Researchers at the Institute of Cancer Research and clinicians at the Royal Marsden Hospital in London have developed a simple three-in-one blood test that could transform treatment of advanced prostate and other cancers. The test pinpoints those men who will respond to treatment with the PARP inhibitor Olaparib. This orally taken drug marketed by AstraZeneca is a targeted therapy for BRCA-related breast, ovarian and prostate cancers that have shown resistance to other treatments such as chemotherapy. The drug was discovered in UK and approved for use in Europe and USA, but only licenced for use by the NHS under certain conditions because of its cost.
Prof Johann de Bono, Regius professor of cancer research at the ICR, and consultant medical oncologist at the Royal Marsden, said: “Our study identifies, for the first time, genetic changes that allow prostate cancer cells to become resistant to the precision medicine olaparib.
“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. 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.
“Not only could the test have a major impact on treatment of prostate cancer, but it could also be adapted to open up the possibility of precision medicine to patients with other types of cancer as well.”
The new test enables clinicians to pinpoint those men who are likely to benefit from olaparib treatment for advanced prostate cancer. It can also analyse DNA in the blood after treatment commencement, determining at an early stage whether treatment is working, and monitor whether the cancer is evolving genetically and might be becoming resistant to the drug.
Olaparib kills cancer cells that have genetic errors, which would otherwise keep them healthy. While many patients respond to the drug, others fail to respond at an early stage or the cancer evolves resistance.
The test could “usher in a new era of precision medicine for prostate cancer” said Prof Paul Workman, CEO of ICR. “Blood tests for cancer promise to be truly revolutionary. They are cheap and simple to use, but most importantly, because they aren’t invasive, they can be employed or applied to routinely monitor patients to spot early if treatment is failing – offering patients the best chance of surviving their disease.”