Blood test may predict risk of bladder cancer

A new blood test may make it possible to gauge a person’s risk of developing bladder cancer by identifying the abnormal pattern of DNA methylation associated with the disease, researchers from Brown University and Dartmouth College medical schools report.

The test assesses a pattern of methylation (ie, chemical changes in DNA influencing which genes are expressed in cells) linked to bladder cancer. By studying the blood of 112 people who had bladder cancer and 118 who didn’t, investigators determined the methylation pattern to look for in immune system cells, then tested the blood of similar numbers of participants under blinded conditions with and without bladder cancer. Those who had the methylation pattern were 5.2 times more likely than those without it to have bladder cancer, after controlling for known risk factors such as smoking.

Further investigation should clarify whether the methylation markers in this study predicted cancer or merely indicated its presence because the participants already had cancer. The authors suggest that the study proves a link between bladder cancer and a readily detected methylation pattern in the blood. This association holds potential for a minimally invasive test that could predict or detect bladder cancer and improve the prognosis.

The National Cancer Institute estimates that approximately 17,770 women were diagnosed with bladder cancer last year. Smoking is the main established risk factor; others include occupational chemical exposures, use of certain hair dyes, exposure to chlorination by-products, individual fluid intake, and dietary variables.

The study was published online February 22 in the Journal of Clinical Oncology.