Evaluating Options for Second-Line HR+, HER2- Breast Cancer Treatment
Katherine Cohen, MSN, FNP-C, provided insights on what to consider when treating patients with HR+, HER2- breast cancer in the second line of treatment.
In a Case-Based Roundtable™ discussion, Katherine Cohen, MSN, FNP-C, discussed evolving second-line treatment options for patients with hormone receptor (HR)-positive, HER2-negative metastatic breast cancer, including CDK4/6 inhibitors.
Among topics of discussion were ESR1 mutations and next-generation sequencing (NGS) testing for such mutations. As Cohen emphasized in an interview with Oncology Nursing News®, liquid biopsies and tissue biopsies can be more appropriate in different cases.
While some mutations are better detected using solid tumor tissue, others are more visible using blood in liquid biopsies. Additionally, Cohen pointed out that using circulating tumor DNA (ctDNA) can aid in assessing a patient’s progression and what treatments best target their particular disease.
Depending on a patient’s mutation status and disease progression, treatment options could include CDK4/6 inhibitors with an aromatase inhibitor or with an endocrine therapy, oral selective estrogen receptor degraders, or antibody drug conjugates (ADCs).
Transcript
The key takeaways are that when you are deciding what therapies to choose moving forward, you should A: be following the [National Comprehensive Cancer Network] guidelines, but B: really exhausting those hormone-sensitive therapies first.
So you do first-line [CDK4/6 inhibitors] with your endocrine targeting therapy, and then you move into the space where perhaps you’re looking for more targeted therapies. And in order to utilize those more targeted therapies, you have to do ctDNA testing. You have to look for potential mutations in that cancer cell in order to target those.
You can do that using tissue, or you can use that doing blood, and ideally you’re doing both, because some mutations are better picked up on using archival tissue or using solid tumor tissue testing, and some, like the ESR1 mutation, are actually better picked up using a liquid biopsy. Archival tissue is actually something you should avoid using. Even if you have a fresh tissue biopsy specimen, it’s still more sensitive to liquid biopsy.
So I think that that’s the key takeaway, is utilizing your NGS testing, utilizing your ctDNA testing, really exhausting your endocrine targeting therapies first, and always keeping an eye out for the patient that has developed endocrine resistance, and then at that time, either transitioning to a targeted agent or an ADC or chemotherapy.
Nurse Practitioners Weigh in on Data From the San Antonio Breast Cancer Symposium
January 16th 2023Loyda Braithwaite, MSN, RN, AGPCNP-BC, AOCNP; and Jamie Carroll, APRN, CNP, MSN, highlight presentations from the 2022 San Antonio Breast Cancer Symposium that will influence oncology nursing practice.
