Triple-Negative Breast Cancer: From Diagnosis to Treatment

If you’re like most people, you’ve likely never heard of triple-negative breast cancer. Or, for that matter, realized there were different types of breast cancer.

As Dr. Prarthna Bhardwaj, a breast medical oncologist at Baystate Regional Cancer Program explains, “There are many types and subtypes of breast cancer. They can be invasive or non-invasive. Factors like these help physicians determine the type of cancer they’re dealing with and, more importantly, how it should be treated.”

What is Triple-Negative Breast Cancer?

Both rare and aggressive, triple-negative breast cancer accounts for 10-15% of all breast cancers. Dr. Bhardwaj says, “TNBC tends to be faster growing. It may often present between mammograms. Its aggressive nature makes it important to begin treatment in a timely manner.”

While researchers don’t entirely understand what makes TNBC so aggressive, they do understand how it differs from other breast cancers.

“Determining the type of cancer a person has involves looking at the cancer cells to identify different characteristics,” explains Dr. Bhardwaj. “Most breast cancer cells have different types of proteins along the edges, called receptors, that allow hormones like estrogen and progesterone to attach and feed the cancer. Another common breast cancer receptor is the HER2, or human epidermal growth factor receptor 2. Like estrogen and progesterone, HER2 feeds cancer and fuels its growth. For most types of breast cancer, treatment targets the identified receptors to help stop or slow the growth of the cancer. Here,” she says, “is where TNBC differs. TNBC cells do not have estrogen, progesterone, or HER2 receptors. Hence, the triple-negative name designation.”

What are the Risk Factors for TNBC?

While people of all ages can develop TNBC, some factors make people more susceptible to the disease. These include:

Mutations in the BRCA1 Gene

Normally, the BRCA1 gene helps repair damaged DNA and keep cell growth under control. However, mutations or defects to that gene are associated with an increased risk of breast cancer. Having the BRCA1 gene is associated with an up to 85% lifetime risk of developing TNBC.

Age

TNBC is most common in women and people assigned female at birth (AFAB) in their 40s and 50s, considerably lower than the average age— 62—of non-TNBC breast cancer diagnosis.

Race

Compared to other races, Black and Hispanic women are more likely to develop TNBC.

Genetics

While you can’t change your genetics or race, there are things you can do to reduce your risk of developing TNBC. These include:

• Maintaining a healthy weight
• Getting regular moderate intensity exercise up to 120-150 minutes per week
• Limiting alcohol use

In addition, Dr. Bhardwaj encourages all patients to know their family history as it relates to breast cancer. “If there’s any history of breast, ovarian, pancreatic or prostate cancer, talk to your provider about your eligibility for genetic testing, which may inform how often you should be screened for breast cancer and reveal genetic mutations that could increase your risk of TNBC.”

Symptoms of TNBC

While TNBC behaves differently than other breast cancers, its symptoms are the same. They include:

• A lump or swelling in the breast or armpit
• Pain in the breast or nipple
• A dimpled or orange peel-like appearance to the skin of the breast
• Abnormal nipple discharge
• Nipple retraction

TNBC is often picked up on regular mammograms and/or follow-up ultrasounds.

How is TNBC Diagnosed?

As with other forms of breast cancer, a diagnosis is confirmed through a biopsy—removal of breast tissue for examination under a microscope—pathology, in which cells are tested for the estrogen or progesterone receptors and the HER2 protein.

Treatment Options for TNBC

As Dr. Bhardwaj noted, TNBC does not have the receptors present in other types of breast cancers; receptors that make many treatment options so effective for those types of cancer. But that does not mean it’s untreatable. In fact, up to 50% of TNBC patients can have their tumors disappear using chemotherapy alone.

And chemotherapy is not the only option.

“Individual treatment plans for TNBC are determined by a number of factors,” says Dr. Bhardwaj. “The first being what stage the cancer is in. Like other cancers, TNBC is staged by the number one through four with one indicating it’s very early in the disease life and it’s very contained and four indicating it’s very advanced and has spread outside the breast.”

Treatment options for TNBC at the different stages typically include:

• Stage 1: Surgery, sometimes followed by radiation, and mostly followed by chemotherapy
• Stage 2 & 3: Six months of a combination of chemotherapy and immunotherapy (medication that boosts your immune system and stimulates it to fight and kill the cancer cells), followed by surgery that is sometimes followed by radiation, and always followed by six months of immunotherapy and sometimes chemotherapy based on response
• Stage 4: Chemotherapy, targeted therapy, and antibody-drug conjugates

Dr. Bhardwaj explains, “Unlike chemotherapy, which is essentially a medicinal cocktail that kills both good and bad cells, antibody-drug conjugates, a new type of treatment for TNBC, targets specific proteins on cancer cells and preferentially dumps chemotherapy into those cells, sparing healthy cells. The result is very promising outcomes for many, many patients.”

The latest current five-year survival rates for TNBC, which don’t reflect the relatively new introduction of immunotherapy, are as follows:

• Stages 1-2: 91%
• Stage 3: 66%
• Stage 4: 12%

What to Do If You’re Diagnosed with TNBC

When it comes to a diagnosis of TNBC, knowledge is power. “Asking questions is the best way to learn what you’re up against,” says Dr. Bhardwaj. Among the must-ask questions she thinks patients should put to their provider are:

• What is the goal of treatment – curative or palliative?
• Is immunotherapy an option?
• What are the possible side effects of treatment?
• Are clinical trials an option?

Beyond their provider, patients can tap other resources, including other TNBC patients, for information and support.

“The TNBC Foundation is an amazing resource for patients,” says Dr. Bhardwaj. “They have lots of information on treatment options, support groups, publications, and online forums where patients can share experiences and insights about different treatment options, after-surgery tips, palliative care, dealing with family, and more. Much of it is also available in Spanish.

“Locally, Rays of Hope, a program offered through the Baystate Health Breast Network, supports patients throughout their cancer journey and raises much needed funds for clinical trials and other work done at the nearby Rays of Hope Center for Breast Cancer Research.”

In addition, Baystate Health lends ongoing support for patients who’ve completed treatment via the Breast Cancer Survivorship Program.

Dr. Bhardwaj adds, “Breast cancer of any kind is no longer a journey anyone must go through alone. There are a lot of good resources out there—even for cancers as unique as TNBC. Finding answers and support can help you manage every stage of the disease with a clearer mind and help you feel more confident and in control of the decisions you make.”