A blood DNA test that can detect whether a tumor has returned or is responding to therapy has been developed by American scientists, in an advance that could revolutionize cancer care.

The achievement promises to transform management of cancer by allowing doctors to monitor the progress of patients with any type of tumor and to adjust their treatment accordingly.

The test, which should be widely available within five years, should spare some patients chemotherapy and radiotherapy that they do not need, while ensuring that others get potentially life-saving extra treatment when the initial course does not kill all the cancer.

It should be capable of detecting even microscopic residual tumors that are missed by imaging methods such as computed tomography (CT) scans.

A further benefit could be less radical surgery, as the test could check whether cancer has spread to lymph nodes or apparently healthy tissue around a tumor, which could be left in place if not diseased. The test could also identify when a treatment is not working.

Continue reading at the Times of London