Johns Hopkins scientists discovered proteins present in blood that identify colon cancer and precancerous polyps. Initial studies of the proteins, CCSA-3 and CCSA-4, suggest they could be used to develop a blood test to identify at-risk individuals.
The researchers drew blood samples from 107 apparently healthy individuals the day before their scheduled colonoscopies and from 28 colorectal cancer patients. Using a particular concentration of scaffold-proteins as a marker for disease, the team were 100% accurate in identifying the 28 existing cancer patients. Using the same protein markers, they also correctly identified 51 of 53 individuals (96.2%) with normal colons and 14 of 18 (77.8%) people with advanced precancerous polyps.
When researchers combined samples, they correctly identified 42 of 46 (91.3%) patients containing both cancers and advanced precancerous polyps. Protein levels were accurate in correctly assessing additional blood samples from 125 people with benign conditions and other cancers.
Results are published in the June 15 issue of Cancer Research.