Jan. 22, 2010 -- WEDNESDAY, Jan. 20 (HealthDay News) -- The first blood test to reliably detect early-stage colorectal cancer and polyps may help identify patients who would gain most from colonoscopy, say Israeli researchers who developed the screen.
The blood test checks for levels of CD24 protein, which is produced early in colorectal cancer development and may play a role in the spread of tumor cells, say the team, who will present their findings Sunday at the Gastrointestinal Cancers Symposium in Orlando, Fla.
"Screening is effective for early colorectal cancer detection and prevention, but for a range of reasons, many people are reluctant to undergo colonoscopy. Most people, however, are willing to have a blood test," lead author Sarah Kraus, head of a research laboratory at Tel Aviv Souraski Medical Center, said in a news release from the American Society of Clinical Oncology (ASCO), which helped organize the meeting.
"The CD24 blood test holds promise for identifying the patients at risk for colorectal cancer and could help guide the best use of colonoscopy resources," she said.
Kraus and her colleagues tested the new blood test in 150 patients undergoing colonoscopy. They found that the test was 92.3 percent sensitive (accurate detection of an abnormality) and specific (able to differentiate certain diseases from other diseases) for detecting colorectal cancer, and 84.2 percent sensitive and 89.2 percent specific for detecting polyps that may develop into cancer.
Additional, larger studies to confirm the findings are needed before the new blood test could be used for colorectal cancer screening, Kraus cautioned.
Another study to be presented at the meeting found that post-surgical (adjuvant) treatment with XELOX -- a combination of capecitabine and oxaliplatin -- was more effective than standard 5-fluorouracil and leucovorin (5-FU/LV) therapy for slowing progression of stage III colon cancer in patients of all ages, including those 70 and older.
The phase III study included almost 1,900 patients. After three years, there was no disease progression in 71 percent of patients who received XELOX and 67 percent of patients who received 5-FU/LV, a statistically significant difference, according to the researchers.
Among patients younger than 70, there was no disease progression in 72 percent of the XELOX group and in 69 percent of the 5-FU/LV group. Among patients older than 70, the figures were 66 percent and 60 percent, respectively, the researchers found.
"These findings indicate that patients with stage III colon cancer benefit more from the newer, XELOX adjuvant treatment regimen than from the traditional adjuvant chemotherapy, and that this benefit persists among older patients," lead author Dr. Daniel G. Haller, professor of medicine and of gastrointestinal oncology at the Abramson Cancer Center, University of Pennsylvania, said in an ASCO news release.
"While treatment decisions should be made on an individual basis, these findings shed important new light on how we can best treat otherwise healthy patients age 70 and older," Haller added.
The American Cancer Society has more about colorectal cancer.
SOURCE: American Society of Clinical Oncology, news release, Jan. 20, 2010