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Risk Management & Treatment

Biomarkers, targeted and immunotherapies for breast cancer

This section covers the following topics:


testing for treatment selection

tests look at samples of blood, tumor or other tissue for changes or abnormalities caused by cancer. These tests can give doctors clues about the cancer, including:

  • how fast the cancer is growing
  • which treatments are most likely to work
  • whether or not the cancer is responding to treatment or growing
  • whether or not the cancer has come back after remission

tests may be used to select treatments, and help patients avoid side effects from treatments that will not work for them. tests used to select a specific treatment are sometimes called "companion diagnostic tests." These tests may be done on tumor tissue or (in many cases) on blood. See our Testing section for more information. 


ER, PR and

After breast cancer tissue is removed by surgery or biopsy, it is standard of care to test all breast cancers for three common biomarkers:

  • estrogen receptors (ER)
  • progesterone receptors (PR) 
  •  


Biomarkers for Advanced Breast Cancer

For people with advanced breast cancer, additional testing may be done to study the genes and proteins within the cancer to help doctors choose the best treatment. Some treatments will work best for people whose cancer cells have specific changes. These treatments are sometimes called targeted therapies. The  for a specific is sometimes called a . Some tests look for only one  at a time. Examples of single  tests for breast cancer include:

  • PIK3CA: Testing for this gene in advanced ER-positive, breast cancer can help identify people most likely to respond to the medication PIQRAY (alpelisib).  
  • PD-L1: Testing for the protein can help identify people with advanced () who are most likely to respond to the drugs Tecentriq (atezolizumab) and Keytruda (pembrolizumab).

Other tests may search for many biomarkers within the same test. Often these panel tests look for multiple markers, including FDA-approved treatments as well as those that have not yet been proven effective in breast cancer. Examples of multiple tumor tests for breast cancer include:

  • FoundationOne
  • MSK-IMPACT


Genetic tests for inherited mutations for treatment selection

Genetic testing for an inherited mutation may be used to guide treatment selection for people diagnosed with breast cancer.  

  • People with advanced breast cancer who test positive for an inherited or mutation may benefit from treatments known as PARP inhibitors. Two PARP inhibitors—Lynparza and —are approved as for treating advanced breast cancer in people with a or mutation.
  • Lynparza may be used to as after treatment for people with an inherited or mutation who have breast cancer this is high risk for recurrence. 
  • People who test positive for other inherited gene mutations may qualify for clinical trials looking at targeted therapies to treat hereditary breast cancer. 


Tumor tests for prognosis 

These tests are used for people with early ER/PR-positive cancers to predict:

  • if the cancer is likely to come back
  • the benefit of adding chemotherapy to the treatment plan
  • how long hormonal therapy should be used

Some examples of the most commonly used prognostic tests for breast cancer are listed below:

  • Oncotype Dx™ 
  • Breast Cancer Index™ 
  • MammaPrint™ 
  • Prosigna™ 


PARP inhibitors 

PARP inhibitors work by blocking a protein used by cells to repair damaged . They were initially developed to treat cancers in people with an inherited gene mutation or mutation.

  • For breast cancer, two PARP inhibitors have received FDA-approval as for treating people with an inherited mutation:
    • Lynparza (olaparib) 
    • ()  
  • For people with early breast cancer at high risk for recurrence:
    • Lynparza may be used as after chemotherapy in people with an inherited or mutation. Although the has not yet approved Lynparza for this indication, doctors may still prescribe it off-label. Several expert guidelines now include recommendations for Lynparza for patients with high-risk, early breast cancer and a or mutation. 

Research is ongoing to learn if PARP inhibitors are affective for treating breast cancer in other situations, including:  

  • people with an inherited mutation in a different gene that repairs damage (for example: , or ).
  • people who do not have an inherited gene mutation, but their tumor tested positive for an acquired mutation in a gene that repairs damage.


Immunotherapies 

Immunotherapies are cancer treatments that help the body’s immune system detect and attack cancer cells. Immune checkpoint inhibitors are a type of used to treat several types of cancer, including breast cancer. Some cancer cells produce proteins which can switch off immune cells and keep them from attacking. Immune checkpoint inhibitors are drugs that prevent cancer cells from switching off immune cells. This allows the immune system to find, unmask and destroy cancer cells. Immune checkpoint inhibitors are approved for treatment of the following types of breast cancer. 

  • Keytruda (pembrolizumab) is approved in combination with chemotherapy for treatment of  that is or locally recurrent and unresectable that tests positive for a called .
  • Keytruda is approved for the treatment of triple-negative breast cancer that is at high risk for recurrence. In this setting, Keytruda is used along with chemotherapy as therapy before surgery. Following surgery, Keytruda is continued alone.

See our section for more information. 


Other targeted therapies

Targeted therapies are treatments that act on certain molecules or targets within cancer cells to prevent the cancer cells from growing or spreading while sparing normal cells. Tumor testing can help doctors identify the patients most likely to benefit from a . Common targeted therapies used in breast cancer include:

  • breast cancers are often treated with drugs that target the protein. Common anti-Her2 therapies include Herceptin (trastuzumab), Perjeta (pertuzumab) and Tukysa (tucatinib) and Phesgo (pertuzumab, trastuzumab and hyaluronidase).
  • People with advanced breast cancer are often treated with CDK4/6 inhibitors. CDK4/6 inhibitors target proteins found in some breast cancers called CDK inhibitors. The three CDK4/6 inhibitors approved for use in breast cancer are: Ibrance (palbociclib), Kisqali (ribociclib) and  Verzenio (abemaciclib).
  • The drug Piqray (alpelisib) is approved for people who have advanced, breast cancer who test positive for a tumor called PIK3CA. PIK3CA is an acquired gene mutation found in some ER-positive breast cancers. 


Table of targeted and immunotherapies for breast cancer

Name of drug Cancer Indication Type of agent
Herceptin
(trastuzumab) 
Early The treatment of breast cancer overexpression () Antibody targeting receptors
  
Perjeta (pertuzumab)
Locally advanced, inflammatory or early   Combined with Herceptin (trastuzumab) and docetaxel as treatment before surgery ( overexpression () Antibody targeting receptors
Phesgo (pertuzumab, trastuzumab combined injection) Early

Before surgery () for tumors larger than 2 cm or node-positive or after surgery ( treatment) for early breast cancer that has a high likelihood of coming back

overexpression () Antibody targeting receptors
Keytruda (pembrolizumab) Early TNBC at high risk for recurrence Before surgery Keytruda is used along with chemotherapy as therapy. Following surgery, Keytruda is continued alone. Triple-negative
(, )
Immune checkpoint inhibitor
Lynparza (olaparib) Early breast cancer at high risk for recurrence Given for one year as  after completion of  or  and local treatment (surgery and, or radiation). or inherited mutation
Kadcyla
(trastuzumab emtansine)
Early treatment of patients with early breast cancer who still have disease after taxane and treatment with Hercptin overexpression () Antibody targeting receptors
Kadcyla
(trastuzumab emtansine)
  For patients who previously received Herceptin and chemotherapy, separately or in combination. Patients should have either received therapy for disease, or developed disease recurrence during or within six months of completing therapy overexpression () Antibody targeting receptors
Tukysa (tucatinib) In combination with Herceptin (trastuzumab) to treat cancer which has progressed after at least one prior treatment with an anti-HER2 treatment in the setting overexpression () Kinase inhibitor
Trodelvy (sacituzumab govitecan-hziy)   For breast cancer that progressed, recurred or did not respond to at least two previous lines of treatment Triple-negative (, ) Antibody-drug conjugate (chemotherapy attached to antibody found in )
Afinitor
(everolimus)
  Combined with Aromasin (exemestane) for postmenopausal women with advanced breast cancer which progressed with Femara (letrozole) or Arimidex (anastrozole)
and
MTOR inhibitor (type of kinase inhibitor)
Piqray
(alpelisib)
Combined with Faslodex (fulvestrant) as treatment in men or post-menopausal women who progressed on or after treatment with hormone therapy. 
and and PIK3CA-positive
Kinase inhibitor
Verzenio (abemaciclib) Used alone to treat men or women with breast cancer that has progressed after treatment with hormone therapy and chemotherapy in the setting. 
and
CDK4/6 inhibitor
Combined with Faslodex (fulvestrant) as treatment in  women whose disease progressed following endocrine therapy. and CDK4/6 inhibitor
Ibrance
(palbociclib)
Combined with an aromatase inhibitor as treatment of 
advanced cancer as initial hormone therapy in postmenopausal women or in men
and CDK4/6 inhibitor
Combined with Faslodex (fulvestrant) as treatment in postmenopausal women or in men whose disease progressed following endocrine therapy and CDK4/6 inhibitor
Kisqali
(ribociclib)
  Combined with an aromatase inhibitor for the treatment of pre/perimenopausal or postmenopausal women as initial hormone based therapy and CDK4/6 inhibitor
  Combined with Faslodex (fulvestrant) for the treatment of postmenopausal women, as initial hormone based therapy.  and CDK4/6 inhibitor
Lynparza (olaparib)    For treatment of patients who have previously received chemotherapy, or hormone therapy for patients with hormone receptor ()-positive disease  or mutation and

()
For treatment of breast cancer or mutation and
Keytruda (pembrolizumab) Combined with chemotherapy for treatment of locally recurrent unresectable or triple negative breast cancer Triple-negative ( and )
PD-L1-positive
Immune checkpoint inhibitor

find-support find-support

The following organizations offer peer support services for people with, or at high risk for breast cancer:

updated: 02/25/2022

paying-for-service paying-for-service

Paying for cancer treatment

The majority of public and private health insurance plans are required to cover cancer diagnosis and treatment; copays, coinsurance and deductibles often apply. Patient costs and coverage for specific doctors, facilities or treatments may vary based on your health plan. Visit our section on Insurance and Paying for Care: Treatment  for more information, links to sample appeal letters and other resources. 

Some pharmaceutical companies have assistance programs that help cover the cost for their medications: 

Organizations that offer co-pay assistance:

Other resources:

  • The American Cancer Society provides information and resources on covering the cost of cancer care. Public assistance, such as Medicaid may be available if you are ineligible for other programs. 
  • Needy Meds: Assistance programs to help patients with cost of medications and other healthcare.
  • Triage Cancer offers tools and resources to help individuals cope with the financial aspects of a cancer diagnosis.

updated: 01/22/2022

paying-for-service paying-for-service

Paying for testing

Insurance companies are required to cover the costs for cancer treatment. However, health plans may vary on the amount of out-of-pocket costs and coverage for specific doctors, facilities or treatments. Your doctor's office and treating hospital should disclose how much your treatment may cost you and work with your insurance company to help you plan for the cost of your care. Visit our Health Insurance Appeals page for additional information on insurance appeals. 

Medicare will cover the cost for genetic testing and testing for people who meet certain criteria. Medicare coverage varies based on the policies of Medicare in your region. Visit this site to find and contact your regional Medicare provider for more information about coverage. The Medicaid website has a link to state Medicaid programs, which list specific eligibility for each state.

Some laboratories have assistance programs that help cover the cost for tumor testing: 

Organizations that offer co-pay assistance:

Other resources:

  • The American Cancer Society provides information and resources on covering the cost of cancer care. Public assistance, such as Medicaid may be available if you are ineligible for other programs. 
  • Triage Cancer offers tools and resources to help individuals cope with the financial aspects of a cancer diagnosis.

updated: 01/22/2022

clinical-trials clinical-trials

The following are studies enrolling people with early breast cancer.  

A number of other clinical trials for patients with breast cancer can be found here.

updated: 03/18/2022

clinical-trials clinical-trials

The following are studies looking at new treatments for people with TNBC.  

A number of other clinical trials for treating patients with TNBC can be found here.

updated: 12/04/2021

Last updated January 25, 2022