Challenges of Treating ‘Triple-Negative’ Breast Cancer

Even its name is daunting to women diagnosed with it — triple-negative breast cancer. It occurs in about 10 to 20 percent of diagnosed breast cancers, and it is more likely to affect African-American or Hispanic women — and/or those with the BRCA1 gene mutation.

The challenges of treating or diagnosing triple-negative breast cancer also lies in its name. This type of cancer tests negative for three of the receptors that drive other forms of breast cancer — the hormones estrogen and progesterone, and a protein called HER2. Hormone receptors are proteins — found in and on breast cells — that pick up hormone signals telling the cells to grow.

Since the tumor cells in triple negative-breast cancer lack the necessary receptors, common treatments — such as hormone therapy and drugs that target estrogen, progesterone, and HER-2 — are ineffective. Moreover, triple negative can be more aggressive than other forms of breast cancer. It is more likely to spread beyond the breast, and there’s a higher chance of recurrence within the first three years after treatment.

No Targeted Therapies
There has been much progress over the past two decades in using cell biology — or the process by which normal cells become progressively transformed into malignancies — to target cancers, explains Jane Mendez, M.D., chief of breast surgery at Miami Cancer Institute. However, there are no targeted therapies approved to treat triple-negative breast cancer, as is the case for other types of cancers, she adds.

While advanced-stage, triple-negative breast cancer is usually treated with chemotherapy, response rates have been low. Women diagnosed with triple-negative breast cancer who also have a BRCA1 or BRCA2 mutation seem to have a better response to a chemotherapy regimen, studies have shown.

“There is still a lot that we don’t know about triple-negative breast cancer,” says Dr. Mendez. “We do know that there’s an association between some of the BRCA1 mutations and triple-negative breast cancer. And we try to see what is the mechanism of action in the BRCA genes, and if we can then find a target. We have all sorts of different strategies to find that target, but currently we don’t have anything that we can offer (triple-negative patients). In cancer research, the triple negative is considered the ‘Holy Grail’ of breast cancer.”

Risk Higher for African-American Women
Triple-negative breast cancer is more common in African-American women in the United States, compared to other groups. According to American Cancer Society (ACS) researchers, the prevalence varies significantly depending on where these women were born. Those born in the U.S. and Western Africa were diagnosed more often with triple-negative breast cancer than women born in East Africa, according to the new research findings published in June.

In a separate study published in July, researchers examined data on 1.1 million women diagnosed with breast cancer from 2010 through 2014, using the United States Cancer Statistics (USCS) database. The results showed that, compared with non-Hispanic white women, non-Hispanic black women and Hispanic women had 2.3-times and 1.2-times higher odds, respectively, of being diagnosed with triple-negative breast cancer.

“I have to point out that triple-negative breast cancer does not only occur in African-American women,” says Dr. Mendez. “It can occur in any patient. Many Caucasian women are diagnosed with triple-negative. African-American women have a higher prevalence, but it is not exclusive to them.”

The challenges of treating triple-negative breast cancer – without remission — is resulting in more women opting for mastectomies. This trend has been primarily driven by genetic testing that reveals specific inherited mutations in BRCA1 and BRCA2 — human genes that produce tumor-suppressor proteins when working properly. Overall, research shows that about 10 percent of cancers are hereditary. But women with BRCA1 and BRCA2 mutations have a significantly higher risk of developing breast cancer.

“Actually, many of these (triple-negative) patients nowadays choose to have mastectomies — even when they don’t have a genetic mutation,” says Dr. Mendez. “That’s because this is so challenging to treat and they’re afraid of a future recurrence.”

Risk Factors and Prevention
Other than ethnicity and family history, there are few other primary risk factors for triple-negative breast cancer that are known at this time. Baptist Health South Florida, along with the U.S. Preventive Services Task Force (USPSTF), the American Society of Breast Surgeons and the American College of Radiology (ACR), continues to support annual mammograms for women at average risk starting at age 40.

But a patient’s ethnicity and personal and family history of cancer should also go into the equation to determine when a woman should start having screening mammograms.

“The breast cancer risk factors that we normally talk about are hormonally driven, but we don’t really know much about risk factors for triple-negative because it’s not hormonally sensitive,” says Dr. Mendez. “So that’s a challenge that we have. So, other than knowing your family history, getting screened and trying to live a healthy life, there’s nothing else you can do at this time.”

Special Mammogram Pricing

In honor of Breast Cancer Awareness Month, and as part of our ongoing commitment to expanding care in our community, Baptist Health is offering special pricing for mammograms for those without insurance throughout October. A screening mammogram is $50 and a diagnostic mammogram is $100, including the radiologist’s fee and 3-D mammography. The offer is available throughout Miami-Dade, Monroe, Broward and Palm Beach counties. A prescription is required.

For patients who don’t have a referring physician: call 786-596-2464 in Miami-Dade, Broward or Monroe; or call Bethesda Women’s Health Center in Palm Beach at 561-374-5300. For more information, or to schedule an appointment, visit BaptistHealth.net/BreastHealth. For appointments in Palm Beach, visit BethesdaWeb.com/BreastHealth. Boca locations will also be participating – for more details please call 561-955-4700.

Tags: breast cancer, Miami Cancer Institute