Simple blood tests can provide surprisingly accurate indications of bladder cancer, according to research conducted by Carmen Marsit, assistant professor of pathology and laboratory medicine.
His paper published in the Journal of Clinical Oncology Feb. 22 indicates that certain patterns of methylation, a mechanism that controls the way genes are expressed, are associated with bladder cancer. After examining a variety of blood samples, Marsit's team could predict with promising accuracy which patients had cancer.
Patterns of methylation also serve as an indication of carcinogenic exposure over a person's life, which otherwise can be hard to detect.
"We kind of see it as an integrated measure of risk," Marsit said. "We can't tell every exposure a person has had. There's no way to keep track of all of that."
"Bladder cancer is difficult to detect," Marsit said. In the future, methylation markers may be a much easier way to detect the disease. "Clinically, it could become a very useful tool," he said.
Previously, researchers looked specifically at bladder tumors. Marsit's research took a new approach, trying to identify the changes to DNA methylation that were not in the target tissue, but in the blood.
Marsit's research is far from finished. "We don't know how predictive it is," Marsit said. The next step is to determine if the patterns are diagnostic or predictive. As of right now, it is uncertain whether the methylation markers associated with bladder cancer are present before the cancer starts growing or are consequences of cancer. "We're kind of teasing out who might get the best use out of this," he said.
The research may also be applicable to other cancers, especially those that are hard to detect. "This is better than looking for little mutations," Marsit said. He hopes to look more deeply into methylation testing for other forms of cancer in the future.
Marsit's research team consisted of Brown researchers Devin Koestler GS, Assistant Professor of Community Health Andres Houseman, Professor of Community Health Karl Kelsey, Postdoctoral Research Associate in Community Health Brock Christensen and Dartmouth Professor of Community and Family Medicine in Epidemiology Margaret Karagas.
