Jenny C. Chang, MD
The challenge of giving patients more or less treatment for their breast cancer, regardless of their subtype, is a question researchers are actively investigating with the use of molecular testing, according to Jenny C. Chang, MD.
State of the Science Summit on Metastatic Breast Cancer.
OncLive: Could you provide an overview of your presentation?
: Breast cancer management is obviously complex and has become increasingly difficult because of the increasing number of tests that we can order, which provide aid in our management of breast cancer. Basically, we still have 3 major subtypes: HR-positive, HER2-positive, and triple-negative breast cancer (TNBC). In each of these subtypes, we can sub-categorize.
We will get a better understanding, rather than test everybody that comes through with full genomic sequencing and circulating tumor cells (CTCs). I am asking whether we can be a little more thoughtful about the tests we order, especially in this era of limiting healthcare costs.
Let’s reflect on the updated ASCO guidelines on tests such as Oncotype DX and MammaPrint. How would you say this helps physicians make better treatment decisions going forward, and do you think those guidelines need to be adjusted again in the near future?
These tests focus on patients for whom [we have trouble] determining whether or not they will benefit from chemotherapy. These tests have been around—I shudder to think—for more than a decade now, but they are still very valuable in determining whether or not a woman may be spared chemotherapy.
In traditional guidelines, we would consider chemotherapy after a certain tumor size—whether the nodes are involved—but these things do not address the biology of the tumor. These tests, like MammaPrint, which is a 70-gene test, and Oncotype
DX, which is a 21-gene test, have been around for a very long time and have been validated in multiple studies. I believe all oncologists use these tests to guide or aid their decision making.
What do you hope community oncologists take away from your talk and can apply to clinical practice?
It is an evolving field. Genomic testing is exciting; it is new, and there are new ways in which we can look at things. We can give a painless blood test and find out CTCs, cell-free DNA, and mutations that are circulating. Studies still need to be done to validate if these mutations, and blocking these mutations, actually translates into clinical benefit. Those studies are being done, but are not yet available.
Also, in the context of a clinical trial, I would be judicious in who I would choose if there are available targets. Overall, it is definitely an exciting time; we know so much more about the biology of cancer. We are moving away from anatomical descriptors to what is actually driving the cancers.
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