Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is an uncommon invasive breast cancer. It affects about 13 in 100,000 women in the U.S. “Triple-negative” refers to the difference between TNBC and other types of breast cancer.

Breast cancer cells have receptors. They act like locks that only certain substances can open. Most receptors respond to estrogen, progesterone and the HER2 protein, which are important in breast cell growth.

Many breast cancer medications work by blocking hormones or HER2. TNBC cells don’t have these receptors. That means those medications aren’t effective against triple-negative breast cancer.

Early-stage TNBC may be curable. But this breast cancer grows very fast and often spreads before it’s diagnosed. Researchers are studying new treatments that may help slow the spread, ease symptoms and help people live longer.

Symptoms of triple-negative breast cancer

TNBC symptoms include:

• A new lump or mass in your breast
• Breast or nipple pain
• Dimpled breast skin
• Nipple discharge
• A nipple turning inward
• Nipple or breast skin that’s dry, flaking, thickened or red
• Swelling in all or part of your breast
• Swollen lymph nodes under your arm or near your collarbone

Talk to a healthcare provider if you have changes in your breasts. Not all changes are breast cancer symptoms. Checking with a provider is the best way to understand what’s going on with your breasts.

Triple-negative breast cancer causes

Researchers don’t know the exact cause. Some TNBCs are related to mutations (changes) in the BRCA1 and BRCA2 genes. These genes normally keep cancer from growing. Cancer can develop when genes change for unknown reasons.

Risk factors

Triple-negative breast cancer is more likely to affect females who are:

• Age 40 and younger
• Inherit BRCA gene changes
• Black or Hispanic

Complications of TNBC

This is a fast-growing disease that may spread early on. It’s also more likely to come back after treatment.

How doctors diagnose triple-negative breast cancer

A healthcare provider will ask about any changes in your breast(s). They’ll check your breast(s) and do tests, including:

• Mammogram
• Breast MRI
• Breast ultrasound

You may have a breast biopsy if imaging tests detect cancer. In this procedure, a surgical oncologist takes a small sample of breast tissue. A medical pathologist examines the tissue under a microscope. They’ll check the status of your estrogen receptor, progesterone receptor and HER2 receptor.

They may check for germline mutations that can develop in a biological parent’s reproductive cells (egg or sperm). The variation changes the genetic material that biological parents pass on to their children. If tests show you have this variation, you may benefit from targeted therapy.

TNBC stages

Your cancer care team will use test results to set a cancer stage. Cancer staging information helps them plan treatment. The five anatomic stages in triple-negative breast cancer are:

• Stage 0: Cancer cells are in your breast ducts, but the cancer hasn’t spread to other areas of your breast.
• Stage I (1): There are cancer cells in nearby breast tissue.
• Stage II (2): Cancer cells form small tumors in places like your underarm lymph nodes or near your lymph nodes. Your care team may call this “locally advanced breast cancer.”
• Stage III (3): Cancer spreads to nearby tissues.
• Stage IV (4): Cancer moves from your breast to places like your brain, liver or lungs.

How is TNBC treated?

Breast cancer surgery is a common treatment for triple-negative breast cancer that hasn’t spread from your breast. Your oncologist may combine surgery with:

• Chemotherapy for early-stage cancer, including stages I and II
• Immunotherapy and chemotherapy to shrink cancerous tumors before surgery
• Radiation therapy after surgery to reduce the chance that cancer will come back (recur)
• Targeted therapy for TNBC that involves BRCA genetic mutations — which may include PARP inhibitors or antibody-drug conjugates

Surgery may not be an option if you have stage IV breast cancer or if breast cancer comes back and develops outside of your breast or in nearby lymph nodes. In that case, treatment often includes chemotherapy. You may have immunotherapy or another type of targeted therapy. Your treatment will depend on your situation.

You may want to participate in a clinical trial. These are research studies where experts test potential treatments. A clinical trial may be a chance to receive new medications or new treatment combinations.

Also, ask your team about palliative care and cancer rehabilitation programs. These treatments can help you manage the impact of cancer symptoms and treatment.

When should I see my healthcare provider?

Breast cancer surgery can cause complications like surgical wound infection or blood clots. Contact your cancer care team if you have infection symptoms, such as:

• Fever (greater than 101 degrees Fahrenheit or 38.4 degrees Celsius)
• Pus draining from the surgical wound
• Redness or skin discoloration that goes beyond the edge of the surgical site
• Blood clot symptoms, including a swollen leg that hurts or having trouble breathing

You should also contact your care team if cancer treatment side effects are more severe than you expect. They may change your medication or recommend ways to manage side effects.

Is there a cure for triple-negative breast cancer?

Treatment may cure cancer that hasn’t spread beyond your breast and lymph nodes in your underarm. A cure is less likely for TNBC that’s spread to your bones, brain, liver or lungs. But there are treatments to help you live longer.

What are TNBC survival rates?

Cancer survival rates are overviews of people’s experiences with cancer. The rates estimate the percentage of people with a specific cancer diagnosis who are alive after a certain time — usually one to five years — after they receive a diagnosis.

The National Cancer Institute (U.S.) estimates the percentage of people with TNBC who are alive five years after their diagnoses. They compare that information with people in the general population. The five-year relative survival rates for TNBC are:

• 91% for localized TNBC, when cancer is in your breast only
• 66% for regional TNBC, which means there’s cancer in nearby lymph nodes or organs
• 12% for metastatic TNBC, when cancer spreads to places like your brain, liver or lungs

The rates don’t predict how long you’ll live with cancer. Survival rate information can be confusing and cause concern. It’s important to remember the rates are estimates. They reflect what other people have experienced. What was true for them may not be true for you. It’s normal to have questions about survival rate information. Ask your oncologists to explain what a rate means in your situation.