Triple-negative metastatic breast cancer

Metastatic breast cancer is breast cancer that has spread outside of the breast to other areas of the body, such as the bones, liver, lungs, or brain. Triple-negative breast cancer is a form of breast cancer that tests negative for estrogen receptor, progesterone receptor, and HER2 receptor expression, hence the nickname triple-negative. If you’re diagnosed with triple-negative breast cancer, it means that antiestrogen therapy or HER2-targeting medicines will not be helpful in treating the cancer. Still, there are a number of effective treatment options available.

Early-stage triple-negative breast cancer is more likely to spread to other areas of the body than other types of breast cancer. In fact, one study found that people with early TNBC were four times more likely to develop metastases. Other research suggests one-third of people with early TNBC will develop metastases. Doctors sometimes call TNBC an aggressive breast cancer because it is more likely to recur, often within the first 4 years after diagnosis.

Anyone can develop triple-negative breast cancer, but research shows certain groups have a higher likelihood of developing it, including:

• Young women
• Black women
• Women of Hispanic ancestry
• Women with an inherited BRCA1 mutation

If early-stage breast cancer recurs, the cancer cells’ receptor status can sometimes be different than they were at the time of the original diagnosis. If you are experiencing a recurrence of an early-stage breast cancer, your medical oncologist should recommend that you have a biopsy. The biopsy helps to:

• Diagnose the cancer
• Confirm the cancer is metastatic
• Confirm the receptor status

You can find more information on how metastatic breast cancer is diagnosed on our pages about metastatic breast cancer and testing.

Receiving a diagnosis of metastatic triple-negative metastatic breast cancer (mTNBC) can feel scary, and it can sometimes feel isolating. Triple-negative breast cancer accounts for approximately 15 percent of all breast cancers. Maybe you’ve heard people say that TNBC is hard to manage because it can’t be treated with hormonal therapies or HER2-targeting medicines like some other breast cancers can. In the past, this was true. But medical advances have introduced treatment options for mTNBC, and a number of new treatments are being studied specifically for mTNBC. You have more options than just chemotherapy. These treatments include:

• Immunotherapy (pembrolizumab)
• Targeted therapies, including PARP inhibitors and an antibody-drug conjugate (ADC) called sacituzumab govitecan (Trodelvy)

Understanding more about this diagnosis can bring a greater sense of control as you and your care team decide on the most effective treatments for you. Below, we’ll walk you through mTNBC in more detail, from diagnosis to treatment and living long term with the disease.

What are the symptoms of triple-negative metastatic breast cancer?

For some people, metastatic breast cancer is found before it causes symptoms, on an imaging scan done as a follow-up after early-stage breast cancer. Others experience symptoms that lead them to see their doctor. The symptoms of triple-negative metastatic breast cancer are the same symptoms seen in other types of metastatic breast cancer. These symptoms can vary depending on where in the body the cancer cells traveled. Below are a few symptoms associated with the four most common areas of breast cancer metastases: the bones, liver, lungs, and brain. For a fuller list of symptoms, visit our page on metastatic breast cancer symptoms.

Bone:

• Unexplained pain in one or more bones
• A fracture or break caused by normal activity

Liver:

• Sudden weight loss or loss of appetite
• Swelling or pain in the abdomen
• Swelling of the legs

Lungs:

• Shortness of breath doing normal activity
• Dry cough
• Coughing up blood
• Chest pain or pain with breathing

Brain:

• Frequent headaches
• Dizziness or balance problems
• Changes in speech, behavior, or vision

All areas of the body:

• Fatigue
• Swelling or a lump under the arm or above the collarbone
• Nausea and vomiting

How triple-negative metastatic breast cancer is diagnosed

The tests used to diagnose metastatic triple-negative breast cancer are the same tests commonly used to diagnose any kind of metastatic breast cancer. Your doctor will likely recommend a biopsy of the new area of cancer to confirm whether it is triple-negative, hormone receptor-positive, or HER2 receptor-positive, because this information guides your treatment options. In addition to a confirming biopsy, you may need additional tests:

• Blood tests can provide information about whether cancer has traveled to organs such as the bones or liver. They can also check for blood tumor markers that may indicate metastasis and can look for signs of anemia that may be a side effect of chemotherapy.
• Bone scans can help doctors learn whether breast cancer has spread to the bones, and to monitor how bone metastases are responding to treatment.
• CAT scans, also called CT scans, create digital x-rays of the inside of organs so doctors can check for areas of possible cancer spread. They can also be used to determine whether treatment is shrinking a tumor.
• PET scans can detect areas of metastasis by capturing images of cancer cell activity throughout the body.
• MRI creates 3D images of the body to detect areas of metastasis and to monitor the cancer’s response to treatment.

You may also be offered genetic testing and genetic counseling. More than 75 percent of breast cancers diagnosed in people who carry a BRCA gene mutation are triple-negative. Even if you’ve already been diagnosed with mTNBC, knowing your BRCA mutation status can help in important ways:

• Getting a confirmation that you carry a BRCA mutation can help answer questions about why you may have developed cancer.
• If you test positive, you can inform family members about your status so they can have an opportunity to be tested if they choose to do so.
• Most importantly, metastatic breast cancers that develop in people who have a BRCA gene mutation can be treated with PARP inhibitors.

If you have genetic testing, it’s best to do so with the guidance of your physician or a genetic counselor who can help you understand your results. Learn more on our page about genetic counseling.

In the past, triple-negative breast cancers of all stages, including mTNBC, could only be treated with chemotherapy. Now, there are more treatments available to treat mTNBC, including immunotherapy and targeted therapies such as PARP inhibitors and antibody-drug conjugates (ADCs):

• Immunotherapy stimulates the body’s immune system to attack cancer cells. Pembrolizumab (Keytruda) is the only immunotherapy currently approved for mTNBC.
• PARP inhibitors stop an enzyme called PARP from repairing cell DNA. There are two PARP inhibitors for mTNBC: olaparib (Lynparza) and talazoparib (Talzenna). To be eligible for these treatments, you must also carry a BRCA mutation.
• Antibody-drug conjugates deliver chemotherapy into cancer cells by targeting specific proteins on the cancer cells. Sacituzumab govitecan (Trodelvy) is the only ADC currently approved to treat mTNBC. However, a number of other ADCs that target mTNBC are showing promise, and may be approved in the future.

As the cancer grows and changes, chemotherapy may still be part of your treatment. There are many chemotherapy options available to treat mTNBC, and different chemotherapy drugs can cause different side effects. It’s important to talk with your care team about your goals in treating the cancer as well as your goals for daily life. The chemotherapy treatments available to you depends on your exact diagnosis and which cancer treatments you’ve had in the past, if any.

There are three types of chemotherapy most often used for metastatic triple-negative breast cancer:

• Anthracyclines kill cancer cells by stopping cell growth. The three anthracyclines used in metastatic breast cancer are:
  • Liposomal doxorubicin HCl liposome injection (Doxil)
  • Doxorubicin (Adriamycin) (sometimes, but not often, used to treat mTNBC)
  • Epirubicin (Ellence) (sometimes, but not often, used to treat mTNBC)
• Taxanes slow or stop tumor growth by stopping cells from dividing. The three taxanes given for metastatic disease are:
  • Docetaxel (Taxotere)
  • Paclitaxel (Taxol)
  • Nab-paclitaxel (Abraxane)
• Platinum-based chemotherapies interfere with the action of DNA inside cancer cells. Some platinum-based medicines are:
  • Cisplatin (Platinol)
  • Carboplatin (Paraplatin)

Other types of chemotherapy may also be used:

• Capecitabine (Xeloda), given alone or with docetaxel or paclitaxel, is effective against some cancers that stop responding to anthracyclines or taxanes.
• Vinorelbine (Navelbine) prevents the function of microtubules, which help cancer cells divide. It can be used alone or with other chemotherapy medicines.
• Gemcitabine (Gemzar) works by starving cancer cells of the nutrition they need to grow. Gemcitabine is usually given with carboplatin. Gemcitabine, given with paclitaxel, is FDA approved for use when an anthracycline stops working or you can’t take it for other reasons.
• Ixabepilone (Ixempra) stops the growth of tumor cells by targeting a protein called tubulin that helps cells multiply. It is approved for use when other chemotherapy medicines don’t work against the cancer or when the cancer stops responding to treatment.
• Eribulin (Halaven) stops the cancer cells from dividing into new cells by interfering with the parts of the cell that help move the information inside them during cell division. It is approved for use in people whose metastatic breast cancer has grown after treatment with at least two other types of chemotherapy, including an anthracycline and a taxane.

Living with triple-negative metastatic breast cancer

Being diagnosed with mTNBC can be overwhelming. It can be hard to think about your daily needs and emotional health when you need to navigate the healthcare system, manage medical bills, and cope with treatment side effects. Be gentle with yourself. Living with metastatic breast cancer means being in treatment indefinitely, so even small steps toward better physical and mental health are extremely important.

The most important thing you can do to maintain the best quality of life possible is to see your medical oncologist regularly and inform them of how the treatment you are receiving is affecting you. When you start treatment, you and your care team will create a plan for treatments as well as any blood tests and scans needed to see how well treatments are working. If the cancer stops responding to one treatment, you may be offered a new one.

Making some lifestyle choices can also help you feel stronger and healthier during treatment. Eating a healthy diet and talking with your doctor about safely maintaining or starting an exercise routine can help with side effects and supporting a sense of well-being. Early research suggests that a doctor-approved exercise routine during metastatic breast cancer treatment can ease pain, fatigue, and anxiety.

Some people also find relief from stress and side effects by supporting their medical treatment with complementary therapies, practices that are not medical but that can be helpful physically and emotionally. Complementary therapies include:

• Acupuncture
• Art therapy
• Massage
• Reiki
• Yoga
• Music therapy

You can learn more about complementary therapies and how to access them by reading our page on complementary therapy.

Clinical trials

Triple-negative breast cancer is a huge field of study for cancer researchers right now. Clinical trials are underway to look at how TNBC responds to new and emerging treatments. Most of the time, treatment trials are open to people with metastatic disease before they open up to people with early-stage disease. This means if you’ve been diagnosed with mTNBC, you have a good chance of qualifying for a clinical trial that’s exploring a new medicine.

While the idea of joining a trial can bring feelings of uncertainty for some people, the reality is that trials offer more check-ins with your care team than standard treatment. Clinical trials can be a way to get access to an effective treatment before it becomes available to the general population. Clinical trials are not a last resort. You can join a clinical trial at any time during treatment for mTNBC as long as you meet the trial’s eligibility requirements.

Learn more about clinical trials.

We know that a diagnosis of metastatic triple-negative breast cancer can trigger intense feelings, and that making treatment decisions can be exhausting and overwhelming. Below you’ll find articles, personal stories, and downloadable resources to help you make sense of the basics of your diagnosis, from understanding the disease to coping with the lifestyle changes that come with it.