Although fecal occult-blood testing is the only available noninvasive screening method that reduces the risk of death from colorectal cancer, it has limited sensitivity.
Dr Imperiale and colleagues from America undertook a study in order to compare an approach that identifies abnormal DNA in stool samples with the Hemoccult II fecal occult-blood test in average-risk, asymptomatic persons 50 years of age or older.
The researchers collected 1 stool specimen for DNA analysis from eligible subjects, and also oversaw standard Hemoccult II testing, and colonoscopy for each participant.
The study included a total of 5486 subjects, out of these, 4404 completed all aspects of the study.
The researchers analyzed a subgroup of 2507 subjects, including all those with a diagnosis of invasive adenocarcinoma or advanced adenoma plus randomly chosen subjects with no polyps or minor polyps.
|The DNA panel detected 29 of 71 invasive cancers plus adenomas with high-grade dysplasia|
|New England Journal of Medicine|
The investigators found that the fecal DNA panel consisted of 21 mutations.
The researchers found that the fecal DNA panel detected 16 of 31 invasive cancers, whereas Hemoccult II identified 4 of 31 (52% vs. 13 %).
The research team noted that the DNA panel detected 29 of 71 invasive cancers plus adenomas with high-grade dysplasia, whereas Hemoccult II identified 10 of 71 (41% vs. 14%).
In addition, the researchers noted that among 418 subjects with advanced neoplasia the DNA panel was positive in 18%, whereas Hemoccult II was positive in 11%.
The research team found that the specificity in subjects with negative findings on colonoscopy was 94% for the fecal DNA panel and 95% for Hemoccult II.
Dr Imperiale concluded, "Although the majority of neoplastic lesions identified by colonoscopy were not detected by either noninvasive test, the multitarget analysis of fecal DNA detected a greater proportion of important colorectal neoplasia than did Hemoccult II without compromising specificity."