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

Triple Negative Breast Cancer

Read our blog, Fierce Fight.

What is triple negative breast cancer (TNBC)?

TNBC is:

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

Triple negative/basal-like tumors are a molecular subtype of breast cancer. Basal-like tumors have cells that look similar to those of the outer (basal) cells surrounding the mammary ducts.

Most triple negative tumors are basal-like (see figure below).

 

Triple Negative-basal Like Tumors Venn Diagram

Learn more about molecular subtypes of breast cancer.

How common is TNBC?

About 10-20 percent of all breast cancers are TNBC or basal-like tumors [47-49,55-56,125].

These tumors tend to occur more often in [53,55-58]:

TNBC may also be more common among Hispanic women compared to white and non-Hispanic white women [57-60].

BRCA1 inherited gene mutations and TNBC

Most breast cancers related to a BRCA1 inherited gene mutation are both triple negative and basal-like [61-63].

TNBC may also be related to a BRCA2 inherited gene mutation [66].

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. TNBC is more likely than ER-positive breast cancer to recur, at least within the first 5 years after diagnosis [47,52,56]. After about 5 years, this difference begins to decrease and over time, goes away [13].

Treatment of TNBC

TNBC is aggressive, but it can be treated effectively. Early TNBC is usually treated with some combination of surgery, radiation therapy and chemotherapy. Treatment for metastatic TNBC may include other drug therapies.

TNBC isn’t treated with hormone therapy because it’s ER-negative. TNBC also isn’t treated with HER2-targeted therapies, such as trastuzumab (Herceptin), because it’s HER2-negative.

Chemotherapy

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 [56].

For people with early TNBC who have cancer remaining in their breast after getting neoadjuvant chemotherapy (given before surgery), treatment with the chemotherapy drug capecitabine may lower the risk of recurrence and improve survival [121].

Platinum-based chemotherapy drugs (including carboplatin and cisplatin) are an option for people with metastatic TNBC who have a BRCA1 or BRCA2 inherited gene mutation [16].

Learn about emerging areas in chemotherapy and other drug therapies for early and locally advanced breast cancer.

Learn about emerging areas in chemotherapy and other drug therapies for metastatic breast cancer.

Immunotherapy

Pembrolizumab (Keytruda) is a checkpoint inhibitor immunotherapy drug used to treat some early TNBC and some metastatic TNBC.

Learn more about pembrolizumab in the treatment of early TNBC.

Learn more about pembrolizumab in the treatment of metastatic TNBC.

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

Learn about emerging areas in immunotherapy and other drug therapies for metastatic breast cancer.

Trop-2 antibody-drug conjugates

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

Learn about emerging areas in Trop-2 antibody-drug conjugates and other drug therapies for metastatic breast cancer.

Clinical trials for people with TNBC

Clinical trials are studying which treatments are the most effective for 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.

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 any stage of breast cancer find and participate in clinical trials.

Race and ethnicity and TNBC

Prevalence

Prevalence rates of TNBC differ by race and ethnicity.

Triple negative/basal-like tumors appear to be more common among Black, non-Hispanic Black and African American women (especially before menopause) compared to women of other ethnicities [53,55-58].

Rates of TNBC are higher among Black women diagnosed with breast cancer (23 percent) than among white women diagnosed with breast cancer (12 percent) [74].

TNBC may also be more common among Hispanic women compared to white and non-Hispanic white women [57-60].

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 or 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 [64].

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 [64,75-80]. Each of these factors may increase the chances of getting TNBC [56,75-80].

Certain reproductive and lifestyle factors may protect more against ER-positive breast cancers than ER-negative breast cancers, including TNBC. So, even though women may have these protective factors, they may not lower the risk of TNBC.

For example, African American and Hispanic women are more likely than white women to [60,64,75-84]:

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

Although these factors lower the risk of breast cancer overall, this benefit may be limited to ER-positive breast cancers [60,75-76,78-79,84-85]. So, even though African American and Hispanic women may have these protective factors, the factors may not lower the risk of TNBC.

There’s even some evidence these factors may increase the risk of TNBC [56,60,75-76,80,84-85].

These topics are under study.

Prognosis

Higher rates of triple negative/basal-like tumors may explain, to some degree, the poor prognosis of breast cancers diagnosed in younger Black, non-Hispanic Black and African American women [57-58,64,86-88].

Also, luminal A tumors, which have the best prognosis of the subtypes, occur less often in premenopausal non-Hispanic Black women compared to postmenopausal non-Hispanic Black women and compared to non-Hispanic white women of either menopausal status [57,65]. 

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.
  • 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 09/10/21

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