Mark Burkard, MD, PhD
Physicians must continue to explore breast cancer tissue to understand the differences among individual tumors, in an effort to predict disease outcomes and eventually develop treatments targeted at less-common subtypes, according to Mark Burkard, MD, PhD.
Currently, an ongoing clinical trial is actively recruiting to obtain 1100 DNA samples to undergo genomic testing for primary breast cancer (NCT01334021). The observational, prospective study will help determine whether researchers can use genetic testing on tumor samples to predict response to select treatments. The researchers also hope to establish whether certain genes become activated that will then make the tumors sensitive or resistant to chemotherapy or hormonal therapy.
Burkard, an associate professor of medicine at the University of Wisconsin School of Medicine and Public Health, provided insight on the genetic landscape of breast cancer during the 2017 OncLive®
State of the Science Summit on Metastatic Breast Cancer.
“One of the biggest and most exciting points is that genomic analyses of cancers, which are available to every oncologist in the United States right now, can profoundly help some patients,” explained Burkard.
In an interview during the meeting, Burkard discussed the steps researchers are taking to address questions on genomics in breast cancer and what subtypes pose the greatest challenges.
OncLive: Please provide an overview of your lecture on genomic testing.
When I say, “genetics,” I mean all of the genes that make a cancer different than the rest of the person. The incredibly exciting but frustrating thing of what we have discovered in the last decade is that almost every cancer is a little bit different. If you are trying to find another patient like the 1 in front of you to help them and know what’s going on, you have to sometimes look at hundreds of patients with breast cancer—and that’s a problem we need to somehow solve in the future.
What steps are being taken to answer these questions?
There are many exciting steps toward that goal. One is just to characterize what the diversity of genomics in human breast cancer is. That has been fairly well addressed through the advances and technology that allowed it. If you keep in mind, 5 years ago, it took $100 million and 10 years to do this for 1 human to look at all of the genes. Now, it can be done for a little over $1000 in 1 week. We now are doing that almost routinely for many different cancers.
We are starting to understand that, but we are also starting to see the complications—one of which is the tremendous diversity between individuals. Another thing I talked about is the recent finding that there is a diversity and changes, or evolution, in the genetics within a person over time.
The research we are doing now [involves] characterizing what is going on, taking patient samples, and understanding the biology. There is a lot of research on what do we do with particular characteristics, and what drugs we have available for these patients that make sense given their genomic characteristics.
One thing I am a big proponent of, and is a call to arms, is we have to be able to share information about our patients. We have a large enough cohort of people for which we know what genes they have, what happened to those patients, what medicines work, and what didn’t work. This is so that when “Miss Jones” walks into the clinic 1 day and you have all of this genomic information, you say, “Aha! You have this rare subtype of cancer that only 0.2% of people have.” You can find those 0.2% of people and figure out what happened to them and use that information to help her. That is something we and other people are working on.
When is the best time for a patient to undergo genomic testing?
This is a little controversial right now. In lung cancer, it is becoming clear that it’s right away. In breast cancer, it has been less useful for individual patients, so there is some argument about that. When I would do it in my patients, or at least strongly think about it and discuss it with them, depends on the type of cancer they have. For the hormone-sensitive cancers, the best time is when the cancer becomes refractory to the antiestrogen therapies.
For the triple-negative breast cancers (TNBCs), these are cancers where the standard of care, right now, is just chemotherapy. Those are patients where you might swing for the fences right away and, if you’re lucky and hit a home run, you may come up with a drug that allows that patient to avoid chemotherapy, sometimes for a long time. Honestly, for most people, you’re not going to hit that home run.