Blood test for colon cancer on the horizon

Investigators at Johns Hopkins Hospital have identified a set of nuclear matrix proteins both specific and sensitive for colorectal cancer. They hope the research will translate into a serum blood test for colorectal cancer within the next several years.

The most recently identified protein, colon cancer specific antigen-2 (CCSA-2), was discussed at the 2008 American Society of Clinical Oncology Gastrointestinal Cancers Symposium, noted by the instructor in the Department of Urology at Johns Hopkins Hospital, Baltimore. CCSA-2 is a highly specific and sensitive marker for colorectal cancer. CCSA-2 not only detects the presence of colorectal cancer but may also differentiate between advanced and nonadvanced adenomas.

The ultimate goal is to combine the biomarkers, five identified so far, into a serum assay that would accurately diagnose colorectal cancer and identify individuals with increased risk for cancer. Other researchers in the laboratory of lead study author are investigating nuclear proteins to diagnose renal cell carcinoma, prostate cancer and bladder cancer.

The study findings are preliminary, “but we have to start somewhere,” reported by a professor of medicine and a distinguished professor of gastrointestinal oncology, at the University of Texas M.D. Anderson Cancer Center in Houston. Indeed, that further multicenter validation of the biomarkers is “clearly warranted.” The next step is to evaluate the sensitivity and specificity of CCSA-2 in an unscreened population.

The holy grail of cancer research is to develop a blood test for screening that has high predictive value. Although endoscopy is a good screening tool for colorectal cancer, it is a relatively complicated test and compliance is poor. About 60% of the eligible population is never screened.