Supporting Patients Through New Breast Cancer Treatments

While breast cancer treatment has evolved to address newer subtypes and biomarkers associated with the disease, oncology nurses and advanced practice providers (APPs) should rely on their knowledge of how to counsel patients on familiar adverse effects (AEs) and treatment expectations, explained a nurse practitioner.

According to Andy Guinigundo, MSN, RN, CNP, ANP-BC, treatment in breast cancer is moving towards accommodating lower amounts of biomarkers, such as HER2-low disease, by adding smaller amounts of treatments to a patient’s therapy regimen.

Additionally, antiestrogen treatments for ER- and PR-positive breast cancer can cause the resistance mutation ESR1, explained Guinigundo. In these situations, estrogen blockers become less effective for patients, and treatments plans must be adjusted.

In spite of these changes, Guinigundo noted that oncology nurses and APPs can provide reassurance and a better experience on treatment by applying their knowledge of common issues to these new treatment regimens. Guinigundo gave the example that stomatitis as an AE of a PI3K-targeted therapy looks the same as stomatitis as an AE of chemotherapy.

Guinigundo is the director of precision oncology at Cincinnati Cancer Advisors and the vice president of the Advanced Practitioner Society for Hematology and Oncology.

Transcript

Some of the biomarkers we should be paying attention to are obviously the traditional ones—ER, PR, HER2—and we know that HER2, which has been around since the late ’90s, has had some recent movement in that treatment of those patients.

We’re using some drugs in very low amounts of HER2 positivity. So where you’re just looking for amplified [biomarkers], now you’re like, “Oh, if you got a little tiny bit of HER2 in there, we can use certain drugs.” You’ve got to keep your eyes open for something…like that that’s been around for a long time.

I mentioned ER, PR—after you’ve been on those antiestrogen therapies, now you can develop, actually, a resistance mutation called ESR1. So [for] ESR1, there’s 1 drug approved. There are many knocking on the door ready to be approved, perhaps, that can treat those patients better.

Our traditional estrogen blockers—aromatase inhibitors, tamoxifen—they’ve stopped working for those patients. So these are the next steps on those.

PI3KCA is a good example of a biomarker to keep an eye out [for]. We have a few agents on that as well. They can be toxic, and that’s where, from a nursing standpoint…we shine, right? So in terms of troubleshooting, supportive care, that’s where a nurse can shine. And certainly teaching, “Hey, look out for this, look out for that. Look out for the hyperglycemia. Look out for stomatitis.”

Things that we can kind of take from our old chemotherapy teaching and now apply to, “Okay, we’re having stomatitis. Stomatitis is still stomatitis, even though it’s caused by this different agent.” We still know how to treat that. We should use that knowledge.

BRCA1 and BRCA2: so in breast cancer, we’re actually looking for what we call germline BRCA1 and BRCA2, and those can lead us to using PARP inhibitors. PARP inhibitors are now approved for earlier stage breast cancer as well as later stage breast cancer, so it’s not just confined to advanced disease. We can actually use [these agents in] earlier stage disease.

In pancreas, in ovarian, they can actually use tumor DNA. So when you look at the tumor, if the tumor has a BRCA mutation, you can use these drugs. With breast cancer, it’s only the germline [mutations]. So it’s a little important distinction there, but those are the most important biomarkers in breast cancer right now.

This transcript has been edited for clarity and conciseness.