Increased DNA integrity in colorectal cancer

Area of Science:

• Biochemistry
• Molecular Biology
• Oncology

Background:

• Blood-based DNA integrity, the ratio of long to short cell-free circulating DNA fragments, is elevated in various cancers.
• Inconsistent findings regarding DNA integrity as a cancer diagnostic marker exist due to varied methodologies.

Purpose of the Study:

• To investigate the diagnostic utility of DNA integrity in colorectal cancer.
• To compare DNA integrity measurements using two distinct formulae.

Main Methods:

• Sera from colorectal cancer patients, benign gastrointestinal disease patients, and healthy controls were analyzed.
• Quantitative polymerase chain reaction measured ALU repeats (115 bp and 247 bp).
• DNA integrity was calculated using Umetani et al. (DNA Int 1) and Wang et al. (DNA Int 2) formulae.

Main Results:

• DNA integrity measurements from both formulae showed strong correlation.
• Significantly higher DNA integrity was observed in colorectal cancer patients versus healthy controls (p=0.005 and p=0.006).
• No significant difference in DNA integrity was found between colorectal cancer patients and those with benign gastrointestinal diseases. Receiver operating characteristic analysis yielded areas under the curve of 0.74 and 0.73, with 71% sensitivity at 75% specificity for discriminating cancer patients from healthy controls.

Conclusions:

• DNA integrity is significantly increased in colorectal cancer patients.
• This marker shows potential utility for colorectal cancer diagnosis in future clinical trials.