Washington: Scientists claimed to have developed a new blood test that can accurately detect whether a person is susceptible to develop bladder cancer.
Researchers at Brown University in Rhode Island said their test measures a pattern of methylation -- a chemical alteration to DNA that affects cell function by altering gene expression.
Methylation is affected by carcinogenic exposures such as smoking and industrial pollution. And scientists believe that abnormal patterns of it in the body could be indicators of an increased likelihood of developing bladder cancer.
"What we might be measuring is an accumulated barometer of your life of exposures that then put you at risk," said Carmen Marsit, an assistant professor of medical science who led the study.
"Will you ever really figure out if eating something when you were 12 gave you cancer? Instead we can use these kinds of markers as an integrated measure of your exposure history throughout your life."
For their study, published in in the Journal of Clinical Oncology, Marsit and his team studied the blood of 112 people who had bladder cancer and of 118 who didn`t.
That gave them the tell-tale pattern of methylation to look for in immune system cells in the blood. Then, under properly blind conditions, they applied that test to the blood of a similar number of people who either had the cancer or didn`t, and made their predictions.
They found that they could indeed determine who had the cancer and who didn`t, based solely on the methylation pattern they observed.
Controlling for the exposure to known risk factors like smoking that the patients reported, the researchers saw that people with the methylation pattern were 5.2 times more likely to have bladder cancer than people who did not have the pattern.
As the samples used in the study came from people who already had the cancer, Marsit said further research is needed to confirm whether methylation markers in their immune system cells were predictors of cancer or just showed that the cancer was already there.
However, the study, at least, proved that the cancer is associated with a methylation pattern that can readily be detected in the blood, Marsit said.
For cancers that are buried deep in the body and are therefore hard to detect, such as bladder cancer, a minimally invasive test that provides either prediction or early detection of cancer could make a big difference in improving a patient`s prognosis, he added.
Testing for methylation in blood cells could also be similarly applicable to other cancers, the researchers added.