Here’s why treating this type of breast cancer can be tricky.
Treatments for breast cancer have advanced significantly over the past few decades. New options have improved outcomes and reduced instances of breast cancer recurrence for many women.
Unfortunately, women with triple-negative breast cancer do not get to benefit from these newer treatment options. This subtype of breast cancer has unique characteristics that limit treatment options.
All breast cancers can be categorized based on their receptor status. “There are different subtypes of breast cancer based on what receptors are expressed on the surface of the breast cancer cell. There are hormone receptors, estrogen and progesterone, and then there’s a protein called HER2,” says Amy Tiersten, MD, oncologist and hematologist at Dubin Breast Center at Mount Sinai Hospital in New York City.
Treatment Options to Rule Out
The types of breast cancer play a big role in treatment options. “The entire prognosis and treatment plan is completely based on the subtype of breast cancer, be it hormone receptor-positive, HER2-positive, or triple-negative,” says Dr. Tiersten. “We use different medications for each situation.”
For example, hormone receptor-positive breast cancer means that receptors on the breast cancer cell are using either estrogen or progesterone to feed cancer growth. Because of the presence of hormone receptors, doctors can use hormone therapy to treat the cancer.
“Anti-estrogen medication plays a very big role in [hormone receptor-positive] breast cancer, both in preventing a recurrence, as well as treating more advanced disease,” says Dr. Tiersten. Anti-estrogen medication works even on breast cancers with progesterone receptors.
HER2 receptor-positive breast cancer can be treated with a newer type of cancer treatment known as targeted therapy. “These are cancers that used to be considered very aggressive, but nowadays, it’s considered a good thing to have HER2-positive breast cancer because we have incredibly effective, targeted antibodies to that HER2 protein,” says Dr. Tiersten.
Treatment Options for Triple-Negative Breast Cancer
Triple-negative breast cancer means that the cancer cells lack all three receptors. Since it’s not being fueled by estrogen or progesterone, hormone therapy is not effective against the cancer growth; since it doesn’t have HER2 receptors, targeted therapy doesn’t work, either.
“At the present time, all we really have for triple-negative breast cancer is your standard, traditional chemotherapy,” says Dr. Tiersten. However, chemotherapy tends to be more effective against triple-negative breast cancer than for other types.
Chemotherapy may be used before surgery (neoadjuvant chemotherapy) or after surgery (adjuvant chemotherapy). When used before surgery, the goal is to shrink the tumor before removing it. By shrinking the tumor first, someone who may have needed a mastectomy (removal of the entire breast) may be able to qualify for just a lumpectomy (removal of the tumor and surrounding tissue from the breast).
Doctors may also recommend radiation therapy for triple-negative breast cancer. This treatment uses high-energy radiation (like x-rays), and it’s usually used after a lumpectomy to kill any remaining cancer cells.
The Future of Triple-Negative Breast Cancer Treatment
Although options are currently limited, new treatment methods are on the horizon. One such option is immunotherapy, which is a type of treatment that “teaches the immune system to find the cancer cells, recognize them as different from your normal cells, and kill them that way,” explains Dr. Tiersten.
“A very large, randomized trial just came out showing for the first time effectiveness for immunotherapy in combination with chemotherapy for triple-negative breast cancer,” says Dr. Tiersten.
The trial led to FDA approval for immunotherapy to treat this type of breast cancer. Although immunotherapy can treat many types of cancer, this is the first time it’s been approved to treat breast cancer, specifically triple-negative breast cancer.
“It’s really important to have a good dialogue with the medical oncologist, [who] should be very forthright about what the various treatment options are, what the goals of therapy are, what the risks and benefits are, detailed information about possible side effects, and how to manage those side effects,” says Dr. Tiersten.
“If the patient is not receiving that sort of information, then that would be a sign that advocating for oneself and finding a situation where those things are being done is important,” says Dr. Tiersten.
Epidemiology, risk factors and the clinical approach to ER/PR negative, HER2-negative (triple-negative) breast cancer. Waltham, MA: UpToDate, 2019. (Accessed on April 9, 2019 at https://www.uptodate.com/contents/epidemiology-risk-factors-and-the-clinical-approach-to-er-pr-negative-her2-negative-triple-negative-breast-cancer.)
Triple negative breast cancer. Dallas, TX: Susan G. Komen, 2019. (Accessed on April 9, 2019 at https://ww5.komen.org/BreastCancer/TripleNegativeBreastCancer.html.)
Triple negative breast cancer. Frisco, TX: National Breast Cancer Foundation, Inc. (Accessed on April 9, 2019 at https://www.nationalbreastcancer.org/triple-negative-breast-cancer.)
What is triple-negative breast cancer? Atlanta, GA: Centers for Disease Control and Prevention. (Accessed on April 9, 2019 at https://www.cdc.gov/cancer/breast/triple-negative.htm.)