Annual testing for fecal occult blood is recommended as first-line screening for the detection of colorectal cancer, but is affected by limited sensitivity.
Dr Johann Karl and colleagues from Germany initiated a proteomics-based search for novel biomarkers to improve the sensitivity of detection of colorectal cancer in stool samples.
The team evaluated 6 markers, including immunologic fecal occult blood test, in a collective of 551 samples.
The research team established the diagnostic performance of each marker and marker combinations.
|The best diagnostic performance was for S100A12|
|Clinical Gastroenterology & Hepatology|
The researchers tested the known stool markers hemoglobin, hemoglobin-haptoglobin, calprotectin, carcinoembryogenic antigen, and the novel fecal markers tissue inhibitor of metalloproteinase-1 and S100A12.
The team found the best diagnostic performance was for S100A12 with an area under the curve of 0.95, followed by tissue inhibitor of metalloproteinase-1.
The area under the curves for hemoglobin-haptoglobin was 0.92, for hemoglobin 0.91, for calprotectin 0.90, and for carcinoembryogenic antigen 0.66.
By using Bayes logistic regression as a mathematic model, the highest sensitivity for the detection of colorectal cancer at 95% specificity was obtained with the marker pair S100A12 and hemoglobin-haptoglobin.
Increasing the specificity to 98%, the combination of S100A12, hemoglobin-haptoglobin, and tissue inhibitor of metalloproteinase-1 resulted in a sensitivity of 82%.
The team noted the highest increase of sensitivity in early tumor stages.
Dr Karl’s team concluded, “Depending on the specificity selected, a marker pair, S100A12 and hemoglobin-haptoglobin, or a triple combination including tissue inhibitor of metalloproteinase-1 detects colorectal cancer at higher rates than immunologic fecal occult blood tests alone.”