Treatment options for breast cancer continue to rapidly evolve. A variety of types of treatment may be open to you, including:
When talking specifically about HR+/HER− breast cancer, endocrine therapy (including aromatase inhibitors, selective estrogen receptor degraders, and selective estrogen receptor modulators) has been the preferred frontline treatment approach for HR+/HER2− metastatic disease until patients developed endocrine resistance.1
Recently, there has been a push to use targeted therapy, including cyclin-dependent kinase 4/6 (CDK4/6) inhibitors such as palbociclib, ribociclib, and abemaciclib, in the management of this type of cancer. Below is additional information on these agents.
Therapy with aromatase inhibitors is 1 of the most common treatments for breast cancer and has been used as initial treatment for many years. For example, exemestane is a steroidal AI, and anastrozole (the most commonly used) and letrozole are nonsteroidal. This distinction is important when considering combination therapy.2 The CDK4/6 inhibitors abemaciclib, palbociclib, and ribociclib have all been approved in combination with aromatase inhibitors. These combinations have shown better response rates and progression-free survival for patients with HR+/HER2− metastatic breast cancer, compared with AI monotherapy.3
Tamoxifen is the most commonly used SERM. It has been a key treatment for patients with ER+ breast cancer for over 30 years.2 While other SERMs have been approved since, they are associated with significant adverse effects so tend not to be used. Tamoxifen can be used together with certain CDK4/6 inhibitors.4
Fulvestrant was the first SERD approved for the treatment of ER+ metastatic breast cancer. It showed a clinical benefit of 69% in patients who were resistant to tamoxifen.5 It is also approved for combination therapy with CDK4/6 inhibitors.
Elacestrant is another US Food and Drug Administration (FDA)-approved SERD that is now being assessed in combination with abemaciclib in patients with ER+/HER2− metastatic breast cancer.6 Preliminary findings show the efficacy is encouraging and the safety profile is manageable.
Imlunestrant, camizestrant, and giredestrant are 3 SERDs in development. All are being assessed in combination with other agents, such as CDK4/6 inhibitors.6-12
Ask your clinician if you have any questions about these treatments and how they may fit for your specific type of breast cancer.
