What are the medications used to treat breast cancer?

From the Guidelines

Breast cancer treatment involves a range of medications, including hormone therapies like tamoxifen or aromatase inhibitors, targeted therapies such as trastuzumab, and chemotherapy regimens combining drugs like doxorubicin, cyclophosphamide, paclitaxel, or docetaxel, with treatment selection depending on cancer subtype, stage, genetic factors, and patient characteristics, as outlined in the most recent guidelines 1.

Medication Types

• Hormone therapy: tamoxifen (20mg daily for 5-10 years) or aromatase inhibitors such as anastrozole (1mg daily) for hormone receptor-positive cancers
• Targeted therapies: trastuzumab (Herceptin) for HER2-positive cancers, typically given every three weeks for a year
• Chemotherapy regimens: combining drugs like doxorubicin, cyclophosphamide, paclitaxel, or docetaxel in specific sequences over 3-6 months
• CDK4/6 inhibitors: palbociclib, ribociclib, or abemaciclib for metastatic hormone-positive breast cancer
• PARP inhibitors: olaparib for patients with BRCA mutations

Treatment Considerations

• Cancer subtype and stage
• Genetic factors, such as PIK3CA mutations or BRCA mutations
• Patient characteristics, including menopausal status and performance status
• Potential side effects and interactions with other medications

Recent Guidelines

The most recent guidelines from 2020 1 provide recommendations for second-line treatment, including the use of fulvestrant with a CDK 4/6 inhibitor, or for those with tumor PIK3CA mutations, fulvestrant with alpelisib, everolimus with either an AI, tamoxifen, or fulvestrant.

Key Points

• Treatment selection should be personalized based on individual patient factors
• Medications work by different mechanisms, including blocking estrogen effects, attacking specific cancer proteins, and killing rapidly dividing cells
• Side effects vary by medication class, and treatment is typically managed by oncologists who develop personalized regimens based on individual patient factors, as supported by previous studies 1

From the FDA Drug Label

Lapatinib tablets are a prescription medicine used: with the medicine capecitabine to treat people with breast cancer that is advanced or that has spread to other parts of the body (metastatic), and: that is HER2-positive (tumors that produce large amounts of a protein called human epidermal growth factor receptor-2), and who have already had certain other breast cancer treatments with the medicine letrozole to treat women who: have gone through the change of life (postmenopausal), and who have metastatic breast cancer that is hormone receptor-positive, HER2-positive, and hormonal therapy is a treatment option for them

Ogivri is indicated in adults for adjuvant treatment of HER2 overexpressing node positive or node negative (ER/PR negative or with one high risk feature [see Clinical Studies (14. 1)]) breast cancer as part of a treatment regimen consisting of doxorubicin, cyclophosphamide, and either paclitaxel or docetaxel Ogivri is indicated in adults: In combination with paclitaxel for first-line treatment of HER2-overexpressing metastatic breast cancer As a single agent for treatment of HER2-overexpressing breast cancer in patients who have received one or more chemotherapy regimens for metastatic disease

The medications used to treat breast cancer include:

• Lapatinib in combination with capecitabine for advanced or metastatic HER2-positive breast cancer
• Lapatinib in combination with letrozole for postmenopausal women with metastatic hormone receptor-positive, HER2-positive breast cancer
• Trastuzumab in combination with paclitaxel for first-line treatment of HER2-overexpressing metastatic breast cancer
• Trastuzumab as a single agent for treatment of HER2-overexpressing breast cancer in patients who have received one or more chemotherapy regimens for metastatic disease
• Trastuzumab in combination with doxorubicin, cyclophosphamide, and either paclitaxel or docetaxel for adjuvant treatment of HER2 overexpressing node positive or node negative breast cancer 2, 3, 3

From the Research

Medications Used to Treat Breast Cancer

• Hormonal therapy is typically the first-line treatment of choice for women with hormone receptor-positive disease, given the overall efficacy and favorable safety profiles of these agents 4
• Medications used in hormonal therapy include:
  • Tamoxifen
  • Aromatase inhibitors such as anastrozole, letrozole, and exemestane 5, 6, 7, 8
  • Fulvestrant 5
• Targeted therapy may also be used, including:
  • CDK4/6 inhibitors 5
  • mTOR inhibitors 5
  • PI3K inhibitors 5
• Chemotherapy may be used in addition to hormonal and targeted therapy 4

Treatment Sequencing

• The optimal treatment sequence for hormone-receptor-positive, HER2-negative advanced breast cancer has not been established 5
• A reasonable approach may be to start with tamoxifen, aromatase inhibitors, or fulvestrant in the absence of visceral crisis, and to ensure adequate ovarian function suppression in pre/peri-menopausal women 5
• Resistance to hormonal therapy is a significant challenge, and multiple modalities are being explored to overcome this resistance, including the use of CDK4/6 inhibitors, mTOR inhibitors, and PI3K inhibitors 5