DNA Test May Gauge Risk of Prostate Cancer's Return

A new DNA test can identify prostate cancer patients at high risk for a return of their cancer, researchers say.

The test uses DNA from biopsy (tissue) samples taken before patients undergo surgery or radiation therapy for their cancer. The test is about 80 percent accurate in predicting which men have a high or low risk of their cancer returning within two years, according to the study.

The findings are scheduled for presentation Saturday at a meeting of the European Society for Radiotherapy and Oncology in Vienna.

Surgery and targeted radiation therapy are the main treatments for cancer that's confined to the prostate. However, cancer returns in 30 percent to 50 percent of patients because its spread outside the prostate was undetected during the initial treatment, said study author Robert Bristow. He is a clinician-scientist at the Princess Margaret Cancer Center in Toronto and a professor at the University of Toronto.

"Men who fail treatment within two years may be at the highest risk of dying from their prostate cancer," he said in a society news release.

"Existing methods for identifying high-risk patients are imperfect, so new tests are required that are better at predicting which patients will have their cancer recur," Bristow said. "These men can then be offered additional treatments, such as chemo- and hormone therapy, that will combat the prostate cancer throughout their entire body, rather than therapies solely focused on the prostate, in order to improve their chances of survival."

The test was assessed in 276 prostate cancer patients with an intermediate risk of cancer recurrence. It needs to be validated over the next few years in different and larger groups, the researchers said.

"If all goes well, then this will lead to a new test for cancer patients that can be turned around in three days and will tell doctors which patients will do well with local treatment alone -- surgery or radiotherapy -- and which will need extra treatment," Bristow said.

Data and conclusions presented at meetings are typically considered preliminary until published in a peer-reviewed journal.

(Source: MedicineNet)