Researchers from the Royal College of Surgeons in Ireland have discovered a pattern of antibodies present in the blood of individuals with colon cancer. This pattern is not found in the blood of most people who do not have the disease. Antibodies are proteins produced by a type of immune system cell called a B-cell.
"Antibody Signature" For Colon Cancer
As published in the new study, the authors describe a "12-antibody signature" that can identify patients with and without colorectal cancer with 83.7% sensitivity and 80% specificity.
- Sensitivity is the ability of a test to correctly identify those with a disease, as actually having the disease.
- Specificity is the ability of a test to correctly identify people without the disease as not having the disease.
The "antibody signature" test correctly identified people with colon cancer as having the disease 83.7% of the time. This means the test has a 16.3% chance of giving a false negative.
The test correctly identified people without colon cancer as not having the disease 80% of the time. This means that 20% of the time, the test will show a false positive - that the person has colon cancer when in fact they do not have the disease.
Test Not Perfect, But Great Step Forward
While this new test isn't perfect, it will add to the toolbox that doctors have to identify people with colon cancer. When found early, before it has spread, colon cancer is curable in most cases. After it has spread to other parts of the body, colon cancer is very hard to treat. It is not considered curable in many cases. This is why developing accurate, minimally invasive colon cancer screening techniques is so important.
Colonoscopy has a sensitivity of 80-85% for smaller pre-cancerous (adenomas) and cancerous growths. Even this "gold standard test" for colon cancer isn't perfect.
The goal is better colon cancer detection. By combining more than one test, for example, a blood test such as the one described in the study, with another test like colonoscopy, doctors will be able to identify more colon cancers earlier, when they are most treatable.
The new blood test discovered by the Irish research team isn't widely available yet. Further research on this test is likely to be conducted. If it proves to be an effective way to catch colon cancer early in most people, it should be ready for use in clinics worldwide within a few years.
