Tailored Treatment for Breast Cancer

Genomic testing can play an important role in breast cancer decisionmaking.

Personalized therapy in breast cancer has advanced over the years, and the Breast Cancer Index test has aided patients in the decision-making process.

As part of the Speaking Out video series, CURE spoke with Marla Sustin, a nurse practitioner at University Hospitals Seidman Cancer Center in Cleveland, about the role of genomic testing and its effect on the decision-making process for personalized therapy in breast cancer care. For example, a practitioner can use the Breast Cancer Index, which is a genomic test to determine a patient’s risk for recurrence between five and 10 years after diagnosis and whether they would benefit from extended hormonal therapy.

Q: How does genomic testing determine the best treatment for patients?

A: It has a great influence in that when you’re looking into genomic testing, you can really identify a certain treatment that would benefit (patients with) that particular type of cancer. ... And it is different for everyone. Genomic testing ... also plays a part in endocrine therapy (decisions) — who would benefit the most and (for) how long. ... Research has shown targeting a specific gene mutation or protein can really decrease (a patient’s) risk of recurrence and death from breast cancer. For example, Herceptin (trastuzumab) was one of the first targeted therapies (approved by the Food and Drug Administration), and we know the success (it) has had over the past 30 to 40 years.

Q: How does the Breast Cancer Index play a role?

A: We have patients who are estrogen- and/or progesterone-positive and are put on anti-estrogen medication, whether it be tamoxifen or one of the aromatase inhibitors. When I first started almost 20 years ago, five years (of treatment with aromatase inhibitors) was it; there was nothing else and you would come off (the drug). Then studies (started to show that) 10 years (of treatment could be) more beneficial. But now we know that’s not for everybody.

And with genomic testing, particularly with the Breast Cancer Index test, it will tell us if a (patient) will benefit with extended therapy, or (benefit with just) five years (of it). And then it will also tell us what (the patient’s) risk of recurrence is. And these drugs can be a little harsh with side effects. So it’s very helpful.

Q: Can you elaborate on how the length of treatment is tailored for patients based on the Breast Cancer Index?

Not one size fits all. We have patients who do very well on medication, and they’re happy either way with five versus 10 years (of treatment). And there are some patients who really have a hard time with it. Some people simply just don’t want to be on medication if they don’t have to be. So with the Breast Cancer Index test, it offers (patients) more information so they can take control of that decision-making.

For example, (a patient underwent) Breast Cancer Index testing, and her results showed only a 4% risk of recurrence; (but it also showed) that she would benefit from extended therapy. The discussion to have is ... (if they would prefer) to continue on (extended therapy for) another five years to bring that down to about 1.5% to 2%. So there’s a lot of joint decision-making.

Q: How does quality of life play a role in shared decision-making?

The medications that are prescribed — the aromatase inhibitors or tamoxifen — work in different ways. ... These medications come with a lot of side effects, and some of them are intolerable. ... So (treatment) does have an effect on everyday life.

Q: How can patients use the Breast Cancer Index in their decision-making process?

I have had patients over the past year or so start asking for (the test). ... It’s going to tell (a patient if they) need to stay on (endocrine therapy) for five years or for 10. They use it as a decision-making tool along with their provider (based on) what their risk (for recurrence) is. ... So they look at (the Breast Cancer Index score) as another tool to help them steer their treatment.

Q: How can patients learn more about their treatment options?

Ask questions and read from reliable sources. ... Ask those questions: Is it for you? Is it something that you would even qualify for? Is it beneficial? Always go to reliable sites, and you can get all your information there and then formulate questions or concerns that you can discuss with your provider.

Transcription edited for clarity and conciseness.

For more news on cancer updates, research and education, don’t forget to subscribe to CURE®’s newsletters here.