The Relationship between the Methylated Septin-9 DNA Blood Test and Stool Occult Blood Test for Diagnosing Colorectal Cancer in Taiwanese People.

backgroundColorectal cancer (CRC) is a common and lethal disease in the world. There is an increasing number of cases in Taiwan and a higher rate at advanced stages. The immune fecal occult blood test (iFOBT) has been used as a screening method in Taiwan for years. A new novel diagnostic tool, the Methylated Septin-9 (MS-9) DNA blood test, had been reported to have high sensitivity and specificity for CRC detection. There are no available data in Taiwan, so we conducted this prospective randomized trial to investigate the relationship among the MS-9 DNA blood test, iFOBT, and a combination of the two tests for diagnosing CRC in Taiwanese people.

methodsFrom July 1, 2012 to December 31, 2013, we prospectively selected 60 plasma samples from patients who were diagnosed with CRC and otherwise, the healthy group by colonoscopy in our hospital. Patients were divided into the CRC group and healthy group. CRC stages 0, I, II and stages III and IV were separately analyzed. We calculated the sensitivity and specificity of each group to determine the relationship among the MS-9 DNA blood test, iFOBT, and a combination of the two tests for diagnosing CRC in Taiwanese people.

resultsThe results of the MS-9 DNA blood test for the 60 samples were divided into three groups, and the sensitivity as well as the specificity of the MS-9 DNA blood test to detect CRC were 47% and 89%, respectively. The results of iFOBT were also divided into three groups, and had higher sensitivity (84%) but lower specificity (55%) using iFOBT to detect CRC. Higher rates could be predicted to detect CRC if both the tests were positive.

conclusionsA combined MS-9 DNA blood test and iFOBT may help in a higher detection rate of CRC. It could be offered to individuals who are unwilling or unable to undergo colonoscopy. Further large prospective, randomized studies are needed in the future.