Triple Negative Breast Cancer


Breast cancer is the most common cancer in American women after skin cancer. About 15 or 20 percent of breast cancers are triple-negative breast cancer. Most people are familiar with breast cancer, but many have not heard of triple-negative breast cancer.

Development and classification

Breast cancer starts from one abnormal cell that grows out of control and forms a mass of abnormal cells called a tumor. There are different kinds of breast cancers, and they behave in different ways. Some breast cancers are estrogen-receptor positive (ER+), which means they need the hormone estrogen to grow. Breast cancers may also be progesterone-receptor positive (PR+), which means the hormone progesterone helps them grow. In addition to hormones, proteins can help breast cancers grow. If a breast cancer is HER2-positive (HER2+), the protein HER2 helps it grow. Breast cancers that are positive for estrogen receptors, progesterone receptors or HER2 can be treated with hormones or drugs that target HER2.

Triple-negative breast cancers test negative for estrogen receptors, progesterone receptors and HER2. They do not need estrogen, progesterone or HER2 to grow, which means they cannot be treated with hormones or drugs used for ER+, PR+ or HER2+ breast cancers. However, many other treatment options are available for triple-negative breast cancer.

The most common subtype of triple-negative breast cancer is called “basal-like.” This term means that the breast cancer cells look somewhat like the cells that line the breast ducts, the tubes in the breast where milk travels. You might have heard your doctor refer to triple-negative breast cancer as a basal tumor, basal breast cancer or basal-like disease. People with basal-like triple-negative breast cancer have the same treatment options as others with triple-negative breast cancer.

Why triple-negative is unique

Triple-negative breast cancer affects a unique population. Compared with other breast cancers, it is more common in young women, in African Americans and Latinas, and in women with the BRCA1 mutation.

Ask your doctor about genetic testing, which can show if you have the BRCA1 mutation. Genetic testing can help identify treatments that will be most successful for you. Gene mutations also are associated with a family risk of breast and ovarian cancers. It is recommended that all patients with triple-negative breast cancer under age 60 be tested for BRCA1 and BRCA2.

Clinical trials and ongoing research

Triple-negative breast cancer is an ongoing focus of research. Clinical trials are underway for patients with and without the BRCA1 mutation. Targeted and combination therapy drugs are being studied as treatment options for triple-negative breast cancer. Ask your doctor if you are a candidate for clinical trials.


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.

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