer, increased number of positive mSEPT9 PCR reactions in plasma samples after surgery was associated with higher rates of mortality (26.3% vs 4.2%, P<0.01), recurrence (47.4% vs 14.1%, P<0.01), and metastasis (36.8% vs 8.5%, P<0.01). 3. In patients with colorectal cancer, the proportion of those with negative CEA was higher than that of those with negative mSEPT9 at 6 months (71.8% vs 55.3%, P=0.035) and 12 months (68.1% vs 48.1%, P=0.028) after surgery.