Triple Negative Breast Cancer
What is triple negative breast cancer?
Triple negative breast cancers are:
Triple negative/basal-like tumors are one of the main molecular subtypes 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).
Learn more about molecular subtypes of breast cancer.
How common is triple negative breast cancer?
About 15-20 percent of all breast cancers are triple negative or basal-like [57-59,65-66].
These tumors tend to occur more often in [63,65-68]:
- Younger women
- Black/non-Hispanic black/African-American women (more on race/ethnicity and subtypes of breast cancer)
Triple negative tumors may also be more common among Hispanic women compared to white/non-Hispanic white women [67-69].
BRCA1 gene mutations and triple negative breast cancer
Triple negative breast cancers may also be related to a BRCA2 gene mutation .
People diagnosed with triple negative breast cancer at age 60 or younger are recommended to get genetic testing for BRCA1 and BRCA2 gene mutations .
Learn more about genetic testing.
Read our perspective on triple negative breast cancers.*
Prognosis for triple negative breast cancer
However, after about 5 years, this difference begins to decrease and eventually goes away .
Treatment of triple negative breast cancer
Triple negative tumors aren’t treated with hormone therapy because they are ER-negative. They also aren’t treated with HER2-targeted therapies, such as trastuzumab (Herceptin), because they are HER2-negative.
Triple negative breast cancers are treated with chemotherapy. People with triple negative breast cancer tend to get more treatment benefit from chemotherapy than people with hormone receptor-positive breast cancers do .
Platinum-based chemotherapy drugs include carboplatin and cisplatin. These drugs are a chemotherapy option for people with triple negative breast cancer who have a BRCA1 or BRCA2 gene mutation .
Whether platinum-based chemotherapy drugs are more effective than other chemotherapy drugs at treating triple negative breast cancers is under study [16,76-79].
Learn more about breast cancer treatment.
Atezolizumab (Tecentriq) is a checkpoint inhibitor immunotherapy drug used to treat some metastatic triple negative breast cancers. All metastatic triple negative breast cancers should be tested for PD-LI status.
Atezolizumab in combination with the chemotherapy drug nab-paclitaxel used to treat PD-L1-positive metastatic triple negative breast cancer. Compared to chemotherapy alone, atezolizumab and nab-paclitaxel may give women with PD-L1-positive metastatic triple negative breast cancer more time before the cancer spreads .
Whether atezolizumab is effective for the treatment of metastatic triple negative breast cancers that do not express (have little or no) PD-L1 is under study .
Learn more about the treatment of metastatic breast cancer.
Trop-2 antibody-drug conjugates
Sacituzumab govitecan-hziy (Trodelvy) is a Trop-2 antibody-drug conjugate. It combines a Trop-2 antibody and the chemotherapy drug irinotecan. This combination allows the targeted delivery of iriotecan to cancer cells that express Trop-2.
Triple negative breast cancers tend to express Trop-2 (triple negative breast cancers have cells with higher levels of the protein Trop-2 than other breast cancers).
Sacituzumab govitecan-hziy is used to treat metastatic triple negative breast cancers. Study findings have shown sacituzumab govitecan-hziy helps shrink tumors in women with metastatic triple negative breast cancers .
Learn more about the treatment of metastatic breast cancer.
Clinical trials for triple negative breast cancer
Clinical trials are studying which treatments are the most effective for triple negative breast cancer.
After discussing the benefits and risks with your health care provider, we encourage you to consider joining a clinical trial.
Susan G. Komen® Breast Cancer Clinical Trial Information Helpline
If you or a loved one needs information or resources about clinical trials, call our Clinical Trial Information Helpline at 1-877 GO KOMEN (1-877- 465- 6636) or email email@example.com.
BreastCancerTrials.org in collaboration with Susan G. Komen® offers a custom matching service to help find clinical trials for people with early triple negative breast cancer and clinical trials for people with metastatic triple negative breast cancer.
Learn more about clinical trials.
Race/ethnicity and triple negative breast cancer
Prevalence rates of triple negative breast cancer differ by race/ethnicity.
Triple negative/basal-like tumors appear to be more common among Black/non-Hispanic black/African-American women (especially before menopause) compared to women of other ethnicities [63,65-68,154].
Triple negative tumors may also be more common among Hispanic women compared to white/non-Hispanic white women [67-69,154].
Prevalence rates of triple negative breast cancer by race/ethnicity, 2012-2016
|Race/ethnicity||Percentage of triple negative breast cancers among total breast cancers diagnosed in women in each group|
American Indian and Alaska Native
Asian and Pacific Islander
|Adapted from American Cancer Society materials .|
Rates of triple negative breast cancer are higher among non-Hispanic black women diagnosed with breast cancer (21 percent) than among non-Hispanic white women diagnosed with breast cancer (10 percent) .
However, when you look at the total number of triple negative breast cancer cases, most 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/ethnicities diagnosed with breast cancer.
Learn more about numbers versus rates when looking at breast cancer statistics.
Although the reasons for racial/ethnic differences in rates of triple negative breast cancer are not clear, some lifestyle factors may play a role .
Compared to white/non-Hispanic white women, Black/African-American women tend to have lower rates of breastfeeding and tend to carry excess weight in the abdomen area [73,80-85]. Each of these factors may increase the chances of having triple negative breast cancer [66,80-85].
Certain reproductive and lifestyle factors may protect more against ER-positive breast cancers than ER-negative breast cancers, including triple negative breast cancers. So, even though women may have these protective factors, they may not lower the risk of triple negative breast cancers.
For example, African-American and Hispanic women are more likely than white women to [73,80-89]:
- 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 [80-81,83-84,89-90]. So, even though African-American and Hispanic women may have these protective factors, the factors may not lower the risk of triple negative breast cancers.
There’s even some evidence these factors may increase the risk of triple negative breast cancers [66,80-81,85,89-90].
These topics are under active study.
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/African-American women [67,91-93].
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 [67,74].
|SUSAN G. KOMEN® SUPPORT RESOURCES|
*Please note, the information provided within Komen Perspectives articles is only current as of the date of posting. Therefore, some information may be out of date.
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