Breast cancer is the most common cancer for women worldwide. (1)
As you age, the immune system weakens, and you’re more likely to develop breast cancer. (2)
In this article, we explore the relationship between breast cancer and the immune system.
Keep reading to find out more…

What Is Breast Cancer?

Breast cancer occurs when mutated cells divide abnormally and form lumps in the breast tissue.
It primarily affects women, but believe it or not, men can get it too.
The most common type of breast cancer starts in the tubes that carry milk to the nipple.
However, breast cancer can develop in several other places, including:
  • Lobules (the glands that produce milk)
  • The nipple itself
  • Connective tissue
  • Blood vessels or lymph vessels
Let’s take a closer look at the effects that breast cancer can have on your immune system…

The Immune System and Breast Cancer

The immune system is your body’s first line of defense against pathogens and other harmful invaders.
It’s also in charge of identifying and destroying mutated cells before they develop into cancer.
But unfortunately, it’s not always successful.
Cancer cells are extremely clever and they have a number of tricks up their sleeves to fool the immune system.
In many cases, they duplicate so quickly that the immune system doesn’t have a chance to keep up.
Before long, they spread and wreak havoc on the body.
They do this in a number of ways:
  • Change their genetic information so that they’re less visible to the immune system
  • Release proteins that “turn off” immune cells
  • Mutate healthy cells around the tumor and cause them to interfere with the immune response
Once the immune system is weakened, the cancer cells break away from the original tumor and start to spread to the lymph nodes: organs that are a key part of immunity.
They contain white blood cells that attack bacteria and infections.
There are hundreds of lymph nodes all over the body, including the armpits.
When cancer cells travel to the lymph nodes in the armpits, it opens the door for cancer to travel to other parts of the body.
Before long, the cancer can reach the liver, brain, bones and lungs—this is called metastatic breast cancer, or stage 4.

Breast Cancer Treatment

On its own, cancer does an impressive job of pulverising the immune system.
Cancer treatment, however, is even worse for immunity.
After all, treatments like chemotherapy are designed to kill living cells, and that means your immune cells take a beating too.
There are a number of different treatments available depending on the stage of cancer, including:
  1. Surgery
  2. Radiation Therapy
  3. Chemotherapy
  4. Immunotherapy
Let’s take a closer look at each one…

1. Surgery

Several types of surgery may be used to remove breast cancer, including:
  • Lumpectomy: Removal of the tumor and some surrounding tissue
  • Mastectomy: Removal of the entire breast or both breasts (double mastectomy)
  • Axillary lymph node dissection: Removal of the lymph nodes
During surgery, you’re given an anesthetic to put you to sleep.
This is great for numbing pain, but not so good for your immune system.
Research shows that certain anesthetics can suppress the immune system and increase the likelihood of cancer spread after surgery. (3)
Then there’s the surgery itself…
When the skin is cut open it can damage the mucous membranes—this exposes it to germs and increases the risk of infection.
To make matters worse, sometimes the lymph nodes have to be removed during surgery.
But wait just a second, your immune system needs those!
The more lymph nodes you lose, the weaker your immunity.
Plus, surgery is stressful, and anything that promotes chronic stress is bad for the immune system.
In small doses, the stress hormone cortisol is beneficial.
However, when it’s released in excess it can suppress immune function. (4)

2. Radiation Therapy

Radiation therapy is often used with surgery.
The tumor is blasted with high-energy radiation.
Ultimately, this changes the cancer’s DNA and causes it to shrink or die.
Radiation is more likely to weaken the immune system if it is directed at the bones.
This is because the bone marrow is where white blood cells are made.
Unfortunately, women with metastatic breast cancer are more likely to need radiation near the bones.
That means a higher risk of a weakened immunity and infection.
Other side effects of radiation include:
  • Fatigue
  • Sensitive skin
  • Swelling
  • Nausea

3. Chemotherapy

Chemotherapy is the biggest, baddest cancer treatment on the block, and it gives the immune system a beating.
In a nutshell, chemo is a powerful drug that targets and rapidly kills cells.
While this is good news for destroying cancer, it’s not so good for the healthy cells in your body.
Unlike radiotherapy, which targets a specific area, chemotherapy works throughout the entire body.
It penetrates bone and destroys precious white blood cells.
Other side effects of chemotherapy include:
  • Hair loss
  • Fatigue
  • Loss of appetite
  • Constipation
  • Diarrhea
  • Mouth sores

4. Immunotherapy

Immunotherapy uses the body’s own immune system to attack cancer cells.
It’s slower than other treatments, but the benefits tend to be longer lasting.
Four of the most common types of immunotherapy are:
  1. Adoptive T cell therapy
  2. Checkpoint inhibitors
  3. Cancer vaccines
  4. Monoclonal antibodies
Let’s take a closer look…

1. Adoptive T Cell Therapy

T cells are a type of white blood cell that kill infected cells, activate other immune cells, and regulate the immune response.
Unfortunately, cancer cells can disrupt T cells, but that’s where adoptive T cell therapy comes in.
Here’s a quick breakdown of the process:
#1: T cell samples are removed from the tumor.
#2: The T cells are modified in a lab to improve their activity.
#3: The T cells are injected back into the body to kick some serious cancer booty.
Research shows that T cell therapy can significantly enhance immune function and increase survival time in breast cancer patients. (5)

2. Checkpoint Inhibitors

Checkpoints are proteins made by cancer cells.
These proteins can switch off T cells and stop them from working.
This is bad news for the cancer patients!
Thankfully, checkpoint inhibitors can block cancer cell proteins.
Ultimately, this allows T cells to switch back on and continue fighting cancer cells.
Early research into checkpoint inhibitor therapy and breast cancer patients has been promising, but more research is necessary.  (6)
However, there are some downsides to checkpoint inhibitors.
For one, they can cause immune cells to become overactive.
This can cause symptoms like:
  • Fatigue
  • Dry, itchy skin
  • Loss of appetite
  • Diarrhea
  • Breathlessness

3. Cancer Vaccines

Cancer vaccines teach the immune system to recognize and destroy cancer cells.
Doctors inject DNA, proteins, and other pieces of cancer cells into the body in small doses.
If all goes well, cancer vaccines can:
  • Prevent cancer from coming back
  • Destroy cancer cells still in the body
  • Stop a tumor from growing or spreading
Most cancer vaccines are still in early development and are only available through clinical trials.
However, a recent study found that vaccines can enhance the immune response to tumors, especially with small tumors or early-stage cancer. (7)
Unfortunately, vaccines can take months to trigger an immune response, so it isn’t suitable for treating advanced tumors.

4. Monoclonal Antibodies

Antibodies are specialized proteins that search and destroy foreign invaders in the body.
However, cancer cells mutate so quickly that the immune system can become overwhelmed.
Luckily, this is where monoclonal antibodies can help.
They’re man-made proteins that target a certain antigen found on cancer cells.
When monoclonal antibodies are injected into the body, they enhance the immune system’s attack on cancer cells.
They do this in two ways:
  1. Mark cancer cells so that the immune system can recognize and destroy them
  2. Deliver T cells closer to cancer cells
Research is still ongoing for the use of monoclonal antibodies for advanced breast cancer.

How Can You Prevent Breast Cancer?

The good news is that breast cancer awareness has increased in recent years.
As a result, early diagnosis has had a significant impact on survival rates.
Here are some steps you can take to strengthen immunity and prevent breast cancer:
  • Maintain a healthy weight
  • Eat a nutritious diet
  • Exercise regularly
  • Limit your alcohol use
  • Don’t smoke
  • Get regular mammograms
If you have any more questions about breast cancer and the immune system, feel free to contact us at Complete Care Health Centers.
We’re happy to answer any questions you may have.