What is Immunotherapy, and How Does it Fight Cancer?

If you’ve heard of immunotherapy — using the immune system to fight cancer — you might think it’s a new idea hatched by scientists in the last couple of decades. But immunotherapy was pioneered in 1891 by Dr. William Coley, who is often considered the “father of immunotherapy.”

Using the Body’s Own Immune System to Fight Cancer

Dr. Coley noticed that a patient who had a bacterial infection at the same time as cancer got better. To test whether the immune system might fight cancer if properly triggered, he injected bacteria into a man with neck cancer. The patient lived another eight years. That success suggested that the body’s own immune system could be used to fight cancer.

Chemotherapy, in addition to surgery and radiation, has become central to cancer care since Dr. Coley conducted those early experiments. Then in the 1970s, scientists developed a form of immunotherapy that improved treatment for bladder cancer. In the years since, researchers around the world have continued to work to expand the success of immunotherapy to treat cancer, with advances developing at a rapid rate over the past several years.

“Immunotherapy has transformed cancer care in the past 5 years, especially, allowing many cancer patients to live years longer than they would have had they been diagnosed even a year or two earlier,” said Dr. Dawn Brooks, a medical oncologist at the D’Amour Center for Cancer Care at Baystate Medical Center who specializes in treating patients with breast and lung cancers.

Why immunotherapy?

Cancer, at its core, is a failure of the immune system to recognize a dangerous cell and destroy it before it multiplies out of control. Immunotherapy “teaches” the immune system to recognize and attack the dangerous cells.

Cancer immunotherapy refers to several approaches and treatments. You may have heard of these terms, which fall under the immunotherapy umbrella: targeted antibodies, cancer vaccines, adoptive cell transfer, tumor-infecting viruses, checkpoint inhibitors, and cytokines.

Another important feature of immunotherapy is how patients feel while they are on treatment. Patients today have fewer side effects than from chemotherapy and can enjoy a better lifestyle, says Dr. Brooks.

Immunotherapy for breast cancer

Melanoma, kidney and lung cancer were some of the earliest to benefit from these recent advances in immunotherapy, according to Dr. Brooks. But today, immunotherapy can be part of a successful treatment plan for breast cancer, too.

“We’ve been excited to have immunotherapy become a treatment option for certain breast cancer patients, and are optimistic that more groups of breast cancer patients will come to benefit from immunotherapy over the next few years

Immunotherapy offers particular hope for breast cancers that are triple negative – an aggressive, difficult-to-treat form of cancer. Triple-negative breast cancer cells lack estrogen, progesterone and HER2 receptors, features that make other types of breast cancer respond well to treatments that specifically block these receptors.

Because of this lack of targets on the cancer cells, chemotherapy remained the only type of drug for treating patients with triple negative breast cancer, while significant advances were being made in treatment of other types of breast cancer. Treating triple-negative breast cancer with immunotherapy has been an exciting possibility for cancer researchers seeking additional treatment options for patients with these hard to treat cancers.

When surgery isn’t an option

Metastatic breast cancer is cancer that has spread beyond the breast. When this has happened medication is used to try to shrink or slow the growth of cancer.

In March 2019, the Food and Drug Administration (FDA) approved an immunotherapy drug called Tecentriq® for use in combination with a form of chemotherapy to treat triple-negative metastatic breast cancer.

Another immunotherapy available for treating triple-negative metastatic breast cancer is Keytruda®. Both treatments have been shown to help certain patients with incurable cancer live longer, in some cases many months or years longer. Cancer doctors consider the features of a patient’s tumor as well as the immune cells attacking the tumor to determine which type drug is the best option for a particular patient.

Breast cancer horizons

While no immunotherapy has been approved yet for early-stage breast cancer, researchers continue to investigate the best treatments for all stages and types of breast cancer.

“Research suggests that patients with early triple negative breast cancer who get immunotherapy have a better chance of living the rest of their lives without a recurrence, or the return, of breast cancer,” notes Dr. Brooks. “We know there is significant benefit of immunotherapy in other types of early cancer, such as lung cancer, and immunotherapy has become standard in these settings. We hope this will also prove true for breast cancer in the near future.”

Is Immunotherapy Right for You?

If you or a loved one has triple-negative breast cancer, talk to your doctor about exploring this innovative treatment. “We have a very exciting clinical trial at the D’Amour Center for Cancer Care that allows some patients with early triple negative breast cancer to receive immunotherapy,” says Brooks “We strongly encourage anyone in the community going through breast cancer treatment to discuss this and other clinical trial options with their cancer doctors to find out whether they might be a candidate.”

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