April 20, 2015 – Tumor and Normal
Anchor lead: Comparing tumor DNA to a person’s normal DNA may be critical, Elizabeth Tracey reports
Analyzing tumor DNA is becoming the norm in cancer treatment, but a study by Victor Velculescu and colleagues at Johns Hopkins shows that unless tumor mutations are compared to those seen in the same person’s non-cancerous tissues, mistakes in treatment decisions may result.
Velculescu: What we found out through this study is that many of the tests that are done today analyze only the tumor sample rather than matched normal tissue from the same patient, and when they do that these tests end up being inaccurate and provide information that may be misleading to the test requester and lead patients to inappropriate therapies. :21
Velculescu estimates that almost half of all cancer patients whose tumor DNA is analyzed but not compared to non-cancerous tissues may not receive optimal treatment, since we all have variations in our DNA that may have been there since birth and are unrelated to the cancer. At Johns Hopkins, I’m Elizabeth Tracey.