Educated Patient® Breast Cancer Summit at MBCC Management of Hormone Receptor-Positive Breast Cancer Presentation: March 4, 2023

Hormone receptor (HR)-positive breast cancer has become well managed with effective treatments such as anti-hormonal therapies in both early and late-stage disease. However, it is important for patients to stay adherent to their medication and follow-up visits, according to an expert.

Dr. William J. Gradishar, a professor of breast oncology at Northwestern University in Chicago, spoke more about the management of HR-positive breast cancer during CURE®’s Educated Patient® Breast Cancer Summit, held live and virtually at the Miami Breast Cancer Conference.

Gradishar explained that breast cancer is usually thought of as one disease, but in fact it is multiple diseases due to the different subtypes. And these breast cancers are categorized by each subtype to have a better understanding of the disease itself and what therapy can best treat it.

HR-positive is one of these subtypes and accounts for two-thirds of all breast cancer diagnoses.

“By doing that, by looking at the markers, we can define patients with hormone receptor-positive breast cancer who are likely to benefit from an anti-hormonal therapy,” he said in an interview with CURE®.

Anti-hormonal therapy are drugs that are used to block estrogen which can stimulate breast cancer cell growth, this is often used in patients with early-stage disease after surgery to reduce the risk of recurrence.

“And we know that that strategy is effective for at least 30 years,” he said. “Anti hormonal therapy is very effective. It's something that's used both for early and late-stage disease. And inevitably an advanced disease will go on to other therapies, but it maintains the quality of life for many patients for an extended period of time. So I think that's what makes it an attractive treatment strategy.”

In advanced disease stages it is as effective — maybe more so — as chemotherapy, with fewer side effects, Gradishar explained. It has also become “very effective” to combine these anti-hormonal therapies with other targeted therapies — but before that happens patients must progress on their first-line therapy, which is often endocrine therapy.

A vast majority of patients with HR-positive breast cancer that is advanced or metastatic will receive an endocrine therapy with or without a targeted agent, such as a CDK4/6 inhibitor, in the first-line setting. However, some do progress which is where the anti-hormonal therapy comes in.

“Many patients, the majority actually, have an extended benefit from that therapy, and in some cases can be measured in years before you have to change their therapy,” he noted. “And then as a general statement, patients with metastatic disease are not cured of their disease by any therapies that we currently have. So, the goal is to extend their survival and while treating them hopefully maintain their quality of life, so that they're able to go about their business.”

Gradishar noted that one of the biggest challenges when treating patients with early stage HR-positive breast cancer is making sure they understand the goal of therapy. Many patients often ask “How do you know it’s working?” to which he answers you don’t. This is because there is nothing to see shrink or disappear, they are treating a microscopic disease.

“One of the challenges of course, is to keep patients on (treatment), because, for anti-hormonal therapy in early stage disease, the duration of therapy is measured in years, usually a minimum of five years,” he said. “So, we have to constantly emphasize the importance of adhering and being compliant with therapy, and also pay attention to any of the side effects that a patient might be experiencing as a result of anti-hormone therapy.”

And it is similar for patients with metastatic or advanced disease. Additionally, the anti-hormonal therapy may be given in combination with another agent so it is important to monitor side effects, so the dosing can be modified to be better tolerated.

“In other words, if (patients are) adherent with it, they're going to reap the benefits. If they're not taking it, or taking it inappropriately, they're not going to reap the benefits,” he added. “So we have to emphasize the importance of those issues to patients and always be sensitive to any side effects they're having. So that we can try and adjust things to maintain their quality of life.”

For patients to do their part they should be communicating with their care team about side effects, stay adherent to their therapy and be compliant with follow-up visits, he said.

“I think it's important to have follow-up, whether you have early or late-stage disease and to be absolutely sure you're taking the medication the way it's supposed to be given,” Gradishar concluded. “And of course, if any symptoms develop, to make sure the health care provider knows about them, so it can be determined whether they're related to the therapy or is it something related to the disease itself.”

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