Scientists have identified aggressive forms of prostate cancers that are nearly three times more fatal to patients over a five year period by measuring active DNA in prostate tumors.

Screening for the genes that were found in nearly a third of patients in the study could provide quicker and more accurate detection of the most lethal types of prostate cancer compared to current tests like the Gleason Grading System, researchers said on Monday in a report in the Proceedings of the National Academy of Sciences.

“We’ve begun the process of identifying genes which predispose poor outcomes,” Arnold Levine, one of the study’s researchers and biologist at the Institute for Advanced Study in Princeton, New Jersey, told Bloomberg. “It’s an early indication.”

According to the National Cancer Institute, prostate cancer is the most common type of cancer in the United States. The institute projects 240,000 new cases and about 34,000 deaths of prostate cancer in the U.S. this year.

The study used data collected from 281 patients from Sweden who were recruited between 1977 and 1999. The data included patient age, whether the patient died from the cancer, and how long the patient survived. The researchers then tested patients’ tumor tissue for genetic expressions linked to prostate cancer.

Researchers were able to identify two subtypes of prostate cancer that were three times more fatal by examining “Stem-cell-like” gene activation patterns.

The results will need to be confirmed in a larger trial, Levine told Bloomberg. His group has begun the second trial, and early data may be available within five years. Survival data will be available in 10 to 15 years, he said.