The Who, What, Where, When and Sometimes, Why.

Triple Negative Breast Cancer

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What is triple negative breast cancer (TNBC)?

Triple negative breast cancer (TNBC) is:

  • Estrogen receptor-negative (ER-negative)
  • Progesterone receptor-negative (PR-negative)
  • HER2-negative

Most triple negative tumors are basal-like (see figure below). Basal-like tumors have cells that look similar to those of the outer (basal) cells surrounding the mammary ducts.

 

Triple Negative-basal Like Tumors Venn Diagram

Triple negative/basal-like tumors are a molecular subtype of breast cancer.

How common is TNBC?

About 15-20 percent of all breast cancers are TNBC or basal-like tumors [46-48,52-54].

TNBC tends to occur more often in [51-56,59-61]:

TNBC may also be more common among Hispanic women compared to non-Hispanic white women [54,57-58].

BRCA1 inherited gene mutations and TNBC

Most breast cancers related to a BRCA1 inherited gene mutation are both triple negative and basal-like [59-61].

The National Comprehensive Cancer Network recommends people diagnosed with TNBC at age 60 or younger get genetic testing [66].

Learn more about genetic testing.

TNBC and breast cancer recurrence

TNBC is often aggressive.

Early TNBC is more likely than early ER-positive breast cancer to recur, at least within the first 5 years after diagnosis [46,50,53].

After about 5 years, this difference begins to decrease and over time, goes away [46,50,53].

Treatment of early TNBC

Early TNBC is aggressive, but it can be treated effectively. It’s usually treated with some combination of surgery, radiation therapy, chemotherapy and immunotherapy.

TNBC isn’t treated with hormone therapy or HER2-targeted therapy because it’s ER-negative and HER2-negative.

Learn about emerging areas in drug therapies for early breast cancer.

Chemotherapy for early TNBC

Early TNBC is treated with chemotherapy. People with TNBC tend to get more treatment benefit from chemotherapy than people with hormone receptor-positive breast cancers do [53].

Some people get chemotherapy before breast surgery. This is called neoadjuvant chemotherapy.

For people with TNBC who have cancer remaining in their breast after neoadjuvant chemotherapy, treatment with the chemotherapy drug capecitabine may lower the risk of recurrence and improve survival [14,67].

Learn more about chemotherapy.

Immunotherapy for early TNBC

Pembrolizumab (Keytruda) is an immunotherapy drug used to treat early TNBC at high risk of recurrence. It’s given before surgery, as part of neoadjuvant therapy.

Learn more about pembrolizumab in the treatment of early TNBC.

Treatment of metastatic TNBC

Treatment for metastatic TNBC includes chemotherapy. It may also include other drug therapies.

TNBC isn’t treated with hormone therapy or HER2-targeted therapy because it’s ER-negative and HER2-negative.

Learn about chemotherapy in the treatment of metastatic breast cancer.

Learn about emerging areas in the treatment of metastatic breast cancer.

Immunotherapy for metastatic TNBC

The immunotherapy drug pembrolizumab (Keytruda) is used to treat some metastatic TNBC.

Learn more about pembrolizumab in the treatment of metastatic TNBC.

Trop-2 antibody-drug conjugates for metastatic TNBC

Sacituzumab govitecan (Trodelvy) is a Trop-2 antibody-drug conjugate used to treat metastatic TNBC.

Learn about sacituzumab govitecan in the treatment of metastatic breast cancer.

Clinical trials for people with TNBC

Clinical trials are studying treatment for early and metastatic TNBC.

After discussing the benefits and risks with your health care provider, we encourage you to consider joining a clinical trial.

Susan G. Komen® Breast Care Helpline

If you or a loved one needs information or resources about clinical trials, call the Komen Breast Care Helpline at 1-877 GO KOMEN (1-877- 465- 6636) or email clinicaltrialinfo@komen.org.

Se habla español.

BreastCancerTrials.org in collaboration with Susan G. Komen® offers a custom matching service to help find clinical trials for people with early TNBC and clinical trials for people with metastatic TNBC.

Learn more about clinical trials

Learn more about what Komen is doing to help people with breast cancer find and participate in clinical trials.

Race, ethnicity and TNBC

Prevalence

Prevalence rates show the proportion of people who have a breast cancer (or other health condition) at a given point in time. Prevalence rates of TNBC differ by race and ethnicity.

Triple negative tumors appear to be more common among non-Hispanic Black and African American women (especially before menopause) compared to women of other ethnicities [51-56].

For example, from 2014-2018 (most recent data available), about 23 Black women per 100,000 women were diagnosed with TNBC compared to about 12 white women per 100,000 women [68].

TNBC may also be more common among Hispanic women compared to non-Hispanic white women [54,57-58].

However, most cases of TNBC cases are in white women. This is because the total number of white women diagnosed with breast cancer is much higher than the total number of women of other races and ethnicities diagnosed with breast cancer.

Learn more about numbers versus rates when looking at breast cancer statistics.

Risk factors

Although the reasons for racial and ethnic differences in rates of TNBC are not clear, some lifestyle factors may play a role [58-62].

Compared to white and non-Hispanic white women, Black and African American women tend to have lower rates of breastfeeding and tend to carry excess weight in the abdomen area [63,69-73]. Each of these factors may increase the chances of getting TNBC [53,69-73].

Certain reproductive and lifestyle factors may be linked to a lower risk of ER-positive breast cancers, but not ER-negative breast cancers, including TNBC.

For example, non-Hispanic Black, African American, Hispanic and Latina women are more likely than white women to [58,63,70-74]:

  • Have more children
  • Have a younger age at first birth
  • Be overweight or obese (before menopause)

Although these factors are linked to a lower risk of breast cancer overall, this benefit may be limited to ER-positive breast cancers [58,69,70-71,75-77 ]. So, even though Black and Hispanic women may have these protective factors, the factors may not be linked to a lower risk of TNBC.

There’s even some evidence these factors may increase the risk of TNBC [53,58,69,72,75-76].

These topics are under study.

Prognosis (chances for survival)

Higher rates of TNBC may explain, to some degree, the poor prognosis of breast cancers diagnosed in younger Black, non-Hispanic Black and African American women [54,63-65,78-80].

Even among women with TNBC, African American women may have poorer survival than white women [81].

Susan G. Komen® Support Resources

  • If you or a loved one needs more information about breast health or breast cancer, call the Komen Breast Care Helpline at 1-877 GO KOMEN (1-877-465-6636). All calls are answered by a trained specialist or oncology social worker in English and Spanish, Monday through Friday from 9:00 a.m. to 10:00 p.m. ET. You can also email the helpline at helpline@komen.org. Se habla español.
  • We offer an online support community through our closed Facebook Group – Komen Breast Cancer group. The Facebook group provides a place where those with a connection to breast cancer can discuss each other’s experiences and build strong relationships in order to provide support to each other. Visit Facebook and search for “Komen Breast Cancer group” to request to join the closed group.
  • Our fact sheets, booklets and other education materials offer additional information.

Updated 11/15/21

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