Blood Tests May Spot Colon Cancer

Sept. 24 -- TUESDAY, Sept. 22 (HealthDay News) -- Simple blood tests may someday become a noninvasive and cost-effective way to detect colon cancer, two new studies suggest.

Researchers were to present studies in Berlin, Germany, on Monday that could offer an alternative to colonoscopy or fecal occult blood tests for diagnosing colorectal cancer, the second leading cause of cancer death in the United States and Europe.

"We have found biomarkers that can be used to screen for colorectal cancer," said Dr. Joost Louwagie, of OncoMethylome Sciences in Liege, Belgium, and lead researcher of one study. "These markers are found in blood, so a regular blood test performed during a regular physical check-up could check for the presence of colorectal cancer."

Louwagie was scheduled to present the finding at the 15th Congress of the European Cancer Organization and 34th Congress of the European Society for Medical Oncology.

For this study, Louwagie's team took blood samples from 193 colon cancer patients and 688 people without colon cancer who were having colonoscopies. The researchers then looked at various genes linked to cancer to find the best ones to distinguish colon cancer.

The researchers found two genes -- SYNE1 and FOXE1 -- were present in abundance in people with colon cancer, but infrequent in those without the disease.

The sensitivity of the test, that is the number cancers it identified, was 58 percent, and the specificity, the proportion of noncancerous patients it identified, was 90 percent. In a second group of patients, specificity was 56 percent and sensitivity was 91 percent.

For patients with early-stage colon cancer, the sensitivity and specificity were lower, at 41 percent and 80 percent respectively, Louwagie noted.

This test will not replace colonoscopy or fecal occult blood tests, the standard tests for colon cancer, but may become another option that many people will find easy and acceptable, Louwagie said. "What we are trying to do is make sure as many people as possible are being screened," he noted.