HER2-Low Breast Cancer Case Presentation

Sayeh Lavasani, MD, MS, is a Medical Oncologist specializing in breast cancer at City of Hope Comprehensive Cancer Center, Duarte, California. Dr Lavasani discusses the revision and practical use of Pathways for the treatment of HER2-low breast cancer at her institution. 

How are clinical pathways developed and used at your cancer center?

Dr Lavasani: The cancer center that I currently work for [City of Hope] has many satellite clinics; in order to unify the practice of medical oncology, we have clinical pathways. We have monthly meetings with our pharmacists where we review all the treatment protocols to ensure that the clinical pathway recommendations are followed. We also do our best to keep the pathways updated with our clinical trials to make enrollment in studies easier.

Within the pathway for patients with HER2-low breast cancer, is there one pathway for HER2-low or do you further stratify patients from there?

Dr Lavasani: Due to the recent evidence per the Destiny-Breast04 clinical trial report that demonstrated improvement in disease-free and overall survival of patients who have low expression of HER2 with T-DXd (trastuzumab deruxtecan), T-DXd is integrated into clinical pathways for HER2-low metastatic breast cancer as a treatment option.

Can you talk a little bit about recent updates in the HER2-low treatment landscape?

Dr Lavasani: Yes. DESTINY-Breast04 was a randomized controlled trial of patients with metastatic breast cancer and HER2-low expression. Patients received either T-DXd or a physician’s choice of chemotherapy. Patients who received T-DXd had significant improvement in both disease-free survival and overall survival. The study was reported at the ASCO Annual Meeting in June 2022 and has improved our clinical practice.

New therapeutic approaches can be tricky to incorporate into the current pathway. What level of evidence is required for you to decide that the clinical pathway needs to be updated?

Dr Lavasani: The update in the clinical pathway is done by the breast cancer committee. We look at all the new evidence and recent study reports and publications. If a well-designed phase II or III study has shown benefit of a therapy that has been approved by the US Food and Drug Administration, we make sure the pathway is updated and recommend that particular treatment option to improve patients’ access to that therapy.

One of the challenges of using clinical pathways is the struggle between standardizing treatment decisions across the patient population and optimizing care for individual patients. How do you balance these priorities in a disease like HER2-low breast cancer?

Dr Lavasani: There are times that more than one treatment is available for a patient. For example, a HER2-low patient who is ER/PR negative can receive sacituzumab govitecan as a second-line therapy or T-DXd. The choice would be per the treating oncologist’s discretion to choose the right therapy for the patient.

What are some other challenges that you face in optimizing decision-making in your practice?

Dr Lavasani: Keeping up with the new emerging treatments makes treatment decisions more challenging, especially for community oncologists who treat multiple tumor types; they are the ones who would reap the most benefit from following clinical pathways.