According to precious studies, 5-methylcytosine (5-mC) and 5-hydroxymethylcytosine (5-hmC) are both important epigenetic markers whose changes are associated with many kinds of diseases, including cancers. This changes may help diagnose cancer. The new detection method for 5-hmC can meet the requirements of liquid biopsy.
The traditional diagnostic methods for colorectal cancer is colonoscopy and pathology which are inconvenient and unpleasant, and sometimes, it is difficult for the very patients to get tissues or get enough tissues to confirm the pathologic diagnosis. In addition, other screening methods for colorectal cancer,such as guaiac-based fecal occult blood testing and a blood test for methylated SEPT9 DNA, have the shortcomings of relatively low sensitivity and specificity. As a result, it is imperative to find a new detection method for early diagnosis of colorectal cancer with the advantages of high sensitivity and specificity, minimally invasive and convenient.
The aim of this multi-center research is to establish a model for the early diagnosis of colorectal cancer by the detection of 5-hmC in plasma cell-free DNA. Patients who are diagnosed with colorectal cancer by colonoscopy and pathology and not received any anti-tumor therapy (Arm A) will be eligible for inclusion. In addition, patients who suffer with adenoma and not received endoscopic resection (Arm B) will be eligible as well as healthy individuals with normal colonoscopy (Arm C). Then, 5-hmC in plasma cell-free DNA will be detected and compared among the three arms of patients (training group) to establish a model to diagnosis other individuals (validation group) who may suffer from colorectal cancer or adenoma.
