Triple Negative Breast Cancer


Most people are familiar with breast cancer but they may not have heard of triple negative breast cancer. About one in every five or six breast cancers is considered triple negative. What does that mean? How will your course of treatment and follow-up be different? To better understand triple negative cancer, you must first understand how breast cancer develops and how it is characterized.

Who is affected by triple negative breast cancer?

Triple negative breast cancer can develop in any woman and has been identified in men with breast cancer, as well. However, young women, African American women and BRCA1 mutation-carriers are affected significantly more often.

Ask your doctor about genetic testing, which can show if you have a BRCA1 mutation. Genetic testing can potentially help identify treatments and/or clinical trials that will be most appropriate for you. You are more likely to carry a BRCA1 or BRCA2 mutation if you have multiple relatives with breast and/or ovarian cancer; however, BRCA testing is recommended for all patients diagnosed with triple negative breast cancer prior to age 60, regardless of their family history. Learn more about genetic testing.

A triple negative breast cancer diagnosis can be especially unsettling because of its unique nature. One of the most important things you can do is to educate yourself about the disease. There are many myths surrounding triple negative breast cancer, such as the misperception that it always comes back and that it always requires a mastectomy. Neither is true; many triple negative breast cancer patients are treated effectively and, often, they have successful breast-conserving surgery. Learn more facts by talking with your medical team and doing research on your own using the additional resources in this guide. The more you know, the more prepared you will be to make confident treatment decisions.

Development and Classification

At one time, all breast cancers were considered to be the same and were treated the same way. However, researchers now have a better understanding of the genetic make-up of breast cancers and have discovered that breast cancers differ from each other in many ways.

Breast cancer starts from one abnormal cell that grows out of control and forms a mass of abnormal cells called a tumor. Some breast cancers need hormones to grow. The cancer cells in these breast cancers contain large amounts of receptors for the hormones estrogen (ER) and/or progesterone (PR). These breast cancers are referred to as ER-positive and/or PR-positive. In addition, a breast cancer cell can have too many receptors for a certain protein called HER2/neu, which is a growth factor. This type of a breast cancer is referred to as HER2-positive. The discovery of these differences led to the development of unique (targeted) treatments for these specific breast cancers. For example, hormone therapy is used for ER-positive and/or PR-positive breast cancers, and anti-HER2 drugs are used to treat HER2-positive breast cancers.

Triple negative breast cancer is so-named because it tests negatively for ER, PR and HER2. Triple negative breast cancers are not likely to respond to hormone therapy or anti-HER2 drugs. You may feel discouraged to learn that these treatments are not options for you, but it’s important to know the standard treatments for breast cancer – chemotherapy, surgery and radiation therapy – are options for triple negative breast cancer. In fact, hormone-negative breast cancer, which includes triple negative breast cancer, may actually respond better to chemotherapy than other types of breast cancer do.

Triple negative breast cancers tend to be more aggressive; that is, they tend to be a higher grade, which means they grow more quickly. In addition, triple negative breast cancer is more likely to spread beyond the breast and to recur (come back). The more aggressive nature of triple negative breast cancer is related to the fact that most (approximately 80 percent) of these tumors have a genetic makeup within the tumor that is called a basal subtype, which allows the cancer to metastasize more easily than a non-triple negative breast cancer. These characteristics can be scary; however, your doctor will consider the best treatment options for you to help eliminate cancer cells and to lower the risk of recurrence. In addition, your doctor will recommend close follow-up care after treatment so that if cancer does recur, it can be treated early. Not all triple negative breast cancers belong to the basal subtype, and some triple negative breast cancers are less aggressive than others. Furthermore, early detection of even the aggressive triple negative breast cancers is still important and can help patients avoid needing chemotherapy. Learn more about treatment and follow-up care.


Myth vs Fact

MYTH: Women with triple-negative breast cancer have all of the same treatment options as women with other types of breast cancers.
FACT: There are many treatment options for TNBC. They include surgery, radiation and chemotherapy. TNBC does not respond to hormone therapies or to HER2 targeted therapies. Scientists are working to identify other targeted therapies that will be effective in treating TNBC. Studies also indicate that some women with TNBC may respond well to immunotherapy.
MYTH: Triple-negative breast cancer always comes back or metastasizes.
FACT: TNBC does not always come back or metastasize. Many women with early-stage disease are treated effectively with no recurrence. TNBC can have a higher rate of recurrence than other types of breast cancer. This is why it is often treated more aggressively when it is diagnosed.
MYTH: Triple-negative breast cancers are hard to treat.
FACT: Your prognosis depends on a number of factors in addition to the triple-negative status, including the tumor size and whether it has spread to nearby lymph nodes. This type does tend to be more aggressive; however, effective treatment options are available. Research has shown that hormone-negative breast cancers, which include triple-negative breast cancer, may actually respond better to chemotherapy than other types of breast cancer. Talk to your treatment team about the treatment regimen that is right for you.
MYTH: Triple-negative breast cancer means I must have a mastectomy.
FACT: In many cases, a lumpectomy and mastectomy will be associated with the same prognosis, but a lumpectomy is less invasive. Talk to your doctor about which surgical option is recommended for your diagnosis. Know all of your options and weigh both the physical and emotional effects of each treatment type. This will help you make the best treatment decision for you.
MYTH: Triple-negative breast cancer affects only African- American women.
FACT: In the United States, approximately 15 percent of breast cancers in white women are triple-negative compared with nearly 30 percent of breast cancers in African-American women. Even though African-American women are more likely to have triple negative disease, this type of breast cancer affects women of all ethnicities.

Additional Resources




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