Advances in Breast Cancer Research

Early Detection of Breast Cancer

Breast cancer is one of a few cancers for which an effective screening test, mammography, is available. MRI (magnetic resonance imaging) and ultrasound are also used to detect breast cancer, but not as routine screening tools.

Ongoing studies are looking at ways to enhance current breast cancer screening options. Technological advances in imaging are creating new opportunities for improvements in both screening and early detection.

One technology advance is 3-D mammography, also called breast tomosynthesis. This procedure takes images from different angles around the breast and builds them into a 3-D-like image. Although this technology is increasingly available in the clinic, it isn’t known whether it is better than standard 2-D mammography, for detecting cancer at a less advanced stage.

NCI is funding a large-scale randomized breast screening trial, the Tomosynthesis Mammographic Imaging Screening Trial (TMIST), to compare the number of advanced cancers detected in women screened for 5 years with 3-D mammography with the number detected in women screened with 2-D mammography. 

Two concerns in breast cancer screening, as in all cancer screening, are:

• the potential for diagnosing tumors that will not become life-threatening (overdiagnosis)
• the possibility of receiving false-positive test results, and the anxiety that comes with follow-up tests or procedures

As cancer treatment is becoming more individualized, researchers are looking at ways to personalize breast cancer screening. They are studying screening methods that are appropriate for each woman’s level of risk and limit the possibility of overdiagnosis.

For example, the Women Informed to Screen Depending on Measures of Risk (WISDOM) study aims to determine if risk-based screening—that is, screening at intervals that are based on each woman’s risk as determined by her genetic makeup, family history, and other risk factors—is as safe, effective, and accepted as standard annual screening mammography.

WISDOM is also making a focused effort to enroll Black women in the trial. Past studies  tended to contain a majority of White women andtherefore, there’s a lack of data on how screening can benefit Black women. Researchers are taking a number of steps to include as many Black women as possible in the study, while also increasing the diversity of all women enrolled.

Breast Cancer Treatment

The mainstays of breast cancer treatment are surgery, radiation, chemotherapy, hormone therapy, and targeted therapy. But scientists continue to study novel treatments and drugs, along with new combinations of existing treatments.

It is now known that breast cancer can be divided into subtypes based on whether they contain estrogen and/or progesterone receptors (that is, are hormone receptor, or HR, positive and whether they have high levels of HER2 protein (HER2 positive).

NCI Experts Discuss Challenges in Breast Cancer Research

As we learn more about the subtypes of breast cancer and their behavior, we can use this information to guide treatment decisions. For example:

• The NCI-sponsored TAILORx clinical trial. The study, which included patients with ER-positive, lymph node-negative breast cancer, found that a test that looks at the expression of certain genes can predict which women can safely avoid chemotherapy.
• The RxPONDER trial found that the same gene expression test can also be used to determine treatment options in women with more advanced breast cancer. The study found that some postmenopausal women with HR positive, HER-2 negative breast cancer that has spread to several lymph nodes and has a low risk of recurrence do not benefit from chemotherapy when added to their hormone therapy. 
• Genomic analyses, such as those carried out through The Cancer Genome Atlas (TCGA), have helped reveal the molecular diversity of breast cancer and eventually could help identify even more breast cancer subtypes. That knowledge, in turn, may lead to the development of therapies that target the genetic alterations that drive those cancer subtypes.

HR-Positive Breast Cancer Treatment Advances

Hormone therapies have been a mainstay of treatment for advanced or metastatic HR-positive cancer. However, there is a new focus on adding targeted therapies to hormone therapy for these cancers. These treatments could prolong the time until chemotherapy is needed and ideally, extend survival. Approved drugs include:

• Palbociclib (Ibrance), ribociclib (Kisqali), and everolimus (Afinitor) have all been approved by the FDA for use with hormone therapy for treatment of advanced or metastatic breast cancer.
  

  Ribociclib Improves Survival in Advanced Breast Cancer

  Used with letrozole, drug is first to extend survival in large trial of metastatic breast cancer.

• Abemaciclib (Verzenio) can be used with hormone therapy or alone, after treatment with hormone therapy, to treat advanced or metastatic HR-positive, HER2-negative breast cancer. These combinations are also being tested to see if they can prevent a relapse after treatment of early-stage ER-positive disease. Indeed, in October 2021, the Food and Drug Administration (FDA) approved abemaciclib in combination with endocrine therapy following surgery to treat some people with early stage HR-positive, HER2-negative breast cancer.
• Alpelisib (Piqray) is approved to be used in combination with hormone therapy to treat HR-positive, HER2-negative breast cancers that have a mutation in the PIK3CA gene.

The drugs above have all been approved to treat metastatic cancer. Research is being done to find out if they can show benefit for people with earlier-stage breast cancers. Study results have been mixed, so scientists continue to explore this question. 

HER2-Positive Breast Cancer Treatment Advances

The FDA has approved a number of targeted therapies to treat HER2-positive breast cancer, including:

• Trastuzumab (Herceptin) and pertuzumab (Perjeta) can both be used in combination with chemotherapy for both early and advanced HER2-positive breast cancer. Trastuzumab has also been approved to prevent a relapse in patients with early-stage HER2-positive breast cancer.
• Trastuzumab deruxtecan is approved for patients who have received two or more targeted treatments for patients with metastatic disease. The drug may also benefit patients who express low levels of HER2, but more research is needed.
• Tucatinib (Tukysa) is approved to be used in combination with trastuzumab and capecitabine (Xeloda) for HER2-positive breast cancer that cannot be removed with surgery or is metastatic. Tucatinib is able to cross the blood–brain barrier, which makes it especially useful for HER-2 positive metastatic breast cancer, which tends to spread to the brain. 
• Lapatinib (Tykerb) has been approved for treatment of some patients with HER2-positive advanced or metastatic breast cancer, together with capecitabine or letrozole. However, a study that tested adding lapatinib to chemotherapy and trastuzumab to treat early-stage breast cancer did not show a significant improvement in outcomes.
• Neratinib Maleate (Nerlynx) can be used in patients with early-stage HER2-positive breast cancer and can also be used together with capecitabine (Xeloda) in some patients with advanced or metastatic disease.
• Ado-trastuzumab emtansine (Kadcyla) is an FDA-approved treatment for patients with metastatic HER2-positive breast cancer. It is also used in some patients with early-stage HER2-positive breast

Triple-Negative Breast Cancer Treatment Advances

Triple-negative breast cancers (TNBC) are the hardest to treat because they lack both hormone receptors and HER2 overexpression, so they do not respond to therapies directed at these targets. Therefore, chemotherapy is the mainstay for treatment of TNBC. However, new treatments are starting to become available. These include:

• Sacituzumab govitecan-hziy (Trodelvy) which is approved to treat patients with TNBC that has spread to other parts of the body. Patients must have received at least two prior therapies before receiving the drug.
• Pembrolizumab (Keytruda), an immunotherapy drug that is approved to be used in combination with chemotherapy for patients with locally advanced or metastatic TNBC that has the PD-L1 protein.
• A different immunotherapy drug, atezolizumab (Tecentriq), is also approved to be used with chemotherapy in patients with metastatic TNBC that has the PD-L1 protein.
• PARP inhibitors work by blocking a protein that is used to repair damage to DNA that occurs during cell division. These drugs, which include olaparib (Lynparza) and talazoparib (Talzenna), effectively target TNBC caused by certain inherited BRCA gene mutations or other alterations that lead to defects in DNA damage repair. They are also approved for metastatic HER2-negative breast cancers in patients who have inherited a harmful BRCA gene mutation. 
• Drugs that block the androgen receptors (AR) or prevent androgen production are being tested in a subset of TNBC cancers that express the AR.

NCI-Supported Research Programs

Many NCI-funded researchers working at the NIH campus, as well as across the United States and world, are seeking ways to address breast cancer more effectively. Some research is basic, exploring questions as diverse as the biological underpinnings of cancer and the social factors that affect cancer risk. And some are more clinical, seeking to translate this basic information into improving patient outcomes. The programs listed below are a small sampling of NCI’s research efforts in breast cancer.

Early Detection and Treatment Research

The Breast Specialized Programs of Research Excellence (Breast SPOREs) are designed to quickly move basic scientific findings into clinical settings. The Breast SPOREs support the development of new therapies and technologies, and studies to better understand tumor resistance, diagnosis, prognosis, screening, prevention, and treatment of breast cancer.

The NCI Cancer Intervention and Surveillance Modeling Network (CISNET) focuses on using modeling to improve our understanding of how prevention, early detection, screening, and treatment affect breast cancer outcomes.

The Confluence Project, from NCI's Division of Cancer Epidemiology and Genetics (DCEG), is developing a research resource that includes data from thousands of breast cancer patients and controls of different races and ethnicities. This resource will be used to identify genes that are associated with breast cancer risk, prognosis, subtypes, response to treatment, and second breast cancers. (DCEG conducts other breast cancer research as well.)

The goal of the Breast Cancer Surveillance Consortium (BCSC), an NCI-funded program launched in 1994, is to enhance the understanding of breast cancer screening practices in the United States and their impact on the breast cancer's stage at diagnosis, survival rates, and mortality.

There are ongoing programs at NCI that support prevention and early detection research in different cancers, including breast cancer. Examples include:

• The Cancer Biomarkers Research Group, which promotes research in cancer biomarkers and manages the Early Detection Research Network (EDRN). EDRN is a network of NCI-funded institutions that are collaborating to discover and validate early detection biomarkers. Within the EDRN, the Breast and Gynecologic Cancers Collaborative Group conducts research on breast and ovarian cancers.
• NCI's Division of Cancer Prevention houses the Breast and Gynecologic Cancer Research Group which conducts and fosters the development of research on the prevention and early detection of  breast and gynecologic cancers.

Health Disparities Research

Black women are more likely to be diagnosed with aggressive subtypes of breast cancer, and they are more likely to die of their disease than white women. To gain an understanding of these disparities, NCI is funding a multi-institution project, the Breast Cancer Genetic Study in African-Ancestry Populations.  The genes of black women with and without breast cancer will be compared to each other, as well as to those of white women who have breast cancer.

The NCI-funded Detroit Research on Cancer Survivors (Detroit ROCS) study will look at the major factors affecting cancer progression, recurrence, mortality, and quality of life among African-American survivors of four different cancers, including breast. Detroit ROCS will examine medical, emotional, social, environmental, and other factors that may affect cancer survival.

Survivorship Research

NCI’s Office of Cancer Survivorship, part of the Division of Cancer Control and Population Sciences (DCCPS), supports research projects throughout the country that study many issues related to breast cancer survivorship. Examples of studies funded include the impact of cancer and its treatment on physical functioning, emotional well-being, cognitive impairment, sleep disturbances, and cardiovascular health. Other studies focus on financial impacts, the effects on caregivers, models of care for survivors, and issues such as racial disparities and communication.

Clinical Trials

NCI funds and oversees both early- and late-phase clinical trials to develop new treatments and improve patient care. Trials are available for breast cancer prevention, screening, and treatment. 

Breast Cancer Research Results

The following are some of our latest news articles on breast cancer research and study updates:

• Pembrolizumab Improves Survival in Advanced Triple-Negative Breast Cancer
• Enhertu Improves Survival for Metastatic "HER2-Low" Breast Cancer
• NCI Study Advances Personalized Immunotherapy for Metastatic Breast Cancer
• New Risk Model Aims to Reduce Breast Cancer Disparities in Black Women
• Enhertu May Be Preferred Therapy for Some Metastatic Breast Cancers
• Combo of Ribociclib, Letrozole Improves Survival in Advanced Breast Cancer

View the full list of Breast Cancer Research Results and Study Updates.