A liquid biopsy test examining DNA circulating in the blood can help determine which men might benefit from PARP-inhibitors, the Guardian reports.
Researchers led by Johann de Bono from the Institute of Cancer Research and the Royal Marsden NHS Foundation Trust in London collected serial circulating free DNA samples from 46 participants of a phase II trial examining the use of the PARP inhibitor olaparib in metastatic prostate cancer. As they report in Cancer Discovery, de Bono and his colleagues noted a decrease in mutation allele frequencies in patients who responded to olaparib treatment as well as mutations that developed among patients who initially responded to therapy but then whose disease progressed.
"From these findings, we were able to develop a powerful, three-in-one test that could in future be used to help doctors select treatment, check whether it is working, and monitor the cancer in the longer term," de Bono tells the Guardian. "We think it could be used to make clinical decisions about whether a PARP-inhibitor is working within as little as four to eight weeks of starting therapy."