Discover treatment options for ER-positive, HER2-negative metastatic breast cancer, including endocrine therapy and targeted drugs for better disease management.

Metastatic breast cancer occurs when cancer spreads beyond the breast to other organs. ER-positive, HER2-negative breast cancer is a common subtype, meaning the cancer cells rely on estrogen to grow but lack excessive HER2 protein. While metastatic breast cancer remains incurable, personalized treatment strategies have significantly improved long-term outcomes.

How Endocrine Therapy Helps
Since ER-positive cancer depends on estrogen, endocrine therapy works by either reducing estrogen levels or blocking its effect on cancer cells, slowing disease progression.

Types of Endocrine Therapy

1. Selective Estrogen Receptor Modulators (SERMs)

   • Tamoxifen blocks estrogen receptors, preventing tumor stimulation.
   • Commonly prescribed for premenopausal women.

2. Aromatase Inhibitors (AIs)

   • Reduce estrogen levels in postmenopausal women by inhibiting conversion of androgens.
   • Examples: Letrozole, Anastrozole, Exemestane.

3. Selective Estrogen Receptor Degraders (SERDs)

   • Fulvestrant eliminates estrogen receptors on cancer cells.
   • Used when resistance to other therapies develops.

CDK4/6 Inhibitors – A Game-Changer
CDK4/6 inhibitors have transformed treatment by blocking proteins that drive cancer cell division. These drugs, including Palbociclib, Ribociclib, and Abemaciclib, enhance the effects of hormone therapy and significantly extend progression-free survival.

Combination Therapy for Better Outcomes

• PI3K Inhibitors – Alpelisib targets PIK3CA-mutated cancers, requiring genetic testing for eligibility.
• mTOR Inhibitors – Everolimus helps overcome resistance when standard endocrine therapy stops working.

When Endocrine Therapy Stops Working
Cancer may eventually resist endocrine therapy. When this happens, treatment strategies include switching therapies, adding targeted drugs, or transitioning to chemotherapy. Regular monitoring helps tailor the best approach.

Conclusion
Advancements in endocrine therapy and targeted treatments offer hope for patients with ER-positive, HER2-negative metastatic breast cancer. By combining therapies and adapting treatments, many patients manage their disease effectively, maintaining a high quality of life. If you or a loved one is affected, consult an oncologist to explore the best treatment options available.