Wouldn’t it be nice to know what’s happening in the prostate, or in a metastatic tumor, without having to do a biopsy? It may be that everything doctors need to know is already in the bloodstream. Brady scientist Paula Hurley, Ph.D., and colleagues are working hard to learn how to decipher the clues: minuscule pieces of DNA, left behind in the blood by cancer cells.

How do bloodhounds follow a trail through the woods? Their noses are particularly good at picking up molecules of scent in the air. Something similar happens with cancer cells. “All cells, including cancer cells, shed tiny pieces of DNA in the blood,” explains Hurley. These small pieces of DNA, called cellfree DNA, can be traced and deciphered. One immediate benefit from this glimpse at a man’s cancer would be to guide his treatment – and avoid treatment that isn’t going to work. In advanced cancer, for example, mutations in the androgen receptor can tell doctors that a man may have developed resistance to the drugs abiraterone and enzalutamide, and that a different form of treatment might be more successful. Another benefit: “Compared to a traditional biopsy of the cancer, a ‘liquid biopsy’ that detects cancer-specific mutations in the blood is less invasive, easier to perform,” and much kinder to the patient for follow-up monitoring,” Hurley notes. “It is also much better at capturing differences in cancer cells between cancer sites.”

With support from the Patrick C. Walsh Prostate Cancer Research Fund and the Department of Defense, Hurley and colleagues are working on improving the sensitivity and specificity of detecting cancer-specific mutations in the blood. Their latest findings were published in Oncotarget.