Circulating cell-free DNA in serum as a biomarker for diagnosis and prognostic prediction of colorectal cancer.

British journal of cancer

PubMedID: 25157833

Hao TB, Shi W, Shen XJ, Qi J, Wu XH, Wu Y, Tang YY, Ju SQ. Circulating cell-free DNA in serum as a biomarker for diagnosis and prognostic prediction of colorectal cancer. Br J Cancer. 2014;111(8):1482-9.
BACKGROUND
To verify whether the concentrations and integrity index of circulating cell-free DNA (ccf-DNA) in serum may be clinically useful for the diagnosis and progression monitoring of colorectal cancer (CRC) patients.

METHODS
Serum samples were collected from 104 with primary CRC, 85 with operated CRC, 16 with recurrent/metastatic CRC, 63 patients with intestinal polyps and 110 normal controls. Long (247?bp) and short (115?bp) DNA fragments in serum were detected by real-time quantitative PCR by amplifying the ALU repeats (ALU-qPCR). Serum carcinoembryonic antigen (CEA) level was detected by ARCHITECT assay.

RESULTS
The median absolute serum ALU115 and ALU247/115 in primary CRC group was significantly higher than those in intestinal polyp and normal control groups (both P<0.0001), in recurrent/metastatic CRC was significantly higher compared with primary CRC (P=0.0021, P=0.0018) or operated CRC (P<0.0001, respectively) and during follow-up, ALU115 and ALU247/115 were increased before surgery and decreased significantly after surgery.

CONCLUSIONS
Combined detection of ALU115, ALU247/115 and CEA could improve the diagnostic efficiency for CRC. Serum DNA concentrations and integrity index may be valuable in early complementary diagnosis and monitoring of progression and prognosis of CRC.