New blood test can detect genes that drive cancer and help to determine best treatment

Researchers have developed a new blood test that they say could be used to identify women whose breast cancer was being driven by the HER2 gene and who could benefit from treatment with trastuzumab (Herceptin) and similar drugs. They believe that the test could be adapted to a range of other cancers and drug targets.

At the moment women whose breast cancer relapses after initial treatment need to have a biopsy to determine which treatments the cancer is most likely to respond to. But cancers can acquire and lose genes over time, and …