Triple-Negative Breast Cancer Stages

Approximately 15% of breast cancer cases are classified as triple-negative, which means the tumor lacks estrogen receptors, progesterone receptors and human epidermal growth factor receptor 2 (HER2). The significance of this classification is that the tumor will not respond favorably to certain hormone therapies that are commonly used for breast cancer, and therefore it can be challenging to treat.

Triple-negative breast cancer stages are determined by a physician based on the extent of the cancer at the time of diagnosis, including the size of the tumor and whether it has spread to other areas of the body. While triple-negative breast cancers are sometimes treated differently than hormone-receptor-positive breast cancers, the staging process is the same.

What are the stages of triple-negative breast cancer?

Breast cancers are typically staged based on a numerical scale that ranges from 0 to 4, with lower numbers indicating smaller and more localized tumors. The stages of triple-negative breast cancer are:

Stage 0 triple-negative breast cancer

Also known as ductal carcinoma in situ (DCIS), a classification of stage 0 triple-negative breast cancer indicates that abnormal cells were detected in—and remain confined to—a milk duct or lobe of a breast. There is no evidence of cancerous cells or noncancerous abnormal cells in the surrounding healthy tissues.

The goal of treatment for stage 0 triple-negative breast cancer is to prevent the abnormal cells from progressing into invasive cancer. Options may include surgery, such as a lumpectomy or mastectomy, followed by radiation therapy to minimize the risk of recurrence. Periodic monitoring and follow-up care are typically recommended to track the effectiveness of treatment and detect any potential recurrence early.

Stage 1 triple-negative breast cancer

At stage 1, triple-negative breast cancer is characterized by a relatively small tumor, usually less than 2 centimeters in diameter. Although cancer cells may have infiltrated nearby breast tissues, they have not spread to surrounding lymph nodes or metastasized to distant organs.

For this early-stage breast cancer, treatment may involve surgery, such as a lumpectomy or mastectomy, to remove the tumor, followed by chemotherapy to target any remaining cancer cells. Despite the aggressive nature of triple-negative breast cancer, early detection and a comprehensive treatment approach can lead to successful management and the best possible outcome and quality of life. Regular follow-up assessments and ongoing medical care are important to allow a physician to monitor the patient’s response to treatment and address any potential recurrence.

Stage 2 triple-negative breast cancer

At stage 2, triple-negative breast cancer has spread beyond the initial tumor site and may involve nearby lymph nodes. The cancer may be further classified as:

• Stage 2A – The tumor is 2 to 5 centimeters in diameter.
• Stage 2B – The tumor is smaller than 2 centimeters in diameter but has spread to nearby lymph nodes.

Usually, stage 2 triple-negative breast cancer is treated with a combination of surgery, such as a lumpectomy or mastectomy, and chemotherapy to target any cancer cells that may have spread throughout the body. Because triple-negative breast cancer does not have estrogen or progesterone receptors and produces minimal or no HER2 protein, it does not respond to hormone therapies or drugs that target HER2. Instead, chemotherapy is the main systemic treatment option.

Stage 3 triple-negative breast cancer

At stage 3, triple-negative breast cancer has grown extensively, invaded nearby tissues and has likely spread to lymph nodes. However, it has not metastasized to distant organs. The cancer may be further classified as:

• Stage 3A – The tumor has spread to nearby lymph nodes.
• Stage 3B – The cancer has invaded the chest wall or skin, causing ulceration or inflammation.
• Stage 3C – The tumor has spread to lymph nodes near the collarbone.

Stage 3 triple-negative breast cancer is often treated aggressively with a combination of surgery, radiation therapy and chemotherapy. While it can be challenging to treat, recent advances in treatment options are improving outcomes on the whole.

Stage 4 triple-negative breast cancer

Also known as metastatic breast cancer, stage 4 triple-negative breast cancer has spread beyond the breast and nearby lymph nodes to other distant organs, such as the lungs, liver, bones or brain. At this advanced stage, the goals of treatment are to control the cancer, manage its symptoms and improve the patient’s quality of life. A tailored treatment plan may involve a combination of systemic therapies, such as chemotherapy and immunotherapy, along with radiation therapy to address specific areas of metastasis. Supportive care, such as pain management, is often an integral part of treatment.

How does breast cancer spread?

If some cancerous cells break away from the original tumor, breast cancer can spread to distant areas of the body. This can happen if the rogue cells attach to the outer wall of a blood vessel or lymph vessel. Once the cancer cells penetrate this outer wall, they can enter the bloodstream or lymphatic system and travel throughout the body.

Where will breast cancer spread to first?

Usually, cancer spreads first to the lymph node that is closest to the original tumor (sentinel node). In a case of breast cancer, the sentinel node is located in the underarm area.

If breast cancer enters the bloodstream or lymphatic system, it can spread throughout the body. Common metastasis sites include the:

• Lungs
• Ribs
• Spinal vertebrae
• Pelvic bones
• Upper arm bones (humerus)
• Thighbones (femur)
• Liver
• Brain

How to determine if breast cancer has spread

Only a physician can determine whether breast cancer has spread and, if so, how far. With that said, certain symptoms may suggest that breast cancer has spread to another area of the body, such as:

A bone

If breast cancer spreads to a bone, it may cause sudden bone pain that persists or worsens despite rest. Other symptoms can include numbness or muscle weakness in an arm or leg. Bone metastasis can also increase calcium levels in the blood, which may cause fatigue, dehydration, nausea and loss of appetite.

The liver

If breast cancer reaches the liver, it may cause pain and swelling near the right shoulder, under the ribcage or in the midsection. Other symptoms can include nausea, vomiting, loss of appetite, unintended weight loss, persistent hiccups, yellowing of the skin or eyes (jaundice), anemia, overwhelming fatigue, drowsiness and confusion.

A lung

If breast cancer spreads to a lung, it may cause chest pain, a persistent cough that may produce blood or mucus, wheezing and shortness of breath.

Benefit from world-class care at Moffitt Cancer Center

The multispecialty team in Moffitt’s renowned Don & Erika Wallace Comprehensive Breast Program offers a full range of advanced treatment options for all stages of triple-negative breast cancer. If you would like to learn more, you can request an appointment with a specialist at Moffitt by calling 1-888-663-3488 or submitting a new patient registration form online. We do not require referrals.