Stage 3 triple-negative breast cancer (TNBC) is more advanced than earlier stages, which can be worrying to hear. It may be reassuring to know that new treatments and earlier diagnoses are now helping people live longer with stage 3 TNBC. (Cancer stages are sometimes noted with Roman numerals, as stages I through IV.)

This article will cover facts about stage 3 TNBC, including potential treatments and how they can improve your prognosis (outlook). Learning more about your diagnosis can help you have better conversations with your cancer care team and feel more confident about your treatment plan.

What Is Stage 3 Triple-Negative Breast Cancer?

Stage 3 TNBC is an advanced stage of invasive breast cancer. According to the National Breast Cancer Foundation, stage 3 disease has spread beyond the primary breast tumor. At this stage, cancer may have grown into nearby muscle tissue or lymph nodes. However, it hasn’t spread to other parts of the body (distant metastasis). When cancer has progressed to distant parts of the body, it’s considered stage 4.

At stage 3, triple-negative breast cancer has spread beyond the primary breast tumor. It may have grown into nearby muscle tissue, skin, or lymph nodes.

Doctors divide stage 3 TNBC into three subcategories: 3A, 3B, and 3C. Stage 3A is the least advanced, and stage 3C is the most advanced. Cancer staging reflects how large the primary tumor is and what nearby tissues are affected.

• Stage 3A breast cancer has spread to nearby lymph nodes.
• Stage 3B cancer has spread deeper into the chest wall or out to the skin. You may notice ulcers (open sores) or inflammation at this stage.
• Stage 3C TNBC has moved into lymph nodes near the collarbone.

How Often Is Stage 3 TNBC Diagnosed?

TNBC isn’t commonly diagnosed at stage 3. In one study of 524 women with TNBC, only 21.9 percent were first diagnosed at stage 3 disease. Stage 3 TNBC is more commonly diagnosed in older women. Just over 27 percent of stage 3 cases were diagnosed in women over age 74. In the same study, only 19 percent of stage 3 diagnoses were in women under 40 years old.

What Are the Symptoms of Stage 3 Triple-Negative Breast Cancer?

Since stage 3 TNBC is advanced breast cancer, you may have symptoms. However, it’s possible to not have any noticeable signs. Some TNBC cases are diagnosed during routine screening tests like mammograms and ultrasounds.

Most people with stage 3 triple-negative breast cancer undergo some combination of surgery, chemotherapy, radiation therapy, and immunotherapy.

Signs and symptoms of stage 3 TNBC include:

• Pain, irritation, and itchy skin on the breast
• New swelling or changes in the shape and size of the breast
• Changes in the texture or pores on the breast, including redness or discoloration, scaly skin, and dimpling (known as orange peel skin or peau d’orange)
• Open sores on the breast
• New lumps in the breast or armpit
• A nipple turning inward
• Changes in nipple skin, like flaking, itching, and peeling
• Nipple discharge that may be cloudy, bloody, or clear

If you notice any of these changes, talk to your doctor right away.

How Is Stage 3 Triple-Negative Breast Cancer Treated?

You’ll work together with your oncologist to decide on a treatment plan for stage 3 TNBC. Most people with stage 3 TNBC undergo some combination of surgery, chemotherapy, radiation therapy, and immunotherapy. Your treatment plan will depend on the size of your tumor and how far it’s spread.

For most types of breast cancer, treatment options focus on blocking hormone receptors and proteins that cancer cells use to grow and divide. These include:

• Estrogen receptors
• Progesterone receptors
• Human epidermal growth factor receptor 2 (HER2) proteins

Unfortunately, TNBC lacks all three of these markers — meaning hormone therapies won’t work. This is why oncologists choose a combination of treatment approaches for TNBC.

Surgery

In stage 3 TNBC, the cancer has spread away from the primary tumor into nearby tissues. Surgery usually involves a mastectomy to remove as much of the cancer as possible. There are a few techniques for mastectomy surgery, depending on whether you want reconstructive surgery.

Not everyone with stage 3 TNBC may be a good candidate for surgery. Some types of stage 3C TNBC may be inoperable. This means the surgeon wouldn’t be able to remove all of the cancer spread in the breast and nearby tissues. Having inoperable stage 3C TNBC doesn’t mean it’s untreatable. Your oncologist will create a different treatment plan using other approaches for your specific case.

Chemotherapy

Chemotherapy is a key part of many stage 3 TNBC treatment plans. These drugs kill cells that grow and divide quickly, including cancer cells.

The five-year relative survival rate with regional TNBC is 67 percent. This means that after five years, women with stage 3 disease are 67 percent as likely to be alive as those without cancer.

Since stage 3 TNBC has spread to nearby tissues making surgery more difficult, chemotherapy is typically given before surgery. This is called neoadjuvant chemotherapy, and it helps shrink tumors and lymph nodes before surgery. Studies show neoadjuvant treatment is effective for stage 3 TNBC. The smaller the tumor is before surgery, the better the chances of removing all of the cancer.

Examples of chemotherapy drugs you may see in your stage 3 TNBC treatment plan include:

• Anthracyclines, like doxorubicin
• Capecitabine (Xeloda)
• Carboplatin
• Gemcitabine (Gemzar, Infugem)
• Methotrexate
• Taxanes, like docetaxel (Beizray, Taxotere) and paclitaxel

Radiation Therapy

Radiation therapy uses intense energy beams to target and destroy cancer cells, even those that are microscopic. Oncologists may use radiation for stage 3 TNBC if:

• You’ve had a mastectomy, to kill any cancer cells left behind after surgery
• Your cancer has spread to the lymph nodes near your collarbone or in your armpits
• You have inoperable stage 3C TNBC

Overall, radiation therapy lowers the chances of your cancer growing back after surgery.

Immunotherapy

Immunotherapies help your immune system recognize and destroy breast cancer cells. Pembrolizumab (Keytruda) is used to treat some types of stage 3 TNBC. You may receive immunotherapy with chemotherapy before surgery. Studies show this combination produces better responses to breast cancer treatment.

PARP Inhibitors

Some types of TNBC have specific genetic mutations (changes) on the cancer cells that fuel the growth of cancer. Mutations in the BRCA1 and BRCA2 genes play a role in TNBC development. Luckily, there are treatments available that work well to shrink these tumors.

PARP inhibitors help kill cancer cells with BRCA1/BRCA2 changes. Olaparib (Lynparza) may be prescribed for one year after breast cancer surgery. PARP inhibitor treatment prevents TNBC from recurring.

What’s the Prognosis With Stage 3 TNBC?

TNBC tends to grow and spread quickly. This means the outlook with TNBC is less positive than other types of breast cancer. Fortunately, doctors and researchers continue to look for better ways to diagnose and treat this disease.

The National Cancer Institute (NCI) follows women diagnosed with TNBC to find out survival rates. They look at the five-year relative survival rate. This measures how likely it is for a person with cancer to be alive five years after their diagnosis when comparing them to the general population.

The NCI Surveillance, Epidemiology, and End Results Program (SEER) lists survival rates based on cancer spread. They define cancer as localized, regional, or distant depending on where it’s located. Stage 3 TNBC is considered regional since it has spread to nearby lymph nodes and tissues.

The five-year relative survival rate with regional TNBC is 67 percent. This means that after five years, women with stage 3 disease are 67 percent as likely to be alive compared to those without cancer.

These statistics apply to broad populations, rather than individuals. Your cancer care team can help you understand how these statistics relate to your specific situation.

Join the Conversation

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