A blood test that detects tumor DNA in patients with early-stage breast cancer may predict a woman’s risk of relapse months before conventional methods. The results are published in Science Translational Medicine.
Breast cancer is a formidable foe for researchers, doctors and patients alike. To date, it is one of the leading causes of cancer death among women. For those fortunate enough to go into remission, the risk of relapse looms as a dangerous possibility. The earlier treatment can begin, the higher the rate of success a patient has. Now, a blood test may help increase those odds.
“We have shown how a simple blood test has the potential to accurately predict which patients will relapse from breast cancer, much earlier than we can currently,” said lead author Dr Nicholas Turner from the Institute of Cancer Research (ICR), London, in a statement.
For the study, researchers took tumor and blood samples from 55 early-stage breast cancer patients who had undergone both chemotherapy and surgery. The tests were personalized to the mutations found in the patient’s tumor. This way, the researchers could implement a technique called “mutation tracking” to uncover DNA shed by a woman's tumor into her bloodstream.
Blood tests were repeated every six months for two years. Over the course of those years, 15 women relapsed. Of those, the blood test predicted the return in 12 of them. The sensitivity of its detection is nothing to scoff at: The test signaled the cancer’s return eight months before it was visible on conventional imaging.
The findings may one day lead to therapy tailored to individual patients, according to the study. However, that day is not yet near, as researchers still need to perform many more tests and trials. For one, the size of this latest trial was small. Second, the study took blood samples for only two years – the researchers therefore don’t know the predictive value of the test after that period of time has passed.
Still, as Paul Workman, chief executive of ICR, said: "Studies like this also give us a better understanding of how cancer changes to evade treatments – knowledge we can use when we are designing the new cancer drugs of the future."