New Blood Test Paves Way for Targeted Treatment for Prostate Cancer

A new three-in-one blood test that analyzes cancer DNA in the bloodstream before and during treatment will allow providers to understand and track which patients are likely to benefit from treatment with olaparib, a PARP inhibitor. Additionally, researchers found which genetic mutations prostate cancers use to resist treatment with olaparib. The study was published in Cancer Discovery (http://cancerdiscovery.aacrjournals.org/content/early/2017/06/16/2159-8290.CD-17-0261).

The researchers used blood samples from 49 men with advanced prostate cancer. They found that patients who responded to olaparib had a 49.6% median drop in circulating DNA levels after only eight weeks of treatment, compared to an increase of 2.1% for men who did not respond to treatment. Men whose circulating DNA levels decreased at eight weeks also survived an average of 17 months, compared to 10.1 months for men whose circulating DNA remained high.

The researchers believe that tests like this one will “usher in a new era of precision medicine for prostate cancer.” However, they caution that more needs to be understood before the tests can move to widespread use.