What is Cell-Free DNA?

A cancer diagnosis is overwhelming and once it happens, it can feel like you will be struck by lightening again. Fear of recurrence even when fully treated and you are told you are cancer free or NED (no evidence of disease), there is often a persistent, nagging fear.

The most common ways to be monitored include blood tests for it or markers or to follow specific blood counts and imaging such as PET scans, CT scans and MRI’s, mammograms and ultrasounds. Scan or test anxiety is real. The anticipation of a test and the wait for results can be overwhelming. You are feeling fine, but maybe you were feeling fine when you were diagnosed too. It was just a routine test after all. And if the scan shows something, what does it mean? Is it too late? Does it mean the cancer spread?
Why can’t we pick up a recorded e before ot shows up on a scan?

Cell-free DNA may be an answer for earlier identification in some cancers. It requires that the tumor be tested at the time of biopsy or surgery and the tumors DNA then identified. The lab then creates a personalized tumor identification-your personal tumor for future testing. Thereafter, during treatment or beyond, a simple blood test can look for that tumor’s specific DNA in your blood. The premise is that it would be in the blood before it settled somewhere else where a scan would pick it up.

While it sounds like a perfect solution to earlier detection of recurrence, researchers are still evaluating its significance. If it is in the blood, should we treat at that point? Is it possible that it would never progress and that the body would eliminate it on its own? Does it make a difference to long term survival or is it just creating anxiety earlier and would not make a difference.

Some would argue that if it is there, just treat. Why take chances? The reason is that treatment can be toxic. There are side effects that cannot be underestimated. In addition, should we be using treatments in our armamentarium now? What if you need them later, but already used them and maxed out on total dose such as with radiation? Or now the tumor has resistance to that medication.

Cell-free DNA has a lot of potential and has been used in some cancers. There remain questions that should be answered through ongoing studies results of which should be available soon. It is worth discussing this option for follow up with your doctor.