You ask, we answer: Metastatic triple-negative breast cancer remission

TNBC is a rare type of cancer. It does not have the three common receptors found on other breast cancer cells — the hormones estrogen or progesterone or the protein HER2.

The absence of these three receptors means it will test negative on these common receptor tests, which is why it is called “triple negative.”

This also makes TNBC harder to treat than most other types of breast cancer. It typically does not respond to hormone therapy or medications that target these receptors.

However, with appropriate treatment, TNBC can still go into remission, meaning there are no signs and symptoms of cancer.

Treatment options in the early stages of TNBC — stages 1 to 3 — include chemotherapy, radiation therapy, or surgery.

In the last stage of TNBC — stage 4 — also known as mTNBC, the cancer has spread to other parts of the body.

Surgery may no longer be an option at this stage. Chemotherapy is the main treatment for most people with mTBNC. Often, doctors will use a combination of chemotherapy medications to enhance their overall efficacy.

After treatment, regular monitoring will include imaging tests, doctor visits, and blood testing to look for any signs of cancer. If none remain, doctors may determine that the person is in pathologic complete remission.

Survival rates indicate what percentage of people with TNBC are alive after a certain amount of time — typically 5 years. These rates do not determine exactly how long a person can expect to live, but they can give an idea of the chances that treatment will be successful.

According to a 2020 review in Cancers (Basel), TNBC has the lowest overall survival rate out of all types of breast cancer. This can be due to several reasons, including:

• how quickly the cancer grows and spreads to other parts of the body
• the stage of the cancer at diagnosis
• the relatively few treatment options available
• the tendency of the cancer to develop resistance to chemotherapy
• the high likelihood that the cancer will come back after treatment

According to the American Cancer Society, the 5-year survival rate for all stages of TNBC combined is 77%. The Surveillance, Epidemiology, and End Results Program (SEER) database groups cancers into three stages:

• Localized — no sign that the cancer has spread outside the breast
• Regional — the cancer has spread outside the breast to nearby tissues or lymph nodes
• Distant (metastatic) — the cancer has spread to distant tissues and organs

Survival rates vary substantially depending on the stage of the cancer:

It is crucial to note that these numbers only apply to the progression level from the first diagnosis. They are not relevant if the cancer grows, spreads, or returns after treatment.

It is also important to be aware that these numbers do not consider every factor. Although survival rates are based on how far the cancer has progressed, a person’s age, overall health status, response to treatment, and other factors can play important roles in their outcome.

A 2021 review published in the journal Cancers (Basel) identified unique characteristics of TNBC cells that have led to the development of new medications targeting these features. These new treatments have the potential to significantly improve patient outcomes.

According to a 2019 study in the American Journal of Cancer Research, the cancer will return after treatment — also known as the recurrence rate — in about 40% of people with stage 1 to 3 TNBC. The other 60% will continue to have disease-free survival over the long term.

TNBC can return in the same place it first occurred — local recurrence — or may return in other parts of the body away from its origin — distant recurrence. About two-thirds of people with recurrent TNBC involve distant recurrence.

According to a 2017 study in the Annals of Surgical Oncology, factors that can increase the risk of distant recurrence include:

• the size of the tumor
• the cancer spreading into blood vessels
• the cancer spreading to the lymph nodes or lymphatic system

Until recently, there was no effective way to tell how likely the cancer would return.

A 2022 study in Scientific Reports suggests that “liquid biopsies” may make it possible for doctors to detect the presence of cancer cells by looking for their DNA in the bloodstream and determining if recurrence is likely.

This technique may also help doctors see how well people with TNBC have responded to treatment.

However, these techniques are still being developed and are not the standard of care. Research continues to evolve in this area.

The most common sites that TNBC spreads to are the interior organs, such as the heart, lungs, and brain.

A 2018 study in BMC Cancer found that in nearly 30% of people with metastatic TNBC, the cancer spread to their brains.

According to a 2020 study in Breast Cancer Research, TNBC is an aggressive form of cancer, so it is more likely to grow and spread more quickly than other types of breast cancer.

Researchers estimate that the cancer will spread to other parts of the body in approximately 46% of people with TNBC.

Triple-negative breast cancer (TNBC) is an aggressive type of cancer. It is often more difficult to treat than other cancers and more likely to spread, also called metastatic TNBC (mTNBC). Additionally, this type of cancer is more likely to return after treatment.

Combination chemotherapy is the main treatment option for all stages of this rare cancer. Surgery is also an option in the early stages of this cancer.

Despite the effectiveness of chemotherapy, survival rates for TNBC are the lowest among people with breast cancer at less than 80%. There is also a much higher likelihood that the cancer will return in people with TNBC than in other types of breast cancer.

Metastatic TNBC is even more challenging to treat and has a relatively poor outlook compared to other stages of this cancer. However, remission is possible, and new medications are in development that better target triple-negative breast cancer cells.