A study, published in Annals of Internal Medicine, sought to identify novel protein biomarkers in stool that would detect colorectal cancer and advanced adenomas at a greater rate than hemoglobin.
Researchers conducted a case-controlled study, collecting 315 stool samples from 12 patients with CRC and 10 controls. Researchers then collected a second series of samples from 81 patients with CRC, 40 with advanced adenomas, 43 with non-advanced adenomas and 129 controls. Finally, researchers received 72 fecal immunochemical test samples from an independent series of 14 CRC patients, 16 patients with advanced adenomas, 18 with non-advanced adenomas and 24 controls.
Here's what they found:
1. Researchers identified 834 human proteins. Twenty-nine of those proteins were statistically significantly enriched in CRC versus control samples.
2. At 95 percent specificity, a combination of four proteins achieved 80 percent sensitivity in detecting CRC and 45 percent sensitivity in detecting advanced adenomas. Both were higher than when hemoglobin was used alone.
3. Select proteins could be used in FIT-based screening programs and could discriminate between CRC and control samples.
Researchers concluded, "Mass spectrometry of stool samples identified novel candidate protein biomarkers for CRC screening. Several protein combinations outperformed hemoglobin in discriminating CRC or advanced adenoma from control samples. Proof of concept that such proteins can be detected with antibody-based assays in small sample volumes indicates the potential of these biomarkers to be applied in population screening."