New Discoveries About Advanced Breast Cancer

By
Lisa Bernstein, MD
WebMD Feature

Reviewed by
Lisa Bernstein, MD

You’ll want to keep up with the latest findings on advanced breast cancer. Scientists are working toward new drugs, a better understanding of the disease itself, and what helps while you go through treatment.

New Medicines

The FDA recently expanded its approval for palbociclib (Ibrance), a drug that targets a protein called CDK 4/6. Doctors can now use it in combination with fulvestrant, a hormonal-therapy drug that targets estrogen. It may be an option if you have metastatic breast cancer that is “hormone-receptor positive,” and you don’t have a type of breast cancer called “HER2,” which promotes the growth of cancer cells. 

The FDA based its decision, in part, on the results of a clinical trial that found that palbociclib plus fulvestrant slowed down metastatic breast cancer by about 5 months.

The agency has also pledged to speed up its review of an immunotherapy drug called sacituzumab govitecan (IMMU-132). It targets a protein called Trop-2 that’s found in many types of cancer.

More New Drugs in the Works

These medications aren’t available yet, but researchers are studying them.

PARP inhibitors. These drugs target PARP — an enzyme involved in DNA repair — and may help people with a BRCA1 or BRCA2 gene mutation.

Tyrosine kinase inhibitors. These drugs block certain enzymes. One of the meds, called lapatinib (Tykerb), is already FDA-approved to treat HER2-positive metastatic breast cancer. Another, called neratinib, may also do that, a new study shows. The results show that neratinib improved survival when given after chemotherapy.

More targeted HER-2 therapies. About 1 in 5 people with breast cancer have too much of a growth-promoting protein known as HER2. Drugs that target this protein are becoming more sophisticated. Examples include margetuximab, a drug that shows promise in reducing tumors, and ONT-380, which may cause fewer side effects.

Other immunotherapy drugs. These meds work by boosting your immune system or by providing a man-made version of an immune system protein. Apart from IMMU-132, another immunotherapy drug, pembrolizumab, shows promise in clinical trials as a potential treatment for metastatic triple-negative breast cancer.

New Discoveries About Advanced Breast Cancer

Learning More About How the Cancer Spreads

A new study challenges the long-held belief that the disease spreads when a single cell “escapes” from the tumor and travels through the bloodstream to other organs.

Researchers at Fred Hutchinson Cancer Research Center and Johns Hopkins Medical Institute discovered that breast cancer cells actually travel in clusters throughout all stages of this spreading, or “metastasis.” Having a better understanding of how cancer behaves will help researchers come up with more targeted ways to stop it.

A few months earlier, a study published in Nature also turned the tables on our understanding of how breast cancer cells move through the body. Experts had thought that these cells have to go through a shape-changing process called EMT before they can spread. But the new study shows that breast tumor cells that went through EMT weren’t involved in metastasis.

“There is a substantial effort underway to develop drugs aimed at reversing the EMT process in order to halt metastasis, but our findings suggest that this approach may not work,” researcher Vivek Mittal, PhD, said in a statement.

How You Can Help

Ask your doctor if there are clinical trials that would be a good fit for you. They test new treatments before they’re available to the public. Your doctor, and the study leaders, can let you know what’s being tested, what your commitment involves, and what the risks and benefits are.

You may also want to look into the Metastatic Breast Cancer Project (mbcproject.org), led by the Broad Institute and the Dana-Farber Cancer Institute. It describes itself as “a nationwide movement of patients, doctors, and scientists” with the common goal of “speed[ing] the development of future therapies.”

To get involved, fill out an online consent form allowing the project to contact your doctors for your medical records and a portion of your stored tumor samples. This information will be added to a national database and shared with metastatic breast cancer researchers everywhere.