Triple-Negative Breast Cancer

August 31, 2015

About 15 to 20 percent of breast cancers are triple-negative. But you may have never heard of triple-negative breast cancerinfo-icon before you got your test results. Knowing the basics of breast cancer can help you understand how triple-negative breast cancer is different from other types of breast cancer.

To find out which type of breast cancer you have, your doctors search for the presence or absence of three receptors. Receptors are proteins that live inside or on the surface of a cellinfo-icon and bind to something in the body to cause the cell to react. The three receptors are:

In ER-info-iconpositive breast cancer, PR-info-iconpositive breast cancer and HER2-positive breast cancer, treatment includes medicines that prevent, slow or stop cancer growth by targeting those receptors. But triple-negative breast cancers need different types of treatments because they test negative for all three receptors. Medicines such as tamoxifeninfo-icon, which targets the estrogen receptor, and trastuzumabinfo-icon (Herceptininfo-icon), which targets HER2, are not helpful in triple-negative breast cancer. Instead, chemotherapyinfo-icon has been shown to be the most effective treatment.

Researchers are learning more about triple-negative breast cancers, including how they behave and what puts people at risk for them. The goal is to find the best ways to use existing treatments and to develop new ones.

Doctors use the same tests and surgeries to choose treatments for triple-negative breast cancers as they do for other kinds of breast cancer. Your treatment will be based on:

  • whether the cancer has traveled to the lymphinfo-icon nodes near your breast
  • the size of the main tumorinfo-icon
  • details in your pathology report, such as tests of the tumor gradeinfo-icon, which shows how quickly the cancer cells are dividing

With early-stageinfo-icon disease, you are likely to have some type of surgery and chemotherapy. You also may have radiation.

Understanding the Basal-like Subtype

You might have heard your doctor call triple-negative breast cancerinfo-icon a basal tumorinfo-icon, basal breast cancer or basal-like disease.

Most triple-negative breast cancers have a basal-like geneticinfo-icon pattern. This means the cells look somewhat like the cells that line the breast ducts, the tubes in the breast where milk travels.

Basal-like breast cancers tend to overexpressinfo-icon, or make too much of, certain genes that encourage cancer growth. Not all triple-negative breast cancers are basal-like, and not all basal-like breast cancers are triple-negative. About 70 to 90 percent of triple-negative breast cancers are basal-like.

Doctors choose treatments because the cancer is triple-negative, not because it’s basal-like. The basal status of the cancer does not factor into treatment decisions. Still, your doctor may tell you the cancer is basal-like because you may see the term as you research triple-negative breast cancer.

Three Myths About Triple-Negative Breast Cancer

As you find out more about your diagnosisinfo-icon, you might learn some people have false beliefs about triple-negative breast cancerinfo-icon. Here are three common myths.

Myth #1: Women with triple-negative breast cancer can have the same treatments as all other women with breast cancer.Fact: Many people do not understand there are different types of breast cancer. You might know women who took a hormonal therapyinfo-icon pill for 5 to 10 years to protect against recurrenceinfo-icon. These women, and some others, may not understand that this option does not exist for you. On the other hand, you may take some of the same chemotherapyinfo-icon medicines as women with other types of breast cancer.

Myth #2: Triple-negative breast cancers are always hard to treat.Fact: Your doctor may tell you triple-negative breast cancer is “harder to treat” than other types of breast cancer. Many triple-negative cancers are aggressiveinfo-icon, but your doctor’s prediction of how well your treatment may work depends not only on its triple-negative status but also on the tumorinfo-icon size and whether the cancer has traveled to the lymphinfo-icon nodes in your armpit. There are some very effective treatments for triple-negative breast cancer.

Myth #3: Only African-Americans get triple-negative breast cancer.Fact: While breast cancers in African-American women are more likely to be triple-negative than those in white women, triple-negative breast cancers affect women of all races.