Immunotherapy Treatment Options & Guidelines for Breast Cancer

Overview

What is immunotherapy for breast cancer?

Immunotherapy is a relatively new breast cancer treatment that uses your immune system to identify, target and cripple breast cancer cells. While chemotherapy and radiation therapy are still standard breast cancer treatments, healthcare providers are optimistic about immunotherapy’s potential to treat recurring breast cancer, metastatic breast cancer and triple-negative breast cancer.

How does immunotherapy work?

To understand how immunotherapy works, it helps to understand how breast cancer develops. Breast cancer happens when something disrupts the way your body produces the cells that make up your breast glands, ducts and tissues.

Like all cells, your breast cells are continually dividing and reproducing. Think of a bathtub being filled with soapy bubbles that divide and subdivide until the tub fills. If something speeds up bubble production, the tub overflows. When something speeds up breast cell production, your breast cells turn into a mass of tissue or tumor. These tumors can be benign or cancerous. When you pull the plug on a tub of bubbles, they flow away. Likewise, breast cancer treatment attempts to pull the plug on cancer cells.

Radiation therapy does that with high-powered X-rays. Chemotherapy does that with drugs. Immunotherapy does that with what’s called active or passive immunotherapies.

What are active immunotherapies?

Active immunotherapies essentially push your immune system to do more to respond to your cancer. Healthcare providers create these immunotherapies by examining your cancer cells for antigens. Antigens are toxins or foreign substances. When your immune system runs into an antigen, it goes after the antigen. By identifying cancer cell antigens, providers can create drugs that focus your immune system on the cancer cells.

What are passive immunotherapies?

Passive immunotherapies are lab-made drugs that improve your immune system’s existing cancer-fighting tools. Immune checkpoint inhibitors are one example of passive immunotherapy.

Your immune system includes proteins called checkpoints that keep your immune system from coming on too strong and doing damage. Cancer-fighting cells that run into immune checkpoints know to move on to other targets. Unfortunately, cancer cells sometimes use these checkpoints to duck your cancer-fighting cells. Immune checkpoint inhibitors are drugs that essentially force your cancer cells into the open.

Does breast cancer respond to immunotherapy?

In short, it’s too soon to say how all the various types and stages of breast cancer will be affected by immunotherapy.

The U.S. Food and Drug Administration (FDA) has approved two immunotherapies. One treats early-stage triple-negative breast cancer. The other is limited to certain metastatic breast cancers. (Metastatic breast cancer is cancer that has gone through metastasis, meaning it has spread from your breast to another area of your body. It’s also known as Stage IV breast cancer.)

Meanwhile, there are hundreds of clinical trials involving immunotherapy, particularly looking at how immunotherapy and chemotherapy could be used together to treat breast cancer.