Because the biology of each patient’s tumor can be understood with genomic testing, the job description for doctors who treat breast cancer is now a little longer than it used to be. And that’s a good thing – for doctors and their patients, says Beth DuPree, M.D., a board-certified general surgeon who specializes in diseases of the breast.
Genomic testing has made it possible for Dr. DuPree and other breast cancer specialists to offer better, more individualized care, because of the sophisticated analysis the tests provide of each patient’s illness.
Before genomic testing, most patients got the same aggressive – and often destructive – chemotherapy treatment. That’s because physicians never knew if they were facing the worst-case scenario: a tumor “determined” to recur and kill.
We interviewed Dr. DuPree to tell us more about how this technology has changed her practice. Dr. DuPree is Medical Director of The Holy Redeemer Breast Health Program, in Southampton, Penn. and Adjunct Assistant professor of Surgery at The University of Pennsylvania.
Dr. DuPree, what information do you get from genomic testing of tumors that you weren’t able to get previously?
Genomic testing tells me how a tumor is genetically programmed to behave. That in turn allows me to tailor each patient’s treatment to the tumor biology. For instance, some tumors are small but aggressive. By aggressive, I mean “more likely to recur.” To stop them, we have to meet their aggression with aggressive treatment such as chemotherapy.
On the other hand, some tumors – even some large ones — are “lazy.” That is, they are very unlikely to come back once they’re removed. Since the point of chemotherapy is to stop tumors from recurring, we can often spare patients with these “lazy” tumors the toxic side effects of chemotherapy. They can do very well with hormonal (anti-estrogen) therapy alone.
Before genomic testing came along, we weren’t able to determine a tumor’s genetically programmed behavior in this way. So we tended to recommend chemotherapy based on stage and grade of the tumor. Therefore many patients received chemotherapy just to be on the safe side.
We’ve now entered a new era for breast cancer treatment — an era of personalized medicine, instead of one-size-fits-all.
The most advanced form of genomic testing is called the Symphony panel of tests. It consists of three different tests called MammaPrint, BluePrint, and TargetPrint. How do you choose which one to use with your patients?
I find MammaPrint to be the most widely applicable test – the one I’ll use first with most of my patients. MammaPrint provides information as to whether a breast cancer is likely to come back. Learning which tumors have a high risk or low risk of recurrence is key to individualizing their treatment. It’s vital information when deciding whether or not to treat with chemotherapy. But testing is always based on the patient’s needs.
MammaPrint, BluePrint, and TargetPrint all yield essential information about the genomic profile of a tumor that can be important in personalizing breast cancer therapy.
Does genomic testing always make clear which action to take with regards to chemotherapy?
Not all tests are created equal. With MammaPrint it’s simple: The risk is high or low. With an earlier genomic test, more than one-third of its results fall into what it calls “the intermediate zone.” That means no clear recommendation can be made about whether chemotherapy would be helpful or not, for those one-third of individuals that receive that result.
Symphony is based on research with far more genes than the earlier test, so its results are more clear-cut. If the test shows you are low risk for recurrence, my oncologists and I can safely recommend avoiding chemotherapy. If you are shown to be at high risk, chemotherapy is recommended. It’s that simple.
Does genomic testing change anything about the type of surgery a patient should have?
No. Surgical management is not changed at all because no one dies of breast cancer in his or her breast. Women and men die of breast cancer that spreads beyond the breast. We do genomic testing to determine what the best, and most personalized, systemic treatment option would be after surgery.
Why is there so much emphasis now on avoiding chemotherapy? Isn’t it better to be safe than sorry?
Genomic testing has actually made the better-safe-than-sorry idea obsolete. Chemotherapy, although lifesaving in many instances, is very toxic to the body and has many side effects. Some patients will only suffer side effects that are temporary and uncomfortable. Hair loss will only change their appearance for a short time. But others may suffer damage that is very serious and long lasting.
Do all physicians who treat breast cancer patients offer genomic testing?
We’re not at that point yet, frankly. As with any technology, there are those who accept the latest science and those who are resistant to change. It took years for surgeons to stop doing Halstead radical, disfiguring mastectomies – even after the science showed that women don’t die of the cancer in their breast but instead from the tumor spreading to the other parts of the body.
We now know from science that the biological genetic make-up of the tumor dictates its behavior. No matter how good I am as a surgeon, I can’t trump biology with my scalpel. The next step is for all of us involved in the care of women and men with breast cancer to catch up to the technology of tumor biology. In other words, we need to treat the whole patient — and that includes providing genomic testing for our patients so we can determine how their tumor is behaving and tailor our care accordingly.
Any final thoughts about this topic?
Knowledge is power. The smarter we become at personalizing our patient’s care, the better we become at treating the whole patient. If we can eliminate chemotherapy for a particular patient and she has the same outcome, then we are champions for her cause. If we give chemotherapy and it is not going to benefit her — then shame on us for not using the technology that has been given to us. Breast cancer treatment has changed drastically in the last 20 years. The disease hasn’t changed, but our understanding of it has.