Circulating and stool nucleic acid analysis for colorectal cancer diagnosis

Abstract

In recent years, the need to identify molecular markers characterized by high sensitivity and specificity in detecting and monitoring early and colorectal cancer lesions has increased. Up to now, none of the markers or panels of markers analyzed have met the rigorous standards required of a screening program. The important discovery of circulating nucleic acids in biological fluids has aroused intense scientific interest because of their usefulness in malignant and non malignant diseases. Over time, their yield and stability have been identified and compared with other “standard” biomarkers. The analysis of circulating DNA from blood and stool is a relatively simple and non-invasive procedure, representing a very attractive marker to detect genetic and epigenetic mutations and to monitor disease progression. A correlation between blood and stool biomarkers could also help to enhance currently available diagnostic approaches. However, various processing and analytic problems need to be resolved before such an approach can be applied in clinical practice.

Keywords: Colorectal cancer, Circulating DNA, Circulating RNA, Early diagnosis, DNA integrity

Core tip: Although the importance of circulating free DNA is widely recognized, numerous studies evaluating its presence in blood and stool samples have reported analytic variability and non conforming approaches. Nonetheless, circulating free DNA has shown high potential as a biomarker for the early non-invasive detection of cancer and for monitoring disease progression. Population studies are now needed to confirm its usefulness for colorectal cancer diagnosis.