An overview of surgery for triple-negative breast cancer (TNBC)

In cancer treatment, a biomarker refers to a biological characteristic of a cancer. Testing for different biomarkers is a key step in diagnosis and treatment, helping to inform a cancer care team what treatments a specific cancer is more likely to respond to.

Triple negative breast cancer (TNBC) is a type of breast cancer that tests negative for three key biomarkers used in breast cancer treatment—estrogen receptors (ER), progesterone receptors (PR), and HER2 proteins. TNBC is generally unresponsive to treatment with hormone therapy and treatments that target HER2 proteins.

Chemotherapy and surgery are the main treatment options for TNBC. Treatment options have also expanded, with newer therapies like immunotherapy and targeted therapy drugs.

While treatment for TNBC is different for everyone, if you or a loved one is diagnosed with TNBC, there is a good chance you will discuss surgical treatment at some point.

What type of surgery is used to treat TNBC?

Surgical treatment for TNBC will aim to remove the primary tumor or tumors in the breast, as well as breast tissue affected by the cancer and any lymph nodes the cancer has spread to. Surgery will often be used in combination with other therapies (which will be discussed below).

After a tumor and/or lymph nodes are removed, tissue samples will be sent to a lab for testing and examination by a healthcare provider called a pathologist. The pathologist will create a pathology report. This report will give the healthcare team a better understanding of how the cancer is behaving, which will help guide additional steps in treatment.

Surgical procedures used to remove breast cancers, including TNBC, fall into two general categories, breast conserving surgery and mastectomy. Lymph node removal is also a common part of treatment.

Breast-conserving surgery

These procedures remove the tumor as well as a margin of healthy tissue around the tumor, which helps ensure no cancer cells are missed. The goal is to remove the cancer entirely while preserving most of the breast. This may be an option if the tumor is relatively small and there are clear margins for removal. Breast-conserving surgery is also called lumpectomy or partial mastectomy.

Mastectomy

This procedure involves removing all the breast tissue, which will remove any cancer contained within breast tissue. This approach may be needed to treat large tumors, multiple tumors, and invasive tumors. There are several types of mastectomy procedures:

• Simple mastectomy, which removes breast tissue only
• Modified radical mastectomy, which removes breast tissue along with lymph nodes
• Skin-sparing/nipple-sparing mastectomy, for people planning on having breast reconstruction surgery after treatment

Lymph node removal

Lymph nodes are small structures that are part of the lymphatic system, the body's network of organs, vessels, and nodes that distribute immune cells and filter out waste, damaged cells, and other unwanted substances.

Cancer cells can break away from tumors and end up in lymph nodes, where they can grow and form other tumors. Surgery to remove lymph nodes near the breast is often performed alongside breast surgery. The location and number of lymph nodes that are removed can vary.

When are different surgeries recommended?

The surgical approach recommended will depend on tumor size relative to breast size, the location of the primary tumor, the number of tumors, if and where the cancer has spread, and other information about the cancer. It will also depend on a person's preferences about treatment.

Along with other breast cancers, TNBC is most often staged using the tumor, node, metastasis (TNM) staging system. At its most basic level, this staging system takes into account the size and location of the tumor, lymph node involvement, and metastasis (spread).

• Stages 0, I, and II are considered early-stage disease. Lumpectomy and mastectomy are both potential treatment options at this stage, with recommendations between the two varying depending on additional characteristics of the cancer, as well as a person's overall health.
• Stage III is considered locally advanced, where the cancer has spread to nearby tissues and lymph nodes. Breast-conserving surgery may be a possibility if chemotherapy or other treatments can successfully shrink the tumor before surgery. If the tumor cannot be shrunk enough, a mastectomy procedure will be performed.
• Stage IV is metastatic disease. Here, surgical treatment is uncommon, and treatment focuses on using systemic therapies like chemotherapy to control the cancer's growth and spread.

Again, it's important to remember that treatment for TNBC is different for everyone. Each case is unique, and a healthcare team will always be your best source of information about treatment options and treatment recommendations.

What therapies are used along with surgery?

Treatment for TNBC almost always involves a combination of therapies. Chemotherapy, radiation therapy, and newer treatment options like immunotherapy and targeted therapy can be used along with surgery, and sometimes used in combination with one another.

As mentioned above, a nonsurgical therapy may be used to shrink a tumor before surgery. Nonsurgical treatments are also often used following surgery, to help eliminate any cancer cells that the surgery was not able to remove and help reduce the risk of recurrence.