What is Triple-Negative Breast Cancer and Why is it Difficult to Treat?

You receive a lot of information when diagnosed with breast cancer including where it’s located, how large it is, and whether it’s fueled by hormones or HER2 protein. Breast cancer treatments vary for each person based on these factors. For some women, hormone receptors are absent and there’s not an overabundance of HER2 protein causing breast cancer to grow. This is called triple-negative breast cancer.

Characteristics of Triple-Negative Breast Cancer

This type of breast cancer is called “triple-negative” breast cancer because it lacks all three of these common characteristics of other breast cancers:

• Progesterone receptors, allows the progesterone hormone to fuel cancer cell growth

• Estrogen receptors, allows estrogen to fuel cancer cell growth

• HER2 protein receptors. The HER2 receptor refers to a protein called the human epidermal growth factor. Too much of this protein can allow cancer to grow.

Triple-negative breast cancer (TNBC) is considered an invasive type of breast cancer, and it typically spreads faster than other forms of breast cancer.

There are some risk factors associated with triple-negative breast cancer. However, as with any cancer, it is not predictable. Triple-negative breast cancer tends to be more common in those who are:

• Under 40 years old

• Have the BRCA1 mutation

• Of African heritage

Triple-Negative Breast Cancer and its Relation to the BRCA Gene Mutation

The BRCA1 and BRCA2 gene mutations can be inherited from either your mother or your father. There is a relationship between these gene mutations and the development of breast cancer and ovarian cancer. There is a higher rate of triple-negative breast cancer among those with the BRCA-1 gene mutation.

The cancer care team will ask questions about your family history and may recommend genetic testing to determine if these genetic mutations are present. If mutations are found, more significant preventive measures to help breast cancer recurrence can be discussed.

Recommended Treatment for Triple-Negative Breast Cancer

Because triple-negative breast cancer doesn’t respond well to other treatments used for hormone-positive or HER2-positive breast cancers, there are fewer standardized treatment paths. However, like most breast cancer patients, surgery is likely to be a part of treatment. There may be some different options to consider if you have triple-negative breast cancer.

Surgery to Remove Triple-Negative Breast Cancer

Lumpectomy may be an option, removing only a small area of the breast tissue around the tumor. Radiation therapy is typically required after a lumpectomy to be sure any leftover cancer cells are killed.

Many triple-negative breast cancer patients opt to remove the entire breast. This is a mastectomy. Some women will also choose to remove the other breast at the same time. This makes it much harder for the triple-negative breast cancer to return. For some, this can offer greater peace of mind.

Your breast cancer surgeon will discuss your best options with the medical oncologist and with you. You can also discuss breast reconstruction options when talking to your surgeon.

Systemic Therapies for Triple-Negative Breast Cancer

The medical oncologist will oversee cancer treatments that use various medicines such as chemotherapy and immunotherapy. Because the cancer doesn’t have hormone receptors that can be blocked, hormone therapy isn’t going to be used for triple-negative breast cancer patients. Targeted therapy used to “target” the HER2 protein receptors is also not an option for TNBC patients.

However, there are treatments that can work including chemotherapy and immunotherapy.

• Chemotherapy is almost always a part of the treatment for triple-negative breast cancer patients. That’s because it moves throughout the body to kill microscopic cancer cells that may be running through the lymph system where they can collect and then attach to another area within the body. The right combination of chemotherapy drugs will be determined by the breast cancer specialist.

• Immunotherapies have been introduced over the past several years that enhance the patient’s immune system, allowing it to identify and eliminate cancer cells. These are most often used in combination with chemotherapy. For those with triple-negative breast cancer cells that have the PD-L1 protein, atezolizumab/Tecentriq® or pembrolizumab/Keytruda® can be used. About 20% of triple-negative breast cancers express this protein and qualify to receive immunotherapy and chemo as a primary treatment option.

Other TNBC patients are able to use immunotherapy as a second line of treatment if the cancer has returned.

Triple-Negative Breast Cancer Treatments Currently in the Clinical Research Process

Because there currently isn’t a standard treatment for triple-negative breast cancer, research is being done extensively to find what works best for as many of these patients as possible. This brings hope to patients, including those at Affiliated Oncologists in the Chicago area. Our oncologists work with breast cancer patients to participate in clinical trials when a trial is appropriate.

Next Steps after a Triple-Negative Breast Cancer Diagnosis

After receiving a triple-negative breast cancer diagnosis you’ll need to schedule an appointment with a medical oncologist. It’s also a good idea to schedule an appointment with a breast cancer surgeon. Before committing to a specific surgery, talk with the medical oncologist to determine if treatment is needed before the cancer is removed.

The Affiliated Oncologists team is here to support you through your entire breast cancer journey, whether it’s triple-negative or another type of breast cancer.

Our breast cancer specialists offer cancer treatment in the south Chicago suburbs including Chicago Ridge, Mokena, Hazel Crest, Oak Lawn, and Palos Heights. Request an appointment with one of our medical oncologists who will coordinate your treatment plan including the timing of surgery and other treatments. We’re also available to provide second opinions.

Categories: Breast Cancer