February 25, 2011

Can A Blood Test Detect Cancer Risk?

By Rhonda Craig, Ivanhoe Health Correspondent

(Ivanhoe Newswire) -- A blood test may be able to accurately detect markers of bladder cancer. A new study shows that cancer associated with a specific methylation pattern (a chemical alteration to DNA that affects which genes are expressed in cells) can readily be detected in the blood.

Since it's not possible to document and assess all of the carcinogenic exposures a person has had in life, researchers hoped to find a more precise way to predict a person's susceptibility to cancer. To do that, a team of scientists examined whether a blood test can accurately detect biomolecular markers of bladder cancer that risky exposures may have left behind. The test measures a pattern of methylation that the team determined is associated with bladder cancer. Methylation is affected by exposures in the environment, such as cigarette smoke and industrial pollutants. Experts believe that abnormal patterns of it could be indicators of an increased likelihood of disease.

"This is important, as bladder cancer can be well treated although the detection of the disease, and follow-up of those with bladder cancer, is very expensive and is difficult for the patient."Carmen Marsit, assistant professor of medical science in the Department of Pathology and Laboratory Medicine at the Warren Alpert School of Medicine at Brown University, told Ivanhoe. "By identifying markers in more accessible samples like blood, we hope to lessen the burden on individuals who are at risk for this disease, and potentially lessen the cost to the healthcare system."

Marsit's team of scientists applied the test to the blood of people who had bladder cancer and people who didn't. The scientists found that they could determine who had the cancer and who didn't, based solely on the methylation pattern they observed. In fact, people with the methylation pattern were 5.2 times more likely to have bladder cancer than people who did not have the pattern.

Researchers say because the samples used in the study came from people who already had the cancer, further research is needed to confirm whether these methylation markers were predictors of cancer or just showed that the cancer was already there.

SOURCE: Journal of Clinical Oncology, February 22, 2011