What to Know About Breast Cancer and COVID-19

Due to a weakened immune system, having breast cancer can put you at risk of developing more severe infections from viruses like SARS-CoV-2—the virus that causes COVID-19 infection.

Furthermore, fears of being infected and pandemic-related delays in new breast cancer diagnoses have affected progress on breast care treatment.

This article explores why people with breast cancer are at an increased risk of developing a COVID-19 infection, how the COVID pandemic has affected the diagnosis and management of breast cancer, and more.

Young woman wearing a mask to protect from COVID-19

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Breast Cancer and COVID-19 Risk

One of the main reasons people with breast cancer are at an increased risk for COVID-19 infection is due to the treatments and medications used to fight cancer, such as radiation and chemotherapy. While these treatments can be highly effective in killing cancerous cells, they also suppress the immune system and increase the risk and dangers of COVID-19 infection.

This increased risk is twofold: the risk of initial infection and increased chances that a COVID-19 infection will turn severe or even fatal. Studies conducted during the pandemic found that people with cancer who had been treated with surgery or chemotherapy for cancer management in the 30 days before being infected with COVID had a higher risk of serious illness. Even a history of cancer increases the risk of complications with COVID-19.

Roughly one-third of all people who were hospitalized with COVID-19 developed severe illnesses, including:

People with cancer are almost four times more likely to need treatment in an intensive care unit (ICU), require mechanical ventilation, or die from COVID-19.

Furthermore, some researchers have suggested the possibility that inflammatory and/or autoimmune processes may be a common consequence of COVID-19 infection. This observation raises further concerns about the risks of dormant (temporarily inactive) cancer cells reawakening in people with COVID-19 infections. However, more data is needed to support this hypothesis.

Fallout From the Pandemic

Restrictions on medical care, screenings, and preventive health measures also caused issues during the pandemic. Diagnostic mammograms were estimated to be 80% below average during the early months of the pandemic; treatments, like surgery and chemotherapy, were prioritized based on disease severity.

One 2021 study estimates that by 2030, nearly 1,000 breast cancer deaths will result from reduced screening during the pandemic and another 1,314 from delayed diagnoses. Overall, the study predicted nearly 2,500 deaths would result from delays in care, diagnosis, and treatment.

Complications of Breast Cancer and COVID-19

Just as people with breast cancer are more likely to become infected and severely ill from COVID-19, they are also more likely to develop complications linked to the virus.

In one 2020 study, unvaccinated people with cancer who developed a COVID-19 infection within two weeks of their cancer treatments had complications, including:

Serious complications from a COVID infection could also affect a person’s treatment plan, delaying or canceling planned cancer treatments and medications. A study published in September 2022 estimates that more than 16,000 people with cancer died of COVID-related complications within the first 10 months of the 2020 pandemic, before vaccines were available.

Hospital-Acquired Infections

In 2020, nearly one-third of cancer patients who developed COVID-related complications became infected with the virus in the hospital for an unrelated reason, highlighting the need to protect people hospitalized for cancer treatments from hospital-acquired infections.

In addition to the risk of more severe infection and potential treatment disruption, people with breast cancer also risk developing post-COVID conditions, becoming “long-haulers.”

Some of the risk factors for ongoing, long COVID complications that people with breast cancer are especially prone to include:

  • Severe illness from the SARS-CoV-2 virus, especially when it requires hospitalization or ICU care
  • Underlying medical conditions present before a COVID diagnosis
  • A weakened immune system

Breast Cancer Treatments and COVID-19

Cancer treatments destroy rapidly reproducing cancer cells, but the chemotherapy and radiation that accomplishes this can also kill healthy cells, particularly immune cells in your bone marrow. When these cells are destroyed, your immune system becomes weaker and more vulnerable to infections. This is why it may be easier for someone undergoing breast cancer treatment to become infected with the SARS-CoV-2 virus and develop a more severe COVID-19 infection.

A COVID-19 infection could complicate a cancer diagnosis and the effectiveness of any treatments you receive. If you become very sick with COVID-19, you may have to discuss with your healthcare provider whether your cancer treatments or your COVID infection would take treatment precedence. In some cases, your healthcare provider may recommend delaying or changing your cancer treatments while you fight an active COVID infection.

Frequently Asked Questions

Is COVID-19 more dangerous for people with breast cancer?

COVID usually leads to more severe illness and more complications in people with cancer due to the immunosuppressant effects of cancer treatments like chemotherapy and radiation.

How will my cancer treatments affect treatment for COVID-19?

Cancer treatments destroy rapidly growing cancer cells, but healthy cells, like immune cells, can be harmed too. If this happens, your immune system won't be able to fight off the COVID infection as well, and you may become sicker than if you weren't undergoing cancer treatment.

Is it safe for people with breast cancer to get a COVID vaccine?

Yes. COVID vaccines do not contain live viruses, so they are safe for people with weakened immune systems. Health officials strongly recommend COVID vaccination for anyone with a weakened immune system or conditions like cancer.

Why are people with breast cancer at a higher risk of getting COVID?

It’s not as much the cancer as the treatments that increase your risk of developing COVID. Cancer treatments weaken your immune system and increase your risk of many infections.

What kinds of complications do people with breast cancer develop from COVID?

People with breast cancer are more likely to become severely sick from COVID-19, requiring hospitalization, intensive care admission, and mechanical ventilation.

How to Stay Safe

People with breast cancer—especially those undergoing treatments that suppress the immune system—should receive one of the four versions of the COVID vaccine approved for use in the United States. In addition to vaccination, the Centers for Disease Control and Prevention (CDC) recommends that people undergoing cancer treatments or with weakened immune systems continue to wear a face mask for additional protection when they are in public or crowded areas—even if they're fully vaccinated.

Other basic infection control measures, like avoiding sick people and practicing good hand hygiene, are also important if you are undergoing breast cancer treatment.


Breast cancer is treated with medications that can make your immune system less effective, increasing your vulnerability to COVID-19 infection. Vaccines are a good way to protect yourself, but people undergoing cancer treatments should also continue wearing masks in public and practicing strict hand hygiene.

Your healthcare provider may need to alter your cancer treatments if you develop COVID-19 to help your body better fight the infection and prevent serious complications.

A Word From Verywell

Breast cancer diagnosis and treatment are often incredibly overwhelming—COVID makes it even more complicated and frightening. Talk to your healthcare provider about ways you can protect yourself if you’re undergoing cancer treatment and how a COVID diagnosis might impact your regular cancer treatments.

The information in this article is current as of the date listed. As new research becomes available, we’ll update this article. For the latest on COVID-19, visit our coronavirus news page.

7 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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By Rachael Zimlich, BSN, RN
Rachael is a freelance healthcare writer and critical care nurse based near Cleveland, Ohio.