Patients with HER2-positive metastatic breast cancer have historically faced aggressive incurable disease. Over the years, more targeted therapies based on biomarker testing have been relatively successful in extending survival for patients but often with potential adverse effects on quality of life and toxicities.

An oral presentation at the 2023 ONA Summit Live Virtual Meeting presented a review of guideline recommendations for biomarker testing and systemic staging in assessment of patients with HER2-positive metastatic breast cancer, compared treatment options, and reviewed the application of collaborative strategies in the management of treatment- and disease-related side effects associated with metastatic HER2-positive breast cancer.1

Recent data from DESTINY-Breast03 and DESTINY-Breast04 have led to approvals and guideline changes for the use of trastuzumab deruxtecan (T-DXd) for second- or third-line treatment of patients with HER2-positive metastatic breast cancer and also for patients with “HER2-low” breast cancer.2,3 HER2-low cancers previously were treated as triple negative cancers, but advances in targeted therapy with T-DXd have led to the ability to treat HER2 receptors in cancers previously thought to be unresponsive for HER2 therapies. This is an exciting development for metastatic breast cancer treatments.

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Other recent studies are showing increased activity in central nervous system (CNS) metastatic sites with systemic therapies, especially tyrosine kinase inhibitors such as tucatinib.4,5 For some patients, this can reduce toxicities of local CNS treatments and can allow a more robust response with systemic therapy on their CNS metastatic disease.

These recent changes in HER-2-directed therapies will hopefully lead to improved outcomes and survival, but the multidisciplinary team will continue to need to focus even more on appropriate diagnosis and interpretation of HER2 status in metastatic breast cancer. The multidisciplinary team is crucial to setting up the appropriate treatment plan and in a timely manner for best outcomes.

Nurses are strong assets in this process and also to help ensure all patients are closely monitored for any potential adverse effects or progression of disease. Disparities in care can have negative impacts on patient response to therapy, and the team must be mindful of how these can negatively influence outcomes when selecting treatment plans and monitoring patients. Nurses are leaders in care collaboration within the oncology team and can play a vital role in outcomes for these patients.

Noele Myers is a medical oncology nurse practitioner at Fox Chase Cancer Center in Philadephia, Pennsylvania.


  1. Myers N. The highs and lows of metastatic HER2-positive breast cancer and the new treatment landscape. Oral presentation at: 2023 ONA Summit Live Virtual Meeting; March 17-19, 2023.
  2. American Society of Clinical Oncology (ASCO). Novel antibody-drug conjugate doubles progression-free survival in metastatic breast cancer with low HER2 expression levels [news release]. Published June 5, 2022. Accessed March 12, 2023.
  3. NCCN Clinical Practice Guidelines in Oncology (NCCN Guidelines®). Central Nervous System Cancers. Version 2.2022 — September 29, 2022. Accessed March 12, 2023.
  4. Bartsch R, Berghoff AS, Preusser M. Breast cancer brain metastases responding to primary systemic therapy with T-DM1. J Neurooncol. 2014;116(1):205-206. doi:10.1007/s11060-013-1257-5
  5. Ramakrishna N, Anders CK, Lin NU, et al. Management of advanced human epidermal growth factor receptor 2-positive breast cancer and brain metastases: ASCO Guideline update. J Clin Oncol. 2022;40(23):2636-2655. doi:10.1200/JCO.22.00520