A blood test which measures the levels of CD24 protein offers promising results for the early detection of colorectal cancer. According to the American Cancer Society, in 2009, 106,100 new cases of colon cancer and 40,870 new cases of rectal cancer were reported. Last year, 49,920 Americans died of colorectal cancer. (1) Physicians unanimously agree that early detection of cancer ensures a better prognosis.
At the 2010 Gastrointestinal Cancers Symposium held in Orlando, Florida, Sarah Kraus, PhD., of the Tel Aviv Souraski Medical Center in Israel presented the findings of a study on the correlation between CD24 levels and the occurrence of colorectal cancer.
The CD24 protein is involved in cell adhesion and metastasis, which is the spread of cancer from the original tumor to other parts of the body, and is associated with colorectal cancer. The aim of the study was to evaluate the presence of CD24 in the blood samples of colorectal cancer patients and of healthy individuals. In the first trial, 150 individuals underwent a colonoscopy and the blood test to specifically analyze CD24 levels. As a validation measure, a second group of 70 individuals underwent the same procedure of colonscopy and blood test. The CD24 levels were approximately 2000 OD/mm2 in normal subjects and 12,000 OD/mm2 in subjects who had colorectal cancer or adenomas, which are benign tumors. The researchers found that the CD24 blood screening was more than 90% sensitive and specific for detecting colorectal cancer and more than 80% accurate at identifying adenomas.
"We found that serum CD24 is elevated in the majority of patients with CRC [colorectal cancer] or adenomas. We believe a simple blood test that measures the levels of CD24 in PBLs [peripheral blood lymphocytes] can successfully distinguish healthy subjects from those with neoplasia [existence of tumors], and may serve as a biomarker for early detection and surveillance of CRC," states Dr. Kraus. (2) The investigators acknowledge the need for further development of this test and project clinical availability in 2 to 3 years.