10/17/2024
In my practice, I like to get a state-of-the-art blood test for my patients with high-risk cancers to see if they have still have cancer cells in their body after treatment. While imaging studies (such as PET CT, CT, MRI, mammograms) are very useful, they may miss picking up very small tumors. These blood tests can often detect tumors even before they are found on imaging, which can prompt us to follow our patients even more carefully and frequently so that we can start treating them ASAP. We know that the sooner we start treating a recurrence, the better the chances are of another remission.
Here’s an example of one of my patients that I followed with the Signatera circulating tumor DNA 🧬 blood test. She had a triple negative breast cancer and underwent treatment with surgery, chemotherapy and radiation therapy. Unfortunately, after treatment, her Signatera test results kept going up. This prompted me to get a PET CT scan which found metastatic cancer in her liver and bones. Had we not been prompted to get the PET CT by her rising Signatera, we would not have been able to start her on treatment as quickly as we did. As you can see in the lab graph, her Signatera test went down right away, indicating a positive treatment result.
It’s important to note, that some patients will have a false positive or a false negative result which is why we don’t rely on just one test. I’ll often look for a trend over time to help me make a better decision on when to order imaging. Additionally, while a positive result may mean cancer has come back, we need to confirm that with a finding of recurrence on a scan before we can start treatment.
Read my published paper on this: https://www.sciencedirect.com/science/article/pii/S2666621924000188
