The blood mSEPT9 is capable of assessing the surgical therapeutic effect and the prognosis of colorectal cancer.

Aim: To investigate the performance of methylated SEPT9 (mSEPT9) in assessing the surgical therapeutic effect and prognosis of colorectal cancer (CRC). Methods: Blood samples before surgery and 1 and 7 days after surgery were obtained from 120 CRC patients, and mSEPT9 and carcinoembryonic antigen (CEA) assays were performed. Results: The mean plasma mSEPT9 level showed 57.6-times and 131.1-times decrease 1 day and 7 days after surgery, respectively. In contrast, mean CEA levels showed 2.51-and 2.70-times decrease 1 and 7 days after surgery. 86.7% of patients can be assessed by mSEPT9 while 44.2% can be assessed by CEA. Positive mSEPT9 detection before surgery correlated with higher risk of death after surgery. Conclusion: mSEPT9 is effective for CRC postsurgical assessment and prognosis prediction.